Enzymatic synthesis and spectroscopic characterization of 1,3‐divernoloyl glycerol fromVernonia galamensis seed oil

cis‐12,13‐Epoxy‐cis‐octadecenoic (vernolic) acid occurs in triglycerides of the seed oil ofVernonia galamensis. The seeds also contain a lipase capable of hydrolyzing the triglycerides. Previous investigators incubated the seed ofVernonia anthelmintica and isolated 5.6% yield of 1,3‐divernoloyl glycerol. We used crude lipase extract fromV. galamensis seed to synthesize 1,3‐divernoloyl glycerol from vernonia oil in pentane at 40% yield. A 94% conversion of the 1,3‐divernoloyl glycerol to pure vernolic acid (5.34% oxirane = 98.9% purity) was achieved by a low‐energy saponification process. The carbon‐13 nuclear magnetic resonance (NMR) spectrum of the 1,3‐divernoloyl glyceride indicates a potential for using carbon‐13 NMR spectroscopy in the identification of isomeric diglycerides. Thus the paper describes the synthesis, spectroscopic and chemical characterization of 1,3‐divernoloyl glycerol, in addition to providing quantitative carbon‐13 NMR studies ofV. galamensis oil.