Alkaloids of Corydalis incisa PERS. V. The Structures of Corydalispirone and Corydalisol

Abstract

Two new alkaloids, corydalispirone, C₂₀H₁₇O₆N, mp 196-198°, [α] D 0°, and corydalisol, C₂₀H₂₁O₅N, mp 160-161°, [α] D +21.4°, were isolated from Corydalis incisa PERS. (Papaveraceae). The structure of corydalispirone was established to be I by the spectroscopic examinations and chemical correlation with bicucullinediol and adlumidinediol, and the structure of corydalisol was determined as VIII by the conversion to d-tetra-hydrocoptisine. Corydalispirone and corydalisol are noted as a new series of isoquinoline-type alkaloids having one more carbon atom at the benzyl moiety, and probably are metabolites of coptisine.