Phenanthroindolizidine alkaloid; isomeric with tylophorine, q.v. Isoln of l-isomer from Tylophora crebriflora S. T. Blake, Asclepiadaceae: E. Gellert et al., J. Chem. Soc. 1962, 1008; K. V. Rao et al., J. Pharm. Sci. 59, 1501 (1970). Antileukemic activity: E. Gellert, R. Rudzats, J. Med. Chem. 7, 361 (1964). d-Isomer isolated from Ficus septica, Moraceae. Synthesis of the dl-form and structure: E. Gellert et al., loc. cit.; B. Chauncy, E. Gellert, Aust. J. Chem. 23, 2503 (1970). Inhibits protein synthesis: G. R. Donaldson et al., Biochem. Biophys. Res. Commun. 31, 104 (1968); E. Battaner, D. Vasquez, Biochim. Biophys. Acta 254, 316 (1971). Mode of action studies: M. T. Huang, A. P. Grollman, Mol. Pharmacol. 8, 538 (1972). Review: R. S. Gupta, Antibiotics 6, 47 (1983).