N-halamine melamine derivatives as novel decontamination and biocidal agents

Abstract

The present disclosure relates to the field of decontamination and biocidal agents. More specifically, the invention relates to novel N-halamine melamine derivatives, compositions comprising them, processes for their production, and methods using the same.

Claims

1. A multihalogenated N-halamine compound or a salt thereof comprising at least two halogenated melamine moieties having formula(V): ##STR00024## wherein E and F are independently selected from hydrogen, halogen, C(O)N(halogen)-melamine; X is a halogen selected from Cl, Br, I and F; and p is selected from 1 to 20.

2. A compound according to claim 1 of formula (V) or a salt thereof: ##STR00025## wherein p is selected from 1 to 20.

3. A compound according to claim 1 of formula (V) or a salt thereof: ##STR00026## wherein p is selected from 1 to 20.

4. A compound according to claim 1, wherein the N-halamine bonds are regenerated by contacting said compound with hypochlorite, hypobromite, hypoiodite, or hypofluorite.

5. A composition comprising a compound according to claim 1 or a salt thereof and at least one ingredient selected from the group consisting of solvents, diluents, binders, resins, polymers, fillers, pigments, dyes, wetting agents, catalysts, thickeners, stabilizers, emulsifiers, texturizers, adhesion promoters, UV stabilizers, flatteners, and biocides.

6. A composition according to claim 5, wherein said composition is selected from a paint, a plastic material, a silicone-based material, a textile, or a coating.

7. A composition according to claim 5, wherein said composition is for use in columns for water treatment.

8. A compound according to claim 1, for use as a decontaminating agent for deactivating a chemical agent and/or neutralizing a biological agent.

9. A compound for use according to claim 8, wherein the chemical agent and/or biological agent is selected from a chemical warfare agent (CWA), particularly sulfur mustard (HD) or O-ethyl-S-2-(N,N-diisopropylamino)ethylmethylphosphonate (VX), or mold or mildew, or a bacterial agent, particularly Escherichia coli, Staphylococcus aureus or Bacillus anthracis.

10. A method for decontaminating or preventing the contamination of a material by a chemical agent and/or a biological agent, said method comprising incorporating into said material or coating onto said material an effective amount of a compound according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The above and other characteristics and advantages of the invention will be more readily apparent through the following examples, and with reference to the appended drawings, wherein:

(2) FIG. 1 is a scheme showing NCl regeneration, when no a-hydrogen is present

(3) FIG. 2 is a scheme showing the reactivity of NCl bonds

(4) FIG. 3 shows some known N-halamines involved in chemical warfare agent decontamination

(5) FIGS. 4A and 4B are graphs showing the killing efficiency of the compounds of the invention towards E. coli (4A) and S. aureus (4B)

(6) FIGS. 5A and 5B are graphs showing the killing efficiency of the compounds of the invention towards B. anthracis at 10ppm (5A) and 100ppm (5B)

(7) FIGS. 6A and 6B are graphs showing the biocidal efficiency of a paint comprising the compounds of the invention towards E. coli (6A) and S. aureus (6B)

(8) FIGS. 7A and 7B illustrate exemplary embodiments of the invention.

DETAILED DESCRIPTION

(9) The phrase a or an entity as used herein refers to one or more of that entity; for example, a compound refers to one or more compounds or at least one compound. As such, the terms a (or an), one or more, and at least one can be used interchangeably herein. [0010] As used in this specification, whether in a transitional phrase or in the body of the claim, the terms comprise(s) and comprising are to be interpreted as having an open-ended meaning. That is, the terms are to be interpreted synonymously with the phrases having at least or including at least. When used in the context of a process, the term comprising means that the process includes at least the recited steps, but may include additional steps. When used in the context of a compound or composition, the term comprising means that the compound or composition includes at least the recited features or components, but may also include additional features or components.

(10) As used herein, unless specifically indicated otherwise, the word or is used in the inclusive sense of and/or and not the exclusive sense of either/or.

(11) The term independently is used herein to indicate that a variable is applied in any one instance without regard to the presence or absence of a variable having that same or a different definition within the same compound. Thus, in a compound in which R1 appears twice and is defined as independently carbon or nitrogen, both R1 can be carbon, both R1 can be nitrogen, or one R1 can be carbon and the other nitrogen.

