A PROCESS FOR THE PREPARATION OF TETRAHYDROANTHRACENES FROM STREPTOMYCES SPP. AND ANTICANCER ACTIVITY THEREOF
20250230477 ยท 2025-07-17
Assignee
Inventors
- Asha Chaubey (Jammu, IN)
- Ravi Singh Manhas (Jammu, IN)
- Jasmine Kour Khosla (Jammu, IN)
- Ajaz AHMED (Jammu, IN)
- Syed Mudabir Ahmad (Jammu, IN)
- Harshita Tiwari (Jammu, IN)
- Amit Nargotra (Jammu, IN)
- Debaraj Mukherjee (Jammu, IN)
- Anindya Goswami (Jammu, IN)
Cpc classification
A61K31/122
HUMAN NECESSITIES
C12P15/00
CHEMISTRY; METALLURGY
International classification
C12P15/00
CHEMISTRY; METALLURGY
Abstract
Streptomyces sp. MTCC-25420 and Streptomyces sp. MTCC-25512 isolated from the Shivalik region of India, has been demonstrated for tetrahydroanthracene antibiotics including setomimycin production. Combination of specific physico-chemical conditions have led to the antibiotic complex formation (upto 5.0 g/L) in 2-10 days of fermentation with maximum production at 4-8 days in shake flask as well as 5 L to 500 L stirred tank bioreactors using modified production media in combination with additional carbon/nitrogen/minerals and elicitations with yields upto 800 mg/L of are 9,9 bianthracene antibiotic setomimycin. Setomimycin significantly abrogated cancer cell proliferation and inhibited cancer cell migration and invasion in highly metastatic cancer cells (MiaPaca-2, MCF-7, HT-29 and HCT-116) of Pancreatic, Breast and Colorectal origin by down regulating ERK and MEK proteins which are the major regulators of cell proliferation, differentiation and apoptosis. Interestingly setomimycin upregulated pro-apoptotic protein Par-4 and downregulated anti-apoptotic protein BCL-2 in Colon as well as breast cancer cells HCT-116 and MCF-7 respectively. Strong affinity of setomimycin towards MEK protein has been confirmed by molecular docking studies and Western blot analysis.
Claims
1. A process for the preparation of tetrahydroanthracene compounds of Formula I ##STR00008## wherein n=1 or 2 and R.sub.1=CH.sub.3; R.sub.2=OH from Streptomyces sp. MTCC-25420 and Streptomyces sp. MTCC-25512 comprising the steps of: i. isolating the Streptomyces sp. MTCC-25420 and Streptomyces sp. MTCC-25512 strains from soil sample; ii. preparing the seed inoculum from the isolated strains Streptomyces sp. MTCC-25420 and Streptomyces sp. MTCC-25512 as obtained in step (i) and transferring 5-10% of two days old seed culture to the production medium containing carbon source (1to 15% w/v), nitrogen source (2 to 10%) and trace salts at pH in the range of 4.0 to 10.0 followed by incubating at a temperature in the range of 15 C.-45 C. for a period in the range of 2-10 days on a rotating shaker at speed in the range of 50-400 rpm to obtain fermented broth; iii. fermentation was initiated in 5-500 L bioreactor by inoculation of 10% inoculum as obtained in step (ii) in production medium having 50.0 g/L of glycerol, followed by glycerol feeding at the rate of 2 g/L/hr after 24 hours of incubation until final glycerol concentration of 150 g/L was achieved in modified production medium (MP-6) with 10 LPM air at 100 rpm agitation; iv. liquid-liquid extraction of fermented broth of 4 to 5 days as obtained in step (ii) and (iii) using selected solvents from the group comprising methanol, ethyl acetate, toluene (combination of methanol-ethyl acetate, ethylacetate-toluene) to obtain tetrahydroanthracenes 200 mg to 5 g/L of Formula I; v. purifying the extract obtained from step (iv) by single step gravity column chromatography by elution with 5%, 10%, 15% and 20% of Toluene in ethyl acetate to obtain pure compound 3 (20-800 mg/L) of formula I as crystalline powder and preparatory HPLC to get pure compounds of formula I (Compound 1:2-80 mg/L; Compound 2:6-280 mg/L).
2. The process as claimed in step (v) of claim 1, wherein tetrahydroanthracenes of formula I is selected from the group comprising: ##STR00009##
3. The process as claimed in claim 1, wherein carbon source is selected from the group comprising monosaccharides, disaccharides and polysaccharides like Glucose, Fructose, Sucrose, Mannitol, Glycerol, gluconic acid, Pectin, Lactose, Maltose, Mannose, Chitosan, Dextrin, molasses, Starch, Xylose, Molasses, Corn steep liquor, Inositol, Chitin, Sorbitol either alone or combination thereof.
4. The process as claimed in claim 1, wherein nitrogen sources is selected from the group comprising Beef extract, Meat solubles, corn meal, Casein, Soyabean Meal, Yeast extract, N/Z amine A, N/Z amine B, Casein hydrolysate, enzyme-hydrolyzed casein, Peptone, Sodium nitrate, Valine, Ammonium nitrate, Urea, Arginine, Asparagine, Ammonium phosphate, Potassium nitrate, Ammonium sulphate, nitrate salts either alone or combination thereof.
5. The process as claimed in claim 1, wherein trace salts are selected from the group comprising Calcium carbonate, Magnesium sulphate, Di-potassium hydrogen phosphate, Ferrous sulphate, Potassium chloride and Sodium chloride, Ammonium sulphate/nitrate.
6. The process as claimed in claim 1, wherein Compounds 1-3 have potent anticancer activity in various cancer cell lines such as breast cancer (MCF-7, MDA-MB231), Human lung cancer (A-549), human pancreatic cancer (MiaPaca-2), Human prostate cancer (PC-3), Colon cancer cell line (HCT-116, HT 29).
7. The process as claimed in claim 1, wherein Setomimycin i.e. Compound 3 significantly abrogated cancer cell proliferation and inhibited cancer cell migration and invasion in highly metastatic cancer cells (MiaPaca-2, MCF-7, HT-29 and HCT-116) of Pancreatic, Breast and Colorectal origin.
