Carotenoid isolated from Solanum dulcamara L., Lycopersicum esculentum Mill., Solanaceae; Tamus communis L., Dioscoreaceae. Isoln by chromatography and structure: Zechmeister, Cholnoky, Ber. 69, 422 (1936). Structure: Karrer et al., Helv. Chim. Acta 13, 268, 1084 (1930); 14, 614, 843 (1931); Winterstein, Angew. Chem. 72, 902 (1960). Revised structure: Cholnoky, Szabolcs, Tetrahedron Lett. 1968, 1931. Stereochemistry: Kelly et al., Acta Chem. Scand. 25, 1607 (1971). Total synthesis: Kjosen, Liaaen-jensen, ibid. 1500.