Two Terpenoid Derivatives with Different 3/5/6/6/<scp>5‐Fused</scp>Pentacyclic Skeletons from<i>Hedyosmum orientale</i>
Yao‐Yue Fan, Cheng‐Yu Zheng, Bin Zhou, Flávia M. Zimbres, María B. Cassera, Jian‐Min Yue
Abstract
Comprehensive Summary Chemical investigation of Hedyosmum orientale led to the identification of two terpenoid derivatives, dyosmunoids A and B ( 1 and 2 ) featuring two different 3/5/6/6/5‐fused pentacyclic ring systems, respectively. Compound 1 is the second natural product of this C 25 terpenoid compound class, and compound 2 is a rare dinor‐C 25 terpenoid with a peroxide bridge. Their structural elucidation was achieved by the comprehensive analysis of spectroscopic data, single‐crystal X‐ray diffraction, and ECD calculation. Putative biosynthetic pathways for compounds 1 and 2 are proposed. Compound 2 exhibited strong antimalarial activity with an IC 50 value of 0.42 μmol·L –1 .