A new bisindole alkaloid, huncaniterine A (1) consisting of corynantheine-type and aspidospermane-type skeletons, has been isolated from the bark of Hunteria zeylanica (Apocynaceae) and the structure was elucidated on the basis of spectroscopic data. Huncaniterine A (1) exhibited a vasorelaxant activity on isolated rat aorta ring. © 2007 The Japan Institute of Heterocyclic Chemistry.