Sesquiterpenes and cyclopeptides from the endophytic fungus Trichoderma asperellum SAMUELS, LIECKF. & NIRENBERG

Abstract

Trichodones A-C (1-3, resp.), three new sesquiterpenes, together with the two known cyclopeptides PF1022F and halobacillin (4 and 5, resp.), have been isolated from the crude extract of the endophytic fungus Trichoderma asperellum SAMUELS, LIECKF. & NIRENBERG residing in the traditional Chinese medicinal plant Panax notoginseng (BURKILL) F.H.CHEN. The structures and configurations of compounds 1-3 were determined by NMR spectroscopy and mass spectrometry. The relative configuration for 1 was determined by analysis of its pertinent coupling constants and NOESY correlations, whereas the absolute configuration of 1 was established by CD spectroscopy. Compounds 4 and 5 displayed antibacterial activities against Enterococcus faecium (CGMCC 1.2025) with IC₅₀ values of 7.30 and 5.24 μM, and against Staphylococcus aureus COL (CGMCC 1.2465) with IC₅₀ values of 19.02 and 14.00 μM, respectively.