Phytochemical and biological studies of Costa Rican Asteraceae part VI - Studies of ent-kaurane diterpenes from Oyedaea verbesinoides for their inhibitory activity on vascular smooth muscle contraction

摘要

From the aerial parts of Oyedaea verbesinoides nine ent-kauranes and a sesquiterpene were isolated. ent-9alpha-Hydroxy-kaur-16-en-19-oic acid, ent-15beta-tigloyloxy-9alpha-hydroxy-kaur-16-en-19-oic acid, ent-15beta-angeloyloxy-9alpha-hydroxy-kaur-16-en-19-oic acid, ent16alpha-hydroxykaurane and 1alpha-angeloyloxy-carotol are new for the genus or the species and ent-15beta-angeloyloxy-7alpha,9alpha-dihydroxykaur-16-en-19-oic acid is reported for the first time. Structure elucidation was based on one and two dimensional NMR as well as Est and CI-MS analysis. Some diterpenes were proven to exhibit inhibitory effects on smooth muscle contraction on rat aorta.