SYNTHESIS AND ANTIMICROBIAL ACTIVITY OF PHENYLSELENYL TRIBROMIDE AND ITS FUSED THIENOPYRIMIDINE DERIVATIVES

Fused thienopyrimidine derivatives of phenylselenyl tribromide (compound III) were synthesized and characterized by spectral and elemental analyses. The parental compound and its derivatives were tested in vitro for their antimicrobial activity. The minimum inhibitory (bacteriostatic or fungistatic) concentrations and minimum bactericidal or fungicidal concentrations were estimated for the two most active compounds: 1-bromo-2-[(E)-1-bromomethyliden]-1,5-diphenyl-6-oxo-2,3,5,6,7,8,9,10-octahydrobenzo[b]thieno[3',2',5,6]pyrimido-[2,1-b][1,4,3] thiaselenazin-12-ium bromide (compound IVc), the derivative with the lowest toxicity, and phenylselenyl tribromide (compound III), the starting chemical with the highest toxicity. These two compounds yielded mainly bactericidal effects on the tested bacteria. In comparison with the minimum bactericidal concentrations of cefotaxime, this effect was significantly weaker. Of the two afore-mentioned compounds, only the derivative IVc demonstrated fungicidal action against yeasts. In comparison with the minimum fungistatic concentrations of fluconazole, the inhibitory potency of this compound against yeasts was two times stronger. The compound manifested fungicidal effects against yeasts at doses of 275 - 310 mu g/mL, while fluconazole yielded only fungistatic actions. Among the studied compounds, III and IVc appear to be most active against yeasts and also possess poor to moderate activity against Grain-positive and Gram-negative bacteria. The antibacterial activity can be improved by introducing changes into the chemical structure of the compounds. Considering the obtained results, these products and their derivatives may be of practical benefit.