UREA MOTIF CONTAINING COMPOUNDS AND DERIVATIVES THEREOF AS ANTIBACTERIAL DRUGS

20210009550 · 2021-01-14

    Inventors

    Cpc classification

    International classification

    Abstract

    The invention relates to compounds which are suitable for treating bacterial diseases and to pharmaceutical compositions containing such compounds. The invention further relates to a kit of parts comprising such compounds and to the use of such compounds as disinfectants.

    Claims

    1. A method for the treatment of a bacterial disease, said method comprising administering a compound having a structure according to Formula I ##STR00057## wherein R.sup.1, R.sup.2, R.sup.7, R.sup.8, R.sup.9 are each independently selected from the group consisting of hydrogen, halogen, cyano, (C.sub.1-C.sub.6)alkyl and (C.sub.1-C.sub.6)haloalkyl; R.sup.3 is NHR.sup.4 or NR.sup.5R.sup.6; R.sup.4 is selected from the group consisting of ##STR00058## and substituted or unsubstituted naphthyl; R.sup.5 and R.sup.6 are each independently selected from the group consisting of substituted or unsubstituted (C.sub.1-C.sub.6)alkyl, substituted or unsubstituted (C.sub.1-C.sub.6)heteroalkyl, substituted or unsubstituted (C.sub.2-C.sub.6)alkenyl and substituted or unsubstituted (C.sub.6-C.sub.10)aryl(C.sub.1-C.sub.6)alkyl; wherein R.sup.5 and R.sup.6 join together with the nitrogen atom to which they are attached to form a ring, which is optionally substituted with one or more independently selected R.sup.51; Y.sup.1 and Y.sup.2 are each independently selected from the group consisting of O, S, SO, SO.sub.2 and CH.sub.2; Y.sup.3 is CR.sup.11R.sup.12; R.sup.11 and R.sup.12 are each independently selected from the group consisting of hydrogen and halogen; R.sup.13 is selected from the group consisting of hydrogen, (C.sub.1-C.sub.6)alkyl, (C.sub.1-C.sub.6)haloalkyl and halogen; R.sup.14 is selected from O(C.sub.1-C.sub.6)alkyl, O(C.sub.1-C.sub.6)haloalkyl, NHCH.sub.3 and substituted or unsubstituted (C.sub.6-C.sub.14)aryl; R.sup.15 is selected from the group consisting of (C.sub.1-C.sub.6)alkyl, (C.sub.1-C.sub.6)haloalkyl and unsubstituted (C.sub.6-C.sub.14)aryl; R.sup.31, R.sup.32, R.sup.33, R.sup.34 and R.sup.35 are each independently selected from the group consisting of hydrogen, substituted or unsubstituted (C.sub.1-C.sub.6)alkyl, C(O)R.sup.14, substituted or unsubstituted (C.sub.6-C.sub.14)aryl(C.sub.1-C.sub.6)alkyl, OR.sup.15 and NHC(O)NHB; R.sup.51 is selected from the group consisting of hydrogen, substituted or unsubstituted (C.sub.1-C.sub.6)alkyl, (C.sub.1-C.sub.6)heteroalkyl, (C.sub.1-C.sub.6)haloalkyl, substituted or unsubstituted (C.sub.2-C.sub.6)alkenyl, substituted or unsubstituted (C.sub.2-C.sub.6)alkynyl, substituted or unsubstituted (C.sub.3-C.sub.8)cycloalkyl, substituted or unsubstituted (C.sub.6-C.sub.10)aryl, substituted or unsubstituted (C.sub.6-C.sub.10)aryl(C.sub.1-C.sub.6)alkyl, substituted or unsubstituted (C.sub.3-C.sub.10)heteroaryl, substituted or unsubstituted (C.sub.3-C.sub.10)heteroaryl(C.sub.1-C.sub.6)alkyl, halogen, CN, NO.sub.2, OR.sup.61, N(R.sup.62)(R.sup.63), N(R.sup.61)(OR.sup.61), S(O).sub.0-2R.sup.61, S(O).sub.1-2OR.sup.61, OS(O).sub.1-2R.sup.61, OS(O).sub.1-2OR.sup.61, S(O).sub.1-2N(R.sup.62)(R.sup.63), OS(O).sub.1-2N(R.sup.62)(R.sup.63), N(R.sup.61)S(O).sub.1-2R.sup.61, NR.sup.61S(O).sub.1-2OR.sup.61, NR.sup.61S(O).sub.1-2N(R.sup.62)(R.sup.63), C(W)R.sup.61, C(W)WR.sup.61, WC(W)R.sup.61, and WC(W)WR.sup.61; R.sup.61 is, in each case, selected from the group consisting of H, alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heteroaryl, and heterocyclyl; R.sup.62 and R.sup.63 are, in each case, independently selected from the group consisting of H, alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heteroaryl, and heterocyclyl; R.sup.64 is independently selected from the group consisting of H, alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heteroaryl, heterocyclyl, and OR.sup.61; W is independently selected from O, S, and N(R.sup.64); B is phenyl, optionally substituted with 1-3 substituents independently selected from the group consisting of hydrogen, (C.sub.1-C.sub.6)alkyl, (C.sub.1-C.sub.6)haloalkyl, halogen, cyano, nitro, O(C.sub.1-C.sub.6)alkyl and O(C.sub.1-C.sub.6)haloalkyl; X is selected from O or S; or a pharmaceutically acceptable salt, solvate or hydrate thereof.

    2. A pharmaceutical composition for use in the treatment of a bacterial disease, wherein said composition comprises a compound of claim 1.

    3. The method according to claim 1, wherein R.sup.3 is NR.sup.4.

    4. The method according to claim 1, wherein R.sup.31, R.sup.33, R.sup.34 and R.sup.35 are hydrogen; R.sup.32 is hydrogen or NHC(O)NHB; R.sup.14 is selected from the group consisting of O(C.sub.1-C.sub.6)alkyl, O(C.sub.1-C.sub.6)haloalkyl and substituted or unsubstituted phenyl; and R.sup.15 is (C.sub.1-C.sub.6)alkyl or (C.sub.1-C.sub.6)haloalkyl.

    5. The method according to claim 1, wherein R.sup.31, R.sup.32, R.sup.34 and R.sup.35 are hydrogen; R.sup.33 is selected from the group consisting of hydrogen, (C.sub.1-C.sub.6)alkyl, CH.sub.2R.sup.16C(O)R.sup.14 and OR.sup.15; R.sup.14 is substituted or unsubstituted phenyl; R.sup.15 is (C.sub.1-C.sub.6)alkyl or (C.sub.1-C.sub.6)haloalkyl; and R.sup.16 is substituted or unsubstituted phenyl.

    6. The method according to claim 1, wherein R.sup.4 is ##STR00059##

    7. The method according to claim 1, wherein ##STR00060## is selected from the group consisting of ##STR00061## and R.sup.13 is hydrogen or halogen.

    8. The method according to claim 1, wherein R.sup.1 is halogen; and R.sup.2 is CH.sub.3 or CF.sub.3.

    9. The method according to claim 1, wherein the bacterial disease is caused by at least one bacteria selected from the group consisting of Listeria monocytogenes, Listeria welshimeri, Staphylococcus aureus, MRSA and clinical isolates thereof, Vancomycin-intermediate Staphylococcus aureus, Vancomycin-resistant Staphylococcus aureus, Staphylococcus haemolyticus, Staphylococcus hominis, Staphylococcus epidermidis, Staphylococcus saprophyticus, Staphylococcus lugdunensis, Staphylococcus schleiferi, Staphylococcus caprae, Streptococcus pneumoniae, Streptococcus viridans, Streptococcus pyogenes, Streptococcus agalactiae, Enterococcus faecalis, Enterococcus faecium, Bacillus licheniformis, Bacillus subtilis, Bacillus anthracis, Bacillus cereus, Bacillus thuringiensis, Bacillus larvae, Mycobacterium tuberculosis, Mycobacterium bovis, Mycobacterium leprae, Mycobacterium ulcerans, Mycobacterium kanasasii, Mycobacterium avium, Mycobacterium paratuberculosis, Mycobacterium scrofulaceam, Mycobacterium microti, Mycobacterium africanum, Mycobacterium canettii, Mycobacterium intracellulare, Mycobacterium simiae, Mycobacterium szulgai, Mycobacterium xenopi, Mycobacterium fortuitum, Mycobacterium chelonei, Mycobacterium marinum, Nocardia asteroids, Rhodococcus equi and Burkholderia thailandensis.

    10. A compound having a structure according to Formula II ##STR00062## wherein R.sup.1 is cyano or halogen, preferably halogen, more preferably chlorine; R.sup.2 is (C.sub.1-C.sub.6)alkyl or (C.sub.1-C.sub.6)haloalkyl; Y.sup.1 and Y.sup.2 are each independently selected from the group consisting of O, S, SO and SO.sub.2; Y.sup.3 is CR.sup.11R.sup.12; R.sup.11 and R.sup.12 are each independently selected from the group consisting of hydrogen and halogen; R.sup.13 is selected from the group consisting of hydrogen, (C.sub.1-C.sub.6)alkyl, (C.sub.1-C.sub.6)haloalkyl and halogen; X is O or S; or a pharmaceutically acceptable salt, solvate or hydrate thereof.

    11. The compound according to claim 10, wherein said compound is selected from the group consisting of 1-(4-chloro-3-methylphenyl)-3-(2,2-difluorobenzo[d][1,3]dioxol-5-yl)urea, 1-(4-chloro-3-(trifluoromethyl)phenyl)-3-(2,2-difluorobenzo[d][1,3]dioxol-5-yl)urea, 1-(4-chloro-3-(trifluoromethyl)phenyl)-3-(2,2-difluorobenzo[d][1,3]dioxol-5-yl)thiourea, 1-(benzo[d][1,3]dioxol-5-yl)-3-(4-chloro-3-(trifluoromethyl)phenyl)urea, and 1-(4-chloro-3-(trifluoromethyl)phenyl)-3-(2,2-difluorobenzo[d][1,3]dioxol-4-yl)urea.

    12-13. (canceled)

    14. A kit comprising a compound according to claim 10 and at least one pharmaceutically acceptable carrier.

    15. A method for disinfection wherein said method comprises contacting bacteria with a compound of claim 10.

    16. The method, according to claim 1, wherein wherein R.sup.7, R.sup.8, R.sup.9 are hydrogen; R.sup.1 is hydrogen or halogen; R.sup.2 is (C.sub.1-C.sub.6)alkyl or (C.sub.1-C.sub.6)haloalkyl; R.sup.13 is hydrogen; R.sup.15 is (C.sub.1-C.sub.6)alkyl or (C.sub.1-C.sub.6)haloalkyl; and B is (C.sub.1-C.sub.6)alkyl, (C.sub.1-C.sub.6)haloalkyl or halogen.

    17. The compound, according to claim 10, wherein R.sup.1 is chlorine; R.sup.2 is CF.sub.3; Y.sup.1 and Y.sup.2 are O; R.sup.11 and R.sup.12 are fluorine; R.sup.13 is hydrogen; and X is O.

    Description

    BRIEF DESCRIPTION OF THE DRAWINGS

    [0140] FIG. 1: Antibacterial activity of kinase inhibitor sorafenib (Bay 43-9006, Nexavar against various gram positive and gram negative bacteria and bacterial strains. No growth of bacteria could be observed by eye at the minimum inhibitory concentration (MIC) of the probe.

    [0141] FIG. 2: Antibacterial activity of PK/X17-1-150 against various gram positive and gram negative bacteria and bacterial strains. No growth of bacteria could be observed by eye at the minimum inhibitory concentration (MIC) of the probe.

    [0142] FIG. 3: Vulcano plottarget identification of sorafenib in multi-resistant S. aureus utilizing the affinity-based protein profiling (AfBPP) platform. Protein hits that are enriched compared to the control and of statistical significance are shown on the upper right. Signal peptidase B (SpsB) is a predominant target identified by these experiments.

    [0143] FIG. 4: Cytotoxicity data of sorafenib, a sorafenib derivative (PK/X17-2-011) and two compounds according to the present invention (PK/X17-1-150 and PK/X17-4-011) against human a panel of three human cell lines.

    [0144] FIG. 5: Stability of sorafenib, a sorafenib derivative (PK/X17-2-011) and two compounds according to the present invention (PK/X17-1-150 and PK/X17-4-011) and negative controls in mouse plasma over a time span of 6 h.

    [0145] FIG. 6: Multiple passages of S. aureus with PK/X17-1-150, ofloxacin and sorafenib showed rapid resistance development in case of sorafenib and ofloxacin. PK/X17-1-150 (example compound 4), a compound according to the present invention, did not induce resistance. MIC: minimal inhibitory concentration, the lowest concentration of a given compound where no bacterial growth can be detected.

