Synthesis and biological evaluation of flavonol-glucose conjugates for cosmeceutical development

Quercetin and kaempferol, two well-known flavonols, were chemically conjugated with glucose to produce the corresponding flavonol glucosides, and the following biological activities were evaluated for cosmeceutical development: antioxidant activity, ability to increase collagen synthesis, and moisturizing activity. Among the synthetic flavonol glucosides, quercetin-3-O-β-D-glucoside significantly enhanced collagen synthesis (60 %) compared to quercetin. Kaempferol-3,7-di-O-β-D-glucoside showed promising skin-moisturizing effects, inducing a sixfold increase in the expression of aquaporin-3. Thus, both quercetin-3-O-β-D-glucoside and kaempferol-3,7-di-O-β-D-glucoside were shown to possess interesting biological activities which warrant their further development as cosmetic ingredients.