Two new ester alkaloids and the alkamines, germine and zygadenine, have been isolated from Zygadenus venenosus. Veratroylzygadenine, C₃₈H₅₁O₁₀N, is a veratric acid ester of zygadenine. Vanilloylzygadenine, C₃₅H₄₉O₁₀N, is a vanillic acid ester of zygadenine. Alkaline hydrolysis of the esters under drastic conditions leads to the formation of an isomer of zygadenine, pseudozygadenine, and treatment of zygadenine under the same conditions also yields pseudozygadenine. The ester alkaloids possess pharmacological activity resembling that of the known veratrum ester alkaloid, veratridine.