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A series of oxime esters was synthesized by esterification of 3-ethoxy-4-benzaldehyde oxime with acid chlorides in the presence of triethylamine. They were evaluated for theirin vitroantifungal activity against three pathogenic fungi, namelyRhizoctonia bataticola, Fusarium udum, andAlternaria porii, and their antibacterial activity against the three bacterial strainsStaphylococcus aureus, Pseudomonas aeruginosa, andKlebsiella pneumoneae. The compounds bearing medium-length alkyl chains showed greater activity than those with long alkyl chains. An electron-donating group in para position of the aryl ring confers highest activity. [ABSTRACT FROM PUBLISHER]

This investigation was undertaken to identify the major secondary metabolite, produced by two Trichoderma harzianum strains (T-4 and T-5) with their antifungal activity against phytopathogenic fungi using poison food technique. The ethyl acetate extract was subjected to column chromatography using n-hexane, ethyl acetate and methanol gradually. Chromatographic separation of ethyl acetate extract of T. harzianum (T-4) resulted in the isolation and identification of palmitic acid (1), 1,8-dihydroxy-3-methylanthraquinone (2), 6-pentyl-2H-pyran-2-one (3), 2(5H)-furanone (4), stigmasterol (5) and b-sitosterol (6), while T. harzianum (T-5) gave palmitic acid (1), 1-hydroxy-3-methylanthraquinone (7), δ-decanolactone (8), 6-pentyl-2Hpyran- 2-one (3), ergosterol (9), harzianopyridone (10) and 6-methyl-1,3,8-trihydroxyanthraquinone (11) as major metabolites. Among compounds screened for antifungal activity, compound 10 was found to be most active (EC50 35.9-50.2µg mL-1). In conclusion, the present investigation provided significant information about antifungal activity and compounds isolated from two different strains of T. harzianum obtained from two different Himalayan locations. [ABSTRACT FROM AUTHOR]

Ethyl acetate extracts of two strains ofTrichoderma koningiiwere evaluated for antifungal activity against soilborne pathogenic fungi,Rhizoctonia solani, Sclerotium rolfsii, Macrophomina phaseolinaandFusarium oxysporumby poisoned food technique. Secondary metabolites, namely δ-decanolactone, 6-pentyl-α-pyranone and 6-(4-oxopentyl)-2H-pyran-2-one were isolated fromT. koningii(T-8) extract while palmitic acid, 6-pentyl-α-pyranone and stigmasterol were isolated fromT. koningii(T-11) extract. Secondary metabolites were identified by1H NMR,13C NMR and mass spectroscopic methods. These metabolites were evaluated for antifungal activity against the test pathogens 6-Pentyl-α-pyranone and 6-(4-oxopentyl)-2H-pyran-2-one exhibited excellent antifungal activity againstS. rolfsii. The antifungal activity though slightly less was comparable to that of hexaconazole, a commercial fungicide. [ABSTRACT FROM PUBLISHER]