The present study was aimed to determine the phytochemicals constituents of Salix mucronata Thunb. leaf extracts and their antioxidant activities. Dried leaf powders were extracted with MeOH, MeOH (85%), MeOH (70%) and distilled water. The different extracts were monitored for phytochemical screening. Total phenolic and flavonoid contents were measured by Folin-Ciocalteu and aluminum chloride assays. The antioxidant potential of tested extracts was evaluated using DPPH, ABTS and total antioxidant capacity (TAC) assays. The results showed that, MeOH (85%) extract exhibited high total phenolic and flavonoid contents (TPC=131.39±2.49 mgGAE /g ext. and TFC= 67.69±1.47 mg RE /g ext.). Also, MeOH (85%) extract showed high antioxidant activities (DPPH SC50= 98.76±0.46 (µg/ml), ABTS= 45.83±0.32 mm Trolox® eq. /100 gm extract and TAC= 199.18±2.19 mg equivalent of ascorbic acid /g ext.). On other hand, EtOAc fraction derived from MeOH (85%) extract exhibited the highest antioxidant activity; DPPH SC50= 50.19±0.24 (µg/ml), ABTS= 76.22±1.61 (mm Trolox® eq. /100 gm ext.) and TAC= 249.86±3.74 (mg equivalent of ascorbic acid /g ext.). This study demonstrated that, S. mucronata leaf is a good source of natural antioxidants. Also, there is a high correlation between the total phenolic content and the antioxidant activity.
Key words: Salix mucronata, antioxidant, phytochemical screening, total phenolic and flavonoid contents.
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