    [0146] FIG. 7: A) Scheme of the fluorescent peptidase assay. A quenched fluorescent substrate (indicated in green) is cleaved by membrane bound SpsB resulting in dequenching of the donor and detectable fluorescence at 510 nm. This assay monitors SpsB activity. B) Principle of the Frster resonance energy transfer assay. DABCYL: 4-(4-dimethylaminophenylazo)benzoic acid; EDANS: 5-((2-aminoethyl)amino)-1-naphthalenesulfonic acid. C) Incubation of SpsB with sorafenib (100 M) and PK/X17-1-150 (100 M) stimulates peptidase activity and enhance substrate cleavage resulting in higher fluorescence at 510 nm compared to DMSO treated control. SpsB: Signal peptidase IB enzyme. Sec: proteins involved in secretion by translocation of substrates through the membrane.

    [0147] FIG. 8: Scheme of secretome (secreted proteins) analysis. Extracellular proteins of PK/X17-1-150 (example compound 4) treated and untreated cells are isolated and identified by massspectrometric (MS/MS) analysis. Many of these secreted proteins are toxins which are produced by bacteria in response to quorum sensing induced by the binding of autoinducing peptides (AIP). MgrA/SarA/R: transcriptional regulators of S. aureus genes.

    [0148] FIG. 9: A) Analysis of secretome at 0.5MIC of PK/X17-1-150 vs DMSO. Essential cell wall biosynthesis proteins are among the processed proteins. B) Analysis of secretome at 0.5MIC of sorafenib vs DMSO. Several known (depicted in red, Schallenberger, M. A.; Niessen, S.; Shao, C.; Fowler B. J.; Romesberg, F. E. J. Bacteriol 2012, 194 (10), 2677-2686) and predicted (by PrediSi, in blue) SpsB substrates are secreted which is in line with the stimulation of SpsB. SpsB: Signal peptidase IB enzyme.

    [0149] FIG. 10: A) Concentration dependent biofilm eradication effect of PK/X17-1-150 on S. aureus DSM 4910 (NCTC 8325) after 20 h of compound treatment. Additional experiments were carried out in absence of compound (control), with oxacillin as marketed drug for comparison and with a combined treatment of oxacillin and PK/X17-1-150 (Ox+PK). Importantly, PK/X17-1-150 revealed the strongest effect. B) Concentration dependent biofilm eradication effect of PK/X17-1-150 on S. aureus DSM 4910 (NCTC8325) after 70 h of compound treatment. Additional experiments were conducted as outlined in FIG. 10A. Here, again PK/X17-1-150 and combination OX+PK revealed most potent effects.

    [0150] FIG. 11: A) Efficacy of PK/X17-1-150 against S. aureus in a murine bloodstream infection model. Bacterial loads in heart (left) and liver (right) were both significantly reduced by 2 log cfu compared to the vehicle control. B) Efficacy of PK/X17-1-150 and levofloxacin against MRSA ATCC 33951 in the neutropenic murine thigh model. A 1-log.sub.10 cfu/g thigh reduction was observed in PK/X17-1-150-treated mice in comparison with sham-treated mice. The same range of reduction was determined for mice treated with the positive control levofloxacin upon i.v. administration.

    [0151] FIG. 12:

    [0152] A) Results of a persister cell assay I. Persister cells were selected from overnight cultures of S. aureus NCTC8325 using 20 g/mL gentamicin for 4 h, washed, diluted to OD.sub.600=0.4 in PBS and incubated with 2.4 M PK/X17-1-150, 24 M sorafenib or 5 g/mL ciprofloxacin as negative control. Samples were taken at several time-points, cells were serially diluted and plated for the determination of CFU/mL. After 70 h a significant reduction of viable cells for PK/X17-1-150 and sorafenib treated cells compared to the DMSO control is observed, whereas there is no change for the ciprofloxacin-treated control.

    [0153] B) Results of a persister cell assay II. S. aureus NCTC8325 cells were grown to OD.sub.600=4 (A) or overnight (B) and incubated with 30 g/mL oxacillin for persister selection in combination with 2.4 M PK/X17-1-150 or PK/X17-4-011 (inactive control), 24 M sorafenib or PK/X17-2-011 (inactive control) or 5 g/mL ciprofloxacin as negative control in TSB-medium. Additionally, compounds were tested without oxacillin to exclude combinatory effects, as the majority of the cells at OD.sub.600=4 and from overnight cultures already are persisters and do not require selection by oxacillin. After 20 h (A) or 70 h (B) of treatment, cells were serially diluted and plated for the determination of CFU/mL. In all cases there is a significant reduction of viable cells for PK/X17-1-150 and Sorafenib treated cells compared to the DMSO control, whereas there is no change observed for ciprofloxacin-, PK/X17-4-011- or PK/X17-2-011-treated controls.

    [0154] FIG. 13:

    [0155] Location of probe PK/X17-1-150 (spheres) within the signal peptidase (surface). a) Surface representation with PK/X17-1-150 shown as spheres, carbon, oxygen, nitrogen, chloride, fluorine atoms are colored purple, red, blue, green, cyan, respectively. b) Detailed representation of the binding site showing PK/X17-1-150 (purple), important active site residues (blue) and residues bound to the probe (gray) in stick representation within the signal peptidase (cartoon). The distances shown correspond to the average values over the last 150 ns of simulation (A).

    [0156] Further, the invention shall be explained in more detail by the following Examples.

    1) MATERIALS AND METHODS

    1.1) Reagents

    [0157] Reagents and solvents were purchased from commercial suppliers (Sigma-Aldrich Co. LLC, Thermo Fisher Scientific Inc., Merck KGaA, TCI Europe GmbH, Fluorochem Ltd. and Alfa Aesar GmbH) and used without further purification, unless otherwise indicated. HPLC-grade solvents or anhydrous solvents (max. 0.01% water content, stored over molecular sieve under an argon atmosphere) were used for all reactions. All experiments were monitored by analytical thin layer chromatography (TLC). TLC was performed on precoated silica gel plates (60 F-254, 0.25 mm, Merck KGaA) with detection by UV (A=254 and/or 366 nm) and/or by coloration using a phosphomolybdate (PMA), and/or potassium permanganate (KMnO4) stain and subsequent heat treatment. Flash chromatography was performed on silica gel 60 (0.035-0.070 mm, mesh 60 , Merck KGaA) with the indicated eluent. Preparative thin layer chromatography (prep TLC) was performed on pre-coated silica layer plates (SIL G-100 UV254, 1.00 mm, Macherey-Nagel GmbH & Co. KG) with the indicated eluent. Common solvents for chromatography [n-hexane (Hex), ethyl acetate (EtOAc), dichloromethane (CH.sub.2Cl.sub.2) and methanol (MeOH)] were distilled prior to use.

    1.2) NMR

    [0158] .sup.1H and proton-decoupled .sup.13C NMR spectra were recorded on a Bruker Avance III HD 300 (300 MHz), a Bruker Avance I 360 (360 MHz), a Bruker Avance III HD (500 MHz) or a Bruker Avance III HD (500 MHz, equipped with a Bruker CryoProbe platform) at 298 K. Chemical shifts are reported in delta () units in parts per million (ppm) relative to distinguished solvent signals [deuterated chloroform (CDCl.sub.3) .sub.H=7.26 ppm and .sub.C=77.16 ppm; deuterated DMSO (DMSO-d.sub.6), .sub.H=2.50 ppm]. The following abbreviations were used for the assignment of the signals: ssinglet, ddoublet, ttriplet, qquartet, mmultiplet. Coupling constants J are given in Hertz [Hz]. HR-MS spectra were recorded in the ESI or APCI mode on a Thermo Scientific LTQ-FT Ultra (FT-ICR-MS) coupled with an UltiMate 3000 HPLC system (Thermo Fisher Scientific Inc.).

    1.3) Cell Culture

    [0159] Cell culture media and supplements were obtained from Sigma Life Science and Life Technologies. A549 and Hela cells were cultured in Dulbecco's Modified Eagle Medium (DMEM high glucose, 4.5 g/L) supplemented with 10% fetal bovine serum (Sigma Life Science) and 2 mM L-glutamine (PAA). NIH/3T3 cells were cultured in Dulbecco's Modified Eagle Medium (DMEM high glucose) supplemented with 10% fetal bovine serum (Sigma Life Science) and 4 mM L-glutamine (PAA). HepG2 cells were cultured in RPMI-1640 medium supplemented with 10% fetal bovine serum (Sigma Life Science) and 2 mM L-glutamine (PAA). All cells were maintained in a humidified 37 C. incubator with 5% CO.sub.2. Cells were detached with trypsin-EDTA.

    1.4) Bacterial Strains and Media

    [0160] Commercially available strains were obtained from the following suppliers: Institute Pasteur, France (Staphylococcus aureus NCTC 8325, S. aureus Mu 50, Listeria monocytogenes EGD-e), American Type Culture Collection, USA (USA 300 FPR3757), (Mycobacterium smegmatis mc.sup.2155, Mycobacterium tuberculosis H37Rv), (Bacillus subtilis 168). DSMZ (Acinetobacter baumannii DSM-30007, Eneterococcus faecium DSM-20477, Pseudomonas aeruginosa DSM-19882, Enterobacter cloacae subsp. Cloacae DSM-30054, Enterobacter aerogenes DSM-30053). Clinical S. aureus isolates (BK95395, BK97296, IS050678, IS050611, VA417350, VA418879, VA402923, VA412350, VA409044, VA402525) were a kind gift from Prof. Markus Gerhard at the Institute of Medical Microbiology and Immunology, Technische Universitt Mnchen. Escherichia coli CFT073 was a kind gift from Dr. Guiseppe Magistro (Klinikum d. Universitt Mnchen Urologische Klinik).

    [0161] Bacterial growth media: LB-medium (1% peptone, 0.5% NaCl, 0.5% yeast extract, pH 7.5), B-medium (1% peptone, 0.5% NaCl, 0.5% yeast extract, 0.1% K2HPO4, pH 7.5); BHB-medium (Brain Heart Infusion, 0.75% brain infusion, 1% heart infusion, 1% peptone, 0.5% NaCl, 0.25% Na2HPO4, 0.2% glucose, pH 7.4); 7H99 medium (4.7 g/L 7H9 powder, 2 mL/L glycerol, 2.5 mL/L 20% Tween 80, 5 g/L BSA (fraction V), 2 g/L dextrose, 850 mg/L NaCl, 3 mg/L catalase).

    2) COMPOUNDS

    Probe Compound

    N-(2-(3-(but-3-yn-1-yl)-3H-diazirin-3-yl)ethyl)-4-(4-(3-(4-chloro-3-(trifluoromethyl)phenyl)ureido) phenoxy)picolinamide (PK/X17-1-058)

    [0162] ##STR00032##

    [0163] To a solution of 4-(4-(3-(4-chloro-3-(trifluoromethyl)phenyl)ureido)phenoxy)picolinic acid (23.1 mg, 0.0511, 1.0 eq.) in dry DMF (0.5 mL) was added HOBt (8.28 mg, 0.0613 mmol, 1.2 eq.), EDC (11.8 mg, 0.0613, 1.2 eq.) and DIEA (17.8 L, 13.2 mg, 0.102 mmol, 2.0 eq.). After the addition of a solution of 2-(3-(but-3-yn-1-yl)-3H-diazirin-3-yl)ethan-1-amine (Li, Z. et al. Design and synthesis of minimalist terminal alkyne-containing diazirine photo-crosslinkers and their incorporation into kinase inhibitors for cell- and tissue-based proteome profiling. Angew. Chem. Int. Ed. Engl. 52, 8551-6 (2013)) (7.71 mg, 0.0562 mmol, 1.1 eq.) in dry DMF (0.5 mL) the mixture was stirred at room temperature for 24 h. The solvent was removed and the residue was purified flash column chromatography on silica (Hex/EtOAc=2/3) to yield the desired product.

    [0164] Yield: 60% (17.6 mg, 0.0308 mmol); workup A (CH.sub.2Cl.sub.2/MeOH=99/1).

    [0165] .sup.1H NMR (500 MHz, DMSO-d.sub.6): [ppm]=9.25 (s, 1H), 9.03 (s, 1H), 8.85 (t, J=6.1 Hz, 1H), 8.52 (d, J=5.6 Hz, 1H), 8.13 (d, J=2.4 Hz, 1H), 7.68-7.58 (m, 4H), 7.37 (d, J=2.6 Hz, 1H), 7.20-7.16 (m, 3H), 3.17 (q, J=7.0 Hz, 2H), 2.83 (t, J=2.7 Hz, 1H), 2.00 (td, J=7.4, 2.7 Hz, 2H), 1.63 (t, J=7.2 Hz, 2H), 1.59 (t, J=7.4 Hz, 2H).

