Tyrosinase-catalyzed hydroxylation of hydroquinone, a depigmenting agent, to hydroxyhydroquinone: A kinetic study

García-Molina, Maria del Mar; Muñoz, José Santiago Álvarez; Martı́nez-Ortiz, Francisco; Martínez, José Rodríguez; Garcı́a-Ruiz, Pedro Antonio; Rodrı́guez-López, José Neptuno; Garcı́a-Cánovas, Francisco

doi:10.1016/j.bmc.2014.04.048

Cited by 32 publications

(31 citation statements)

References 38 publications

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“…and Supporting Information Fig. 1SI suggests that this compound is another alternative substrate of tyrosinase , rather than inhibitor or inactivator. It was therefore decided to test the possible activity of tyrosinase on BR.…”

Section: Resultsmentioning

confidence: 96%

4-n-butylresorcinol, a depigmenting agent used in cosmetics, reacts with tyrosinase

et al. 2016

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4-n-Butylresorcinol (BR) is considered the most potent inhibitor of tyrosinase, which is why it is used in cosmetics as a depigmenting agent. However, this work demonstrates that BR is a substrate of this enzyme. The E m (met-tyrosinase) form is not active on BR, but E ox (oxy-tyrosinase) can act on this molecule, hydroxylating it to o-diphenol. In turn, this is oxidized to an oquinone, which isomerizes to a red p-quinone. Thus, for tyrosinase to act on this compound, a mechanism to generate E ox in the medium is required, which can be achieved by means of hydrogen peroxide or ascorbic acid. A kinetic analysis of the proposed mechanism allows its kinetic characterization: catalytic constant k BR cat (8.49 6 0.20 s 21 ) and Michaelis-constant K BR M (60.26 6 8.76 lM). These findings are compared with those for other monophenolic substrates of tyrosinase. Studies of BR docking to the E m form of the enzyme show that the hydroxyl group in C-1 position is oriented toward the copper atom A (CuA), as in it is L-tyrosine. As regards E ox , BR is oriented with the carbon in C-6 position ready to be hydroxylated. The reaction of BR originates o-quinones, which isomerize to p-quinones, which in turn, could react with thiol compounds, a finding that could have important implications for pharmacology and the cosmetic industry. , initial p-quinone formation rate; V p2Q max , maximum action rate of tyrosinase on 4-n-butylresorcinol

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Section: Resultsmentioning

confidence: 96%

4-n-butylresorcinol, a depigmenting agent used in cosmetics, reacts with tyrosinase

et al. 2016

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“…In a similar way, in treatments with rhododendrol it has been described that the o -quinones produced from this compound by the action of tyrosinase, affect the redox balance of the cell [17,19]. The action of tyrosinase on hydroquinone has been characterized kinetically recently [13,20]. …”

Section: Introductionmentioning

confidence: 99%

Action of tyrosinase on alpha and beta-arbutin: A kinetic study

et al. 2017

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The known derivatives from hydroquinone, α and β-arbutin, are used as depigmenting agents. In this work, we demonstrate that the oxy form of tyrosinase (oxytyrosinase) hydroxylates α and β-arbutin in ortho position of the phenolic hydroxyl group, giving rise to a complex formed by met-tyrosinase with the hydroxylated α or β-arbutin. This complex could evolve in two ways: by oxidizing the originated o-diphenol to o-quinone and deoxy-tyrosinase, or by delivering the o-diphenol and met-tyrosinase to the medium, which would produce the self-activation of the system. Note that the quinones generated in both cases are unstable, so the catalysis cannot be studied quantitatively. However, if 3-methyl-2-benzothiazolinone hydrazone hydrochloride hydrate is used, the o-quinone is attacked, so that it becomes an adduct, which can be oxidized by another molecule of o-quinone, generating o-diphenol in the medium. In this way, the system reaches the steady state and originates a chromophore, which, in turn, has a high absorptivity in the visible spectrum. This reaction allowed us to characterize α and β-arbutin kinetically as substrates of tyrosinase for the first time, obtaining a Michaelis constant values of 6.5 ± 0.58 mM and 3 ± 0.19 mM, respectively. The data agree with those from docking studies that showed that the enzyme has a higher affinity for β-arbutin. Moreover, the catalytic constants obtained by the kinetic studies (catalytic constant = 4.43 ± 0.33 s-1 and 3.7 ± 0.29 s-1 for α and β-arbutin respectively) agree with our forecast based on 13 C NMR considerations. This kinetic characterization of α and β-arbutin as substrates of tyrosinase should be taken into account to explain possible adverse effects of these compounds.

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“…Hydroquinone (HQ) is a pharmaceutical compound used not only as a skin-whitening agent, but also to condense tyrosinase in the generation mechanism of melanin [1,2]. Hydroquinone can prevent tyrosine, dopa, and dopaquinone after a series of reaction of melanin and may achieve the whitening effect.…”

Section: Introductionmentioning

confidence: 99%

Formulation and Characterization of Hydroquinone Nanostructured Lipid Carriers by Homogenization Emulsification Method

Lin

Kuo

et al. 2017

Journal of Nanomaterials

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Nanostructured lipid carrier (NLC) was prepared by homogenization emulsification method and improved with modified surfactants. The properties of nanoparticles were investigated using the NLC system for hydroquinone (HQ) as a model drug and by increasing the light stability of hydroquinone. The optimized condition of NLC in stirring was 1200 rpm, the homogenized speed was 8000 rpm, solid oil to liquid oil ratio was 3 : 7, and lecithin to surfactant ratio was 3 : 1. The particle size was 393.30 ± 28.23 nm and the encapsulation efficiency was 22.13 ± 2.66%. The zeta-potential of HQ-NLC was better than −30 mV. In the thermogravimetric analysis (TGA) studies, adding of PLANTACARE 2000 UP for HQ-NLC has better heat resisting property than the HQ-NLC only. The addition of PLANTACARE 2000 UP to NLC shows better permeability (125.10%) than that of Blank. In the stability studies, the HQ-NLC after UVA/UVB irradiation has better inhibition rate (34.25%) than that of the Blank. In the present study, NLC system has successfully improved the light stability and the skin permeability of active compound. Therefore, the NLC might be a potential delivery vehicle for transdermal products in the future.

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Tyrosinase-catalyzed hydroxylation of hydroquinone, a depigmenting agent, to hydroxyhydroquinone: A kinetic study

Cited by 32 publications

References 38 publications

4-n-butylresorcinol, a depigmenting agent used in cosmetics, reacts with tyrosinase

4-n-butylresorcinol, a depigmenting agent used in cosmetics, reacts with tyrosinase

Action of tyrosinase on alpha and beta-arbutin: A kinetic study

Formulation and Characterization of Hydroquinone Nanostructured Lipid Carriers by Homogenization Emulsification Method

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