Chemical Constituents and Tyrosinase Inhibitory Activity of Ethyl Acetate Extract of the Leaves of Morus alba L. from Vietnam

Abstract Four compounds (DB1–4) were isolated from the Mulberry leaves (Morus alba L.) collected in Thai Nguyen province by chromatographic methods. These compounds were identified as: Kaempferol-3-O-β-D-glucopyranoside (DB1), quercetin 3-O-α-L-rhamnopyranoside (DB2), isofraxidin-7-O-β -D-glucopyranoside (DB3), and (±) -3, 5, 6, 7, 8, 4’-hexahydroxyflavane (DB4). Their structures were elucidated by spectroscopic methods, including mass spectrometry (MS) and nuclear magnetic resonance (NMR). Compound DB4 was isolated from Mulberry leaves for the first time. Compound DB4 also showed potential tyrosinase inhibitory effects with IC50 values of 12.02 ± 2.63 μg/ml. Keywords: Morus alba L., tyrosinase inhibitors, kaempferol-3-O-β-D-glucopyranosid, quercetin 3-O-α-L-rhamnopyranoside, isofraxidin-7-O-β-D-glucopyranoside Cite this Article Duc LV, Thanh TB, Thu HLT. Chemical constituents and tyrosinase inhibitory activity of ethyl acetate extract of the leaves of Morus alba L. from Vietnam. Research & Reviews: A Journal of Pharmacology. 2018; 8(1): 21–26p.