New synthetic method of 8-oxocoptisine starting from natural quaternary coptisine as anti-ulcerative colitis agent

Abstract

Quaternary coptisine (1), a natural bioactive quaternary protoberberine alkaloid (QPA), was treated with potassium ferricyanide in aqueous solution of 5 N sodium hydroxide leading to the acquisition of 8-oxocoptisine (2) with much higher yield than reported in the literature. This is the first report of the oxidation of a natural QPA by applying potassium ferricyanide as an oxidant. 8-Oxocoptisine showed significant anti-ulcerative colitis efficacy in vitro with EC₅₀ value being 8.12 × 10^− 8 M.

Keywords::

• 8-oxocoptisine
• quaternary coptisine
• potassium ferricyanide
• anti-ulcerative colitis

Acknowledgments

This work was financially supported by grants from National Science and Technology Project of China (No. 2011ZX09307-002-01) and National Natural Science Foundation of China (No. 81373269; 81202546).