Three new monomeric indole alkaloids from the roots of Catharanthus roseus.

Two new alkaloid glycosides (1 and 2) and a new monomeric indole alkaloid (3), together with 13 known ones (4-16), were isolated from the roots of Catharanthus roseus. The structures of new compounds were elucidated on the basis of the spectroscopic methods. The absolute configuration of compound 3 was established by the modified Mosher's method.