(12) When any variable occurs more than one time in any moiety or formula depicting and describing compounds employed or claimed in the present invention, its definition on each occurrence is independent of its definition at every other occurrence. Also, combinations of substituents and/or variables are permissible only if such compounds result in stable compounds.

(13) The term optional or optionally as used herein means that a subsequently described event or circumstance may, but need not, occur, and that the description includes instances where the event or circumstance occurs and instances in which it does not. For example, optionally substituted means that the optionally substituted moiety may incorporate a hydrogen atom or a substituent.

(14) If a substituent is designated to be absent, the substituent is not present.

(15) The term about is used herein to mean approximately, in the region of, roughly, or around. When the term about is used in conjunction with a numerical range, it modifies that range by extending the boundaries above and below the numerical values set forth. In general, the term about is used herein to modify a numerical value above and below the stated value by a variance of 10%.

(16) The term carboxyl as used herein refers to a group of formula R1C(O)R2 wherein each of R1 and R2 is independently hydrogen or a lower alkyl as defined below.

(17) The term amino as used herein denotes a group of the formula NRR wherein R and R are independently hydrogen, alkyl, alkoxy, cycloalkyl, heterocycloalkyl, aryl or heteroaryl. Alternatively, R and R, together with the nitrogen to which they are attached, can form a heterocycloalkyl. The term primary amino denotes a group wherein both R and R are hydrogen. The term secondary amino denotes a group wherein R is hydrogen and R is not. The term tertiary amino denotes a group wherein both R and R are not hydrogen. Particular secondary and tertiary amines are methylamine, ethylamine, propylamine, isopropylamine, phenylamine, benzylamine dimethylamine, diethylamine, dipropylamine and diisopropylamine.

(18) The term alkyl as used herein denotes an unbranched or branched chain, saturated, monovalent hydrocarbon residue containing 1 to 20 carbon atoms. The term lower alkyl denotes a straight or branched chain hydrocarbon residue containing 1 to 6 carbon atoms. Lower alkyl groups include methyl, ethyl, propyl, butyl, pentyl, isopentyl, neopentyl, hexyl, heptyl, and octyl. C.sub.1-C.sub.20 alkyl as used herein refers to an alkyl composed of 1 to 20 carbons.

(19) The term alkylene as used herein denotes a divalent saturated linear hydrocarbon radical of 1 to 20 carbon atoms or a branched saturated divalent hydrocarbon radical of 2 to 20 carbon atoms, unless otherwise indicated. Except in the case of methylene, the open valences of an alkylene group are not attached to the same atom. Examples of alkylene radicals include, but are not limited to, methylene, ethylene, propylene, 2-methyl-propylene, 1,1-dimethyl-ethylene, butylene, 2-ethylbutylene.

(20) The term alkynyl as used herein refers to a radical of a straight-chain or branched hydrocarbon group having from 2 to 20 carbon atoms and one or more carbon-carbon triple bonds (e.g., 1, 2, 3, or 4 triple bonds).

(21) The terms heteroalkyl, heteroalkylene, and heteroalkynyl as used herein denotes an alkyl, an alkylene or an alkynyl group as defined above which further includes at least one heteroatom (e.g., 1, 2, 3, or 4 heteroatoms) selected from oxygen, nitrogen, or sulfur within and/or placed at one or more terminal position(s) of the parent chain.

(22) The term cycloalkyl denotes a monovalent saturated monocyclic or bicyclic hydrocarbon group of 3 to 10 ring carbon atoms. In particular embodiments cycloalkyl denotes a monovalent saturated monocyclic hydrocarbon group of 3 to 8 ring carbon atoms. Bicyclic means consisting of two saturated carbocycles having one or more carbon atoms in common. Particular cycloalkyl groups are monocyclic. Examples for monocyclic cycloalkyl are cyclopropyl, cyclobutanyl, cyclopentyl, cyclohexyl or cycloheptyl. Examples for bicyclic cycloalkyl are bicyclo[2.2.1]heptanyl, or bicyclo[2.2.2]octanyl.

