5′,6′-Dehydroguiachrysine and 5′,6′-dehydroguiaflavine, two curarizing quaternary indole alkaloids from the stem bark of Strychnos guianensis

Two new quaternary indole alkaloids 5′,6′-dehydroguiachrysine and 5′,6′-dehydroguiaflavine were isolated from Strychnos guianensis stem bark. Their structures were determined by analysis of spectral data. Their inhibitory effects on neuromuscular transmission are also reported and compared to that of other quaternary alkaloids