(+/-)-heterocarpine, a hydroxymethylated isoquinoline alkaloid from Ceratocapnos heterocarpa

Heterocarpine, a novel alkaloid from Ceratocapnos heterocarpa, has been cha racterised as (+/-)-1-hydroxymethyl-2-(3-hydroxy-4-methoxybenzyl)-7-hydroxy -6-methoxy-1,2,3,4-tetrahydroisoquinoline. The alkaloid was synthesized fro m the corresponding 3,4-dihydro isoquinoliniun salt. A key step in the proc ess is the acid resin catalysed methanolysis of the l-carbamoyl isoquinolin e. The structural correlation of the hydroxymethylated alkaloids heterocarp ine and malacitanine with their unsubstituted counterparts capnosine and ca seamine, also present in the plant, might be of biosynthetic significance. (C) 1998 Elsevier Science Ltd. All rights reserved.