Research Journal of Recent Sciences ______ ______________________________ ______ ____ ___ ISSN 2277 - 2502 Vol. 2 ( ISC - 2012 ), 1 3 - 14 (201 3 ) Res. J. Recent . Sci. International Science Congress Association 13 Short Communication Biological Evaluation of 1, 3 - Bis - (2 - Substitutedamino - 6 - Substitutedimino - 1, 3, 5 - Thiadiazin - 4 - yl) - Thiourea Derivatives as Antimicrobial agents Shelke M.E. H.V.P.M.’s College of Engineering and Technology Amravati M.S., INDIA Avai lable online at: www.isca.in Received 3 rd September 2012, revised 28 th December 2012, accepted 23 rd January 201 3 Abstract A series of 1,3 - bis (2 - substitutedamino - 6 - substituted - imino - 1,3,5 - thiadiazin - 4 - yl) - thiourea [ 3a(i) to 3f (iii)] have been obtained by basification of their hydrochlorides [2a(i) to 2f (iii)].The latter were synthesized by the interaction of 1,3 - bis (N - substitutedamidinothiocarbamido) - thiourea (1) and N - aryl/alkylisocyanodichlorides in 1:2 molar ratio. The compound (1) was prepared initially by the condensation of aryl/alkylisothiocyanate and 1,3 - diformamidinothiourea in 1:2 molar ratios. The structure of all these compounds was established on the basis of IR and NMR spectral data. All the synthes ized compounds have been assayed for their antibiological activity against both gram - positive and gram - negative human pathogens and found that they possess insecticidal, and bacteriocidal. Some 1,3,5 - thiadiazine compounds show remarkable biological activi ty. Keywords: Thiourea, 1, 3, 5 - thiadiazine, antimicrobial activity . Introduction The literature survey reveals that the thiourea and its derivatives having 1,3,5 - thiadiazine nucleus enhanced pharmaceutical, agricultural and industrial values 1 . So, the medicines containing thiadiazines nucleus are now used extensively in medical, biomedical and biotechnological faculties. It has been shown to posses industrial 2 , medicinal 3 - 4 fungicidal , insecticidal 5 - 7 , values. The synthetic applications of N - aryl/alkyl isocyanodichlorides 8 - 10 have been investigated and shown to have enough potential in the synthesis of nitrogen and sulphur containing heterocyclic compounds, thus with an aim to synthesize 1,3,5 - thiadiazine, reaction of N - aryl/alkylisocyanodichlorides have been carried out with different 1,3 - bis (N - substitutedamidinothiocarbamido) thiourea (1) in 1:2 molar ratios. Material and Methods "Any chemical moiety which inhibits the growth of microorganism or kill it is called as Antimicrobial activity". All 1,3, 5 - thiadiazines compounds were screened for their antibacterial activity using cup plate diffusion method. 8 - 10 bacterial organisms used include both gram positive and gram negative strains like S. aureus , S. typhi, A. aerogenes, E. coli and B. subtilis . The medium was prepared by dissolving 28 gm of ingredients in one liter of distilled water and was sterilized at 121°C temperature and 15 lbs/inch pressure in an autoclave for 15 minutes. After sterilization it was cooled down to 50°C and poured into ste rile petriplates and allowed to solidify. The media plates were then seeded with 24 hrs old active nutrient growth culture of the test organism in order to obtain lawn culture. The compounds were dissolved in 50% dimethylformamide (DMF) solvent at fix conc entration 100 mg/ml To these added 2 drops of test solutions of synthesised compounds. Plane DMF solvent was used as control. The plates were then incubated at 37°C for 24 hrs. After incubation the zones of inhibition were recorded around the wells and res ult are cited in table – 1 . Experimental: All chemicals used were of analar grade. N - aryl/alkylisocyanodichlorides were prepared according to literature method 7 . Melting point of all synthesized compounds was determined in open capillary and uncorrected; IR spectra were recorded on Perkin - Elmer spectrometer in the range 4000 - 400 cm - 1 in KBr pellets. PMR spectra were recorded with TMS as internal standard using CDCl 3 and