BACKGROUND Hyperpigmentary disorders like melasma, actinic and senile lentigines are a major cosmetic concern. Therefore, many topical products are available, containing various active ingredients aiming to reduce melanin production and distribution. The most prominent target for inhibitors of hyperpigmentation is tyrosinase, the key regulator of melanin production. Many inhibitors of tyrosinas...

N-(3,5-Dihydroxybenzoyl)-6-hydroxytryptamine (2) was a novel inhibitor of L-3,4-dihydroxyphenylalanine (DOPA) oxidase activity of human HMV-II melanoma tyrosinase. The IC₅₀ values for 2 and three reference compounds, N-(3,5-dihydroxybenzoyl)serotonin, 6-hydroxyindole, and kojic acid, were 9.1, 842, 22, and 310 µM, respectively, indicating that the 6-hydroxyindole moiety was more effective than ...

In the present study, new Schiff's base derivatives: (Z)-4-amino-5-(2-(3- fluorobenzylidene)hydrazinyl)-4H-1,2,4-triazole-3-thiol (Y1), (Z)-3-((2-(4-amino-5- mercapto-4H-1,2,4-triazol-3-yl)hydrazono)methyl)phenol (Y2), (Z)-2-((2-(4-amino-5- mercapto-4H-1,2,4-triazol-3-yl)hydrazono)methyl)phenol (Y3) and 3-((Z)-(2-(4- (((E)-3-hydroxybenzylidene)amino)-5-mercapto-4H-1,2,4-triazol-3-yl)hydrazono)m...

In this study, total phenols (TP) and proanthocyanidins (PAs) in the leaves branches of Cinnamomum camphora were investigated, isolated PAs determined using reversed-phase high performance liquid chromatography electrospray ionization mass spectrometry (HPLC-ESI-MS). The anti-tyrosinase antioxidant activities also evaluated. Furthermore, scanning study dihydroxyphenylalanine (L-DOPA) oxidation ...

Because tyrosinase catalyzes melanin synthesis, tyrosinase inhibitors are important in cosmetic skin-whitening. Oxidative stress contributes to skin aging and can adversely affect skin health, which means antioxidants active in skin cells may support skin health. We examined 25 traditional Chinese herbal medicines that might be useful for skin-whitening and skin health. Extracts (100microg/mL) ...

Introduction Melanin is a dark pigment produced by about 10% of skin cells in the innermost layer of the epidermis (1). This compound is a heteropolymer of indole derivatives and is produced inside melanosomes through a series of oxidative reactions involving the amino acid tyrosine in the presence of the enzyme tyrosinase (Fig. 1). The type and amount of produced melanin in the melanosomes gen...