Qualitative and quantitative analyses of phenolic compounds by HPLC–DAD–ESI/MS in Tunisian Pistacia vera L. Leaves unveiled a rich source of phenolic compounds with a significant antioxidant potential

The phenolic profile of 11 varieties (male and female) of Tunisian pistachio (Pistacia vera L.) leaves were investigated using HPLC–DAD–ESI/MS. Thirty-six phenolic compounds were identified, belonging to proanthocyanidins, flavonols O-glycosides, and galloyl derivatives, some of these compounds were identified for the first time in P. vera L. Leaves. The leaves are good sources of phenolic compounds, flavonols group was the most abundant in the studied analyze, accounting for 65–74% of the total phenolic compounds. Leaves from Mateur’s variety from El Guettar–Gafsa region were the one that showed the highest concentration of these group compounds as well as for total phenolic compounds. Galloyl derivatives were represented for 16–29% of the total, except for the male Sfaxian variety that presented the highest concentration (10.58 mg/g). The results showed that discriminant analysis applied to the phenolic compounds concentration data differentiates mainly the sex of the varieties and the geographical origin of P. vera leaves. Pistachio leaves samples were grouped by discriminant analysis into three groups depending on the sex varieties and geographical origin. The extract of pistachio leaves also showed substantial antioxidant activity, which can be attributed to their phenolic contents. These results support that Pistachio leaves could be exploited to obtain a promising source of new promising bioactive compounds.