Imidazo[4,5-a]quinindolines as highly effective antibacterial agents
摘要:
Resistance to antimicrobial agents is a concern that exists globally and has a considerable impact on human and animal health, so that the discovery of new antibacterial compounds has become increasingly more important in combating infectious disease. In this paper, imidazo[4,5-a]quinindolines are introduced as new antibacterial agents against Gram-positive and Gram-negative bacteria. These pentacyclic compounds are synthesized by the reaction of N-alkyl-5-nitrobenzimidazoles with 2-(1-alkyl-1H-3-indolyl)acetonitrile under basic conditions in excellent yields. The structures of newly synthesized compounds were characterized by IR, H-1 NMR, C-13 NMR, and mass spectral data. The antibacterial activities of the synthesized compounds were screened against standard strains of two Gram-positive and two Gram-negative bacteria using the broth microdilution method. Most of the compounds studied showed promising activities against both types of bacteria.
Results: We have developed a visible-light-mediated oxygenation of indole tertiary amines into corresponding aldehydes, using photoredox system (Scheme 1). Based on Stern-Volmer plots, series of quenching experiments mechanism is proposed. Mentioned method allows to obtain indole aldehyde derivatives and can be used for synthesis of natural compound such as (-)-Vincorine with biologically active properties