Various substituted carbazolo-thiazoles 6 (a-o) have been synthesized in good yields by molecular hybridization approach. These synthesized compounds were evaluated for their in vitro anti-tubercular activity against Mycobacterium tuberculosis H 37 Rv strain at National Institute of Allergy and Infectious Diseases (NIAID), Bethesda, MD, USA. Among the tested series, compound 6c (MIC = 21 µM) exhibited the most promising anti-mycobacterial activity. A brief structure activity relationship (SAR) studies revealed that electron donating groups (OCH 3 and OH) especially on the phenyl ring of thiazole motif exhibited positive correlation with antimycobacterial activity. In addition, they displayed low cytotoxicity against a mammalian Vero cell line using MTT assay, thereby providing a high therapeutic index. This study reveals the significance of molecular hybridization and the scope for the development of carbazole clubbed thiazole compounds as potential anti-mycobacterial agents.

Four homoisoflavanones of the 3-benzylidene-4-chromanone type, some of which were previously isolated from Caesalpinia pulcherrima, were synthesised to determine their anti-inflammatory activity and cytotoxicity. A range of four different homoisoflavanones (compounds 4a-4d) were synthesised from the corresponding substituted phenols. ¹H- and ¹³C-NMR data together with high-resolution mass spectroscopy data were employed to elucidate the structures. Anti-inflammatory activity was determined in mice with acute croton oil-induced auricular dermatitis. In vitro cytotoxicity was tested against a Chinese hamster ovarian cell line using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) assay. Compound 4a exhibited a tendency to inhibit oedema in a dose-dependent manner after 3 and 6 h of treatment. Compounds 4b-4d also inhibited oedema, although a clear dose-response relationship was not observed. Compounds 4a-4c were found to be less cytotoxic than compound 4d. Compound 4b was the least cytotoxic. Compounds 4a-4d exhibited anti-inflammatory activity and varying levels of cytotoxicity.

A series of five homoisoflavanone analogues have been synthesized from the corresponding 3,5-methoxy phenols via chroman-4-one in three steps. The complete NMR elucidation of these homoisoflavanone analogues is reported. The use of 2D NMR techniques (COSY, NOESY, HSQC and HMBC) proved to be very useful tools in the elucidation of homoisoflavanone analogues. The homoisoflavanone analogues exhibit an AA 0 BB 0 spin pattern in the ring B of the homoisoflavanone. These homoisoflavanone analogues are potential antifungal and anti-inflammatory agents.

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