Sesquiterpenes from the Leaves of Magnolia delavayi Franch. and Their Cytotoxic Activities

Thirteen sesquiterpenes including eight new ones, magnodelavins A?H ( 1 – 8 ), were obtained from the 95 % ethanolic extract of the leaves of Magnolia delavayi Franch . The structures of the new compounds were determined by exhaustive ¹H‐, ¹³C‐, 2D‐NMR, UV, IR, and HR‐ESI‐MS data, as well as X‐ray crystallographic analysis. Compounds 9 and 10 showed potent cytotoxic activities against HL‐60, A‐549, SMMC‐7721, MCF‐7, and SW480 human cancer cell lines in vitro using MTS assay.