Spirobenzylisoquinoline Alkaloids from Corydalis caucasica

Abstract

In continuing our studies on Corydalis Medik. (Papaveraceae, subfamily Fumarioideae) growing in Turkey, from which isoquinoline alkaloids have been isolated, we now report the isolation of (+)-fumaritine, (+)-fumariline, (+)-ochotensimine, (-)-corpaine and (±)-sibiricine as well as other isoquinoline alkaloids from Corydalis caucasica DC. The isolation of (+)-fumaritine represents is the first report of the naturally occurring enantiomer of the known (-)-fumaritine. The absolute configuration was established through a study of CD spectra. (+)-Fumaritine and (+)-fumariline are monooxygenated in ring C; while the known (-)-corpaine and (±)-sibiricine are dioxygenated. (+)-Fumariline, (-)-corpaine and (±)-sibiricine were further characterized their sodium borohydride reduction products.