Design and Synthesis of benzo g quinoxaline 5 10 dione Derivatives and their Biological Evaluation as Antimycobacterial Agents

Abstract

Quinoxaline derivatives constitute the important part of various antibiotics viz. hinomycin, levomycin and actinoleutin that inhibit the growth of various bacteria and are found to be cytotoxic against various transplantable tumours. Quinoxaline derivatives have also been reported to exhibit a wide range of biological activities viz. antifungal, antibacterial, antitubercular etc. Quinoxaline ring also consititutes an important part of antileprotic drug clofazimine which is also widely indicated for treatment of multidrug resistant tuberculosis. Compounds belonging compound series 6 were synthesized by Reaction Scheme I and Compound series 6, Compound series 7 and Compound series 8 were synthesized by Reaction Scheme II. Structure of all the newly synthesized compounds were confirmed by FTIR, 1H NMR, 13C NMR, MS spectral data interpretation and elemental analysis. Selected newly synthesized compounds were screened for their antimycobacterial activity against Mycobacterium tuberculosis H37Rv by L.J. Slope Conventional Method. Among the newly synthesized compounds, compounds with electron donating groups viz. 6h synthesized by Reaction Scheme I, 6e Reaction Scheme II, 7j synthesized by Reaction II and 8e synthesized by Reaction Scheme II at the phenyl ring attached to 4 position of pyridine ring, enolic carbonyl group, 5 position of pyrazoline ring and 5 position of pyrazoline ring having carbothiamide group at 1 position respectively placed to C 7 of Benzo g quinoxaline 5,10 dione ring exhibited most significant antimycobacterial activity. These compounds may act as lead for antimycobacterial agents in future. newline