CNS stimulant from roots and rhizome of Gelsemium sempervirens (L.) Ait., Loganiaceae. Isoln: Gerrard, Pharm. J. 13, 641 (1883); Moore, J. Chem. Soc. 97, 2223 (1910); 99, 1231 (1911); Sayre, Watson, J. Am. Pharm. Assoc. 8, 708 (1919); Chou, Chin. J. Physiol. 5, 131 (1931), C.A. 25, 40856 (1931); Schwarz, Marion, Can. J. Chem. 31, 958 (1953). Structure: Conroy, Chakrabarti, Tetrahedron Lett. 1959 (4), 6; Lovell et al., ibid. 1; Roe, Gates, Tetrahedron 11, 148 (1960). NMR spectroscopic study: Y. Schun, G. A. Cordell, J. Nat. Prod. 48, 969 (1985). Partial syntheses: W. E. Earley et al., Tetrahedron Lett. 29, 3781, 3785 (1988).