Antamanide Analogs as Potential Inhibitors of Tyrosinase

Abstract

The tyrosinase enzyme, which catalyzes the hydroxylation of monophenols and the oxidation of o-diphenols, is typically involved in the synthesis of the dark product melanin starting from the amino acid tyrosine. Contributing to the browning of plant and fruit tissues and to the hyperpigmentation of the skin, leading to melasma or age spots, the research of possible tyrosinase inhibitors has attracted much interest in agri-food, cosmetic, and medicinal industries. In this study, we analyzed the capability of antamanide, a mushroom bioactive cyclic decapeptide, and some of its glycine derivatives, compared to that of pseudostellarin A, a known tyrosinase inhibitor, to hinder tyrosinase activity by using a spectrophotometric method. Additionally, computational docking studies were performed in order to elucidate the interactions occurring with the tyrosinase catalytic site. Our results show that antamanide did not exert any inhibitory activity. On the contrary, the three glycine derivatives AG9, AG6, and AOG9, which differ from each other by the position of a glycine that substitutes phenylalanine in the parent molecule, improving water solubility and flexibility, showed tyrosinase inhibition by spectrophotometric assays. Analytical data were confirmed by computational studies.

Synthesis, anti-browning effect and mechanism research of kojic acid-coumarin derivatives as anti-tyrosinase inhibitors

“…Using l -DOPA as the substrate and phosphate buffer solution as the blank control, the activity of TYR was determined using an ultraviolet spectrophotometer (UV-2401PC) ( Honisch et al, 2022 ). The substrate l -DOPA (0.5 mM) and TYR solution (200 U/mL) were prepared with phosphate buffer solution (PBS), and the solution of tested compounds or KA was prepared by dissolved in DMSO and diluted with PBS (the final concentration of DMSO < 0.1 %).…”

Targeting the vital non-structural proteins (NSP12, NSP7, NSP8 and NSP3) from SARS-CoV-2 and inhibition of RNA polymerase by natural bioactive compound naringenin as a promising drug candidate against COVID-19

“…The obtained data from the dlg file was analyzed [58] . The estimated inhibition constant (Ki ex ) is Computed by the equation [59] . …”

“…ΔGex is a semiempirical free energy approximation (derived from molecular mechanics and experimental parameters), R is 1.98719 cal.K −1 .mol −1 , and T is 298.15 K [59] . Discovery Studio Visualizer software was used to specify the number of hydrophobic and hydrogen bonds between the receptors with each ligand.…”

Friedel–Crafts reactions for biomolecular chemistry

“…Since the adhesive properties are effective even under underwater conditions, synthetic glues often rely on DOPA compositions as a bioinspired material. 127,128 Simply speaking, although direct hydroxylation/oxidation of tyrosine amino acid would provide DOPA by formally inserting an oxygen atom into the C-H bond, phenol derivatives tend to undergo the formation of various oxidation products including ortho-benzoquinone unless there is an enzymatic control of reactions, 129 representing a synthetic challenge of DOPA. An approach originally reported by Boger and co-workers was a selective acetylation reaction toward the aromatic ring of the tyrosine starting material using excess AlCl 3 at 100 °C (Scheme 8D and Fig.…”