8. The process as claimed in claim 1, wherein Setomimycin i.e. Compound 3 down-regulates ERK and MEK proteins which are the major regulators of cell proliferation, differentiation and apoptosis, alongside it upregulates pro-apoptotic protein Par-4 and downregulated anti-apoptotic protein BCL-2 in Colon as well as breast cancer cells HCT-116 and MCF-7 respectively, and molecular docking studies and western blot analysis further support strong affinity of setomimycin towards MEK protein.
Description
BRIEF DESCRIPTION OF DRAWINGS
[0019]
[0020]
[0021]
[0022]
[0023]
SUMMARY OF THE INVENTION
[0024] Accordingly, present invention provides a process for the preparation of tetrahydroanthracene compounds of Formula I
##STR00002## [0025] wherein n=1 or 2 and R.sub.1=CH.sub.3; R.sub.2=OH [0026] from Streptomyces sp. MTCC-25420 and Streptomyces sp. MTCC-25512 comprising the steps of: [0027] i. isolating the culture of Streptomyces sp. MTCC-25420 and Streptomyces sp. MTCC-25512 from soil sample collected from Shivalik foothills 32.7266 N, 74.8570 E, Jammu, India; [0028] ii. transferring 5-10% of two days old seed culture of Streptomyces sp. MTCC-25420 and Streptomyces sp. MTCC-25512 as obtained in step (i) to production medium containing 1 to 10% w/v carbon source, nitrogen source and trace salts at pH in the range of 4.0 to 10.0 followed by incubating at a temperature in the range of 15 C.-45 C. for a period in the range of 2-10 days on a rotating shaker at speed in the range of 50-400 rpm to obtain fermented broth; [0029] iii. liquid-liquid extract of fermented broth as obtained in step (ii) using selected solvents from the group comprising methanol-ethyl acetate, ethylacetate-toluene or acetone-toluene to obtain tetrahydroanthracenes 200 mg-5 g/L of Formula I; [0030] iv. purifying the extract obtained from step (iii) by gravity column chromatography/preparatory HPLC to get tetrahydroanthracenes of formula I (Compound 1:2-80 mg/L; Compound 2:6-280 mg/L; Compound 3:20-800 mg/L). [0031] In an embodiment of the present invention, tetrahydroanthracenes of formula I is selected from the group comprising:
##STR00003##
[0032] In yet another embodiment of the present invention, carbon source is selected from the group comprising monosaccharides, disaccharides and polysaccharides like Glucose, Fructose, Sucrose, Mannitol, Glycerol, gluconic acid, Pectin, Lactose, Maltose, Mannose, Chitosan, Dextrin, molasses, Starch, Xylose, Molasses, Corn steep liquor, Inositol, Chitin, Sorbitol either alone or combination thereof.
[0033] In yet another embodiment of the present invention, nitrogen sources is selected from the group comprising Beef extract, Meat solubles, corn meal, Casein, Soyabean Meal, Yeast extract, N/Z amine A, N/Z amine B, Casein hydrolysate, enzyme-hydrolyzed casein, Peptone, Sodium nitrate, Valine, Ammonium nitrate, Urea, Arginine, Asparagine, Ammonium phosphate, Potassium nitrate, Ammonium sulphate, nitrate salts either alone or combination thereof.
[0034] In yet another embodiment of the present invention, trace salts are selected from the group comprising Calcium carbonate, Magnesium sulphate, Di-potassium hydrogen phosphate, Ferrous sulphate, Potassium chloride and Sodium chloride, Ammonium sulphate/nitrate.
[0035] In yet another embodiment of the present invention, Compounds 1-3 have potent anticancer activity in various cancer cell lines such as breast cancer (MCF-7, MDA-MB231), Human lung cancer (A-549), human pancreatic cancer (MiaPaca-2), Human prostate cancer (PC-3), Colon cancer cell line (HCT-116, HT 29).
[0036] In yet another embodiment of the present invention, Setomimycin i.e. Compound 3 significantly abrogated cancer cell proliferation and inhibited cancer cell migration and invasion in highly metastatic cancer cells (MiaPaca-2, MCF-7, HT-29 and HCT-116) of Pancreatic, Breast and Colorectal origin.
[0037] In yet another embodiment of the present invention, Setomimycin i.e. Compound 3 down-regulates ERK and MEK proteins which are the major regulators of cell proliferation, differentiation and apoptosis, alongside it upregulates pro-apoptotic protein Par-4 and downregulated anti-apoptotic protein BCL-2 in Colon as well as breast cancer cells HCT-116 and MCF-7 respectively, and molecular docking studies and western blot analysis further support strong affinity of setomimycin towards MEK protein.
[0038] In yet another embodiment of the present invention, Compounds 1-3 have potent antimicrobial activity against a panel of Gram positive human pathogens such as Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Micrococcus luteus and MRSA/MDRs.
DETAILED DESCRIPTION OF THE INVENTION
[0039] Present invention provides a process for the preparation of tetrahydroanthracenes of Formula I from Streptomyces sp. MTCC-25420 and Streptomyces sp. MTCC-25512 and anticancer activity thereof, which comprises specific fermentation conditions in combination for production of tetrahydroanthracenes of Formula I upto 5.0 g/L and upto 800 mg/L yields of setomimycin of formula 3 or even higher in presence of certain elicitors/precursors, wherein, Setomimycin (Compound-3) significantly abrogated cancer cell proliferation and inhibited cancer cell migration and invasion in highly metastatic cancer cells (MiaPaca-2, MCF-7, HT-29 and HCT-116) of Pancreatic, Breast and Colorectal origin.
##STR00004## [0040] wherein n=1 or 2 and R.sub.1=CH.sub.3; R.sub.2=OH
[0041] Present invention provides a process for the preparation of Tetrahydroanthracenes of Formula I, including rare 9,9-bianthrylanthracene antibiotic Setomimycin (Compound-3) from new source i.e. Streptomyces sp. MTCC-25420 and Streptomyces sp. MTCC-25512 from NW Himalayan region.
[0042] The process for the production of tetrahydroanthracenes of Formula I involves solid state as well as submerged fermentation, wherein consistent extracellular as well as intracellular production takes place in various fermentation media in shake flask as well as in bioreactor upto 500 L size, under various fermentation conditions (either alone or in combination).
[0043] Essential trace elements salts like Calcium carbonate, Magnesium sulphate, Di-potassium hydrogen phosphate, Ferrous sulphate, Potassium chloride and Sodium chloride, Ammonium sulphate/nitrate etc. are necessary in combination with various constituents of fermentation media for the growth of the organism and production of tetrahydroanthracenes.
