Aristololactams and aporphines from the stems of Fissistigma oldhamii (Annonaceae)

Abstract

Two aristololactams, aristololactam GI (1) and aristololactam GII (2), and three aporphines, fissistigamide A (3), fissistigamide B (4) and fissistigmine (5), together with nineteen known alkaloids, one flavone and one anthraquinone were isolated from the ethanol extracts of the stems of Fissistigma oldhamii (Annonaceae). Their structures were elucidated primarily by analysis of NMR, IR, UV, MS and CD data. Alkaloid 1 is a chiral aristololactam formed from a phenylpropanoid derivative attached to a 3,4-dihydroxy aristololactam scaffold. The absolute configuration of 1 was determined by comparing experimental and calculated ECD spectra. The anti-inflammatory activity of the crude extracts and the five alkaloids were tested by measuring the amount of TNF-α and IL-6 released from LPS stimulated RAW264 cell via ELISA. The results demonstrated that the CHCl(3)-soluble part and alkaloid 2 exhibited significant anti-inflammatory activity in vitro in both assays.