CHEMICAL CONSTITUENTS AND ANTIOXIDANT ACTIVITY OF Salix tetrasperma ROXB

Résumé

Six (1-6) and two (7-8) compounds were obtained from ethyl acetate extract of S. tetrasperma Roxb bark and leaves,
respectively. Structures of isolated compounds were determined by spectroscopic data, including 1H NMR, 13C
NMR, and two dimensional NMR as β-sitosterol glucoside (1), 3,4-dihydroxybenzoic acid (2), 2-
(hydroxymethyl)phenol (3), 1,3-dihydroxyphenol (4), 3-(hydroxymethyl)phenol (5), 4-methylbenzaldehyde (6), 1,2-
dihydroxybenzene (7) and 3’,4’,5,7-tetrahydroxyflavone (8). Interestingly, compounds 2, 4, 5, 6, and 8 were
reported for the first time isolated from this plant. The antioxidant activities of all crude extracts were evaluated by
the diphenylpicrilhydrazyl (DPPH) method. Among all extracts, methanol extract of the bark has the highest
antioxidant activity with an IC50 value of 6.85 μg/mL. The activity of ethyl acetate extract of the root (IC50 19.53
μg/mL) was stronger than the bark (IC50 22.69 μg/mL).