Complete 1H and 13C assignments of two new sesquiterpenoids from Dendrobium aduncum.

Two new sesquiterpenoids, dendroaduoid A (1) and dendroaduol (2), together with four known sesquiterpenoids were isolated from the stems of Dendrobium aduncum. Their structures were identified by HR‐ESI‐MS and NMR experiments, and the complete assignments of 1H and 13C NMR data for two new sesquiterpenoids were obtained by the aid of HSQC, HMBC, 1H‐1H COSY, NOESY, and ECD techniques. The cytotoxic effects of the isolated compounds on four tumor cell lines (HCT‐116, HepG2, A549, and SW1990) were evaluated using MTT assay. Otherwise, the inhibitory activity of these six sesquiterpenoids on glycosidase was also evaluated. [ABSTRACT FROM AUTHOR]