A new minor diketopiperazine from the sponge-derived fungus Simplicillium sp. YZ-11.

Chemical investigation of the cultures of a sponge-derived fungus Simplicillium sp. YZ-11 led to the isolation of a new minor diketopiperazine alkaloid cyclo-(2-hydroxy-Pro-Gly) (1) and a natural lactone (S)-dihydro-5-[(S)- hydroxyphenylmethyl]-2(3H)-furanone (2), together with five known ergostane-type sterols (3-7). Their structures were established based on extensive spectroscopic methods ((1)H and (13)C NMR, (1)H-(1)H COSY, HSQC and HMBC) and optical rotation analysis.