Indole alkaloid from Vinca rosea Linn., Apocynaceae: G. Svoboda, J. Am. Pharm. Assoc. 47, 834 (1958); G. Svoboda et al., ibid. 48, 659 (1959). Structure: Gorman, Sweeny, Tetrahedron Lett. 1964, 3105. Cytotoxicity: D. G. I. Kingston, J. Pharm. Sci. 67, 272 (1978).