New -kaurene and germacrene derivatives from Hemseley and their biological activity.

Hemseley is a well-known traditional herbal medicine used for heat-related ailments. In Taiwan, boiled extracts of are also used as desserts called grass jelly. In this study, the hexane extract from 75% EtOH of showed potent activities on inhibition of β-glucuronidase (eβG) and NO production and cytotoxicity against MCF-7 and HepG2 cancer cell lines. Furthermore, using various flash columns and HPLC chromatography on the bioactive layer led to the isolation of twelve compounds (-), including a new -kaurene, mesokaurol A (), and a new germacrene derivative, mesogermapene A (). Their structures were elucidated by extensive spectroscopic analyses, especially 2 D NMR and mass data. Biological assays showed that compound (linolenic acid) had specific activity on inhibition of eβG (68.27%) at 100 µg/mL but was non-inhibitory to human β-glucuronidase. Compound possessed significant cytotoxicity against MCF-7 (EC = 9.76 µM) and HepG2 (EC = 8.64 µM) cancer cell lines.