Melanogenic acceleratory effect of Helminthostachys zeylanica root extract was examined using murine B16 melanoma cells and the potent active compounds
were identified. Two quercetin glycosides namely 4'-O-β-D-glucopyranosyl-quercetin-3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranoside 3, 4'-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-quercetin-3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranoside, and three ugonins, ugonin J, K, and
L were isolated from H. zeylanica root extract by a series of chromatography. In order to elucidate the correlation
of structure activity, ten quercetin glycosides included 3 and three quercetin derivatives were synthesized using rutin as a starting material.
The identification of isolated compounds from H. zeylanica root extract and the synthesized quercetin glycosides were confirmed by NMR, MALDI
or UPLC-TOFMS, IR, UV spectrum, and specific optical rotation. Among the quercetin
glycosides, quercetin-3-O-β-D-glucopyranoside1, quercetin-3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranoside 2, and 3 showed intracellular melanogenesis acceleratory activity and 3-O-methylquercetin showed
extracellular melanogenesis acceleratory activity in a dose dependent manner. These
compounds showed no effect for the mushroom tyrosinase activity which catalyzes the
rate limiting reaction of melanogenesis. Therefore they may have an effect on a gene
expression relating to melanogenesis in melanoma cells.
