Rhytidhyesters A - D, 4 New Chlorinated Cyclopentene Derivatives from the Endophytic Fungus Rhytidhysteron sp. BZM-9.

Four new chlorinated cyclopentene derivatives, rhytidhyesters A - D (1:  - 4: ), were isolated from sp. BZM-9, an endophytic fungus from . The planar structures of compounds 1:  - 4: were mainly elucidated by 1D, 2D NMR, and HRESIMS data. Their absolute configurations were established by X-ray crystallographic analysis, quantum chemical C NMR, and electronic circular dichroism calculations. Compounds 1: and 2: are a pair of epimers. Moreover, all the isolated compounds were evaluated for cytotoxic activities against 3 human colon cancer cell lines (SW620, HT29, SW480) and antimicrobial activity against . All compounds exhibited weak to moderate antiproliferative activities with IC values ranging from 15.4 to 37.7 µM but were inactive against .