Pyrrolizidine alkaloids. Biosynthesis of trichodesmic acid

Abstract

¹⁴ C-Labelled threonine (3), isoleucine (4), valine (5), and leucine (6) were incorporated specifically into trichodesmic acid (12), the necic acid component of the pyrrolizidine alkaloid trichodesmine (2) produced by Crotalaria globifera. Degradation of the ⁴C-labelled trichodesmic acid showed that threonine and isoleucine mainly label one half of the C₁₀ acid, while valine and leucine predominantly label the other half of the acid.