ANTIMICROBIAL AND ANTIVIRAL ACTIVITY OF SPIROINDOLINONES BEARING BENZOTHIAZOLE MOIETY

In this study, 5-chloro-1'-methyl-5'-nitro-3H-spiro[1,3-benzothiazole-2,3'-indole]-2'(1'H)-one (3u) was synthesized by the reaction of 1-methyl-5-nitro-1H-indole-2,3-dione (1m) with 2-amino-4-chlorothiophenol (2) in ethanol. The structure of 3u was confirmed by the spectral (IR, H-1 NMR, HSQC-2D, LCMS-ESI) data and elemental analysis. The new spiroindolinone derivative 3u, along with previously reported spiroindolinone derivatives 3a-t bearing benzothiazole or 5-chlorobenzothiazole moiety were tested for in vitro antimicrobial activity against selected strains. Among the tested compounds, 3i and 3l displayed the highest efficacy against Staphylococcus aureus and Candida albicans. Only 3b was found to be significantly active against Staphylococcus epidermidis. 3a-n were evaluated for in vitro antituberculosis activity against Mycobacterium tuberculosis H37Rv, but most of the tested compounds showed weakly antitubercular activity. All compounds were also evaluated against some DNA and RNA viruses in CRFK, HeLa and HEL cells. Cytotoxicities of the tested compounds were generally very high compared to standards.