Two major alkaloids were isolated from root bark of Perriera madagascariensis Courchet (Simaroubaceae). The first alkaloid was identified as 4,7-dimethoxy-1-vinyl-â-carboline (1), previously isolated from stems of the same plant. The second alkaloid, to which the trivial name kirondrine was given, was new, and its structure (2) was established largely by means of 1D and 2D NMR techniques as a dimeric alkaloid biogenetically related to compound 1. Compound 2 might correspond to the dimeric alkaloid formerly isolated from stems of P. madagascariensis.