Maslinic acid (2-α,3-β-dihydroxyolean-12-en-28-oic acid) is a pentacyclic triterpene abundant in the cuticular lipid layer of olive fruits (Bianchi et al.，1994) .It is a compound of 30 carbon atoms grouped in five cycles that have several substitutes. Maslinic acid presents two hydroxyl groups bound to carbons 2 and 3,one carboxyl group bound to carbon 17, and a double bond between carbons 12 and 13.It is a highly hydrophobic compound of low water solubility. Maslinic acid is synthesized in plants via the cytoplasmic acetate/mevalonate pathway that leads to oxidosqualene (Seo et al., 1988).Oxidosqualene is cycled by various oxidosqualene cyclases, among them β-amyrin synthase, which catalyzes the transformation of oxydosqualene into β-amyrin (olean-12-3n-3β-ol). Afterwards,β-amyrin is converted by successive reactions into erythrodiol, oleanolic acid, and finally maslinic acid (Saimaru et al.,2007; Stiti et al.,2007).