From the dry mycelia of Aspergillus echinulatus: Quilico, Panizzi, Ber. 76, 348 (1943). Structure: Casnati et al., Gazz. Chim. Ital. 92, 105 (1962); Romanet et al., Bull. Soc. Chim. Fr. 1963, 1048. Absolute configuration: Nakashima, Slater, Tetrahedron Lett. 1967, 4433; 1971, 2649. Synthetic studies: Houghton, Saxton, J. Chem. Soc. C 1969, 595, 1003; Takamatsu et al., Tetrahedron Lett. 1971, 4661. Total synthesis of optically active cis isomer: eidem, ibid. 4665; S. Inoue et al., J. Pharm. Soc. Jpn. 97, 558 (1977). Epimerization of echinuline with triethylamine in ethanol gives the trans isomer, epi-echinuline, Westley et al., Anal. Chem. 40, 1888 (1968).