Methyl chanofruticosinate type alkaloids from the aerial parts of Kopsia lancibracteolata Merr.

A chemical investigation on the 70% ethanol extract from the leaves and stems of Kopsia lancibracteolata Merr. resulted in the isolation of three new methyl chanofruticosinate type alkaloids, 12-hydroxyl prunifoline A (1), 12-hydroxyl prunifoline C (2), and N(4)-oxide prunifoline D (3). Structural elucidation of all the compounds was performed by spectral methods such as 1D- and 2D-NMR, IR, UV, and HR-ESI-MS. The isolated alkaloids were tested in vitro for cytotoxic potential against five tumor cell lines (BGC-823, HepG2, MCF-7, SGC-7901, and SK-MEL-2). As a result, alkaloid 3 exhibited significant cytotoxic activity against all tested tumor cell lines with IC50 values from 7.2 to 8.9 μM.