UNCARIAGAMBIRIINES B AND C, ALKALOID-CATECHIN HYBRIDS FROM UNCARIA GAMBIR LEAVES

摘要

Gambiers, aqueous extracts from the leaves and twigs of Uncaria gambir, are used medicinally in Asian countries. Previously, we reported the isolation of uncariagambiriine (1) from U. gambir leaves, and its unique structure regarded as a catechin-alkaloid hybrid. Our continuing studies led to the isolation of two previously undescribed compounds named uncariagambiriines B (2) and C (3), in addition to the flavonoid glycosides, hyperoside and isoquercitrin. The structures of 2 and 3, isomeric to 1, were elucidated based on their spectral data.