Dynamic Analysis of Phorbol Esters in the Manufacturing Process of Fatty Acid Methyl Esters from <Emphasis Type="Italic">Jatropha curcas</Emphasis> Seed Oil

Jatropha curcas seed oil, which is unsuitable as an edible oil but has received attention as a novel vegetable fat and oil resource, contains tumor-promoting phorbol esters. Currently, six types of derivatives of 12-deoxy-16-hydroxyphorbol (DHPEs) in J. curcas oil have been identified, and their toxicological safety for humans is being discussed. However, it is reported that most DHPEs disappear during the transesterification process. We investigated the dynamics of phorbol esters in the manufacturing process of fatty acid methyl esters from J. curcas seed oil. With the assumption that the precursor ion was the fragment ion (m/z = 311) from the frame unit of phorbol esters and their derivatives, we developed an LC–MS method for detecting the product ion (m/z = 165), which was obtained by cleavage of the fragment ion. The derivatives generated from the structural changes of the phorbol esters existed in fractions of glycerine–water in the manufacturing process; however, phorbol esters and their derivatives were not detected in the fatty acid methyl esters that were produced via a high-vacuum distillation process. Investigation into the dynamics of phorbol esters confirmed that the contents of phorbol esters, including DHPEs, in the fatty acid methyl esters were under detection limits.