Antimicrobial cuparene-type sesquiterpenes, enokipodins C and D, from a mycelial culture of Flammulina velutipes

Two new cuparene-type sesquiterpenes, enokipodins C (1) and D (2), were iso lated from culture medium of an edible mushroom, Flammulina velutipes, alon g with enokipodins A (3) and B (4). The structures of 1 and 2 were determin ed using spectroscopic methods (HRMS, H-1 and C-13, and 2D NMR). The absolu te configuration of enokipodin C was determined from the observed IH NMR ch emical shifts and NOEs in NOESY experiments after conversion into the corre sponding esters with the chiral reagent 2-(2'-methoxy-1'-naphthyl)-3,4-dich lorobenzoic acid. All the metabolites showed antimicrobial activity against a fungus, Cladosporium herbarum, and Gram-positive bacteria, Bacillus subt ilis and Staphylococcus aureus.