DMSO - d 6 . TLC checked the purity of the compounds on silica gel - G plates with layer thic kness of 0.3mm. The parent compound 1,3 - bis (N - substitutedamid - inothiocarbamido) thiourea (1a - f) was prepared by refluxing the mixture of 1,3 - diformamidinothiourea 11 with aryl/ alkylisothiocyanate in 1:2 molar ratio in acetone ethanol medium for 12 h. on water bath. Results and Discussion Various thiourea derivatives [3a(i) to 3f(iii)] were prepared using 1,3 - bis (N - substitutedamidinothiocarbamido) - thiourea and N - aryl/alkylisocyanodichlorides. All the compounds synthesized were adequately characterized by their elemental analyses and spectral IR, UV and H - NMR. All the synthesized compounds have been assayed for their antibiological activity against both gram - positive and gram - negative human pathogens and found that they possess insecticidal, and bacteri cidal Research Journal of Recent Sciences ______ _ _ _______________________________ ______________ _ _______ _ ISSN 2277 - 2502 Vol. 2 ( ISC - 2012 ), 1 3 - 14 (201 3 ) Res. J. Recent. Sci . International Science Congress Association 14 Table - 1 Physical Data and Antimicrobial Activity of the Compounds [3a (i) to 3f (iii)] . Compd R R 1 Yield % m.p. ( 0 C) Gram Positive Gram Negative S. aureus B. subtilis A. aerogenes E. coli S. typhi [3a(i)] Phenyl Phenyl 60 254 + ++ +++ ++ +++ [3a(ii)] Phenyl p - Chloro - phenyl 58 257 +++ ++ ++ - + [3a(iii)] Phenyl Ethyl 64 242 + +++ - + ++ [3b(i)] p - Chlorophenyl Phenyl 71 252 ++ + + ++ +++ [3b(ii)] p - Chlorophenyl p - Chloro - phenyl 69 264 ++ + ++ + ++ [3b(iii)] p - Chlorophenyl Ethyl 73 272 + + + + - ++ [3c(i)] p - Tolyl Phenyl 62 268 +++ ++ ++ + +++ [3c(ii)] p - Tolyl p - Chloro - phenyl 58 257 ++ +++ ++ - ++ [3c(iii)] p - Tolyl Ethyl 63 256 ++ - + + +++ [3d(i)] Ethyl Phenyl 67 261 +++ + +++ ++ - [3d(ii)] Ethyl p - Chloro - phenyl 72 272 ++ - + - ++ [3d(i ii)] Ethyl Ethyl 58 242 + - ++ ++ +++ [3e(i)] Methyl Phenyl 62 232 ++ ++ +++ - +++ [3e(ii)] Methyl p - Chloro - phenyl 59 227 ++ + ++ ++ ++ [3e(iii)] Methyl Ethyl 61 231 + ++ - - +++ [3f(i)] t - Butyl Phenyl 67 242 + + + + - [3f(ii)] t - Butyl p - Chloro - phenyl 69 251 +++ - ++ ++ +++ [3f(iii)] t - Butyl Ethyl 73 237 - ++ +++ ++ + * All Compounds gave satisfactory C, H, N, and S analysis. ( - ) = Inactive (Less than 10 mm) (+) = Weakly Active (10 - 14 mm) ( ++ ) = Moderately Active (15 - 18 mm ) (+ + +) = High ly Active (19 - 35 mm) All the bacterial organisms studied are human pathogens. The activity is compared with standard drug ciprofloxacine at the same concentration. From the experimental data it has been observed that the compounds 3a(i), 3b(i), 3c(i), 3c (iii), 2d(iii), 3e(i), 3e(iii) and 3f(ii) shows high activity against S. typhi and compounds 3a(iii), 2b(ii), 3b(iii), 3e(ii), 3d(ii), and 3e(ii) shows moderate activity while remaining compounds are inactive against same pathogen. Similarly compound 3a(i) , 3b(i), 3d(i), 3d(iii), 3e(ii), 3f(ii) and 3f(iii) shows moderate activity and remaining compounds shows inactivity against E. coli . In case of Gram - positive bacteria like S. aureus the compound 3a(ii), 3e(ii), 3d(i) and 3f(ii) shows highly activity whi le compound 3b(i), 3b(ii), 3c(ii), 3c(iii), 3d(ii), 3e(i) and 3e(ii) shows moderately activity against the same bacteria. The compound 3a(iii) and 3c(ii) were effective against the B. subtilis organisms. As newly thiadiazines shows remarkable antimicrobial activity, these compounds can be easily used as alternative drugs for the treatment of various diseases. Conclusion As outline in synthesis process, important novel thiourea have been synthesized. All the structure of the above compounds was in good agre ement with Spectral and Analytical data.and also shows novel biological activity. Reference s 1. Aboul - Fadi T., Hussein M.A., ElShorbagi A.N., Kallil A.R. , Arch.Pharm (Weinbeim), 335, 2002 ,(438). 2. Alfred K. and Tantaway A., Arch.Pharm.(Weinbeim) , 311, 935 ( 19 78) 3. 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