[0044] The tetrahydroanthracene producers, i.e. Streptomyces sp. MTCC-25420 and Streptomyces sp. MTCC-25512 are capable to grow at pH 4.0 to pH 10.0 with Setomimycin production at wide pH range i.e. pH 5.0, 6.0, 7.0, 8.0, and 9.0 with preferred pH of 6.0 to 8.0.
[0045] Streptomyces sp. MTCC-25420 and Streptomyces sp. MTCC-25512 grow at temperatures ranging from 15 C. to 45 C. with the preferred temperature for Formula-1 production at 20 C. to 40 C.
[0046] Streptomyces sp. MTCC-25420 and Streptomyces sp. MTCC-25512 provide the production of tetrahydroanthracenes (Formula-1) within 2-10 days depending on the production medium and fermentation conditions with the yield of crude extract ranging from 200 mg/L to 5.0 g/L or even higher in presence of certain elicitors/precursors e.g. Valine, Arginine, Asparagine, Sodium acetate and Glycerol.
[0047] Antibiotic (Compounds 1-3) has potent antimicrobial activity against a panel of Gram positive human pathogens such as Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Micrococcus luteus and Methicillin-resistant Staphylococcus aureus (MRSA)/Multi drug resistant bacteria (MDRs).
[0048] Compounds 1-3 have shown potent anticancer activity against various cancer cell lines such as breast cancer (MCF-7, MDA-MB231), Human lung cancer (A-549), human pancreatic cancer (MiaPaca-2), Human prostate cancer (PC-3), Colon cancer cell line (HCT-116, HT-29). Wherein, Setomimycin (Compound-3) significantly abrogated cancer cell proliferation and inhibited cancer cell migration and invasion in highly metastatic cancer cells (MiaPaca-2, MCF-7, HT-29 and HCT-116) of Pancreatic, Breast and Colorectal origin.
[0049] The culture was maintained on glass test tube of 18150 mm.sup.2 size having agar slants (Table 1) by transferring a loopful of culture from matured slant and kept for incubation at 28 C.2 C. for about one week with subsequent sub-culturing after every two weeks. The Pre-inoculum was prepared in a narrow mouth 500 mL Erlenmeyer flask containing 150 mL medium (Table 2) by transferring loopful of freshly grown culture.
[0050] The inoculated medium was incubated at about 28 C.2 C. for about 48-72 hours on a rotating shaker at 250 rpm. 5-10% of pre inoculum was transferred to 1000 mL Erlenmeyer flasks containing 300 mL seed medium (Table 3). The inoculum was prepared by incubating the flasks at 28 C.2 C. for about 48-72 hours on a rotating shaker at 250 rpm.
[0051] Preferably 5-10% of two days old seed culture (inoculum) was transferred to 1000 mL Erlenmeyer flasks containing 300 mL production media (Table 4) and incubated at 15 C.-45 C. for 2-10 days on a rotating shaker at 100-300 rpm followed by liquid-liquid extraction using methanol-ethyl acetate or ethyl acetate-hexane or ethyl acetate-toluene, acetone-toluene or methanol-dichloromethane or methanol-chloroform or ethyl acetate-acetone or combination of these.
[0052] Monosaccharides, disaccharides and polysaccharides including Glucose, Fructose, Sucrose, Mannitol, Glycerol, Pectin, Lactose, Maltose, Mannose, Gluconic acid, Chitosan, Dextrin, Starch, Xylose, Molasses, Corn steep liquor, Inositol, Chitin, Sorbitol etc. are useful for the production of tetrahydroanthracenes; wherein, preferred carbon sources are glucose, starch, dextrin, chitosan, molasses, gluconic acid and glycerol either alone or combinations of these nutrients. Among these, glycerol and starch is most preferable carbon sources for antibiotic production or in combinations with, soyabean meal, sodium acetate, glycerol and glucose.
[0053] Organic as well as inorganic nitrogen sources like Beef extract, Casein, Soya Meal, Oatmeal, Yeast extract, N/Z amine A, N/Z amine B, Casein hydrolysate, Peptone, Sodium nitrate, Valine, Ammonium nitrate, Urea, Arginine, Asparagine, Ammonium phosphate, Potassium nitrate, Ammonium sulphate support tetrahydroanthracenes production; wherein preferred nitrogen sources are soybean meal, yeast extract, peptone, sodium/potassium nitrate, casein, casein hydrolysate and ammonium nitrate or combinations of these nutrients. Meat solubles, peptone, Beef extract, corn meal, enzyme-hydrolyzed casein, and nitrate salts are also useful.
[0054] Trace elements salts like Calcium carbonate, Magnesium sulphate, Di-potassium hydrogen phosphate, Ferrous sulphate, Potassium chloride and Sodium chloride, Ammonium sulphate/nitrate etc. are helpful in combination for the growth of the organism and production of tetrahydroanthracenes.
[0055] Setomimycin (Compound-3) has potent antimicrobial activity against a panel of Gram positive human pathogens such as Staphylococcus aureus, Bacillus, subtilis, Bacillus cereus, Micrococcus luteus and Methicillin-resistant Staphylococcus aureus (MRSA)/Multi drug resistant bacteria (MDRs).
[0056] The antibiotic Setomimycin (Compound-3) has potent anticancer activity against various cancer cell lines viz. breast cancer (MCF-7, MDA-MB231), Human lung cancer (A-549), human pancreatic cancer (MiaPaca-2), Human prostate cancer (PC-3), Colon cancer cell line (HCT-116, HT 29), wherein, Setomimycin significantly abrogated cancer cell proliferation and inhibited cancer cell migration and invasion in highly metastatic cancer cells (MiaPaca-2, MCF-7, HT-29 and HCT-116) of Pancreatic, Breast and Colorectal origin.
[0057] Setomimycin (Compound-3) demonstrates downregulation of ERK and MEK proteins which are the major regulators of cell proliferation, differentiation and apoptosis. Interestingly setomimycin upregulated pro-apoptotic protein Par-4 and down regulated ant-apoptotic protein BCL-2 in Colon as well as breast cancer cells HCT-116 and MCF-7 respectively.
