Anti-tubercular and anti-inflammatory activities of azetidin-2-one derivatives and their effects on the activity of Phospholipase A2.

The title compounds have been synthesized and tested for structure activity relationship for Phospholipase A2 (PLA2) [E.C. 3.1.1.4] enzyme inhibition. The in vitro anti-tubercular, PLA(2) enzyme inhibitory activities of azetidin-2-one derivatives and in vivo anti-inflammatory studies using mice are highlighted. The analogues of azetidin-2-one were prepared based on the initial activity against Mycobacterium tuberculosis (Mtb). Certain azetidin-2-one analogues described herein showed moderate to good anti-tubercular activity. In particular, two compounds (4f) and (4g) exhibited MIC values of 1.56 and 0.78 microg/mL respectively against the Mtb H(37)Rv strain. Chloro substitution on aryloxy acid apparently enhanced the antimycobacterial activity and also PLA2 inhibition in the azetidin-2-one series described herein. The ability of azetidin-2-one analogues as anti-inflammatory agents has also been determined. The results show some correlation between anti-inflammatory, anti-tubercular activity and expression of PLA2 enzyme.

Anti-calmodulin acridone derivatives modulate vinblastine resistance in multidrug resistant (MDR) cancer cells.

Multidrug resistance (MDR) is one of the main obstacles limiting the efficacy of chemotherapy treatment of tumors. Parent acridones 1A and 1B were prepared by the Ullmann reaction followed by cyclization and N-alkylation. N-(omega-Chloroalkyl) analogues were subjected to iodide catalyzed nucleophilic substitution reaction with secondary amines to get the compounds 3A-13A and 3B-13B, which enhanced the uptake of vinblastine in KBChR-8-5 cells to a greater extent (2.6-13.1-fold relative to control) than verapamil. The study on the structure-activity relationship revealed that substitution of -H at position C-4 in acridone nucleus by -OCH3 increased the cytotoxic and anti-MDR activities. The ability of acridones to inhibit calmodulin dependent cyclic AMP phosphodiesterase has been determined and the results have shown a strong positive correlation between anti-calmodulin activity and cytotoxicity in KBChR-8-5 cells or anti-MDR activity.