Pistacia lentiscusby-product as a promising source of phenolic compounds and carotenoids: Purification, biological potential and binding properties

Abstract The hydro-distilled leaves of Pistacia lentiscus are considered as an agricultural residue and of no commercial value yet. In this study, chromatographic purification of a methanolic fraction of Pistacia lentiscus L. (lentisk) distilled leaves yielded pure compounds, including Quercitrin (QUE) and Loliolid (LOL) which are characterized, for the first time, in the lentisk leaves’ residue. The inhibitory potential of QUE and LOL was investigated against tyrosinase and acetylcholinesterase activities using enzymatic assays and lysozyme fibrillation through Thioflavin-T fluorescence assay. Their binding mode to Bovine Serum Albumin (BSA) was also assessed by several spectroscopic analyses. Results show that QUE was more potent to inhibit enzyme activity than LOL. Besides, the Thioflavin-T assay confirmed that only QUE was able to block the fibril formation at a concentration of 25 µg/mL. Furthermore, the BSA quenching mechanism by QUE and LOL is a static process with conformational changes in BSA. Interestingly, our findings may provide novel insights into the potentiality of lentisk to be used as a bioresource for the generation of Quercitrin and Loliolid which can be commercially exploited in the field of cosmeceuticals and nutraceuticals.