Characterization of chemical constituents with their antioxidant and anti-melanogenesis activities from the roots of Ampelopsis japonica

Three glycosylated stilbenes (1-3), two anthraquinones (4, 5), one lignan (6), five tannins (7-11), two amino acids (12, 13), and one auronol (14) were isolated from the root of Ampelopsis japonica. All compounds, except for 4, 6, and 11 were obtained from this species for the first time. Compounds 6-9 could notably inhibit ROS generations in HaCaT keratinocyte cells with IC50 values of 5.28, 4.83, 0.87, and 1.66 mu M, respectively. Compounds 8-10 showed potent DPPH free radical scavenging effects with IC50 values of 14.37, 16.08, and 12.11 mu M, individually. In anti-melanogenesis assay, only 8 and 9 could decrease 7.93% and 11.66% melanin contents induced by alpha-MSH in B16F10 melanoma cells at 40 mu M and moderately inhibit tyrosinase activities. By far, galloylhamameloses 8 and 9 were found to exhibit both antioxidant and anti-melanogenesis properties that could be further developed as cosmeceutical agents for skin disorders.