    [0166] .sup.13C NMR (126 MHz, DMSO-d.sub.6): [ppm]=166.1, 163.3, 152.5, 152.2, 150.4, 147.8, 139.4, 137.1, 132.1, 126.7 (q, J=30.3 Hz), 123.2, 123.2 (m), 121.6, 122.9 (q, J=273.3 Hz), 120.5, 116.9 (q, J=5.3 Hz), 114.2, 108.7, 83.2, 71.9, 34.1, 32.0, 31.3, 27.3, 12.7 (observed complexity is due to the CF splitting).

    [0167] ESI-HR-MS (m/z) [M+H.sup.+] 571.1467 calcd. for C.sub.27H.sub.23ClF.sub.3N.sub.6O.sub.3.sup.+; found, 571.1472.

    2.2) General Procedure for the Synthesis of Urea and Thiourea Containing Compounds

    [0168] A solution of the corresponding commercially available isocyanate or thioisocyanate (1.1 eq.) in dry dichloromethane (3 mL) was cooled to 0 C. After the addition of the corresponding amine (1.0 eq.) the reaction mixture was allowed to warm to room temperature and the reaction was stirred at room temperature for 20 h. Individual work up and purification yielded the desired urea or thiourea containing compounds. In brief, the solvent was removed followed either by purification by flash column chromatography on silica (Hex/EtOAc or CH.sub.2Cl.sub.2/MeOH; workup A) or by the precipitation from DMF through the addition of water (10 fold excess) and collection of the product by centrifugation (17000 g, 10 min) (workup B).

    EXAMPLE 1

    Methyl 3-(4-(3-(4-chloro-3-(trifluoromethyl)phenyl)ureido)phenoxy)benzoate (PK/X17-1-052)

    [0169] ##STR00033##

    [0170] Yield: 91% (1.40 g, 3.01 mmol); workup A (CH.sub.2Cl.sub.2/MeOH=99/1).

    [0171] .sup.1H NMR (250 MHz, CDCl.sub.3): [ppm]=7.78-7.72 (m, 1H), 7.69 (br s, 1H), 7.60-7.55 (m, 2H), 7.45 (br s, 1H), 7.41-7.27 (m, 3H), 7.20-7.09 (m, 3H), 6.92-6.84 (m, 2H), 3.89 (s, 3H).

    [0172] .sup.13C NMR (63 MHz, CDCl.sub.3): [ppm]=167.1, 157.6, 153.9, 153.6, 137.2, 133.1, 132.1, 131.9, 130.1, 128.9 (q, J=31.6 Hz), 126.4 (m), 124.6, 124.1, 123.6, 123.4, 122.6 (q, J=273.3 Hz), 120.0, 119.2, 119.1 (m), 52.5 (observed complexity is due to the CF splitting).

    [0173] ESI-HR-MS (m/z) [M+H.sup.+] 465.0824 calcd. for C.sub.22H.sub.17ClF.sub.3N.sub.2O.sub.4.sup.+; found, 465.0825.

    EXAMPLE 2

    1-(4-Benzoylphenyl)-3-(4-chloro-3-(trifluoromethyl)phenyl)urea (PK/X17-1-144)

    [0174] ##STR00034##

    [0175] Yield: 70% (121 mg, 0.289 mmol); workup B.

    [0176] .sup.1H NMR (500 MHz, DMSO-d.sub.6): [ppm]=9.35 (s, 1H), 9.31 (s, 1H), 8.16-8.11 (m, 1H), 7.77-7.62 (m, 9H), 7.56 (t, J=7.6 Hz, 2H).

    [0177] .sup.13C NMR (126 MHz, DMSO-d.sub.6): [ppm]=194.5, 152.2, 143.8, 139.0, 137.7, 132.2, 132.1, 131.4, 130.4, 129.3, 128.5, 126.8 (q, J=30.7 Hz), 123.4, 122.8, 122.8 (q, J=273.0 Hz), 117.6, 117.0 (q, J=5.7 Hz) (observed complexity is due to the CF splitting).

    [0178] ESI-HR-MS (m/z) [M+H.sup.+] 419.0769 calcd. for C.sub.2iH.sub.16ClF.sub.3N.sub.2O.sub.2.sup.+; found, 419.0766.

    EXAMPLE 3

    4-(3-(4-Chloro-3-(trifluoromethyl)phenyl)ureido)-N-methylbenzamide (PK/X17-1-145)

    [0179] ##STR00035##

    [0180] Yield: 64% (98.2 mg, 0.264 mmol); workup B.

    [0181] .sup.1H NMR (500 MHz, DMSO-d.sub.6): [ppm]=9.25 (s, 1H), 9.10 (s, 1H), 8.31 (q, J=4.2 Hz, 1H), 8.14-8.11 (m, 1H), 7.78 (d, J=8.8 Hz, 2H), 7.66-7.61 (m, 2H), 7.53 (d, J=8.8 Hz, 2H), 2.76 (d, J=4.5 Hz, 3H).

    [0182] .sup.13C NMR (126 MHz, DMSO-d.sub.6): [ppm]=166.1, 152.3, 141.8, 139.2, 132.1, 128.1, 128.0, 126.8 (q, J=30.5 Hz), 123.2, 122.8 (q, J=273.0 Hz), 122.5 (m), 117.6, 116.9 (q, J=5.8 Hz), 26.2 (observed complexity is due to the CF splitting).

    EXAMPLE 4

    1-(4-Chloro-3-(trifluoromethyl)phenyl)-3-(2,2-difluorobenzo[d][1,3]dioxol-5-yl)urea (PK/X17-1-150)

    [0183] ##STR00036##

    [0184] Yield: 91% (148 mg, 0.375 mmol); workup A (CH.sub.2Cl.sub.2/MeOH=99/1).

    [0185] .sup.1H NMR (500 MHz, DMSO-d.sub.6): [ppm]=9.22 (s, 1H), 9.07 (s, 1H), 8.09 (d, J=2.3 Hz, 1H), 7.68-7.59 (m, 3H), 7.33 (d, J=8.7 Hz, 1H), 7.12 (dd, J=8.8, 2.2 Hz, 1H).

    [0186] .sup.13C NMR (126 MHz, DMSO-d.sub.6): [ppm]=152.5, 142.8, 139.2, 137.8, 136.0, 132.0, 131.3 (t, J=252.2 Hz), 126.7 (q, J=30.5 Hz), 123.2, 122.8 (q, J=273.1 Hz), 122.5 (m), 116.9 (q, J=6.0 Hz), 114.2, 110.1, 101.7 (observed complexity is due to the CF splitting).

    [0187] ESI-HR-MS (m/z) [M+H.sup.+] 395.0216 calcd. for C.sub.16H.sub.9ClF.sub.6N.sub.2O.sub.3.sup.+; found, 395.0211.

    EXAMPLE 5

    1-(4-Chloro-3-(trifluoromethyl)phenyl)-3-(4-methoxyphenyl)urea (PK/X17-1-155)

    [0188] ##STR00037##

    [0189] Yield: 40% (56.6 mg, 0.164 mmol); workup B.

    [0190] .sup.1H NMR (500 MHz, DMSO-d.sub.6): [ppm]=9.08 (s, 1H), 8.64 (s, 1H), 8.10 (d, J=2.2 Hz, 1H), 7.65-7.57 (m, 2H), 7.36 (d, J=8.9 Hz, 2H), 6.87 (d, J=8.9 Hz, 2H), 3.72 (s, 3H).

    [0191] .sup.13C NMR (126 MHz, DMSO-d.sub.6): [ppm]=154.8, 152.6, 139.6, 132.1, 132.0, 126.7 (q, J=30.5 Hz), 122.9. 122.9 (q, J=273.0 Hz), 122.0, 120.6, 116.7 (q, J=5.6 Hz), 114.0, 55.2.

    [0192] ESI-HR-MS (m/z) [M+H.sup.+] 345.0612 calcd. for C.sub.15H.sub.13ClF.sub.3N.sub.2O.sub.2.sup.+; found, 345.0608.

    [0193] The analytical data corroborate with the literature data in Zhang, L., Darko, A. K., Johns, J. I. and McElwee-White, L. (2011), Eur. J. Org. Chem., 2011: 6261-6268. doi: 10.1002/ejoc.201100657.

    EXAMPLE 6

    1-(Benzo[d][1,3]dioxol-5-yl)-3-(4-chloro-3-(trifluoromethyl)phenyl)urea (PK/X17-1-159)

    [0194] ##STR00038##

    [0195] Yield: 26% (37.7 mg, 0.105 mmol); workup A (CH.sub.2Cl.sub.2/MeOH=99/1).

    [0196] .sup.1H NMR (500 MHz, DMSO-d.sub.6): [ppm]=9.11 (s, 1H), 8.74 (s, 1H), 8.08 (d, J=2.2 Hz, 1H), 7.64-7.58 (m, 2H), 7.18 (d, J=2.0 Hz, 1H), 6.84 (d, J=8.3 Hz, 1H), 6.79 (dd, J=8.4, 2.0 Hz, 1H), 5.98 (s, 2H).

    [0197] .sup.13C NMR (126 MHz, DMSO-d.sub.6): [ppm]=152.5, 147.2, 142.4, 139.5, 133.5, 132.0, 126.7 (q, J=30.6 Hz), 123.0, 122.9 (q, J=273.1 Hz), 122.1 (m), 116.7 (m), 111.6, 108.1, 101.4, 100.9 (observed complexity is due to the CF splitting).

    [0198] ESI-HR-MS (m/z) [M+H.sup.+] 359.0405 calcd. for C.sub.15H.sub.11ClF.sub.3N.sub.2O.sub.3.sup.+; found, 359.0407.

    EXAMPLE 7

    1-(4-Chloro-3-(trifluoromethyl)phenyl)-3-(3,4-dimethoxyphenyl)urea (PK/X17-1-160)

    [0199] ##STR00039##

    [0200] Yield: 96% (147 mg, 0.392 mmol); workup A (CH.sub.2Cl.sub.2/MeOH=99/1).

    [0201] .sup.1H NMR (500 MHz, DMSO-d.sub.6): [ppm]=9.07 (s, 1H), 8.68 (s, 1H), 8.09 (d, J=2.3 Hz, 1H), 7.65-7.57 (m, 2H), 7.21-7.17 (m, 1H), 6.91-6.85 (m, 2H), 3.74 (s, 3H), 3.71 (s, 3H).

    [0202] .sup.13C NMR (126 MHz, DMSO-d.sub.6): [ppm]=152.5, 148.7, 144.4, 139.5, 132.7, 132.0, 126.7 (q, J=30.5 Hz), 123.0, 122.9 (q, J=273.1 Hz), 122.1 (m), 116.7 (q, J=5.7 Hz), 112.3, 110.7, 104.3, 55.8, 55.4 (observed complexity is due to the CF splitting).

    [0203] ESI-HR-MS (m/z) [M+H.sup.+] 375.0718 calcd. for C.sub.16H.sub.16ClF.sub.3N.sub.2O.sub.3.sup.+; found, 375.0720.

    EXAMPLE 8

    1-(4-Chloro-3-(trifluoromethyl)phenyl)-3-(3,4,5-trimethoxyphenyl)urea (PK/X17-1-162)

    [0204] ##STR00040##

    [0205] Yield: 98% (163 mg, 0.402 mmol); workup A (CH.sub.2Cl.sub.2/MeOH=99/1).

    [0206] .sup.1H NMR (500 MHz, DMSO-d.sub.6): [ppm]=9.10 (s, 1H), 8.79 (s, 1H), 8.09 (d, J=2.4 Hz, 1H), 7.67-7.58 (m, 2H), 6.80 (s, 2H), 3.75 (s, 6H), 3.61 (s, 3H).

    [0207] .sup.13C NMR (126 MHz, DMSO-d.sub.6): [ppm]=152.9, 152.4, 139.4, 135.3, 132.8, 132.0, 126.7 (q, J=30.6 Hz), 123.2, 122.9 (q, J=273.1 Hz), 122.3 (m), 116.8 (q, J=5.6 Hz), 96.4, 60.1, 55.7 (observed complexity is due to the CF splitting).

    [0208] ESI-HR-MS (m/z) [M+H.sup.+] 405.0824 calcd. for C.sub.17H.sub.17ClF.sub.3N.sub.2O.sub.4.sup.+; found, 405.0828.

    EXAMPLE 9

    1-(4-Chloro-3-(trifluoromethyl)phenyl)-3-(2,2-difluorobenzo[d][1,3]dioxol-4-yl)urea (PK/X17-1-164)

    [0209] ##STR00041##

    [0210] Yield: 38% (62 mg, 0.157 mmol); workup A (Hex/EtOAc=4/1).

