Benzylisoquinoline alkaloids from gnetum parvifolium

The investigation of the chemical constituents from the lianas of Gnetum parvifolium resulted in the isolation of three new benzylisoquinoline alkaloids, (+/-)-N-methylhigenamine (1), (-)-N-methylhigenamine N-oxide (2), and (+/-)-8-(p-hydroxybenzyl)-2, 3,10,11-tetrahydroxyprotoberberine (3), together with two known alkaloids, higenamine and trigonelline. The structures of 1-3 were determined by chemical methods and spectral analysis including 2D NMR and NOE studies.