Synthesis and antimycobacterial activity of symmetric thiocarbohydrazone derivatives against Mycobacterium bovis BCG

In this work, we reported the synthesis and evaluation of antimycobacterial and antifungal activity of a series of thiocarbohydrazone derivatives which are thiacetazone congeners. The target compounds were synthesized in superior yields by reacting thiocarbohydrazide with different aromatic aldehydes and methyl ketones. Compounds 8, 19 and 25 were found to be the most potent derivatives, exhibiting acceptable activity against Mycobacterium bovis BCG compared to thiacetazone and ethambutol as reference substances. Compounds 8, 15 and 25 exhibited the highest activity against Candida albicans. The most active compounds had a completely different aromatic ring system with various electronic, steric and lipophilic natures. This is understandable in light of the fact that carbohydrazone derivatives must undergo a metabolic activation step before exerting their anti-TB activity and different SAR rules govern each one of these two processes

Screening of membrane active antimicrobial metabolites produced by soil actinomycetes using membrane models

The focus of this study was antimicrobial membrane-activity of actinomycetes isolated from some soils of Iran. In this work, soil samples were collected from desert and farming zones of Northern and Central Iran. A total number of 45 actinomycetes were isolated from the soil samples. In the primary screening performed to evaluate antimicrobial activity, isolated microorganisms were analyzed in terms of their general inhibition effects to indicator strains E. coli, C. albicans, and S. cervisae. It has been found that 12 actinomycetes were effective against test microorganisms. In the secondary screening to determine membrane-active metabolites producing microorganisms, isolates having an inhibitory effect against test microorganisms, were analyzed for membrane activity using a Rapid Chromatic Detection method. Based on color changes that are easily identified by the naked eye and recorded by UV-vis spectrophotometery, two actinomycetes had membrane-activity effect and were stored for the sake of further study and identification