(23) The term heterocyclyl denotes a radical of a 3- to 14-membered non-aromatic ring system having ring carbon atoms and 1 to 4 ring heteroatoms, wherein each heteroatom is independently selected from nitrogen, oxygen, and sulfur. In heterocyclyl groups that contain one or more nitrogen atoms, the point of attachment can be a carbon or nitrogen atom, as valency permits. A heterocyclyl group can either be monocyclic (monocyclic heterocyclyl) or polycyclic (e.g., a fused, bridged or spiro ring system such as a bicyclic system (bicyclic heterocyclyl) or tricyclic system (tricyclic heterocyclyl)), and can be saturated or can contain one or more carbon-carbon double or triple bonds. Heterocyclyl polycyclic ring systems can include one or more heteroatoms in one or both rings. Heterocyclyl also includes ring systems wherein the heterocyclyl ring, as defined above, is fused with one or more carbocyclyl groups wherein the point of attachment is either on the carbocyclyl or heterocyclyl ring, or ring systems wherein the heterocyclyl ring, as defined above, is fused with one or more aryl or heteroaryl groups, wherein the point of attachment is on the heterocyclyl ring, and in such instances, the number of ring members continue to designate the number of ring members in the heterocyclyl ring system.

(24) The term aryl denotes a radical of a monocyclic or polycyclic (e.g., bicyclic or tricyclic) 4n+2 aromatic ring system (e.g., having 6, 10, or 14 a electrons shared in a cyclic array) having 6-14 ring carbon atoms and zero heteroatoms provided in the aromatic ring system. Aryl also includes ring systems wherein the aryl ring, as defined above, is fused with one or more carbocyclyl or heterocyclyl groups wherein the radical or point of attachment is on the aryl ring, and in such instances, the number of carbon atoms continue to designate the number of carbon atoms in the aryl ring system. Unless otherwise specified, each instance of an aryl group is independently unsubstituted (an unsubstituted aryl) or substituted (a substituted aryl) with one or more substituents.

(25) The term heteroaryl denotes a a radical of a 5-14 membered monocyclic or polycyclic (e.g., bicyclic, tricyclic) 4n+2 aromatic ring system (e.g., having 6, 10, or 14 electrons shared in a cyclic array) having ring carbon atoms and 1-4 ring heteroatoms provided in the aromatic ring system, wherein each heteroatom is independently selected from nitrogen, oxygen and sulfur. In heteroaryl groups that contain one or more nitrogen atoms, the point of attachment can be a carbon or nitrogen atom, as valency permits. Heteroaryl polycyclic ring systems can include one or more heteroatoms in one or both rings. Heteroaryl includes ring systems wherein the heteroaryl ring, as defined above, is fused with one or more carbocyclyl or heterocyclyl groups wherein the point of attachment is on the heteroaryl ring, and in such instances, the number of ring members continue to designate the number of ring members in the heteroaryl ring system. Heteroaryl also includes ring systems wherein the heteroaryl ring, as defined above, is fused with one or more aryl groups wherein the point of attachment is either on the aryl or heteroaryl ring, and in such instances, the number of ring members designates the number of ring members in the fused polycyclic (aryl/heteroaryl) ring system. Polycyclic heteroaryl groups wherein one ring does not contain a heteroatom (e.g., indolyl, quinolinyl, carbazolyl, and the like) the point of attachment can be on either ring, i.e., either the ring bearing a heteroatom (e.g., 2-indolyl) or the ring that does not contain a heteroatom (e.g., 5-indolyl). Examples of heteroaryl moieties include pyrrolyl, furanyl, thienyl, imidazolyl, oxazolyl, thiazolyl, triazolyl, oxadiazolyl, thiadiazolyl, tetrazolyl, pyridinyl, pyrazinyl, pyrazolyl, pyridazinyl, pyrimidinyl, triazinyl, azepinyl, diazepinyl, isoxazolyl, benzo furanyl, isothiazolyl, benzothienyl, indolyl, isoindolyl, isobenzo furanyl, benzimidazolyl, benzoxazolyl, benzoisoxazolyl, benzothiazolyl, benzoisothiazolyl,

(26) As understood from the above, alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, cycloalkyl, heterocyclyl, aryl, and heteroaryl groups, as defined herein, are, in certain embodiments, optionally substituted with one or more subsitutents selected from halogen, lower alkyl, carboxyl, hydroxyl, sulfonyl, and amino.

(27) The following examples, which further describe the invention, are offered by way of illustration and are not intended to limit the invention in any manner.

