allo-aromadendrane- and picrotoxane-type sesquiterpenes from Dendrobium moniliforme.

Eight sesquiterpenes, four stilbene derivatives along with two lignans have been isolated from lipophilic fraction of stems of Dendrobium moniliforme (Orchidaceae). Among the eight sesquiterpenes, one allo-aromadendrane-type and four picrotoxane-type sesquiterpenes were identified to be new compounds, and alpha-dihydropicrotoxinin was isolated as a new natural product. Their structures were established on the basis of spectroscopic analysis.