[0058] Setomimycin (Compound-3) interacts with MEK1 by forming hydrogen bond with Lys 97, Asp 190 and Ser212 as per molecular docking studies, wherein strong affinity of Setomimycin towards MEK protein was confirmed by Western blot analysis.
EXAMPLES
[0059] The following examples are given by way of illustration of the working of the invention in actual practice and should not be construed to limit the scope of the present invention.
Example 1: Isolation and Characterization of Streptomyces sp. MTCC-25420 and Streptomyces sp. MTCC-25512
[0060] The actinobacteria strains Streptomyces sp. MTCC-25420 and Streptomyces sp. MTCC-25512 were isolated from soil sample collected from Shivalik foothills 32.7266.sup.0 N, 74.8570.sup.0 E, Jammu, India on Starch-Casein agar (SCA) medium. The pure cultures were maintained and preserved on same medium. The morphological characteristics were investigated on ISP2 and SCA, respectively at 28 C.2 C. The mycelial organization and sporulation were observed by light microscopy and scanning electron microscopy (SEM). The cultural characteristics of isolate grown on SCA were observed as powdery white colony with circular and smooth ends. Aerial colonies appear white during early growth and yellow pigmentation starts appearing with time.
[0061] Molecular characterization was performed by 16S rRNA gene sequencing using universal primers 27F (5AGAGTTTGATCCTGGCTCAG-3) and 1492R (5GGCTACCTTGTTACGACTT-3) using Emerald Amp GT master mix. The 1500 bp amplicon was purified by Gel elution/SAP. The purified product was sequenced by Sanger sequencing and the partial sequence was assembled and submitted to NCBI with Accession numbers MW199142 and OM540363. The culture has been submitted to Microbial Type Culture Collection, India with Accession no. MTCC-25420 and MTCC-25512.
Example 2: Maintenance of Culture
[0062] The cultures Streptomyces sp. MTCC-25420 and Streptomyces sp. MTCC-25512 were maintained on glass test tubes of 18150 mm.sup.2 size having agar slants (Table 1) by transferring a loopful of culture from matured slant and kept for incubation at 28 C.2 C. for about one week with subsequent sub-culturing after two weeks. The glycerol stocks and lyophilized cultures were kept for long term storage of the culture for future purpose.
TABLE-US-00001 TABLE 1 Components of media for preservation of cultures Streptomyces sp. MTCC-25420 and Streptomyces sp. MTCC-25512 Ingredients (g/L) Starch 10.0 KNO.sub.3 2.0 K.sub.2HPO.sub.4 2.0 Casein 0.3 MgSO.sub.4.sub.7H.sub.2O 0.05 NaCl 2.0 CaCO.sub.3 0.02 FeSO.sub.4.7H.sub.2O 0.01 pH 7.0 Agar 20.0
Example 3: Preparation of Pre-Inoculum and Inoculum
[0063] Pre-inoculum was prepared in a narrow mouth 500 mL Erlenmeyer flask containing 150 ml medium (Table 2) by transferring loopful of culture from freshly grown culture. The inoculated medium was incubated at about 28 C.2 C. for about 48-72 hours on a rotating shaker at 250 rpm.
TABLE-US-00002 TABLE 2 Components of media used for pre-inoculum preparation Ingredients (g/L) Soluble starch 25.0 Soyabean meal 15.0 Yeast extract 2.0 CaCO.sub.3 4.0 pH 7.0
[0064] Preferably, 5-10% of pre-inoculum was transferred to 1000 mL Erlenmeyer flasks containing 300 ml seed medium (Table 3). The inoculum was prepared by incubating the flasks at 28 C.2 C. for about 48-72 hours on a rotating shaker at 250 rpm.
TABLE-US-00003 TABLE 3 Components of media used for Seed Inoculum Ingredients (g/L) Glycerol 100.0 Soyabean meal 2.0 CaCO.sub.3 3.0 K.sub.2HPO.sub.4 1.0 MgSO.sub.4 1.0 NaCl 2.0 pH 7.0
Example 4: Production of Tetrahydroanthracenes
[0065] Preferably, 5-10% of two days old seed culture (inoculum) was transferred to 1000 mL Erlenmeyer flasks containing 300 ml production media as shown in (Table 4) and incubated at 28 C.2 C. for 2-10 days on a rotating shaker at 250 rpm followed by liquid-liquid extraction using methanol-ethyl acetate.
TABLE-US-00004 TABLE 4 Composition of different media used for setomimycin production S. No. Medium Composition in g/L 1 PM-1 Glycerol-20.0; Soyabean meal-20; Sodium chloride-3.0 2 PM-2 Starch-25.0; Soyabean meal-15.0; Yeast extract- 2.0; CaCO.sub.3-4.0 3 PM-3 Dextrin-1.0; Glucose-1.0; Soyabean meal-5.0; Yeast extract-2.0; CaCO.sub.3-1.50 4 PM-4 Glucose-50.0; Glycerol-5.0; Peptone-10.0; Malt extract-1.50; Soyabean meal-10.0; MgSO.sub.47H.sub.2O- 1.0; CaCO.sub.3-5.0; Beef extract-5.0 5 PM-5 Glucose-2.0; Soyabean meal-10.0; Starch-30.0; Corn Steep liquor-1.0; Peptone-3.0; CaCO.sub.3-5.0 6 PM-6 Starch-10.0; KNO.sub.3-2.0; Casein-0.30; K.sub.2HPO.sub.4 2.0; MgSO.sub.4-0.05, NaCl-2.0 7 PM-7 Starch-10.0; CaCO.sub.3-3.0; K.sub.2HPO.sub.4-1.0; (NH.sub.4).sub.2 SO.sub.4; 2.0 MgSO.sub.4-1.0; NaCl-1.0 8 PM-8 Starch-10.0; Casein-10.0; Peptone-1.0; Yeast extract-1.0 9 PM-9 KNO.sub.3-1.0; K.sub.2HPO.sub.4 0.5; MgSO.sub.4-0.5; NaCl-0.5 g; FeSO.sub.4-0.010; Starch-20.0 10 PM-10 Oatmeal-10.0; MgSO.sub.4-1.0; KCl-1.0; KH.sub.2PO.sub.4-0.5; K.sub.2HPO.sub.4-0.5; CaCl.sub.2-2.0; Yeast extract-4.0; Malt extract-4.0 11 PM-11 Starch-24.0; Dextrin-46.0; Yeast extract-5.0; Peptone-4.0; Soyabean meal-5.0; K.sub.2HPO.sub.4-1.0; CaCO.sub.3-1.0; MgSO.sub.4-1.0 12 PM-12 yeast