Synthesis and antifungal activities of some new tetrahydro-2H-1,3,5-thiadiazine-2-thiones.

A number of new 3-benzyl-5-[alpha-(substituted)carboxymethyl]- tetrahydro-2H-1,3,5-thiadiazine-2-thiones has been synthesized as prodrugs by incorporating the amine group of some amino acids into tetrahydro-2-H-1,3,5-thiadiazine-2-thione ring. The compounds have been prepared by the reactions of benzylamine with potassium hydroxide, carbon disulphide formaldehyde and various amino acids. The structures of the compounds have been elucidated by UV, IR, 1H-NMR, mass spectra and elementary analysis. The in vitro activity of these compounds against yeast-like fungi (Candida albicans, C. parapsilosis, C. pseudotropicalis, C. stellatoidea) was investigated by tube dilution method. Their minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) values were determined. All the compounds were found to be active between 3.12-12.5 micrograms/ml against the four fungi tested.