Diterpenes and sesquitrpenes from Mikania banisteriae

Abstract

Two new ent-kaurane diterpenes, 18,19-diacetoxy-ent-kaur-16-ene and 17-oxo-ent-kaur-15(16)-en-18-oic acid, were isolated from the aerial parts of Mikania banisteriae, together with the known ent-kauranes ent-kaur-16-en-18-oic acid and ent-kaur-16-en-18-ol. The structures were established by mass spectrometry, 1H NMR and partly 13C NMR spectroscopy. In addition, the sesquiterpene lactones eudesma-4(15),7(11)-dien-8β,12-olide and eudesma-4(15),7(11),8(9)-trien-12-olide as well as the sesquiterpenes 1β,6α-dihydroxyeudesm-4(15)-ene and caryophylleno-xide were identified by direct comparison (TLC, GC, GC-MS) with authentic samples. The chemotaxonomic significance is briefly discussed. ent-Kaur-16-en-18-oic acid and ent-kaur-16-en-19-oic acid showed no antifeedant, antimicrobial and antiinflammatory properties.