    [0211] .sup.1H NMR (500 MHz, DMSO-d.sub.6): [ppm]=9.40 (br s, 1H), 9.04 (br s, 1H), 8.09 (s, 1H), 7.66 (dd, J=8.5, 1.1 Hz, 1H), 7.65-7.61 (m, 2H), 7.16 (t, J=8.3 Hz, 1H), 7.11-7.07 (m, 1H).

    [0212] .sup.13C NMR (126 MHz, DMSO-d.sub.6): [ppm]=151.8, 143.1, 138.9, 133.0, 132.1, 131.0 (t, J=252.5 Hz), 126.8 (q, J=30.8 Hz), 124.5, 123.2, 123.0, 122.8, 122.8 (q, J=273.1 Hz), 116.9 (q, J=5.6 Hz), 116.5, 104.4 (observed complexity is due to the CF splitting).

    [0213] ESI-HR-MS (m/z) [M+H.sup.+] 395.0216 calcd. for C.sub.16H.sub.9ClF.sub.6N.sub.2O.sub.3.sup.+; found, 395.0216.

    EXAMPLE 10

    1-(4-Chloro-3-(trifluoromethyl)phenyl)-3-(2,2-difluorobenzo[d][1,3]dioxol-5-yl)thiourea (PK/X17-1-166)

    [0214] ##STR00042##

    [0215] Yield: 74% (128 mg, 0.312 mmol); workup A (CH.sub.2Cl.sub.2/MeOH=99/1).

    [0216] .sup.1H NMR (500 MHz, DMSO-d.sub.6): [ppm]=10.17 (s, 1H), 10.05 (s, 1H), 8.06 (d, J=2.5 Hz, 1H), 7.78 (dd, J=8.7, 2.5 Hz, 1H), 7.67 (d, J=8.7 Hz, 1H), 7.61 (d, J=2.1 Hz, 1H), 7.40 (d, J=8.6 Hz, 1H), 7.14 (dd, J=8.6, 2.1 Hz, 1H).

    [0217] .sup.13C NMR (126 MHz, DMSO-d.sub.6): 5 [ppm]=180.3, 142.5, 140.1, 139.1, 135.3, 131.6, 131.4 (t, J=252.5 Hz), 128.9, 126.1 (q, J=30.8 Hz), 125.5 (m), 122.9 (q, J=5.6 Hz), 122.7 (q, J=273.1 Hz), 120.7, 109.9, 107.8 (observed complexity is due to the CF splitting).

    [0218] ESI-HR-MS (m/z) [M+H.sup.+] 410.9988 calcd. for C.sub.16H.sub.9ClF.sub.6N.sub.2O.sub.8S.sup.+; found, 410.9986.

    EXAMPLE 11

    1-(4-Chloro-3-(trifluoromethyl)phenyl)-3-(naphthalen-2-yl)urea (PK/X17-4-002)

    [0219] ##STR00043##

    [0220] Yield: 29% (43.0 mg, 0.118 mmol); workup A (Hex/EtOAc=4/1).

    [0221] .sup.1H NMR (500 MHz, DMSO-d.sub.6): 5 [ppm]=9.25 (s, 1H), 9.07 (s, 1H), 8.18 (d, J=2.4 Hz, 1H), 8.13 (d, J=1.9 Hz, 1H), 7.87-7.79 (m, 3H), 7.68-7.61 (m, 2H), 7.50 (dd, J=8.8, 2.1 Hz, 1H), 7.48-7.44 (m, 1H), 7.39-7.35 (m, 1H).

    [0222] .sup.13C NMR (126 MHz, DMSO-d.sub.6): 5 [ppm]=152.5, 139.4, 136.9, 133.7, 132.1, 129.3, 128.5, 127.5, 127.1, 126.8 (q, J=30.6 Hz), 126.4, 124.2, 123.1, 122.9 (q, J=273.0 Hz), 122.4, 119.8, 116.8 (q, J=5.6 Hz), 114.0 (observed complexity is due to the CF splitting).

    [0223] ESI-HR-MS (m/z) [M+H.sup.+] 365.0663 calcd. for C.sub.18H.sub.13ClF.sub.3N.sub.2O.sup.+; found, 365.0662.

    EXAMPLE 12

    1-(4-Benzylphenyl)-3-(4-chloro-3-(trifluoromethyl)phenyl)urea (PK/X17-4-003)

    [0224] ##STR00044##

    [0225] Yield: 72% (120 mg, 0.296 mmol); workup A (Hex/EtOAc=3/1).

    [0226] .sup.1H NMR (300 MHz, DMSO-d.sub.6): [ppm]=9.13 (br s, 1H), 8.78 (br s, 1H), 8.10 (d, J=2.0 Hz, 1H), 7.66-7.56 (m, 2H), 7.37 (d, J=8.5 Hz, 2H), 7.32-7.11 (m, 7H), 3.88 (s, 2H).

    [0227] .sup.13C NMR (75 MHz, DMSO-d.sub.6): [ppm]=152.4, 141.6, 139.4, 137.1, 135.2, 132.0, 129.0, 128.6, 128.4, 126.7 (q, J=30.5 Hz), 125.9, 122.9, 122.8 (q, J=273.0 Hz), 122.1 (m), 118.9, 116.6 (q, J=6.0 Hz), 40.5 (observed complexity is due to the CF splitting).

    [0228] ESI-HR-MS (m/z) [M+H.sup.+] 405.0976 calcd. for C.sub.21H.sub.17ClF.sub.3N.sub.2O.sup.+; found, 405.0975.

    EXAMPLE 13

    1-(4-Chloro-3-(trifluoromethyl)phenyl)-3-(4-ethylphenyl)urea (PK/X17-4-004)

    [0229] ##STR00045##

    [0230] Yield: 78% (110 mg, 0.320 mmol); workup A (Hex/EtOAc=3/1).

    [0231] .sup.1H NMR (500 MHz, DMSO-d.sub.6): [ppm]=9.11 (br s, 1H), 8.74 (br s, 1H), 8.10 (d, J=2.4 Hz, 1H), 7.64-7.58 (m, 2H), 7.36 (d, J=8.5 Hz, 2H), 7.12 (d, J=8.5 Hz, 2H), 2.54 (q, J=7.6 Hz, 2H), 1.15 (t, J=7.6 Hz, 3H).

    [0232] .sup.13C NMR (126 MHz, DMSO-d.sub.6): [ppm]=152.4, 139.5, 137.7, 136.8, 132.0, 128.0, 126.7 (q, J=30.5 Hz), 123.0, 122.9 (q, J=273.0 Hz), 122.1 (m), 118.8, 116.7 (q, J=5.7 Hz), 27.6, 15.8 (observed complexity is due to the CF splitting).

    [0233] ESI-HR-MS (m/z) [M+H.sup.+] 343.0820 calcd. for C.sub.16H.sub.15ClF.sub.3N.sub.2O.sup.+; found, 343.0819.

    EXAMPLE 14

    1-(4-Chloro-3-methylphenyl)-3-(2,2-difluorobenzo[d][1,3]dioxol-5-yl)urea (PK/X17-4-017)

    [0234] ##STR00046##

    [0235] Yield: 60% (84.0 mg, 0.247 mmol); workup A (Hex/EtOAc=3/1).

    [0236] .sup.1H NMR (500 MHz, DMSO-d.sub.6): [ppm]=8.91 (br s, 1H), 8.78 (br s, 1H), 7.65 (d, J=2.1 Hz, 1H), 7.43 (br s, 1H), 7.32-7.29 (m, 3H), 7.08 (dd, J=8.8, 2.2 Hz, 1H), 2.29 (s, 3H).

    [0237] .sup.13C NMR (126 MHz, DMSO-d.sub.6): [ppm]=152.5, 142.8, 138.4, 137.5, 136.4, 135.6, 131.3 (t, J=252.1 Hz), 129.0, 125.9, 120.7, 117.5, 113.7, 110.1, 101.3, 19.9 (observed complexity is due to the CF splitting).

    [0238] ESI-HR-MS (m/z) [M+H.sup.+] 341.0499 calcd. for C.sub.16H.sub.12F.sub.2N.sub.2O.sub.3.sup.+; found, 341.0498.

    EXAMPLE 15

    1-(2,2-difluorobenzo[d][1,3]dioxol-5-yl)-3-(3-(trifluoromethyl)phenyl)urea (PK/X17-4-018)

    [0239] ##STR00047##

    [0240] Yield: 85% (149 mg, 0.414 mmol); workup A (Hex/EtOAc=3/1).

    [0241] .sup.1H NMR (500 MHz, DMSO-d.sub.6): [ppm]=9.09 (br s, 1H), 9.00 (br s, 1H), 8.00 (s, 1H), 7.66 (d, J=2.1 Hz, 1H), 7.58 (d, J=8.6 Hz, 1H), 7.51 (t, J=7.9 Hz, 1H), 7.32 (d, J=8.7 Hz, 2H), 7.12 (dd, J=8.7, 2.2 Hz, 1H).

    [0242] .sup.13C NMR (75 MHz, DMSO-d.sub.6): [ppm]=152.5, 142.8, 140.4, 137.7, 136.2, 131.3, 129.9, 129.5 (q, J=31.4 Hz), 124.2 (q, J=272.5 Hz), 122.0, 118.3 (q, J=3.9 Hz), 114.3 (q, J=4.1 Hz), 114.0, 110.0, 101.6 (observed complexity is due to the CF splitting).

    [0243] ESI-HR-MS (m/z) [M+H.sup.+] 361.0606 calcd. for C.sub.16H.sub.10F.sub.6N.sub.2O.sub.3.sup.+; found, 361.0605.

    EXAMPLE 16

    1-(4-Chloro-3-(trifluoromethyl)phenyl)-3-phenylurea (PK/X17-3-004)

    [0244] ##STR00048##

    [0245] Yield: 13% (44.0 mg, 0.140 mmol); A (CH.sub.2Cl.sub.2/MeOH=2/1).

    [0246] .sup.1H NMR (500 MHz, DMSO-d.sub.6): [ppm]=9.15 (br s, 1H), 8.83 (br s, 1H), 8.11 (d, J=2.3 Hz, 1H), 7.66-7.59 (m, 2H), 7.46 (d, J=7.7 Hz, 2H), 7.29 (t, J=7.9 Hz, 2H), 7.00 (t, J=7.4 Hz, 1H).

    [0247] .sup.13C NMR (126 MHz, DMSO-d.sub.6): [ppm]=152.4, 139.4, 139.2, 132.0, 128.8, 126.7 (q, J=30.5 Hz), 123.0, 122.9 (q, J=273.1 Hz), 122.3, 122.2 (m), 118.6, 116.7 (q, J=5.5 Hz) (observed complexity is due to the CF splitting).

    [0248] ESI-HR-MS (m/z) [M+H.sup.+] 315.0507 calcd. for C.sub.14H.sub.11ClF.sub.3N.sub.2O.sup.+; found, 315.0507.

    EXAMPLE 17

    Butyl 4-(3-(4-chloro-3-(trifluoromethyl)phenyl)ureido)benzoate (PK/X17-3-005)

    [0249] ##STR00049##

    [0250] Yield: 93% (200 mg, 0.482 mmol); workup B.

    [0251] 1H NMR (500 MHz, DMSO-d.sub.6): [ppm]=9.30-9.23 (m, 2H), 8.11 (d, J=2.1 Hz, 1H), 7.89 (d, J=8.7 Hz, 2H), 7.68-7.58 (m, 4H), 4.24 (t, J=6.5 Hz, 2H), 1.72-1.64 (m, 2H), 1.46-1.37 (m, 2H), 0.93 (t, J=7.4 Hz, 3H).

    [0252] .sup.13C NMR (126 MHz, DMSO-d.sub.6): [ppm]=165.4, 152.1, 143.9, 139.0, 132.1, 130.4, 126.8 (q, J=30.8 Hz), 123.3, 123.2, 122.8 (q, J=273.0 Hz), 122.7 (m), 117.7, 117.0 (q, J=5.5 Hz), 64.0, 30.3, 18.8, 13.7 (observed complexity is due to the CF splitting).

    [0253] ESI-HR-MS (m/z) [M+H.sup.+] 415.1031 calcd. for C.sub.19H.sub.19ClF.sub.3N.sub.2O.sub.3.sup.+; found, 415.1032.

    EXAMPLE 18

    1-(4-Chloro-3-(trifluoromethyl)phenyl)-3-(4-phenoxyphenyl)urea (PK/X17-3-006)

    [0254] ##STR00050##

    [0255] Yield: 92% (203 mg, 0.499 mmol); workup B.

    [0256] .sup.1H NMR (500 MHz, DMSO-d.sub.6): [ppm]=9.13 (s, 1H), 8.84 (s, 1H), 8.11 (d, J=2.3 Hz, 1H), 7.66-7.59 (m, 2H), 7.48 (d, J=8.9 Hz, 2H), 7.36 (t, J=8.0 Hz, 2H), 7.09 (t, J=7.4 Hz, 1H), 7.02-6.94 (m, 4H).

