In the course of the structure elucidation of perivine (I), a major alkaloid of Catharanthus roseus and C. lanceus, the authors had occasion to convert I to the hitherto unknown pentacyclic deoxy compound 11. The isolation of an alkaloid, pericyclivine, identical to substance 11 from the leaves of C. lanceus, is now reported. Following the procedure utilized for C. roseus, the A fraction from C. lanceus leaf (100 Gm.) was chromatographed on alumina (partially deactivated, Alcoa F-20). After elution of perivine, leurosine, and yohimbine, crude pericyclivine was obtained from the chloroform-benzene(2 : 1) eluates. Two crystallizations from ethanol afforded 0.225 Gm. of pericyclivine (CsHpsNrO?), m.p. 232-233', monoclinic prisms with elongation parallel to the b axis, pK'a 6.75 (33% DMF), [α]ᵈ: +5.2 (c= 1.0, CHCls), which was shown to be identical to 11, prepared from perivine (I), by comparison of I.R. and NMR spectra and mixed melting points. An examination of the NMR spectrum of pericyclivine indicated that the ester function (CHs singlet 3.05 6) at C-16 was oriented toward the indole moiety as shown in IT. Treatment of the base with sodium methoxide in methanol resulted in epimerization of the estermethyl (3.78 6) to yield the known dehydroxymethyl akuammidine (IV). This represents the first example of an alkaloid in this series containing only an ester function at C-lG. The finding of this alkaloid, an obvious progeny of perivine, indicates that perivinol or its biosynthetic equivalent must exist in C. lanceus. It will be interesting to see if dimeric compounds containing perivine will eventually be discovered in this plant.