Design, synthesis and antimicrobial evaluation of methyl pyridyl-2,4- dioxobutanoates and some new derived ring systems.

This work describes the synthesis of new series of compounds derived from methyl pyridyl- 2,4-dioxobutanoates that contain pyridine ring attached to substituted bioactive heterocyclic moieties in order to investigate their preliminary in vitro antibacterial and antifungal activities. The results revealed that most of the tested compounds exhibited significant activity against P. aeruginosa. and E. coli. They also displayed considerable activity against S. aureus and B. subtilis. On the other hand, the compounds displayed moderate antifungal activity.

Design, synthesis and biological screening of some pyridinylpyrazole and pyridinylisoxazole derivatives as potential anti-inflammatory, analgesic, antipyretic and antimicrobial agents.

A series of substituted pyridinylpyrazole (or isoxazole) derivatives were synthesized and evaluated for their anti-inflammatory (AI) activity using formalin-induced paw edema bioassays. Their inhibitory activities of cyclooxygenase-1 and cyclooxygenase-2 (COX-1 and COX-2) were also determined. The analgesic activity of the same compounds was evaluated using rat-tail withdrawal technique. Their antipyretic activity was also evaluated. The results revealed that compounds 4a,b, 6a, 8a, 14c and 15a exhibited significant AI and analgesic activities. Compounds 5a, 6a and 8a displayed good antipyretic activity. Compounds 14c and 15a showed good COX-2 inhibitory activity and weak inhibition of COX-1. Additionally, the most active compounds were shown to have a large safety margin (ALD50 >300-400 mg / Kg) and minimal ulcerogenic potentialities when administered orally at a dose of 300 mg/Kg. Docking studies for 14c and 15a with COX-2 showed good binding profile. Antimicrobial evaluation proved that most of the compounds exhibited distinctive activity against the gram negative bacteria, P. aeruginosa and E coli.