Two New Chalcone Glycoside Compounds from Viburnum lantana (Family Caprifoliaceae) and Antioxidant Activity of its Hydroalcoholic Extract

In the present study, two novel chalcone glycosides, trans-3-ethoxy-4-O-(glucopyranoside) -2', 3', 4', 5', 6' -pentahydroxy chalcone (compound 1) and trans-3-methoxy-4-O-(glucopyranoside) -2', 3', 4', 5', 6' -pentahydroxy chalcone (compound 2) have been isolated from the leaves of Viburnum lantana L. The structures were elucidated by using 1H-NMR, 13C-NMR, 2D-NMR such as HMQC, HMBC and NOE experiments and UV-Vis, MS and IR spectra. The antioxidant property of hydroalcoholic extract was evaluated by DPPH style. The results revealed that the leave extract possesses significant antioxidant activity (IC50 = 52 µg/mL). This study indicates that hydroalcoholic extract of the leaves from this species is an important source of chalcone and flavonoid derivatives, as well as of useful natural antioxidants. These chalcone glycoside compounds were isolated for the first time from V. lantana leaves.