Antimicrobial and antioxidant screening of N'-substituted sulphonyl and benzoyl derivatives of 4-Pyridine carboxylic acid hydrazide

In this research program, the antibacterial, antifungal and antioxidant activities of six N_-substituted sulfonyl and benzoyl derivatives of lead molecule PCH were reported. Out of these compounds, sulphonyl derivatives 2,3 and benzoyl derivative 5 showed moderate to good activity against different strains of gram-positive and gram-negative bacteria including B. cereus, B. subtilis, B. thruingiensis and S. pyogenes, S. fecalis and E. coli ATCC 8739. Moreover, upon antifungal screening, the compound, N?-[[2,4,6-trimethylbenzene] sulfonyl]pyridine-4-carbohydrazide possessed good antifungal activity against Candida species, a causative agent of systemic fungal infections. Antioxidant study demonstrated more than 50% inhibition in DPPH assay for sulphonyl derivative 2 indicating its potential as antioxidant while the other derivatives expressed low level of radical scavenging property

Antibacterial, antifungal and antioxidant activities of some medicinal plants

The purpose of this study was to evaluate the antibacterial, antifungal and antioxidant activities of medicinal plants. The antibacterial activity of methanolic extracts of three medicinal plants [Swertia chirata, Terminalia bellerica and Zanthoxylum armatum] were tested against Gentamicin [standard drug] on eleven gram positive and seventeen gram negative bacteria by agar well method. It was revealed that seven-gram negative and six gram positive bacterial species were inhibited by these plant extracts. Minimum inhibitory concentrations [MIC] of the extracts were determined by broth micro-dilution method. The significant MIC value of Swertia chirata was 20mg/ml against Serratia marcesens, Zanthoxylum armatum was 10 mg/ml against Aeromonas hydrophila and Terminali bellerica was 20mg/ml against Acinetobacter baumanii as well as Serratia marcesens. Antifungal screening was done for methanolic extracts of these plants by agar well method with the 6 saprophytic, 5 dermatophytic and 6 yeasts. In this case Griseofulvin was used as a standard. All saprophytes and dermatophytes were showed resistance by these plants extracts except Microsporum canis, which was inhibited by Z. armatum and S. chirata extracts. The significant MIC value of Zanthoxylum armatum was 10mg/ml against Microsporum canis and Swertia chirata was 10mg/ml against Candida tropicalis. The anti-oxidant study was performed by DPPH free radical scavenging assay using ascorbic acid as a reference standard. Significant antioxidant activities were observed by Swertia chirata and Zanthoxylum armatum at concentration 200microg/ml was 70% DPPH scavenging activity [EC[50]=937.5microg/ml] while Terminalia bellerica showed 55.6% DPPH scavenging activity [EC[50]=100ug/ml]. This study has shown that these plants could provide potent antibacterial compounds and may possible preventive agents in ROS related ailments