Two new monoterpene glycosides from the endophytic fungus <i>Diaporthe nobilis</i> and their cytotoxic effects

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