The antineoplastic bisindole vincaleukoblastine (TLB) (1) and two monomers, akuammicine (2) and tetrahydroalstonine, have been isolated from C. trichophyllus roots, and periformyline (3) has been obtained from its leaf alkaloid fractions. Pericyclivine (4) and five alkaloids, leurosine, vincarodine, akuammicine, vindoline and ajmalicine, have been isolated from two acid fractions of C. roseus leaves. Carbon-13 nmr spectra of two monomeric indole alkaloids, akuammicine and pericyclivine, have been assigned.