    [0257] .sup.13C NMR (126 MHz, DMSO-d.sub.6): [ppm]=157.5, 152.5, 151.1, 139.4, 135.1, 132.0, 130.0, 126.7 (q, J=30.5 Hz), 123.0, 122.9, 122.9 (q, J=273.0 Hz), 122.2 (m), 120.5, 119.7, 117.7, 116.7 (q, J=5.7 Hz) (observed complexity is due to the CF splitting).

    [0258] ESI-HR-MS (m/z) [M+H].sup.+407.0769 calcd. for C.sub.20H.sub.16ClF.sub.3N.sub.2O.sub.2.sup.+; found, 407.0770.

    EXAMPLE 19

    1,1-(1,3-Phenylene)bis(3-(4-chloro-3-(trifluoromethyl)phenyl)urea (PK/X17-3-003)

    [0259] ##STR00051##

    [0260] A solution of 4-chloro-3-(trifluoromethyl)phenyl isocyanate (339 mg, 1.53 mmol, 2.2 eq.) in dry dichloromethane (10 mL) was cooled to 0 C. After the addition of m-phenylenediamine (75.0 mg, 0.694 mmol, 1.0 eq.) the reaction mixture was allowed to warm to room temperature and the reaction was stirred at room temperature for 20 h. The solvent was removed followed by the precipitation from DMF through the addition of water (10 fold excess) and collection of the product by centrifugation (17000 g, 10 min).

    [0261] Yield: 50% (192 mg, 0.348 mmol).

    [0262] .sup.1H NMR (500 MHz, DMSO-d.sub.6): [ppm]=9.08 (s, 2H), 8.92 (s, 2H), 8.14 (s, 2H), 7.74 (t, J=2.0 Hz, 1H), 7.61 (d, J=1.4 Hz, 4H), 7.22-7.17 (m, 1H), 7.09 (dd, J=7.9, 2.0 Hz, 2H).

    [0263] ESI-HR-MS (m/z) [M+H.sup.+] 551.0471 calcd. for C.sub.22H.sub.15Cl.sub.2F.sub.6N.sub.4O.sub.2.sup.+; found, 551.0486.

    REFERENCE EXAMPLE 1

    1-(2,2-Difluorobenzo[d][1,3]dioxol-5-yl)-3-phenylurea (PK/X17-4-011)

    [0264] ##STR00052##

    [0265] Yield: 17% (38.0 mg, 0.130 mmol); workup A (Hex/EtOAc=4/1).

    [0266] .sup.1H NMR (500 MHz, DMSO-d.sub.6): [ppm]=8.88 (s, 1H), 8.72 (s, 1H), 7.66 (d, J=2.1 Hz, 1H), 7.46-7.43 (m, 2H), 7.32-7.26 (m, 3H), 7.08 (dd, J=8.7, 2.2 Hz, 1H), 7.00-6.95 (m, 1H).

    [0267] .sup.13C NMR (126 MHz, DMSO-d.sub.6): [ppm]=152.6, 142.8, 139.5, 137.4, 136.6, 131.3 (t, J=252.2 Hz), 128.8, 122.1, 118.4, 113.5, 110.1, 101.2 (observed complexity is due to the CF splitting).

    [0268] ESI-HR-MS (m/z) [M+H.sup.+] 293.0732 calcd. for C.sub.14H.sub.11F.sub.3N.sub.2O.sub.3.sup.+; found, 293.0732.

    REFERENCE EXAMPLE 2

    1-(2,2-Difluorobenzo[d][1,3]dioxol-5-yl)-3-(p-tolyl)urea (PK/X17-4-013)

    [0269] ##STR00053##

    [0270] Yield: 63% (131 mg, 0.428 mmol); workup A (Hex/EtOAc=4/1).

    [0271] .sup.1H NMR (500 MHz, DMSO-d.sub.6): [ppm]=8.83 (s, 1H), 8.61 (s, 1H), 7.66 (d, J=2.1 Hz, 1H), 7.34-7.28 (m, 3H), 7.10-7.04 (m, 3H), 2.24 (s, 3H).

    [0272] .sup.13C NMR (126 MHz, DMSO-d.sub.6): [ppm]=152.6, 142.8, 137.4, 136.9, 136.7, 131.3 (t, J=252.2 Hz), 130.9, 129.2, 118.5, 113.4, 110.1, 101.1, 20.4 (observed complexity is due to the CF splitting).

    [0273] ESI-HR-MS (m/z) [M+H.sup.+] 307.0889 calcd. for C.sub.16H.sub.13F.sub.2N.sub.2O.sub.3.sup.+; found, 307.0887.

    REFERENCE EXAMPLE 3

    1-(2,2-Difluorobenzo[d][1,3]dioxol-5-yl)-3-mesitylurea (PK/X17-4-014)

    [0274] ##STR00054##

    [0275] Yield: 39% (74.0 mg, 0.221 mmol); workup A (Hex/EtOAc=4/1).

    [0276] .sup.1H NMR (500 MHz, DMSO-d.sub.6): [ppm]=8.93 (br s, 1H), 7.68 (br s, 1H), 7.65 (d, J=2.1 Hz, 1H), 7.27 (d, J=8.8 Hz, 1H), 7.08 (dd, J=8.8, 2.1 Hz, 1H), 6.88 (s, 2H), 2.22 (s, 3H), 2.14 (s, 6H).

    [0277] ESI-HR-MS (m/z) [M+H.sup.+] 335.1202 calcd. for C.sub.17H.sub.17F.sub.2N.sub.2O.sub.3.sup.+; found, 335.1201.

    REFERENCE EXAMPLE 4

    1-(2,2-Difluorobenzo[d][1,3]dioxol-5-yl)-3-octylurea (PK/X17-4-020)

    [0278] ##STR00055##

    [0279] Yield: 31% (59.0 mg, 0.180 mmol); workup A (Hex/EtOAc=3/1).

    [0280] .sup.1H NMR (500 MHz, DMSO-d.sub.6): [ppm]=8.62 (s, 1H), 7.63 (d, J=2.1 Hz, 1H), 7.23 (d, J=8.7 Hz, 1H), 6.96 (dd, J=8.8, 2.1 Hz, 1H), 6.17 (t, J=5.6 Hz, 1H), 3.05 (q, J=6.8 Hz, 2H), 1.45-1.37 (m, 2H), 1.26 (br s, 10H), 0.84 (t, J=6.9 Hz, 3H).

    [0281] .sup.13C NMR (126 MHz, DMSO-d.sub.6): [ppm]=155.1, 142.8, 137.6, 136.8, 131.3 (t, J=252.1 Hz), 112.6, 109.9, 100.4, 39.1, 31.3, 29.7, 28.8, 28.8, 26.4, 22.1, 14.0 (observed complexity is due to the CF splitting).

    [0282] ESI-HR-MS (m/z) [M+H.sup.+] 329.1671 calcd. for C.sub.16H.sub.23F.sub.2N.sub.2O.sub.3.sup.+; found, 329.1671.

    REFERENCE EXAMPLE 5

    N-Methyl-4-(4-(3-phenylureido)phenoxy)picolinamide (PK/X17-2-011)

    [0283] ##STR00056##

    [0284] Yield: 63% (93.9 mg, 0.259 mmol); workup A (Hex/EtOAc=3/2).

    [0285] .sup.1H NMR (500 MHz, DMSO-d.sub.6): [ppm]=8.81 (s, 1H), 8.76 (q, J=4.6 Hz, 1H), 8.70 (s, 1H), 8.50 (d, J=5.6 Hz, 1H), 7.58 (d, J=8.9 Hz, 2H), 7.46 (d, J=7.7 Hz, 2H), 7.38 (d, J=2.5 Hz, 1H), 7.31-7.26 (m, 2H), 7.18-7.13 (m, 3H), 7.00-6.96 (m, 1H), 2.78 (d, J=4.9 Hz, 3H).

    [0286] .sup.13C NMR (75 MHz, DMSO-d.sub.6): [ppm]=166.0, 163.8, 152.6, 152.4, 150.4, 147.4, 139.6, 137.6, 128.8, 121.9, 121.5, 119.9, 118.3, 114.0, 108.6, 26.0.

    [0287] ESI-HR-MS (m/z) [M+H.sup.+] 363.4152 calcd. for C.sub.20H.sub.19N.sub.4O.sub.3.sup.+; found, 363.1450.

    3) BIOLOGICAL AND PHARMACOLOGICAL TESTS

    3.1) Cytotoxicity Assay (MTT)

    [0288] The MTT assay was performed in 96 well plates. A549, HeLa and HepG2 cells were seeded with 4000 cells/well, whereas NIH/3T3 cells were seeded with 2000 cells/well. Cells were grown to 30-40% confluence at 37 C. and 5% CO.sub.2 over a time span of 24 h. The medium was removed and 100 L medium/well containing varying concentrations of the respective compound and a final DMSO concentration of 0.1% were added to the cells in triplicates and incubated at 37 C. and 5% CO.sub.2 for 24 h. 20 L Thiazolyl blue tetrazolium bromide (5 mg/mL in PBS, Sigma Aldrich) were added to the cells and incubated at 37 C. and 5% CO.sub.2 for 4 h until complete consumption was observed. After removal of the medium, the resulting formazan was dissolved in 200 L DMSO. Optical density was measured at 570 nm (562 nm) and background subtracted at 630 nm (620 nm) by a TECAN Infinite M200 Pro.

    [0289] The results of MTT testing in various cell lines (FIG. 4) reveal toxicity of PK/X17-1-150 (example compound 4) at concentrations higher compared to the antibacterial MICs providing a therapeutic window for efficacy studies.

    3.2) Plasma Stability Assay

    [0290] The in vitro stability was tested by a LC-MS based method. Mouse plasma was purchased from biowest (mouse plasma w/lithium heparin, sterile filtered S2162-010) and used as a 1:1 dilution with potassium phosphate buffer (0.1 M, pH 7.4). Final assay concentration of DMSO from compound stocks was 1%. AV1, a -lactone with known low plasma stability, was used as positive control at a concentration of 50 M. The compound stability test in plasma was initiated by the addition of 10 M compound of interest (50 M in the case of AV1) to 250 L of diluted mouse plasma at 37 C. Directly after compound addition the reaction mixture was shortly mixed by vortexing and the first sample of 25 L was withdrawn (time point 0 min). Every sample was quenched immediately by the addition 30 L of pre-chilled acetonitrile. The reaction mixture was incubated at 37 C. with gentle shaking at 600 rpm. At certain time points (5, 10, 20, 30, 60, 120, 240, 360 min) additional samples (25 L) were taken for every test compound, quenched as described and stored at 20 C. For analysis by LC-MS all samples were allowed to warm to rt and centrifuged at 17000 g for 5 min. The supernatants were filtered through modified nylon centrifugal filters (0.45 M) and transferred to LS-MS glass vials. Quantitative LC-MS analysis was performed by LCQ-Fleet Ion Trap Mass Spectrometer equipped with an APCI ion source and a DionexHPLC system using a Waters Xbridge BEH130 C18 column (5 M 4.6100 mm). Data analysis was performed by Thermo Scientific Xcalibur software. Shortly, ion peaks from single ion monitoring mass detection were integrated. Peak areas at the time point 0 min were set to 100% and peak decline with time was expressed relative to 100% at t=0 min. Plasma stability was determined in three independent experiments.

    [0291] Sorafenib as well as PX/X17-1-150 (example compound 4) exhibit excellent stability in plasma for several hours which represents an ideal condition for clinical studies (FIG. 5).

    3.3) Minimal Inhibitory Concentration (MIC)

    [0292] Minimum inhibitory concentrations (MICs) represent the lowest concentration of sample that will inhibit the visible growth of a microorganism after overnight incubation, and was obtained by a 96 well plate-based assay (Thermo Scientific) with serial dilutions of the probes tested. In the case of Staphylococcus aureus, 5 ml of fresh media was inoculated with 5 L of the corresponding bacterial overnight culture (1:100) and incubated at 37 C. with gentle shaking (200 rpm) until the cultures reached an OD.sub.600 of 0.4-0.6. Bacteria were diluted in fresh medium to a concentration of 10.sup.5 CFU/mL. In the case of all other bacteria species tested, fresh media was inoculated 1/10000 and directly used for testing. Diluted bacterial cultures (99 L) were added to various concentrations of probe (1 L of the respective stock in DMSO). A growth control containing DMSO (1 L) and cultivated medium (99 L) and a sterile control containing fresh medium (100 L) were run on every 96 well plate in triplicates. After incubation at 37 C. with gentle shaking (200 rpm) for 24 h, the dilution series was analysed for microbial growth, usually indicated by turbidity and/or a pellet of bacteria at the bottom of the well. The lowest concentration in the dilution series at which no growth of bacteria could be observed by eye was defined as the minimum inhibitory concentration (MIC) of the probe. MIC values were determined by three independent experiments with at least triplicate runs for each concentration.

