Constituents from the stems of Goniothalamus griffithii.

A new cyclopeptide, grifficyclocin A (1), and a new aporphine alkaloid, griffinin (2) were isolated together with two known styryllactones from the stems of Goniothalamus griffithii. Their structures were identified spectroscopically and chemically. Among them, the griffinin (2) was isolated as the enol form in two tautomers, and the two known styryllactones, goniothalamin (3) and 8- O-acetylgoniotriol (4), showed selective in vitro antitumor activities.