extract-1.0; beef extract-1.0; casamino acids- 2.0; glucose- 10.0 13 PM-13 Glycerol-10.0; CaCO.sub.3 3.0; K.sub.2HPo.sub.4 1.0; (NH.sub.4).sub.2 SO.sub.4; 2 MgSO.sub.4-1; NaCl-1.0 14 PM-14 Glycerol-20.0; soluble starch-20.0; peptone-10.0; meat extract-5.0; CaCO.sub.3-3.0 15 PM-15 Tryptone-1.0; yeast extract-0.30 16 PM-16 Dextrose-4.0; Yeast extract-4.0; Malt extract-10.0 17 PM-17 Oat meal-2.0; trace salt solution (FeSO.sub.47H.sub.2O-0.01, MnCl.sub.24H.sub.2O-0.01, ZnSO.sub.47H.sub.2O-0.01) 18 PM-18 Soluble starch-1.0; K.sub.2HPO.sub.4-0.1; MgSO.sub.47H.sub.2O-0.1; NaCl-0.1; (NH.sub.4)2SO.sub.4-0.2; CaCO.sub.3-0.2; trace salt solution (FeSO.sub.47H.sub.2O-0.01, MnCl.sub.24H.sub.2O-0.01, ZnSO.sub.47H.sub.2O-0.01) 19 PM-19 L-Asparagine-0.1; glycerol-1; K.sub.2HPO.sub.4-0.1; trace salt solution(FeSO.sub.4H.sub.2O-0.01, MnCl.sub.24H.sub.2O-0.01, ZnSO.sub.47H.sub.2O-0.01) 20 PM-20 Peptone-1.0; yeast extract-0.4; FeSO.sub.47H.sub.2O-1.0 21 PM-21 L-Tyrosine-0.10; glycerol-1; K.sub.2HPO.sub.4-0.1; trace salt solution (FeSO.sub.47H.sub.2O-0.01, MnCl.sub.24H.sub.2O-0.01, ZnSO.sub.47H.sub.2O-0.01) 22 PM-22 Sucrose-3.0; sodium nitrate-0.20; K.sub.2HPO.sub.4-0.10; MgSO.sub.47H.sub.2O-0.05; KCl-0.05; FeSO.sub.47H.sub.2O-0.01
[0066] The solvent extracts were evaluated by weight as well as their HPLC/LCMS profiling for tetrahydroanthracenes production.
Example 5: Effect of pH on Tetrahydranthracenes Production
[0067] The culture was grown over a broad pH range from pH 5.0 to 9.0. Inoculum was added in 500 ml Erlenmeyer flask containing 100 mL of production medium with varied pH. Setomimycin production was highest at pH 6.5-7.5, although production was observed at wide pH range (pH 5.0 to 9.0).
Example 6: Effect of Temperature on Tetrahydranthracenes Production
[0068] Streptomyces sp. MTCC-25420 and Streptomyces sp. MTCC-25512 can be grown over a broad temperature range from 10 C. to about 45 C. The inoculum was added in 500 mL Erlenmeyer flask containing 100 ml of production medium and flasks were incubated at varied temperatures i.e. 10 C., 20 C., 30 C., 40 C. and 50 C. Optimum production of tetrahydroanthracenes appears to occur at a temperature of about 20 to 40 C.
Example 7: Effect of Carbon Sources on Production of Tetrahydroanthracenes
[0069] Carbon sources that are essential component for the growth and production of tetrahydroanthracenes and Setomimycin were evaluated. All types of carbon sources i.e. Monosaccharides, Disaccharides and Polysaccharides such as Glucose, Fructose, Sucrose, Mannitol, Glycerol, Pectin, Lactose, Maltose, Mannose, Chitosan, Dextrin, Starch, Xylose, Mollases, Corn steep liquor, Inositol, Chitin, Sorbitol.
Example 8: Effect of Nitrogen Sources on Production of Tetrahydroanthracenes
[0070] Various nitrogen sources such as Beef extract, Casein, Soya Meal, Yeast extract, Oatmeal, N/Z amine A, N/Z amine B, Casein hydrolysate, Peptone, Sodium nitrate, Valine, Ammonium nitrate, Urea, Arginine, Asparagine, Ammonium phosphate, Potassium nitrate, Ammonium sulphate support the production of tetrahydroanthracenes.
Example 9: Effect of Agitation and Inoculum Percent on Production of Tetrahydroanthracenes
[0071] To study the effect of agitation the Streptomyces sp. MTCC-25420 and Streptomyces sp. MTCC-25512 was grown on selected production medium with agitation range from 50 to 400 rpm and it has been observed that agitation from 100 rpm to 300 rpm supports maximum production of tetrahydroanthracenes with 10% seed inoculum.
Example 10: Production of Tetrahydroanthracene in Fermenter
[0072] The time course of tetrahydranthracenes production was evaluated by transferring the freshly grown cultures in Seed inoculum and further to the production medium. The growth and production were evaluated by sampling the fermentation broth after regular intervals. Antibiotic complex formation starts after 24 hours and optimum production was found after 4-8 days of incubation. Tetrahydroanthracene antibiotics were produced in 5 L to 500 L stirred tank bioreactor using modified production medium PM-7 (Table 4) with combination of other ingredients providing additional carbon/nitrogen/minerals and elicitations. The inoculum was prepared using freshly grown culture of vegetative stage in conical flask using PM-2 medium (Table 4). The 5-10% of 2-4 days old inoculum was transferred to the fermenter. For the efficient growth the volume of air used was 0.05 to 1.5 (vvm) with agitation speed of 50 to 400 rpm at 28 C.2 C. for 2-10 days. Further, the fermented broth obtained after 6 days of incubation was homogenised with 10% methanol for about 2 hours. The homogenised broth was then extracted at least thrice with ethyl acetate in the ratio of (1:1 v/v). The organic phase, thus obtained was concentrated on a rotary evaporator at 50 C. and pure setomimycin was quantified by HPLC. Tetrahydroanthracene formation starts within the 24 hours of incubation and highest production occurs between 4 to 8 days fermentation, wherein Setomimycin yields range from 30 mg/L to 800 mg/L in combination with various carbon and nitrogen sources along with trace elements, elicitors and precursors (Table 5).