    [0293] The antibacterial activity of example compound 4 was demonstrated in an in vitro test. Sorafenib was tested as a reference. Both compounds were tested against various bacterial strains. LB medium: 1% peptone, 0.5% NaCl, 0.5% yeast extract, pH 7.5; B medium: 1% peptone, 0.5% NaCl, 0.5% yeast extract, 0.1% K2HPO4, pH 7.5; BHB medium: 0.75% brain infusion, 1% heart infusion, 1% peptone, 0.5% NaCl, 0.25% Na2HPO4, 0.2% glucose, pH 7.4.

    TABLE-US-00001 TABLE 1 IC.sub.50 values for inhibition of bacterial growth. MIC (M) of Example MIC (M) strain medium compound 4 of Sorafenib Staphylococcus B 0.3 3 aureus USA300 S. aureus Mu50 B 0.3 3 Staphylococcus B 0.3 3 aureus DSM18827 Staphylococcus B 0.3 3 aureus NCTC8325 Staphylococcus B 0.3 5 aureus Bk95395 Staphylococcus B 0.3 5 aureus Bk97296 Staphylococcus B 0.3 5 aureus IS050678 Staphylococcus B 0.3 3 aureus IS050611 Staphylococcus B 0.3 5 aureus VA417350 Staphylococcus B 0.3 5 aureus VA418879 Staphylococcus B 0.3 5 aureus VA402923 Staphylococcus B 0.3 5 aureus VA412350 Staphylococcus B 0.3 3 aureus VA409044 Staphylococcus B 0.3 5 aureus VA402525 Mycobacterium LB 1 6 smegmatis mc.sup.2 155 Mycobacterium 7H9 2 25 tuberculosis H37Rv Bacillus subtilis LB 1 5 Acinetobacter B 10 >100 baumannii Pseudomonas B >100 >100 aeruginosa Enterobacter cloacae B >100 >100 subsp. Cloacae Enterobacter B >100 >100 aerogenes

    [0294] The antibacterial activity of compounds of the invention was demonstrated in an in vitro test in which the compounds were tested against S. aureus NCTC 8325 by minimum inhibitory concentration (MIC) assays. The assay was performed as described above.

    TABLE-US-00002 TABLE 2 IC.sub.50 values for inhibition of bacterial growth of S. aureus NCTC 8325. Compound of example no. IC.sub.50 (M) 1 0.5 2 1 3 30 4 0.3 5 3 6 10 7 30 8 30 9 1 10 1 11 1 12 1 13 1 14 1 15 1 16 3 17 0.6 18 0.6 19 1 Reference Example 1 >100 Reference Example 2 >100 Reference Example 3 >100 Reference Example 4 >100 Reference Example 5 >100 Probe compound (PK/X17-1-058) 10

    3.4) Resistance Development Assay

    [0295] For resistance development by sequential passaging, exponential growing S. aureus NCTC 8325 was diluted 1:100 in 1 mL MHB medium containing sorafenib, example compound 4 (PK/X17-1-150) or Ofloxacin as positive control as well as DMSO or 0.1 M NaOH as growth/negative controls. Bacteria were incubated at 37 C. with shaking at 200 rpm, and passaged in 24 h intervals in the presence of sorafenib, example compound 4 (PK/X17-1-150) or Ofloxacin at different concentrations (0.25MIC, 0.5MIC, 1MIC, 2MIC, 4MIC). Cultures from the second highest concentrations that allowed growth (OD.sub.6003) were diluted 1:100 into fresh media containing different concentrations of the respective antimicrobial (0.25MIC, 0.5MIC, 1MIC, 2MIC, 4MIC). If a shift in MIC levels was observed, concentrations of the respective antimicrobial were adjusted accordingly for the following passaging. This serial passaging was repeated for 27 days.

    [0296] Serial passaging of S. aureus in the presence of subinhibitory levels of example compound 4 (PK/X17-1-150) over a period of 27 days showed no resistant development, whereas serial passaging of S. aureus in the presence sorafenib resulted in resistance development within the same time frame (FIG. 6). Bacteria showed first signs of lower sensitivity against sorafenib within the first 5 days, while the minimal inhibitory concentration increased by a factor 40 within the first 10 days. Furthermore, preliminary results indicate that PK/X17-1-150 (example compound 4) is still active against S. aureus that developed resistance against sorafenib.

    3.5) Activity Based Protein Profiling with Photoprobe X17PP1 (pABPP, Probe Compound) in S. aureus NCTC8325

    [0297] The gel-free affinity-based protein profiling (AfBPP) platform (Evans, M. J.; Cravatt, B. F. Chem. Rev. 2006, 106 (8), 3279-3301) was utilized to identify the protein target of sorafenib and structurally related compounds in S. aureus. A photoreactive derivative of sorafenib (PK/X17-1-058 (Probe compound)) bearing a terminal alkyne handle was incubated with S. aureus cells in vivo. After irradiation the cells were lysed and the terminal alkyne modified with a biotin-containing linker via click chemistry. Proteins, which were in this way irreversibly attached to a biotin molecule, were enriched on avidin beads, which bind biotins via affinity-based interaction. Following tryptic digest the samples were measured by LC-MS/MS and analyzed using MaxQuant and Perseus. We identified type I signal peptidase (SpsB), an essential serine-protease, as a possible protein target of this compound class (FIG. 3). Further in vitro experiments will be conducted to biochemically validate SpsB as the molecular target of sorafenib and related compounds.

    [0298] For overnight culture 5 mL of B medium (1% peptone, 0.5% NaCl, 0.5% yeast extract, 0.1% K2HPO4, pH 7.5) were inoculated with 50 L of a cryostock (1:100) and incubated by shaking at 37 C. (200 rpm) for 14 h. The overnight culture was diluted 1:10 into 100 mL B medium. After 7 h growth an equivalent of OD.sub.600=20 of the culture was harvested at 6000g and 4 C. for 10 min and washed with PBS. Cells were resuspended in 0.5 mL PBS. For competition experiments samples were incubated with 0.5 mM sorafenib in DMSO or DMSO only as control (final concentration of 1%) for 45 min at 25 C. and 700 rpm. After preincubation 50 M photoprobe X17PP1 in DMSO or DMSO as control (final concentration of 2%) were added and incubated for another 45 min at 25 C. and 700 rpm. After compound treatment samples were diluted in 4 mL PBS, transferred to petri dishes and irradiated with UV light at 360 nm (Philips TL-D BLB UV) for 30 min on ice. The suspension was transferred to falcons and bacteria were harvested by centrifugation at 6000g and 4 C. for 10 min and washed with PBS.

    [0299] Cell pellets were resuspended in 0.5 mL PBS with 1EDTA-free Complete mini protease inhibitors (Roche) on ice and transferred to Precellys Glass/Ceramic Kit SK38 2.0 mL tubes. Cells were lysed with a Precellys24 Homogenizer (Bertin Technologies, Montigny-le-Bretonneux, France) (at 5500 rpm for 15 s. Lysis was performed 6 times with 2 min cooling breaks on ice after each run. 300 L of the lysates were transferred to 1.5 mL microcentrifuge tubes and treated with 8 g/mL lysostaphin (Sigma) for 20 min at 37 C. and 700 rpm. Membranes were separated from cytosol by centrifugation for 1 h at 4 C. and 21,000g. Membrane fraction was then washed twice with PBS using an ultrasonic rod (Bandelin Sonopuls, Berlin, Germany) at 10% intensity for 10 s for resuspension. Protein concentrations were determined using bicinchoninic acid assay (Pierce BCA Protein assay kit, Thermo Fisher Scientific, Pierce Biotechnology, Rockford, Ill., USA) and used for normalization.

    [0300] For click chemistry 300 L of membrane and cytosol fractions were treated with 60 M Biotin-PEG.sub.3-N.sub.3 (CLK-AZ104P4-100, Jena Bioscience, Jena, Germany), 1 mM TCEP, 0.1 mM TBTA ligand and 1 mM CuSO.sub.4. The samples were incubated for 1 h at RT in the dark. Subsequently proteins were precipitated using 1.2 mL of cold acetone over night at 80 C.

    [0301] The precipitated proteins were centrifuged at 16900g and 4 C. for 15 min and formed protein pellets were washed two times with 1 mL cold methanol (80 C.). Resuspension was achieved by sonication (15 sec at 10% intensity with an ultrasonic rod). Pellets were resuspended in 0.5 mL 0.4% SDS in PBS at RT by sonication (15 sec at 10% intensity). For enrichment 50 L avidin-agarose beads (Sigma) were prepared by washing the three times with 1 mL 0.4% (w/v) SDS in PBS. Protein solution were added to the washed avidin-agarose beads and incubated under continuous inverting at 20 rpm and RT for 1 h. Beads were washed three times with 1 mL 0.4% SDS in PBS, two times with 1 mL 6 M urea in water and three times with 1 mL PBS. All centrifugation steps were conducted at 400 g for 2 min at RT.

    [0302] The beads with bound proteins were resuspended in 200 l denaturation buffer (7 M urea, 2 M thiourea in 20 mM pH 7.5 HEPES buffer). Proteins were reduced on-bead with 5 mM TCEP at 37 C. and 1200 rpm for 1 h. Subsequent alkylation was performed with 10 mM Iodoacetamide at 25 C. and 1200 rpm for 30 min in the dark. Alkylation was quenched by the addition of 10 mM dithiothreitol for 30 min at RT. For digestion 1 L LysC (0.5 g/L) (Wako Pure Chemical Industries, Richmond, Va., USA) was added to each sample and incubated at RT and 1200 rpm for 2 h. Afterwards samples were diluted 1:4 with 50 mM TEAB and digested with 1.5 L trypsin (0.5 g/L) (Promega Sequencing Grade Modified, Promega, Madison, Wis., USA) over night at 37 C. The reaction was stopped by adding formic acid (FA) to a final concentration of 0.5% (final pH of 2-3). Peptides were desalted and labelled by stable isotope dimethyl labeling (Boersema P. J. et al., Nat protoc 2009, 4 (4), 484-94)) on-column using 50 mg SepPak C18 columns (Waters). For this SepPak C18 columns were equilibrated with 1 mL acetonitrile, 1 mL elution buffer (80% ACN, 0.5% FA) and 31 mL aqueous 0.5% FA solution. Subsequently the samples were loaded by gravity flow, washed with 51 mL aqueous 0.5% FA solution and labeled with 5 mL of the respective dimethyl labeling solution. The following solutions were used: 30 mM NaBH.sub.3CN, 0.2% CH.sub.2O, 10 mM NaH.sub.2PO.sub.4, 35 mM Na.sub.2HPO.sub.4, pH 7.5 (light (L)), 30 mM NaBH.sub.3CN, 0.2% CD.sub.2O, 10 mM NaH.sub.2PO.sub.4, 35 mM Na.sub.2HPO.sub.4, pH 7.5 5 (light (M)) and 30 mM NaBHD.sub.3CN, 0.2% .sup.13CD.sub.2O, 10 mM NaH.sub.2PO.sub.4, 35 mM Na.sub.2HPO.sub.4, pH 7.5 5 (heavy (H)). For technical replicates the labels were permuted. Labeled peptides were eluted with 500 L of elution buffer, mixed for quantification and lyophilized using a vacuum centrifuge.

    [0303] Prior to mass spectrometry samples were dissolved in 0.5% FA and filtered using 0.45 m centrifugal filter units (VWR). Samples were analyzed via HPLC-MS/MS using an UltiMate 3000 nano HPLC system (Dionex, Sunnyvale, Calif., USA) equipped with Acclaim C18 PepMap100 75 m ID2 cm trap and Acclaim C18 PepMap RSLC, 75 M ID15 cm separation columns coupled to an Orbitrap Fusion (Thermo Fisher Scientific Inc., Waltham, Mass., USA). Peptides were loaded on the trap and washed for 10 min with 0.1% formic acid, then transferred to the analytical column and separated using a 120 min gradient from 3% to 25% acetonitrile (Orbitrap Fusion) in 0.1% formic acid and 5% dimethyl sulfoxide (at 200 nL/min flow rate). LTQ Orbitrap Fusion was operated in a 3 second top speed data dependent mode. Full scan acquisition was performed in the orbitrap at a resolution of 120000 and an ion target of 4e5 in a scan range of 300 1700 m/z. Monoisotopic precursor selection as well as dynamic exclusion for 60 s were enabled. Precursors with charge states of 2-7 and intensities greater than 5e3 were selected for fragmentation. Isolation was performed in the quadrupole using a window of 1.6 m/z. Precursors were collected to a target of 1e2 for a maximum injection time of 250 with inject ions for all available parallelizable time enabled (Universal method, Eliuk et al, Thermo Scientific Poster Note PN40914). Fragments were generated using higher-energy collisional dissociation (HCD) and detected in the ion trap at a rapid scan rate. Internal calibration was performed using the ion signal of fluoranthene cations (EASY-ETD/IC source).

