Two new indole alkaloids from Hunteria zeylanica.

Two new indole alkaloids, 14β-hydroperoxy-eburnamine (1) and 18α-hydroxy-eburnamine (2), together with three known indole alkaloids, (-)-eburnamonine (3), (-)-eburnamenine (4), and eburnamine (5) were isolated from Hunteria zeylanica collected in Hainan Province of China. Their structures were determined by spectroscopic analysis. The relative configuration of 2 was deduced by NOE experiment and evidenced by the calculations for energy minimization with the molecular modeling program Chem3D Ultra 10.0.