EXAMPLE 1

Chlorinated Melamine

(28) Melamine, 1,3,5-triazine-2,4,6-triamine is an organic base, with vast use, in combination with formaldehyde, as melamine resin in the plastic industry. Melamine has been found particularly advantageous since the amine groups, of guanidine nature, may also serve as handles for attachment to commercial polymers or polymerizable moieties. Moreover, melamine contains three amines that could be converted into 1 to 6 active NCl groups. Full chlorination of melamine was carried out by 5% hypochlorite bleach in slightly acidic to neutral pH. Resulting hexachloromelamine (1) served as a chlorinating agent for further reactions. Partially chlorinated melamines 2, 3 and 4 were obtained by disproportionation of chlorine atoms, when hexachloromelamine was mixed and heated with various ratios of melamine (Scheme 1)[11]. These partially chlorinated melamines were used for further conjugation of the melamine moiety.

(29) ##STR00008##

EXAMPLE 2

Melamine Polymethacrylate Derivatives

(30) As a rule, effective CWA decontamination is achieved by large quantities of decontaminant, as compared to the toxic agent. Hence, the preparation of melamine-based polymers, where most of the amine moieties remain available for subsequent chlorination might afford a highly reactive polymer. Another requirement of these polymers was to sustain their ability for regeneration (no a-hydrogen atoms). To accommodate these requirements, we designed a methacryloyl-melamine monomer, where a single polymerization handle is attached via an amide bond to one of the melamine amine groups, while the other two remain free (scheme 2). In a similar manner, more than one methacrylate group may be attached, to form cross-linked polymers.

(31) Acylation of melamine is usually carried out by prolonged heating with the desired acid anhydride or amide, while acid halides seem to have little or no effect on melamine [12]. The use of high temperatures (170-200 C.), combined with large amounts of acid derivatives (usually serving as solvents), gives rise to di- and tri-amides of melamine in many cases [13].

(32) A more recent work described the preparation of melamine amides directly from halogenated melamines. In comparison to standard amide formation, where an acid chloride reacts with an amine to form an amide while releasing HCl, the proposed reaction between an acid halide and chloromelamine forms the desired amide while releasing Cl, (scheme 2) [14]. Although this work dealt with the formation of tris amides and tris carbamates, the relatively mild conditions (75 C., 3 h) prompted us to attempt monoamidation by the reaction of monochloromelamine 4 with methacryloyl chloride, to form the desired monomer.

(33) ##STR00009##

(34) The reaction of 4 with one equivalent of methacryloyl chloride in CCI, resulted in partial polymerization of the desired monomer. This could be explained by the release of chlorine radicals in the reaction mixture, upon formation of the amide. These radicals initiated the polymerization process (scheme 3). To verify this, the reaction was repeated in methacryloyl chloride as solvent, for 18 h. The resulting precipitate was proven to consist of methacrylic polymer bearing melamine groups. Thus, in one step, both amidation and polymerization were performed. Due to the fact that this polymerization took place in methacryloyl chloride, the product was a copolymer of melamine methacrylamide and methacryloyl chloride 5.

(35) Copolymer 5 was subjected to chlorination by dilute hypochlorite bleach in slightly acidic pH (5-6). As a result, the amine groups were chlorinated and the acid chloride underwent hydrolysis to the corresponding acid. The chlorinated copolymer 6 was identified by .sup.1H NMR, .sup.13C NMR, FTIR-ATR and gave a positive result when placed on a KI-starch paper (strong purple stain). As a rule, melamines, and especially polymelamines, are rather insoluble and could be evaluated in NMR only in DMSO-d.sub.6. However, all chlorinated melamines, monomers or polymers alike, exhibited violent exothermic reaction to DMSO-d.sub.6 and thus, NMR spectra of the chlorinated molecules could be run only in pyridine-d.sub.5.

(36) ##STR00010##

(37) The same conditions were used to prepare a cross-linked polymer based on melamine and methacrylate. In this case, diamidation, followed by polymerization was carried out on dichloromelamine 3, to afford chains of polymethacrylic acid linked by melamine moieties 7, which were later chlorinated to give 8 (scheme 4).

(38) A similar reaction, carried out on trichloromelamine 2, afforded the highly cross-linked polymer 9, which was subsequently chlorinated by hypochlorite bleach in the usual manner to give polymer 10 (scheme 4).

(39) ##STR00011##

(40) In order to study the influence of melamine groups on polymer decontaminating activity, a similar polymer was prepared, based on methacrylamide, whose amide groups were subsequently chlorinated in the same manner (11, scheme 5).