TABLE-US-00005 TABLE 5 Composition of modified production media used for tetrahydroanthracenes production S. No. Medium Composition g/L 1 MP-1 Glycerol-50.0; CaCO.sub.3-3.0; K.sub.2HPO.sub.4-1.0; Gluconic acid-2.0; (NH.sub.4).sub.2 SO.sub.4; 2.0 MgSO.sub.4-1; NaCl-2.0 2 MP-2 Glycerol-50.0; CaCO.sub.3-3.0; K.sub.2HPO.sub.4-1.0; Gluconic acid-2.0; (NH.sub.4).sub.2 SO.sub.4; 2.0 MgSO.sub.4-1; NaCl-2.0; Valine-1.0 3 MP-3 Glycerol-100.0; CaCO.sub.3-3.0; K.sub.2HPO.sub.4-1.0; Gluconic acid-2.0; (NH.sub.4).sub.2 SO.sub.4; 2.0 MgSO.sub.4-1.0; NaCl-2.0 4 MP-4 Glycerol-50.0; CaCO.sub.3-3.0; K.sub.2HPO.sub.4-1.0; Soyabean meal-2.0; MgSO.sub.4-1.0; NaCl-2.0 5 MP-5 Glycerol-50.0; CaCO.sub.3-3.0; K.sub.2HPO.sub.4-1.0; Soyabean meal-2.0; MgSO.sub.4-1.0; NaCl-2.0 valine-1.0 6 MP-6 Glycerol-100; Soyabean meal-2.0; CaCO.sub.3-3.0; K.sub.2HPO.sub.4-1.0; MgSO.sub.4-1.0; NaCl-2.0
[0073] Further, various carbon & nitrogen sources were used in combination with different trace elements (Table 6) to produce tetrahydroanthracenes from pH 4.0 to 10.0
TABLE-US-00006 TABLE 6 Various carbon, nitrogen sources and trace elements used in combination for tetrahydroanthracenes production S. Carbon Nitrogen No. sources sources Trace elements 1 Glucose Beef extract Calcium carbonate 2 Fructose Casein Magnesium sulphate 3 Sucrose Soyabean Meal Di-potassium hydrogen phosphate 4 Mannitol Yeast extract Ferrous sulphate 5 Glycerol Oat meal Potassium chloride 6 Pectin N/Z amine A Sodium chloride 7 Lactose N/Z amine B Ammonium sulphate 8 Maltose Casein hydrolysate Ammonium nitrate 9 Mannose Peptone 10 Chitosan Sodium nitrate 11 Dextrin Ammonium nitrate 12 Starch Urea 13 Xylose Ammonium phosphate 14 Mollases Potassium nitrate 15 Cornsteep Ammonium sulphate liquor 16 Inositol Arginine 17 Chitin Asparagine 18 Sorbitol Valine
[0074] All the biological materials used in the invention were procured from HIMEDIA, Laboratories Pvt. Ltd 23, Vadhani Ind. Est., LBS marg, Mumbai-400086, India.
Example 11: Extraction of Tetrahydroanthracenes from Fermentation Broth
[0075] For the extraction of bioactives, the fermented broth obtained after 6 days of incubation was homogenised with 10% methanol for about 2 hours. The homogenised broth was then extracted thrice with ethyl acetate in ratio of 1:1 (v/v). The organic phase thus obtained was concentrated on a rotary evaporator at 50 C. LC-MS profile of the crude extract indicated the presence of tetrahydroanthracenes compounds in the extract, which were purified by column chromatography/preparatory TLC/preparatory HPLC.
Example 12: Isolation and Characterization of Tetrahydroanthracene Compounds
[0076] The isolation of compounds was carried out through open glass gravity column chromatography. Slurry of the crude extract was made using silica 60-120 (5.0 g) which was loaded on a glass column packed with silica 60-120. For purification, elution was carried out by ethyl acetate and thereafter, polarity was increased step by step by adding ethyl acetate to toluene in the order of 5%, 10%, 15% and 20%. A small fraction of 25 mL each was collected and monitored through TLC after charring with anisaldehyde. Fractions were pooled together based on similarity of R.sub.f values of the spots as well as the purity of the isolated fractions. Total seven sub-fractions were collected, wherein fractions 1-3 were further mixed and subjected to silica open glass gravity column and Compounds 1 and 3 was purified, while, Compound 2 was purified from fraction 3-7. The pure sub fractions thus obtained were pooled together and concentrated on rotary evaporator at 30-35 C. under reduced pressure which were further confirmed by .sup.1H NMR and .sup.13C NMR. The purity of compounds was checked by HPLC chromatography.
[0077] Compound 1 was obtained as brown solid having molecular mass of 300.0 as obtained by LCMS fragmentation.
##STR00005##
[0078] .sup.1H NMR (400 MHz, CDCl.sub.3) 16.28 (s, 1H), 9.76 (s, 1H), 7.51 (t, J=8.0 Hz, 1H), 7.17 (d, J=7.6 Hz, 1H), 7.08 (s, 1H), 6.89 (dd, J=7.9, 0.8 Hz, 1H), 4.18 (s, 1H), 3.50 (d, J=18.3 Hz, 1H), 2.73 (dd, J=18.3, 1.7 Hz, 1H), 2.41 (s, 3H), 1.48 (s, 3H). .sup.13C NMR (101 MHz, CDCl.sub.3) 205.6, 202.5, 166.6, 158.3, 139.0, 133.1, 132.0, 119.3, 118.4, 113.3, 112.0, 108.2, 71.8, 63.0, 47.5, 32.1, 27.5.
[0079] The PMR spectra suggest that the compound contains 16 protons: 6 protons from 2 methyl groups, 2 protons from one methylene group, 4 protons from olefinic and/or aromatic moieties, 1 protons a CH, and 3 protons from 3 hydroxyl groups, and in CMR 17 peaks of carbons were found, 2 in carbonyl region, 2 in aromatic with substitution, 1 in hydroxylated region, 8 in aromatic, 1 in methylene and 2 in methyl region, further, molecular mass of 300.0 as obtained by LCMS fragmentation confirmed the structure of compound 1 as a monomer which is in accordance with literature reports. Two IR spectra revealed that the compound contains CC and hydroxyl groups. By calculating the 21 degrees of unsaturation and UV absorptions of the compound indicates that it contains naphthocyclinone or anthracyclinone skeleton as a chromophore and it contains no sugar moiety.
