OBJECTIVES In food industry, the inhibition of tyrosinase is very important, because this enzyme catalyzes the oxidation of phenolic compounds found in fruits and vegetables into quinones, which contribute in undesirable color and taste of fruits and vegetables. Teucrium polium L. var. gnaphalodes (Lamiaceae), a wild-growing flowering plant that has many applications in food preparations and tr...

For the first time in the present study the effects of vanillin, vanillyl alcohol, vanillic acid, as well as the newly synthesized vanillin derivative, bis-vanillin, were investigated on the oxidation of dopamine hydrochloride by mushroom tyrosinase. Among them, vanillin and bis-vanillin act as activators, while vanillyl alcohol and vanillic acid exhibited inhibitory effects, the IC50 values be...

The present work describes the synthesis of few hydroxylated amide derivatives as melanogenesis inhibitors. In vitro, in vivo and computational studies proved that compound 6d is a highly potent melanogenesis inhibitor compared to standard kojic acid. The title amides 4a-e and 6a-e were synthesized following simple reaction routes with excellent yields. Most of the synthesized compounds exhibit...

27 For screening of skin-whitening ingredients that modulate inhibition of melanogenesis, 28 tyrosinase promoter-based assay using a 3D spheroid culture technique is a beneficial tool to 29 improve the accuracy of raw material screening in cosmetics through mimicking of the in 30 vivo microenvironment. Although the advantages of high-throughput screening (HTS) are 31 widely known, there has bee...

Free radical scavenging and tyrosinase inhibition activity of thirteen aromatic oils from Thai medicinal plants were investigated. A stable free radical DPPH (1, 1-diphenyl-2-picryhydrazyl) was used in the free radical scavenging assay and mushroom tyrosinase enzyme was used in the tyrosinase inhibition test. The two assays were performed in 96-well plates and the absorbance measured by a well ...

Tyrosinase catalyzes two distinct sequential reactions in melanin biosynthesis: The hydroxylation of tyrosine to dihydroxyphenylalanine (DOPA) and the oxidation of DOPA to dopaquinone. Developing functional modulators of tyrosinase is important for therapeutic and cosmetic purposes. Given the abundance of thiourea moiety in known tyrosinase inhibitors, we studied other thiourea-containing drugs...

We investigated the kinetics of 4N-acetyl-pentapeptides, Ac-P1, Ac-P2, Ac-P3, and Ac-P4, regarding inhibition of mushroom tyrosinase activity. The peptides sequences of Ac-P1, Ac-P2, Ac-P3, and Ac-P4 were Ac-RSRFK, Ac-KSRFR, Ac-KSSFR, and Ac-RSRFS, respectively. The 4N-acetyl-pentapeptides were able to reduce the oxidation of l-DOPA by tyrosinase in a dose-dependent manner. Of the 4N-acetyl-pen...

Anisaldehyde characterized in the seeds of Pimpinella anisum L. (Umbelliferae), also known as aniseed, was found to inhibit the oxidation of L-3,4-dihydroxyphenylalanine (L-DOPA) by mushroom tyrosinase (EC 1.14.18.1) with an ID50 of 43 μg/mL (0.32 mM). The inhibition kinetics analyzed by a Lineweaver-Burk plot established anisaldehyde to be a noncompetitive inhibitor for this oxidation. On the ...

Marigold (Tagetes erecta L.) has long been used as a medicinal herb for a number of therapeutic activities. In the present study, the cytotoxicities of ethanol and ethyl acetate extracts of marigold flowers and their inhibitory effects on elastase and tyrosinase enzymes were investigated. An MTT assay was performed to measure the cytotoxicity of these two extracts on the H460 lung cancer and th...

The study was aimed at investigating the antimelanogenic and antioxidant properties of essential oil when extracted from the leaves of Artemisia argyi, then analyzing the chemical composition of the essential oil. The inhibitory effect of the essential oil on melanogenesis was evaluated by a mushroom tyrosinase activity assay and B16F10 melanoma cell model. The antioxidant capacity of the essen...