(41) ##STR00012##

EXAMPLE 3

Polyurea Melamine

(42) The general reaction of acid halides with chloromelamines (described in scheme 2) was utilized in the preparation of a novel family of melamine polymers, containing carbonyl groups as linkers between any two melamine moieties. Triphosgene (a stable substitute to phosgene) was reacted with dichloromelamine 3 or trichloromelamine 2 to form a chain polyurea-melamine 12 or branched polyurea-melamine 14, respectively (scheme 6). These polymers were subsequently chlorinated by the usual method to form polymers 13 and 15. These polymers contain a large amount of chlorinated melamines per weight, as compared to the polymethacrylate derivatives, due to the small carbonyl linker.

(43) ##STR00013##

EXAMPLE 4

Bis-melamine Derivatives

(44) In general, bismelamines bearing two melamine moieties were prepared by reacting diacid chlorides with two equivalents of monochloromelamine 4, as described before. Among these diacid chlorides: adipoyl dichloride (resulting in bismelamine amide 16 and chlorinated bismelamine amide 17, scheme 7) and two carboxyl chloride-terminated PEGs (resulting in bismelamine carbamates 18 and 19, and chlorinated carbamates 20 and 21, scheme 8). Polymers based on these bismelamines were prepared by the reaction of the diacid chlorides with dichloromelamine 3 (Scheme 9).

(45) ##STR00014##

(46) ##STR00015##

(47) ##STR00016##

EXAMPLE 5

Tris-melamine Derivatives

(48) A small molecule bearing three melamine moieties was prepared from 1,3,5-tricarbonyl trichloride benzene, which was reacted in the usual manner with three equivalents of monochloromelamine 4. 1,3,5-tricarbonyl trismelamineamide 26 was subsequently converted to the chlorinated form 27 by treating with hypochlorite bleach at pH=5 (Scheme 10).

(49) ##STR00017##

EXAMPLE 6

Hexakismelamine

(50) Hexachlorocyclotriphosphazene was used as a starting material to prepare a small molecule with six melamine groups attached to a cyclophosphazene core. The typical procedure that we carried out during this work, namely the reaction of acid chloride with monochloromelamine to form the amide, proved less successful in the case of phosphazene chloride. A maximum of four melamine groups were attached to the core in this reaction. This result repeated itself upon changing solvents, increasing the reaction temperature and duration, and even upon the addition of base.

(51) Finally, the desired hexakismelamine cyclotriphosphazene was prepared by the rather facile reaction of hexachlorocyclotriphosphazene with six equivalents of melamine in boiling water (Scheme 11). Increase in reaction time or starting material concentration resulted in formation of cyclophosphazene-melamine polymers. Unfortunately, the desired product 28 could not be chlorinated, since, under the reaction conditions, the cyclotriphosphazene core collapsed.

(52) ##STR00018##

(53) A small molecule bearing six melamine moieties was prepared from mellitic acid, which was initially converted into hexa acid chloride with PCl.sub.5, and was then reacted in the usual manner with six equivalents of monochloromelamine 4. Benzene hexakismelamineamide 29 was subsequently converted to the chlorinated form 30 by treating with hypochlorite bleach at pH=5 (Scheme 12).

(54) ##STR00019##

EXAMPLE 7

Determination of the Available Chlorine in Melamine Halamines

(55) The determination of active chlorine in the synthesized melamine halamines was carried out in the usual manner for the determination of available chlorine in hypochlorite solutions, through iodometric method [15].

(56) The results are displayed in Table 1 (a percentage range denotes several measurements on various batches).

(57) TABLE-US-00001 TABLE 1 Active Chlorine Percentage of Chlorinated Compounds Compound % Cl 1 38-43% 2 31% 3 25-27% 4 13-14% 6 19% 8 13% 11 13% 13 49% 15 42% 17 56% 20 48% 21 46% 24 50% 25 42% 27 58% 30 41%

EXAMPLE 8

Decontamination of Chemical Warfare Agents (CWAs)

(58) Caution: These experiments should only be performed by trained personnel using applicable safety procedures. Some of the decontamination reactions are violent and exothermic.

