DISTRIBUTION OF Ω-1-METHYL- FATTY ACIDS REGARDING TO CAPSAICINOIDS CONTENT IN FRUITS AND PLANTS OF CAPSICUM

Abstract

Capsaicinoids, the pungent compounds of Capsicum (Chili) fruits, are amides of vanillylamine with ω-1-methyl-fatty acids of nine to eleven carbons. Isotopic studies have revealed that vanillylamine come from phenylalanine via the phenylpropanoid pathway, while the ω-1-methyl-fatty acids come from valine or leucine via isobutyrate or isovalerate, but the intermediate biochemical steps of the biosynthesis of these fatty acids are still obscure. Furthermore, there is no clear experimental evidence for the presence of these ω-1-methylated fatty acids precursors of capsaicinoids in fruits or other tissues of Capsicum plants. The objective of this study was to investigate by HPLC and GC/MS the presence and distribution of these branched fatty acids in fruits and biomass of cell cultures from several species of Capsicum in relation to the content of capsaicinoids. Capsaicinoids were detected exclusively in placental tissue and in biomass of cell suspension cultures. Its content regarding to the ripening stage of the fruits showed a typical growth pattern, reaching a stationary phase of accumulation during its transition from green to the final color, characteristic of each species. Interestingly, ω-1-methylated fatty acids were positively detected in tiny amounts in the placental tissue, but also in other parts of the fruit, and putatively in leaves adjacent to the peduncle of fruits