Biosynthesis of Corydaline and of Ochotensimine

Abstract

Radioactivity from [3- 14 C]tyrosine and from [methyl- 14 C]methionine is incorporated nonrandomly into predicted positions of corydaline and ochotensimine in Corydalissolida and C. ochotensis, respectively. The methyl group of methionine supplies the C-methyl group of corydaline and the exocyclic methylene group of ochotensimine, as well as the "bridge" carbon atom and the exocyclic O- and N-attached one-carbon units of each alkaloid. Maintenance of the 3 H/ 14 C ratio of [methyl- 3 H, 14 C]methionine within these units of corydaline is consistent with incorporation of intact CH 3 groups.Partial loss of 3 H relative to 14 C is observed in the course of a Schmidt reaction of [2- 3 H, 2- 14 C] acetate.