(59) Decontamination of CWAs by melamine halamines was usually evaluated by solid state magic angle spinning (MAS) .sup.31P or .sup.13C NMR. The halamines were tested against sulfur mustard (HD) and VX (O-ethyl-S-2-(N,N-diisopropylamino)ethyl methylphosphonate), which are susceptible to oxidation. In a typical test [16], the melamine halamine powder (ca. 40 mg) was used to fill a 4-mm ZrO.sub.2 rotor. Next, VX or .sup.13C-labeled HD [17] (2-3 mg, 5-6.5%) were applied directly to the center of the sample. The rotor was sealed with a fitted Kel-F cap. .sup.31P (for VX) or .sup.13C (for HD) MAS NMR experiments were carried out on a 500 MHz Avance (Bruker) spectrometer equipped with a 4-mm standard CP-MAS probe using direct excitation (no CP). The observation frequency was 202 MHz (.sup.31P) and 125 MHz (.sup.13C). Remaining CWA quantity and decontamination products were determined.

(60) In cases where decontamination reactions were violent, the reaction was carried out in a regular glass tube, and after the reaction was over (complete termination of fumes), the contents were extracted with MeOH-d.sub.4, filtered, transferred to an NMR tube and analyzed. Table 2 describes decontamination efficacy (%) and time.

(61) TABLE-US-00002 TABLE 2 Decontamination efficacies Compound VX HD 1 >99% in 1 h >99% in 1 day 2 3 4 6 >99% in 1 h >99% in 2 hours 8 77% in 5 days >99% in 1 day 11 No VX in extraction 13 >99% in 1 h >99% in 2 hours 15 96% in 1 day >99% in 1 h 17 >99% in 0.5 h >99% in 0.5 h 20 >99% in 1 day >99% in 1 h 21 >99% in 0.5 h >99% in 0.5 h 24 >99% in 0.5 h >99% in 0.5 h 25 >99% in 0.5 h >99% in 0.5 h 27 >99% in 0.5 h >99% in 0.5 h 30 >99% in 0.5 h >99% in 0.5 h

(62) As expected, the major decontamination product for VX was the non-toxic product ethyl methylphosphonic acid (EMPA). For sulfur mustard, decontamination products usually include hydrolysis products, such as thiodiglycol (TDG), oxidation products, such as sulfur mustard sulfoxide or sulfone, or elimination products, such as divinyl sulfide (DVS) [16]. However, analyzing decontamination products of the reaction between halamines and sulfur mustard revealed that, in this case, a different mechanism takes place and multi-chlorinated compounds are produced (Scheme 13). As we found out, in the case of no evident violent reaction, oxidation to the sulfoxide occurs as the initial step, followed by excess chlorination takes place mainly on the a methylene (adjacent to the sulfoxide). When a violent reaction is evident, no oxidation happens, and excess chlorination occurs on the terminal methylene (adjacent to the existing chlorine atom). The difference in chlorination sites are attributed to shifting acidities of the methylene hydrogens, during the oxidation of sulfide to sulfoxide. These findings are consistent with the limited information given in the literature [18].

(63) ##STR00020##

EXAMPLE 9

Decontamination of Biological Agents

(64) Halamines are well known in their capacity to efficiently kill bacteria. Nevertheless, since the melamine-derived halamines are novel compounds, we tested two of them against bacteria, to ascertain that they exhibit the same behavior. Later, we tested all new melamine halamines against Bacillus anthracis, as a worst-case screen. In the first test, chlorinated and non-chlorinated polymers 6 and 13 (10 ppm each) were tested against E. coli ATCC 25922 (2.910.sup.6 CFU) and S. aureus ATCC 29213 (1.910.sup.6 CFU). Non-chlorinated polymers gave no effect at all, while both chlorinated polymers showed 6-log kill within 5 minutes (FIGS. 4A and 4B).

(65) Since these model compounds showed strong activity against bacteria, Bacillus anthracis, a more robust challenge was used for the screening of novel melamine-derived halamines. The initial test comprised of reacting 410.sup.6 spores with 10 or 100 ppm of tested halamines. Most of the halamines at 100 ppm concentration exhibited 6-log kill after 1 hour, and 5-log kill within 30 minutes (FIGS. 5A and 5B).

(66) The efficacy of halamines to decontaminate Bacillus spores was presented previously only once. A group at the University of California at Davis, in collaboration with the HaloSource company showed that Bacillus subtilis (an anthrax surrogate) was placed on textiles treated with hydantoin-derived halamine (FIG. 3). The percent reduction in live spores was around 100% in 48 hours, depending on the fabric used [19].

(67) It is noteworthy that compound 11 is derived from commercial poly methacrylamide and does not contain a melamine moiety. It was tested as a negative control, since it did not exhibit good decontaminating results against sulfur mustard or VX.

