Pentacyclic triterpenic acids from Argania spinosa

Abstract

This work reports for the first time the presence of pentacyclic triterpenic acids in Argania spinosa. By solid/liquid extraction with absolute ethanol and GC-FID analysis, we report that ursolic acid is the major triterpene in the leaf and fruit of argan (0.10-0.44% DW), followed by significant amounts of oleanolic acid (0.05-0.19% DW). Their contents in the leaf were four times higher than in the fruit. Minor levels of betulinic and maslinic acids were also determined in the fruit pulp. Our results suggest that the developmental stage of the plant organ and the environmental conditions modulate the biosynthesis of triterpenic acids in argan. Advanced stages of ontogeny and severe climatic conditions induced a selective production of lupenyl and ursanyl structures. Argan fruits and leaves constitute interesting raw materials for the obtaining of ursolic and oleanolic acids that are strongly demanded by the functional food and pharmaceutical industries. The utilization of dry pulp of argan fruits, a by-product of the argan oil industry, for the obtaining of new triterpene-based formulations of high added value would increase the profitability of these crops and might help to guarantee the survival of the A. spinosa forests in the long term. Practical applications: Argan fruits and leaves constitute interesting raw materials for obtaining ursolic and oleanolic acids. Morocco accumulates every year more than 44500tons of dry fruit pulp as a by-product of the argan oil industry. The utilization of this biomass for the obtaining of bioactive compounds of high added value that could be used in the design of new functional food and drugs would help to increase the profitability of the argan crops and represent an intelligent manner of contributing to the A. spinosa survival. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.