Two new monoterpene glycosides from the endophytic fungus Diaporthe nobilis and their cytotoxic effects

Two new monoterpene glycosides, diaporthosides A (1) and B (2), were purified from Diaporthe nobilis, an endophytic fungus isolated from the medicinal plant Polygonatum odoratum. Their structures were determined by comprehensive spectroscopic analysis. The absolute configuration of compound 1 was assigned by comparing its experimental ECD spectrum with the calculated spectrum using quantum-chemical ECD calculations. In addition, compounds 1 and 2 were evaluated for cytotoxic activity against the HGC-27 cancer cell line, with compound 1 exhibiting moderate activity (IC50 = 46.93 ± 1.06 μM).