(68) While the invention has been described using some specific examples, many modifications and variations are possible. It is therefore understood that the invention is not intended to be limited in any way, other than by the scope of the appended claims.

EXAMPLE 10

N-halamine Melamine Coated/Bound Nanoparticles

(69) This family is based on commercial functionalized silica or synthesized silica nanoparticles. The melamine moieties are either covalently bound to a functional group on the silica core, or serves as a coating of the silica core. These silicone-based melamine halamines are suited to be incorporated into surfaces (e.g. polymeric sheets, silicone products) or may be used as coatings. Some examples are described in the following schemes:

(70) A. Binding melamine onto commercial propionyl chloride functionalized silica

(71) ##STR00021##

(72) B. Preparation of silica nanoparticles and coating with melamine-methacrylate co-polymers

(73) ##STR00022##

(74) D. Preparation of silica polymer bearing melamine halamine moieties

(75) ##STR00023##

EXAMPLE 11

Biocidal Efficacy Test for Melamine-Halamine Containing Paint

(76) Test samples were prepared by first preparing melamine-halamine containing paints: 4 mL matt polyurethane paint was mixed with 0.25 mL thinner containing varying amounts (2-5%) of various chlorinated melamine-halamine compounds (compounds 13, 25 or 27, see table below). Transparency sheets were painted with original and melamine-halamine containing paint and following drying, they were cut into 2.52.5 cm rectangles. Original paint samples and melamine-halamine paint samples were challenged with Staphylococcus aureus (ATCC 29213) and Escherichia coli (ATCC 25922). A sandwich test was employed to evaluate the efficacies of the chlorinated samples. For a typical test, 25 L of the bacterial suspension was placed in the center of a sample in a sterile Petri dish and covered with a second identical size of sample. After contact times of 30, 60, and 120 min, the samples were placed (back to back) in sterile conical centrifuge tubes containing 5.0 mL of a 0.02 N sodium thiosulfate solution to quench any oxidative chlorine and vortexed for 2 min. The samples were then removed, and the quenched solution was diluted serially with 100 mM phosphate buffer, pH 7 (10.sup.1, 10.sup.2, 10.sup.3). Then, 4 drops of 10 L of original and each diluted solution were placed on a BHIA plate. The plates were incubated at 37 C. for 24 h, and then bacterial colonies were counted for further analysis.

(77) TABLE-US-00003 TABLE 3 Biocidal efficacies E. coli ATCC 25922 S. aureus ATCC 29213 Total Total Bacterial Bacterial Contact Concen- Concen- Time tration Log tration Log Sample (min) (cfu/mL) reduction (cfu/mL) reduction Original 0 6.19 10.sup.6 0 4.47 10.sup.6 0 30 3.75 10.sup.6 0.22 2.53 10.sup.6 0.27 60 4.38 10.sup.6 0.15 1.52 10.sup.6 0.50 120 8.41 10.sup.5 0.87 2.38 10.sup.6 0.30 2% 0 6.19 10.sup.6 0 4.47 10.sup.6 0 compound 30 5.00 10.sup.5 1.09 9.70 10.sup.5 0.69 V 60 8.75 10.sup.2 3.85 1.10 10.sup.4 2.63 (13) 120 2.50 10.sup.2 4.39 1.67 10.sup.3 3.45 5% 0 6.19 10.sup.6 0 4.47 10.sup.6 0 compound 30 1.25 10.sup.2 4.70 8.33 10.sup.2 3.75 V 60 Below detection limit Below detection limit (13) (125) (167) >4.7 log reduction >4.4 log reduction 120 Below detection limit Below detection limit (125) (167) >4.7 log reduction >4.4 log reduction 5% 0 6.19 10.sup.6 0 4.47 10.sup.6 0 compound 30 6.02 10.sup.5 1.01 1.89 10.sup.6 0.40 II 60 7.13 10.sup.3 2.94 1.35 10.sup.6 0.55 (25) 120 5.00 10.sup.2 4.09 2.57 10.sup.4 2.27 5% 0 6.19 10.sup.6 0 4.47 10.sup.6 0 compound 30 2.75 10.sup.6 0.35 1.53 10.sup.6 0.49 III 60 2.73 10.sup.5 1.36 2.52 10.sup.6 0.28 (27) 120 2.25 10.sup.4 2.44 1.02 10.sup.4 2.67

BIBLIOGRAPHY

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