Bisorbibetanone, a novel oxidized sorbicillin dimer, with 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity from a fungus

We isolated a novel oxidized sorbicillin dimer (1) as yellowish amorphous p owder from the fermentation broth of Trichoderma sp. USF-2690 strain isolat ed from a soil sample. The structure of the compound was determined by eluc idation of spectroscopic evidence. The compound was revealed to possess a n ew carbon skeleton in the group of oxidized sorbicillin dimers and was name d bisorbibetanone. The stereostructure of bisorbibetanone was analyzed on t he basis of the spectral data. In 1,1-diphenyl-2-picrylhydrazyl (DPPH) radi cal scavenging assay, bisorbibetanone gave an ED50 value of 62.5 mu M after standing for 30 min. (C) 1999 Elsevier Science Ltd. All rights reserved.