    [0304] Peptide and protein identifications were performed using MaxQuant 1.5.1.2 software with Andromeda as search engine using following parameters: Carbamidomethylation of cysteines as fixed and oxidation of methionine as well as acetylation of N-termini as dynamic modifications, trypsin/P as the proteolytic enzyme, 4.5 ppm for precursor mass tolerance (main search ppm) and 0.5 Da for fragment mass tolerance (ITMS MS/MS tolerance). Searches were performed against the Uniprot database for S. aureus NCTC 8325 (taxon identifier: 93061, downloaded on 8.5.2014). Quantification was performed using dimethyl labeling with the following settings: light: DimethLys0, DimethNter0; medium: DimethLys4, DimethNter4 and heavy: DimethLys8, DimethNter8 with a maximum of 4 labeled amino acids. Variable modifications were included for quantification. The I=L, requantify and match between runs (default settings) options were used. Identification was done with at least 2 unique peptides and quantification only with unique peptides.

    [0305] For statistics with Perseus 1.5.1.6 three biological replicates consisting of three technical replicates each were analysed. Putative contaminants, reverse hits and proteins, identified by side only, were removed. Dimethyl labeling ratios were log 2(x) transformed and filtered to contain at least two valid values within technical replicates. Ratios were z-score normalized and average values of technical replicates were calculated. P-values were obtained by a two sided one sample t-test over the three biological replicates.

    3.6 SpsB FRET with Membrane Fraction

    [0306] Cells were grown according to stationary phase, harvested (12.000g, 10 min, 4 C.), digested with lysostaphin (end conc: 20 U/mL, 37 C., 1 h) and sonicated (30 s, 20%, Bandelin Sonoplus, Berlin, Germany). Intact cells and debris were removed by centrifugation: 12.000g, 10 min, 4 and membranes collected: 39.000g, 75 min, 4 C. Membranes were resuspended in 2 mL cold 50 mM sodium phosphate buffer pH 7.5 and protein concentration determined by BCA (Roti-Quant universal, Carl Roth GmbH+Co. KG, Karlsruhe, Germany) assay.

    [0307] 0.1 mg/mL membranes in 50 mM sodium phosphate buffer pH 7.5 were used for the FRET (Frster resonance energy transfer) assay and incubated with 1 L compound (in DMSO) and 10 M SPase I FRET substrate (Sequence of SceD peptide): DABCYL-AGHDAHASET-EDANS (Protein AGHDAHASET has SEQ ID NO. 1, DABCYL: 4-(4-dimethylaminophenylazo)benzoic acid; EDANS: 5-((2-aminoethyl)amino)-1-naphthalenesulfonic acid, Anaspec Inc., Fremont, Calif., USA). Fluorescence turnover was determined on a TECAN plate reader (Tecan infinite 200Pro, Tecan Group Ltd., Zurich, Switzerland) at 37 C. using 340 nm as excitation and 510 nm as emission wavelengths in fluorescence top reading mode.

    [0308] Addition of sorafenib and PK/X17-1-150 increased SpsB peptidase activity (FIG. 7A-C) demonstrating that binding to the enzyme stimulates substrate turnover.

    3.7) Analysis of S. aureus NCTC8325 Secretome after Treatment with Sorafenib

    [0309] The following protocol is based on the publication from Schallenberger et al. (Schallenberger, M. A.; Niessen, S.; Shao, C.; Fowler B. J.; Romesberg, F. E.; J Bacteriol 2012, 194 (10), 2677-2686). For overnight cultures 50 mL of B medium (1% peptone, 0.5% NaCl, 0.5% yeast extract, 0.1% K2HPO4, pH 7.5) were inoculated with 50 L of a cryostock (1:100) and incubated by shaking at 37 C. (200 rpm) for 16 h. The overnight culture was diluted to OD.sub.600 of 0.1 into 40 mL B medium per biological replicate. After 5 h growth at 37 C. OD.sub.600 were measured, cells harvested by centrifugation at 3000g and 4 C. for 15 min and washed with PBS. Cells were resuspended in fresh B medium to a cell density of ca. 1.510.sup.9 CFU/mL. 10 mL of the cells were incubated with 0.5MIC of PK/X17-1-150 (0.15 M) or sorafenib (1.5 M) or DMSO as control in 50 mL tubes for 1.5 h at 37 C. (200 rpm). After treatment OD.sub.600 were measured and serial dilutions plated for cell number determination. Cells were pelleted by centrifugation at 3000g for 15 min and 6000g for 5 min. The supernatants were collected and filtered (0.22 M filter). Subsequently proteins were precipitated using 20% (wt/vol) trichloroacetic acid and an overnight incubation @ 4 C. Proteins were harvested by centrifugation at 9000g, and washed two times with 90% acetone. Protein pellets were air dried and dissolved in 8 M urea in 50 mM Tris pH 8.0. Protein concentrations were measured using BCA assay (Pierce BCA Protein assay kit, Thermo Fisher Scientific, Pierce Biotechnology, Rockford, Ill., USA). Protein concentrations were normalized according to protein concentrations (as determined by BCA assay), as no change in cell numbers at 0.5MIC could be observed.

    [0310] Proteins were reduced with 10 mM TCEP at 37 C. and 1200 rpm for 1 h. Subsequent alkylation was performed with 12.5 mM Iodoacetamide at 25 C. and 1200 rpm for 30 min in the dark. Alkylation was quenched by the addition of 12.5 mM dithiothreitol for 30 min at RT. For digestion 2 L LysC (0.5 g/L) was added to each sample and incubated at RT and 700 rpm for 2 h. Afterwards samples were diluted 1:5 with 50 mM TEAB and digested with 2 L trypsin (0.5 g/L) over night at 37 C. The reaction was stopped by adding formic acid (FA) to a final concentration of 0.5% (final pH of 2-3). Peptides were desalted on-column using 50 mg SepPak C18 columns (Waters). For this SepPak C18 columns were equilibrated with 1 mL acetonitrile, 1 mL elution buffer (80% ACN, 0.5% FA) and 31 mL aqueous 0.5% FA solution. Subsequently the samples were loaded by gravity flow, washed with 31 mL aqueous 0.5% FA solution, eluted with 500 L of elution buffer and lyophilized using a vacuum centrifuge.

    [0311] Prior to mass spectrometry samples were dissolved in 0.5% FA and filtered using 0.45 m centrifugal filter units (VWR). Samples were analyzed via HPLC-MS/MS using an UltiMate 3000 nano HPLC system (Dionex, Sunnyvale, Calif., USA) equipped with Acclaim C18 PepMap100 75 m ID2 cm trap and Acclaim C18 PepMap RSLC, 75 M ID15 cm separation columns coupled to an Orbitrap Fusion (Thermo Fisher Scientific Inc., Waltham, Mass., USA). Peptides were loaded on the trap and washed for 10 min with 0.1% formic acid, then transferred to the analytical column and separated using a 120 min gradient from 3% to 25% acetonitrile (Orbitrap Fusion) in 0.1% formic acid (at 200 nL/min flow rate). LTQ Orbitrap Fusion was operated in a 3 second top speed data dependent mode. Full scan acquisition was performed in the orbitrap at a resolution of 120000 and an ion target of 4e5 in a scan range of 300 1700 m/z. Monoisotopic precursor selection as well as dynamic exclusion for 60 s were enabled. Precursors with charge states of 2-7 and intensities greater than 5e3 were selected for fragmentation. Isolation was performed in the quadrupole using a window of 1.6 m/z. Precursors were collected to a target of 1e2 for a maximum injection time of 250 with inject ions for all available parallelizable time enabled (Universal method, Eliuk et al, Thermo Scientific Poster Note PN40914). Fragments were generated using higher-energy collisional dissociation (HCD) and detected in the ion trap at a rapid scan rate. Internal calibration was performed using the ion signal of fluoranthene cations (EASY-ETD/IC source).

    [0312] Peptide and protein identifications were performed using MaxQuant 1.5.1.2 software with Andromeda as search engine using following parameters: Carbamidomethylation of cysteines as fixed and oxidation of methionine as well as acetylation of N-termini as dynamic modifications, trypsin/P as the proteolytic enzyme, 4.5 ppm for precursor mass tolerance (main search ppm) and 0.5 Da for fragment mass tolerance (ITMS MS/MS tolerance). Searches were performed against the Uniprot database for S. aureus NCTC 8325 (taxon identifier: 93061, downloaded on 8.5.2014). Quantification was performed using MaxQuant's LFQ algorithm. The I=L, requantify and match between runs (default settings) options were used. Identification was done with at least 2 unique peptides and quantification only with unique peptides.

    [0313] For statistics with Perseus 1.5.1.6 three biological were analysed. Putative contaminants, reverse hits and proteins, identified by side only, were removed. LFQ intensities were log 2(x) transformed and filtered to contain at least one valid value. Data was filtered to contain at least two MS/MS count in all three replicates of either DMSO or compound treated samples or both. Protein ratios (0.5MIC sorafenib/DMSO and 8MIC sorafenib/DMSO) were calculated and z-score normalized. P-values were obtained by a two sided one sample t-test over the three biological replicates.

    [0314] In agreement with results of the FRET peptidase assay (FIG. 7) stimulation of protein secretion was also obtained in whole cells upon incubation with 0.5MIC of PK/X17-1-150 or sorafenib (FIG. 8). Analysis of the secretome (sum of all secreted proteins) revealed a strong increase of extracellular proteins which are predicted SpsB substrates.

    3.8) Minimum Biofilm Eradication Concentration (MBEC)

    [0315] To each well of a flat-bottomed 96-well plate (BD Biosciences, BD 351172) 200 L of overnight culture of bacteria diluted 1:100 in media is added. Plates are incubated for 24 hours at 37 C. to establish biofilms. After 24 hours, the wells are carefully emptied by inverting the plate and gently shaking. A pre-mixed solution of media and compound stock solution is added to each well and plates are incubated at 37 C. At 16 hours after pre-established biofilms are treated with compound, the media from each well is removed, biofilms are washed three times with 200 L PBS to remove planktonic cells, and biofilms are regrown overnight at 37 C. in 200 L of fresh media. 100 L of supernatant from each well are transferred to a fresh 96-well flat bottomed plate and the OD at 595 nm is measured using a plate reader (POLARstar Omega, BMG Labtech). Concentrations of compound yielding a regrown OD of less than 0.1 correspond to the MBEC. Six replicates are completed for each concentration of compound as well as positive and negative controls.

    [0316] The results are shown in FIG. 10A, which shows the concentration dependent biofilm eradication effect of PK/X17-1-150 on S. aureus DSM 4910 after 20 h of compound treatment. DMSO was used as negative control compound, Oxacillin was used as positive control compound. Levels of crystal violet retained were measured spectrophotometrically at an OD of 595 nm. Concentrations of compound yielding a regrown OD of less than 0.1 correspond to the MBEC. Six replicates are completed for each concentration of compound as well as controls. PK/X17-1-150 revealed the strongest effect.

    [0317] Similar results are shown in FIG. 10B, which show concentration dependent biofilm eradication effect of PK/X17-1-150 on S. aureus DSM 4910 after 70 h of compound treatment. DMSO was used as negative control compound, Oxacillin was used as positive control compound. Levels of crystal violet retained were measured spectrophotometrically at an OD of 595 nm. Concentrations of compound yielding a regrown OD of less than 0.1 correspond to the MBEC. Six replicates are completed for each concentration of compound as well as controls. PK/X17-1-150 and the combination Ox+PK revealed most potent effects.

    3.9) Animal Model Data

    [0318] FIG. 11A shows the efficacy of PK/X17-1-150 against S. aureus in a murine bloodstream infection model. Bacterial loads in the heart (left) and liver (right) of S. aureus-infected mice treated with 20 mg/kg of PK/X17-1-150 (squares) or vehicle alone (circles). Each symbol represents an individual mouse. Compilation data from three independent experiments are presented. N=14 for vehicle and PK/X17-1-150. Horizontal lines represent the mean values. **, p<0.01. Bacterial loads in heart (left) and liver (right) were both significantly reduced by 2 log cfu compared to the vehicle control.

