Origin of the Methylenedioxy Groups of the Alkaloid Protopine

Abstract

THERE is a rapidly increasing body of evidence in the literature that all biological methylation processes, as well as many other ‘single-carbon’ biological syntheses, have a common pattern. It has been shown that the N-methyl groups of the alkaloids hordenine^1,2 and nicotine³, and the N- and O-methyl groups of the alkaloid ricinine⁴, have the same origin as the labile methyl groups in animal metabolism. Similarly, the O-methyl groups of barley lignin have been shown to fit this same pattern⁵. We have recently extended these observations to the methylenedioxy and N-methyl groups of the alkaloid protopine.