In our continuing search (1-7) for cyclopeptide alkaloids from Ziziyphus species, we report here the isolation and characterization of the cyclopeptide alkaloids mauritine-D and nummularine-B from the bark of Zizyphus xylopyra Willd. These alkaloids have not previously been reported from this source. In our continuing phytochemical investigation of biologically active constituents from Simaroubaceae spp., we report here the Occurrence in root barks of Quassia africana Baill. (syn. Simaba africana Baill.) of three alkaloids (canthin-6-one, 4,5-dimethoxycanthin-6-one, β-carboline-1-propionic acid) and quassin, an additional quinoid different from those previously isolated from this plant (1). Their structures were established by spectroscopy and direct comparison with authentic samples.