[0080] Compound 2 was obtained as brown powder with the molecular mass 598.0 as obtained by LCMS fragmentation.
##STR00006##
[0081] .sup.1H NMR (400 MHz, CDCl.sub.3) 9.98 (s, 2H), 7.20 (dd, J=9.3, 6.8 Hz, 2H), 6.82 (d, J=7.8 Hz, 2H), 6.34 (d, J=8.2 Hz, 2H), 4.16 (s, 2H), 2.93 (d, J=18.5 Hz, 2H), 2.59 (d, J=18.5 Hz, 2H), 1.21 (s, 6H), 1.17 (s, 6H).
[0082] .sup.13C NMR (101 MHz, CDCl.sub.3) 205.2, 202.1, 164.7, 157.6, 137.8, 132.5, 132.4, 124.0, 116.6, 111.9, 111.3, 108.6, 70.9, 58.7, 44.7, 32.0, 27.8.
[0083] The PMR spectra suggest that the compound contains 30 protons: 12 protons from 4 methyl groups, 4 protons from two methylene group, 6 protons from olefinic and/or aromatic moieties, 2 protons from two CH, and 6 protons from 6 hydroxyl groups, and in CMR 17 peaks of carbons were found, 2 in carbonyl region, 2 in aromatic with substitution, 1 in hydroxylated region, 8 in aromatic, 1 in methylene and 2 in methyl region, further, molecular mass 580.0 as obtained by LCMS fragmentation confirmed the structure of compound 2 which is in accordance with literature reports. Two IR spectra revealed that the compound contains CC and hydroxyl groups. By calculating the 21 degrees of unsaturation and UV absorptions of the compound indicates that it contains naphthocyclinone or anthracyclinone skeleton as a chromophore and it contains no sugar moiety.
[0084] Compound 3 (Setomimycin) was obtained as red crystalline solid with the molecular mass 580.0 as obtained by LCMS fragmentation.
##STR00007##
[0085] .sup.1H NMR (400 MHz, CDCl.sub.3) 10.04 (s, 1H), 9.93 (s, 1H), 7.33 (t, J=8.0 Hz, 1H), 7.22-7.15 (m, 2H), 6.93 (d, J=7.8 Hz, 1H), 6.83 (d, J=7.9 Hz, 1H), 6.59 (d, J=8.3 Hz, 1H), 6.21 (d, J=7.5 Hz, 2H), 3.94 (s, 1H), 3.63 (s, 1H), 3.12 (d, J=17.6 Hz, 1H), 2.58 (d, J=17.8 Hz, 1H), 1.95 (s, 3H), 1.63 (s, 3H), 1.34 (s, 3H), 1.22 (s, 3H). .sup.13C NMR (101 MHz, CDCl.sub.3) 208.5, 203.3, 199.6, 191.1, 166.5, 164.8, 158.8, 158.5, 158.1, 138.7, 137.0, 134.3, 133.9, 133.5, 133.2, 125.8, 125.1, 124.3, 117.5, 116.5, 114.1, 113.4, 113.0, 112.6, 112.5, 109.3, 108.6, 72.1, 60.9, 60.6, 47.2, 33.9, 29.4, 28.2, 23.0.
[0086] The PMR spectra suggest that the compound contains 28 protons: 12 protons from 4 methyl groups, 2 protons from a methylene group, 2 proton from two CH, 7 protons from olefinic and/or aromatic moieties, and 5 protons from 5 hydroxyl groups, and in CMR, 34 carbons were found, 4 in carbonyl region, 5 in aromatic with substitution, 17 in aromatic, 3 in oxygenated region, 1 in methylene and 4 in methyl region. IR spectra revealed that the compound contains CC and hydroxyl groups. By calculating the 21 degrees of unsaturation and UV absorptions of the compound indicates that it contains naphthocyclinone or anthracyclinone skeleton as a chromophore and it contains no sugar moiety.
Example: 13 Minimum Inhibitory Concentration of Setomimycin
[0087] The minimum inhibitory concentrations (MIC) of purified compound showing significant zones of inhibition in the preliminary antimicrobial assay using agar well diffusion method were evaluated. MIC assay was carried out by a microtiter broth dilution method with some modifications. Stock solution of each pathogen was prepared in normal saline solution i.e. 0.85% NaCl (w/v) at a concentration of 10.sup.8 cells/ml and finally diluted with respective growth media to give approximately 10.sup.5 CFU/ml for all organisms. Different dilutions of compound was prepared (2-500 g/ml) by serial dilutions. 100 l of each concentration (2-500 g/ml) of the compound was loaded onto each well and was mixed with 100 l of diluted pathogens containing 10.sup.5 CFU/ml. Each plate had a set of controls: a column with broad-spectrum antibiotics (ciprofloxacin) as positive controls, a column without compound, and one without the relevant test organism. The microtitre plates were then incubated overnight at 37 C. for bacterial pathogens and 28 C. for fungal pathogens and were analysed after incubation. The lowest inhibitory dilution, at which there was no visible growth, was considered as MIC as shown in Table 7.
TABLE-US-00007 TABLE 7 Minimum Inhibitory Concentrations of Compounds 1-3 against Gram positive bacteria Test organism Compound-1 Compound-2 Compound-3 Staphylococcus aureus 25 12 8 Bacillus cereus 12 6 4 Bacillus subtilis 12 6 16 Micrococcus luteus 6 4 8
Example: 14 Anticancer Activity of Compounds (1-3) Against Panel of Cancer Cell Lines
[0088] Compound Setomimycin showed potent anticancer properties against diverse range of cancer cells of different origin as shown in Table 8. 510.sup.3 cells were seeded/well in a 96 well plate and treated with Compounds (1-3) for 48 hours with 100 M concentration range to a panel of cancer cell lines. After 44 hour MTT with final concentration of 0.5 mg/ml were added to cells and incubated for 4 hour at 37 C. until formazon crystals are formed. MTT was removed and formazon crystals were lysed by DMSO for 30 minutes at 37 C., the absorbance was measured at 570 nM and the IC.sub.50 values were calculated using graph pad prism.
