The main objective of this study was to isolate active compounds of methanol extract from Dendrobium
venustum and evaluated for cytotoxic activity against KB-oral cavity cancer cell. This extract led to the isolation of
three known compounds which included flavanthrinin, gigantol and batatasin III. Their structures were determined by
spectroscopic analysis (NMR, MS) and by comparison with previously reported data. These compounds were
evaluated for cytotoxic activity against KB-oral cavity cancer cell. Flavanthrinin and batatasin III showed moderate
cytotoxic activity with IC50 values of 64.32 and 81.67 µ M, respectively. Ellipticine and doxorubicin were used as
positive controls with the IC50 values of 4.83 and 1.93 µM, respectively