    [0319] FIG. 11B shows the efficacy of PK/X17-1-150 and levofloxacin against MRSA ATCC 33591 in the neutropenic murine thigh model. PK/X17-1-150 (20 mg/kg) and the corresponding vehicle were administered orally after 30 min, 4 and 8 h after bacterial inoculation, whereas levofloxacin (5 mg/kg) and the corresponding vehicle were administered intraperitoneally after 2, 6 and 10 h after bacterial inoculation. N=6 for vehicle i.p., levofloxacin i.p. and for PK/X17-1-150; n=5 for vehicle p.o. Data are expressed as mean valuesSD. **, p<0.01; ***, p<0.001. A 1-log.sub.10 cfu/g thigh reduction was observed in PK/X17-1-150-treated mice in comparison with sham-treated mice. The same range of reduction was determined for mice treated with the positive control levofloxacin upon i. v. administration.

    3.10) Data Obtained with Persister Cells

    [0320] As the generation and treatment of persister cells is highly dependent on the conditions and there is no consistency in the scientific community, two assays with different conditions were performed to corroborate effects resulting from PK/X17-1-150 treatment.

    [0321] Persister cell assay I. S. aureus NCTC 8325 cells were inoculated from an exponentially growing culture at 00.sub.600=0.4-0.5 1:1000 into tryptic soy broth (TSB, 17 g/L casein peptone, pancreas hydrolysate, 3 g/L soy peptone (papain hydrolysate), 2.5 g/L di-Potassium hydrogen phosphate, 5 g/L sodium chloride, 2.5 g/L glucose monohydrate, pH 7.30.2; CASO Broth, Carl Roth GmbH+Co. KG) and grown for exactly 15 h at 37 C. and 200 rpm. Cells were serially diluted and plated to determine cell numbers before any treatment. Persisters were prepared by treating the culture with 20 g/mL gentamicin (40MIC in NCTC 8325) for 4 h at 37 C. and 200 rpm. An H.sub.2O-treated control culture was incubated in the same way. Persisters (and control cells) were washed three times with PBS (5000g, 5 min) and diluted to OD.sub.600=4 in PBS. Serial dilutions were prepared for plating and determination of CFU/mL. 8MIC concentrations of PK/X17-1-150 (2.4 M) and sorafenib (24 M) and 5 g/mL ciprofloxacin (20MIC) as negative control were added 1:1000 to 10 mL aliquots of the diluted persisters in 100 mL flasks and incubated at 37 C. and 200 rpm for 70 h. At indicated times cells from 1 mL samples were harvested (10000g, 3 min), washed with PBS to remove the compound and resuspended in 1 or 0.1 mL PBS for the determination of CFU/mL by plating serial dilutions on agar plates. Three biological replicates were prepared and means, standard deviations and p-values (unpaired parametric t-test) were determined with Prism (GraphPadPrism v6.05, GraphPad Software). After 70 h there is a significant reduction of viable cells for PK/X17-1-150 and Sorafenib treated cells compared to the DMSO control, whereas there is no change for the ciprofloxacin-treated control.

    [0322] Persister cell assay II. Tryptic soy broth (50 mL in 250 mL culture flasks) was inoculated 1:1000 with overnight cultures of NCTC 8325 and grown at 37 C. and 200 rpm until an OD.sub.600 of 4 was reached or overnight (ON). Serial dilution were prepared and plated to determine the cell numbers in the inoculum. The cultures were aliquoted a 1 mL and treated with 30 g/mL oxacillin (30MIC) combined with 8MIC of test compounds (2.4 M PK/X17-1-150 or PK/X17-4-011, 24 M sorafenib or PK/X17-2-011). Additionally compounds were tested without oxacillin to exclude combinatory effects, as the majority of the cells at OD.sub.600=4 and from overnight cultures already are persisters and do not require selection by oxacillin. After 20 h (A) or 70 h (B) of treatment, cells were harvested, washed two times with PBS (10000g, 3 min), serially diluted and plated on agar plates for determination of surviving cell numbers.

    [0323] There is a significant reduction of viable cells for PK/X17-1-150 and Sorafenib treated cells compared to the DSMO control, whereas there is no change observed for ciprofloxacin-, PK/X17-4-011- or PK/X17-2-011-treated controls.

    3.11) Molecular Docking

    1.) Preparation of the Systems

    [0324] For the preparation of the systems, the signal peptidase crystal structure with the PDB code 4wvj was used for the simulations. The bound peptide was removed and the protein was solvated in a water box using tleap module of the Amber15 (Case, D. A.; J. T. B.; Betz, R. M.; Cerutti, D. S.; Cheatham, T. E. III; Darden, T. A.; Duke, R. E.; Giese, T. J.; Gohlke, H.; Goetz, A. W.; Homeyer, N.; Izadi, S.; Janowski, P.; Kaus, J.; Kovalenko, A.; Lee, T. S.; LeGrand, S.; Li, P.; Luchko, T.; Luo, R.; Madej, B.; Merz, K. M.; Monard, G.; Needham, P.; Nguyen, H.; Nguyen, H. T.; Omelyan, I.; Onufriev, A.; Roe, D. R.; Roitberg, A.; Salomon-Ferrer, R.; Simmerling, C. L.; Smith, W.; Swails, J.; Walker, R. C.; Wang, J.; Wolf, R. M.; Wu, X.; York D. M.; Kollman, P. A. AMBER 2015. In University of California, San Francisco.: 2015.) program package by applying a 12 buffer region around protein atoms (yielding a model consisting of 30,000 atoms).

    2.) Molecular Dynamic Simulations

    [0325] All simulations were performed using the ff03 (Duan, Y.; Wu, C.; Chowdhury, S.; Lee, M. C.; Xiong, G.; Zhang, W.; Yang, R.; Cieplak, P.; Luo, R.; Lee, T. Journal of Computational Chemistry 2003, 24, 1999-2012.), GAFF (Wang, J.; Wolf, R. M.; Caldwell, J. W.; Kollman, P. A.; Case, D. A. J. Comput. Chem. 2004, 25, 1157-1174.) and TIP3P (Jorgensen, W. L.; Chandrasekhar, J.; Madura, J. D.; Impey, R. W.; Klein, M. L. The Journal of Chemical Physics 1983, 79, 926-935.) force field parameters for the solute, PK/X17-1-150, and solvent, respectively. Missing bonded parameters for the probe were obtained using the antechamber package (Wang, J.; Wang, W.; Kollman, P. A.; Case, D. A. Journal of Molecular Graphics and Modelling 2006, 25, 247-260.) of Amber15, with the RESP charges calculated by the Gaussian09 software (Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Scalmani, G.; Barone, V.; Mennucci, B.; Petersson, G. A.; Nakatsuji, H.; Caricato, M.; Li, X.; Hratchian, H. P.; lzmaylov, A. F.; Bloino, J.; Zheng, G.; Sonnenberg, J. L. Hada, M.; Ehara, M.; Toyota, K.; Fukuda, R.; Hasegawa, J.; Ishida, M.; Nakajima, T.; Honda, Y.; Kitao, O.; Nakai, H.; Vreven, T.; Montgomery Jr., J. A.; Peralta, J. E.; Ogliaro, F.; Bearpark, M. J.; Heyd, J.; Brothers, E. N.; Kudin, K. N.; Staroverov, V. N.; Kobayashi, R.; Normand, J. Raghavachari, K.; Rendell, A. P.; Burant, J. C.; lyengar, S. S.; Tomasi, J.; Cossi, M.; Rega, N. Millam, N. J.; Klene, M.; Knox, J. E.; Cross, J. B.; Bakken, V.; Adamo, C.; Jaramillo, J. Gomperts, R.; Stratmann, R. E.; Yazyev, O.; Austin, A. J.; Cammi, R.; Pomelli, C.; Ochterski, J. W.; Martin, R. L.; Morokuma, K.; Zakrzewski, V. G.; Voth, G. A.; Salvador, P.; Dannenberg, J. J. Dapprich, S.; Daniels, A. D.; Farkas, .; Foresman, J. B.; Ortiz, J. V.; Cioslowski, J.; Fox, D. J. Gaussian 09, Gaussian, Inc.: Wallingford, Conn., USA, 2009.). Prior to the minimization of the models, the density of the systems was adjusted to 1 g/cm.sup.3 using an in-house python script. Hydrogens and heavy atoms were minimized consecutively using the SANDER module of Amber15. Periodic boundary conditions were applied. Long-range electrostatic interactions were calculated using the particle mesh Ewald method (Essmann, U.; Perera, L.; Berkowitz, M. L.; Darden, T.; Lee, H.; Pedersen, L. G. J. Chem. Phys. 1995, 103, 8577-8593.). A non-bonded cutoff of 12 and a time step of 1 fs were used. The systems were heated up to 300 K in the NVT ensemble using a stepwise fashion as performed in our previous works (Marcinowski, M.; Rosam, M.; Seitz, C.; Elferich, J.; Behnke, J.; Bello, C.; Feige, M. J.; Becker, C. F.; Antes, I.; Buchner, J. J. Mol. Biol. 2013, 425, 466-474; Schneider, M.; Rosam, M.; Glaser, M.; Patronov, A.; Shah, H.; Back, K. C.; Daake, M. A.; Buchner, J.; Antes, I. Proteins: Structure, Function, and Bioinformatics 2016.). The SHAKE algorithm was used to constraint all bonds involving hydrogens (Ryckaert, J.-P.; Ciccotti, G.; Berendsen, H. J. Journal of Computational Physics 1977, 23, 327-341.). The production runs were performed in the NPT ensemble for 150 ns and 100 ns for the PK/X17-1-150 bound complex and the apo-protein, respectively. The cuda-enabled graphics processing units (GPUS) version of the pmemd module of Amber15 was used (Gtz, A. W.; Williamson, M. J.; Xu, D.; Poole, D.; Le Grand, S.; Walker, R. C. Journal of Chemical Theory and Computation 2012, 8, 1542-1555; Salomon-Ferrer, R.; Gotz, A. W.; Poole, D.; Le Grand, S.; Walker, R. C. Journal of Chemical Theory and Computation 2013, 9, 3878-3888.).

    3.) Docking and Binding Free Energy Calculations

    [0326] A stepwise and comparative protocol was followed to find the binding site of the probe. Two plausible binding sites were detected using surface based analysis and analyzing their distances to the active site. The probe was docked to these two grooves separately, using the DynaDock approach of our in-house modeling program DynaCell (Antes, I. Proteins: Structure, Function, and Bioinformatics 2010, 78, 1084-1104.). The docking was performed in two steps; broad sampling and the molecular dynamic based energy refinement of the selected poses. The energetically-highest ranked five poses (total of ten poses coming from two different binding sites) were further simulated up to 5 ns using the same simulation scheme introduced above. The Molecular Mechanics-Generalized Born Surface Area approach (MMGBSA) (Srinivasan, J.; Cheatham, T. E.; Cieplak, P.; Kollman, P. A.; Case, D. A. J. Am. Chem. Soc. 1998, 120, 9401-9409.) was applied to calculate the binding free energies of these 10 complexes. The pose with the lowest binding free energy was chosen for further analysis. For the MMGBSA calculations, three distinct production runs (starting with different velocities) were performed on each equilibrated structure to yield 20 ns simulation time in total (time step 1 fs, a total of 225,000 complex frames (375,000). The MMGBSA. py module (Miller III, B. R.; McGee Jr, T. D.; Swails, J. M.; Homeyer, N.; Gohlke, H.; Roitberg, A. E. J. Chem. Theory Comput. 2012, 8, 3314-3321.) of Amber15 (Case, D.; Babin, V.; Berryman, J.; Betz, R.; Cai, Q.; Cerutti, D.; Cheatham III, T.; Darden, T.; Duke, R.; Gohlke, H. Proteins 2006, 65, 712-725.) was used to combine these frames and calculate the binding free energy. The contribution of the solvent was computed with Generalized Born Surface Area (GBSA) with a probe radius of 1.4 A and the rnbondi2 radii set (Srinivasan, J.; Trevathan, M. W.; Beroza, P.; Case, D. A. Theoretical Chemistry Accounts: Theory, Computation, and Modeling (Theoretica Chimica Acta) 1999, 101, 426-434.) using the modified GB model introduced by Case et al. (Onufriev, A.; Bashford, D.; Case, D. A. The Journal of Physical Chemistry B 2000, 104, 3712-3720; Onufriev, A.; Bashford, D.; Case, D. A. Proteins: Structure, Function, and Bioinformatics 2004, 55, 383-394.). The entropic contributions to the free energy of binding were not included in the calculation scheme as it has been shown that such costly computations do not significantly improve the results (Hou, T.; Wang, J.; Li, Y.; Wang, W. J. Chem. Inf. Model. 2010, 51, 69-82; Genheden, S. J. Comput. Aided Mol. Des. 2011, 25, 1085-1093; Genheden, S.; Ryde, U. J. Chem. Theory Comput. 2011, 7, 3768-3778.).