Sesquiterpenes from the Leaves ofMagnolia delavayi Franch . and Their Cytotoxic Activities

Abstract Thirteen sesquiterpenes including eight new ones, magnodelavins A−H (1–8), were obtained from the 95 % ethanolic extract of the leaves ofMagnolia delavayiFranch. The structures of the new compounds were determined by exhaustive1H‐,13C‐, 2D‐NMR, UV, IR, and HR‐ESI‐MS data, as well as X‐ray crystallographic analysis. Compounds9and10showed potent cytotoxic activities against HL‐60, A‐549, SMMC‐7721, MCF‐7, and SW480 human cancer cell lines in vitro using MTS assay.