Evaluation of total antioxidant potential of Pistacia lentiscus var. chia leaves extracts using UHPLC–HRMS

• Drying affects the AAR and TPC of mastic tree leaves while results to higher TFC.
• MAE water extracts showed the highest yield for both fresh and freeze dried leaves.
• UAE water extracts showed the highest AAR, while SE water extracts the highest TPC.
• UAE ethanol extracts claim the highest TFC followed by SE ethanol extracts.
• UHPLC analysis showed that fresh mastic leave water extracts are rich in flavonoids.

In this study, Pistacia lentiscus var. chia leaves were dehydrated by freeze drying and the initial, final moisture content and the drying kinetics were examined. Soxhlet Extraction (SE), Microwave Assisted (MAE) and Ultrasound Assisted Extraction (UAE) were employed to recover extracts with high antioxidant activity, total phenolic and flavonoid content from fresh and dried leaves. Fresh leaves showed higher yield and antioxidant potential, with MAE extracts exhibiting the greatest extraction yield (48.11 ± 0.56% d.b.), followed by UAE (39.39 ± 1.13% d.b.) and SE (31.99 ± 1.55% d.b.). UAE extracts exhibited the highest antioxidant activity (IC50 = 37.13 ± 2.7 μg/mL), while SE extracts showed the highest total phenolic content (314.88 ± 0.01 mg GAE/g dry extract). UAE extracts of dried leaves exhibited total flavonoid content (106.5 ± 0.02 mg QE/g dry extract). Moreover, UHPLC-ESI–HMRS was performed to the extract with the highest antioxidant activity and confirmed the presence of isomers of galloyl quinic acid, quercetin and kaempferol glucosides, luteolin and neorehmannioside.