TABLE-US-00008 TABLE 8 Cytotoxicity (IC.sub.50) of Compounds (1-3) against different cancer cells of Colon, Breast, Lung, Pancreatic and Prostrate origin Cell lines MCF- HT- MDA- MiaPaca- HCT- Compounds 7 29 MB-231 A549 2 PC3 116 Panc-1 FR2 Compound-1 9.56 8.64 13.6 38.91 12.72 14.72 10.36 15.62 48.7 Compound-2 11.22 15.45 12.52 38.73 8.31 17.47 18.91 21.31 62.31 Compound-3 6.9 4.2 7.5 11.45 4.57 7.02 5.3 48 53.29
Example 15: Antiproliferative Properties of Setomimycin
[0089] Colony formation assay was performed to further certify the antiproliferative properties of setomimycin in four different cancer cell lines viz. HT-29, MiaPaca-2, HCT-116 and MCF-7. Interestingly, setomimycin showed promising results near the IC.sub.50 values across all four cell lines as shown in
Example 16: Anti-Invasive Properties of Setomimycin
[0090] The above results depict significant antiproliferative effects of setomimycin in different cell lines near IC.sub.50 values. Transwell invasion assay was performed to check the anti-invasive properties of setomimycin. Interestingly the invasion of the cells from the upper chamber of insert were significantly inhibited to the lower chamber where growth medium with fetal bovine serum was present acting as the chemoattractant with increasing concentration of setomimycin in HCT-116 as well as MCF-7 as shown in
[0091] (A-B) 1.210.sup.6 HCT-116 and MCF-7 cells were seeded in the upper chamber of inserts in serum free medium and treated with indicated concentration of setomimycin for 48 hours. (After 48 hours the invaded cells from lower insert were fixed with ice cold methanol and stained with 0.1% crystal violet for 20-30 minutes. After staining the inserts were washed with dH.sub.2O thoroughly and cells from three different fields in each treated condition were counted and photographed under an inverted microscope (20 magnifications). (C-D) Bar graph representing the number of invaded cells (n=3, error bars indicate SD).
Example 17: Anti-Migratory Property of Setomimycin
[0092] Scratch assay was performed in the panel of cancer cell lines with varying degree of invasive and migratory capabilities as shown in
[0093] 510.sup.5 cells were seeded onto 6 well plate and grown upto more than 90% confluency. After the proper attachment of cells wounds were created with the help of a 20-200 L sterile pipette tip. Subsequently the cells were treated with indicated concentration of setomimycin and vehicle (DMSO). The images were taken under inverted microscope at 20 magnification.
Example 18: Docking Study of Setomimycin on Cancer Targets
[0094] The molecular docking studies were performed using GLIDE module of Schrdinger software. For molecular docking crystal structure of V600E oncogenic mutant BRAF (4XV2), ERK1 (4QTB), ERK2 (6GDQ), MEK1 (3SLS), Src (4MXO) and STAT3 (6NUQ) was downloaded from RCSB protein data bank. Docking of co-crystalised ligands to its respective target using XP precision generated poses with similar orientation and less RMSD with respect to co-crystalised ligand. Thus, further studies were carried out using Glide XP mode. Among all the targets, the antibiotic setomimycin showed the highest docking score (6.808 kcal/mol) with the target MEK1 (Table 9). Moreover, the dock score of setomimycin, in comparison to the known inhibitors of the selected targets, was the highest in case of MEK1. The rescoring of the top docking pose of setomimycin was done by calculating DG-binding with MMGBSA and it showed the highest binding affinity (43.77 kcal/mol) with MEK1. It was further observed that setomimycin interacts with MEK1 by forming hydrogen bond with Lys 97, Asp 190 and Ser212. Lys 97 helps in the binding of ATP to MEK1. Asp 190 is an important catalytic residue involves in the abstraction of a proton of a threonine or tyrosine on ERK1/2. Most of the reported inhibitors act by binding with these residues. Therefore, setomimycin may exhibit anti-proliferative properties by inhibiting MEK1.
TABLE-US-00009 TABLE 9 Docking score of Setomimycin with various cancer targets Target Protein Docking score (kcal/mol) BRAF 6.148 ERK1 4.830 ERK2 4.721 MEK1 6.808 Src 5.106 STAT3 2.122
Example 19: Effect of Setomimycin on Anticancer Target Pathways and Apoptosis
[0095] Strong active potential of setomimycin against tumor cell proliferation and migration at nearby concentration of IC.sub.50 values was depicted by MTT data. Further, molecular docking studies predicted the strong affinity of setomimycin targeting MEK pathway. ERK and MEK are the major signaling pathways regulating cancer cell proliferation, differentiation and apoptosis. Therefore, Western blotting was carried out to check the effects of Setomimycin on ERK and MEK proteins. Phospho MEK was found to be down regulated with increasing concentration of setomimycin validating it as antitumor candidate. Interestingly, Par-4 which is a pro-apoptotic protein was upregulated and BCL-2 an antiapoptotic protein was downregulated by Setomimycin. These results demonstrate the strong antitumor capability of Setomimycin regulating proliferation and metastasis, which further induces pro-apoptotic marker as well, diminishing the expression of anti-apoptotic proteins as shown in
Advantages of the Invention
[0096] The main advantages of the present invention are: [0097] It provides an improved and efficient process for tetrahydroanthracenes production from Streptomyces sp. MTCC-25420 and Streptomyces sp. MTCC-25512, wherein much higher yields are obtained in short fermentation cycle as compared to the previous reports. [0098] Production upto 5.0 g/L extract of tetrahydroanthracenes can be achieved under specified fermentation conditions in combination of production media and certain elicitors/precursors [0099] Setomimycin yields of 800 mg/L or even higher could be achieved in specified fermentation conditions and in the presence of certain elicitors/precursors, which is much higher than the reported yields [0100] Setomimycin has shown activity against different cancer cell lines of Colon, Breast, Lung, Pancreatic and Prostrate origin. [0101] Setomimycin significantly abrogated cancer cell proliferation and inhibited cancer cell migration and invasion in highly metastatic cancer cells (MiaPaca-2, MCF-7, HT-29 and HCT-116) of Pancreatic, Breast and Colorectal origin. [0102] Strong antitumor capability of Setomimycin has been demonstrated by regulating proliferation and metastasis, which further induces pro-apoptotic marker as well, diminishing the expression of anti-apoptotic proteins.