scholarly journals THE RECENT UPDATE OF DEOXYARBUTIN: A SKIN DEPIGMENTATION AGENT WITH TYROSINASE INHIBITION TARGETING

2020 ◽  
pp. 1-7
Author(s):  
MUCHTARIDI MUCHTARIDI ◽  
MENTARI LUTHFIKA DEWI
Keyword(s):  
Kojic Acid ◽  
Enzyme Inhibitor ◽  
Clinical Manifestations ◽  
Tyrosinase Inhibitor ◽  
Tyrosinase Inhibition ◽  
Considerable Potential ◽  
Abnormal Accumulation ◽  
Tyrosinase Enzyme ◽  
The Stability ◽  
Further Development

Melanin is produced through the process of melanogenesis, which serves to protect the skin from the damaging effects of UV radiation. Abnormal accumulation of melanin will aesthetically disturb even interfere with health. One of the clinical manifestations of abnormal accumulation of melanin is the incidence of melasma. Some of the tyrosinase enzyme inhibitor agents most widely used as Hydroquinone, Kojic acid and Arbutin do not give satisfactory results and cause serious side effects. Hydroquinone is known to cause ochronosis exogenous and cytotoxic. Kojic acid is known to cause allergies and mutagenic, while arbutinisis is known to have cytotoxic properties lower than hydroquinone, but less satisfactory depigmentation activity. There was a compound that has been synthesized by removing the hydroxy group of arbutin, known as deoxyarbutin (4-[Tetrahydro-2H-Pyrans-2-yl) oxy] phenol). Deoxyarbutin (dA) shows Ki 10-fold is lower than hydroquinone and 350-fold is lower than arbutin. IC50dA is 17.5+0.5 µmol/l, while the IC50 hydroquinone is 73.7+9.1 µmol/l. In terms of security, dA indicates that cell viability is 95% higher than hydroquinone. However, dA is thermolabile and photolabile. Several studies have shown satisfactory results to improve the stability of dA, that these compounds are considerable potential for further development as a depigmentation agent. The aim of this review is to describe how the potency of dA as a tyrosinase inhibitor interferes melanogenesis process through the latest depigmentation agent, its safety, efficacy and stability.

scholarly journals FORMULATION, STABILTY TEST AND ENZYME ACTIVITY TEST TYROSINASE OF CREAM PEPARATIONS FROM HERENDONG FRUIT EXTRACT(Melastoma affine D. Don)

2020 ◽  
Vol 5 (2) ◽  
pp. 149-173
Author(s):  
Zuraida Sagala ◽  
Kurnia Telaumbanua
Keyword(s):  
Enzyme Inhibitors ◽  
Enzyme Inhibitor ◽  
Mechanical Test ◽  
Ethanol Extract ◽  
Activity Test ◽  
Irritation Test ◽  
Ic50 Values ◽  
Tyrosinase Enzyme ◽  
Ethanol Extracts ◽  
The Stability

One way to prevent or inhibit melanin formation is by inhibiting tyrosinase activity (Lloyd,2011). Tyrosinase enzyme is an enzyme that plays a role in the formation of skin pigments or known as melanogenesis. In the process of melanogenesis, the enzyme tyrosinase acts as a catalyst in two different reactions, namely the hydroxylation process of tyrosine to dihydroxy-phenylalanine (L-DOPA) and oxidation of L-DOPA to quinone DOPA. Tyrosinase in skin tissue is activated by solar UV radiation so that it accelerates the process of melanin production (Fais et al.  2009).  This  study  was  conducted  to  determine  the  stability,  effectiveness  of  cream preparations from ethanol extracts of Harendong fruit (Melastoma affine D. Don) as tyrosinase enzyme inhibitors so it can be used as a cosmetic ingredient for whitening or skin lightening. Results Cream with variants of Harendong (Melastoma affine D. Don) ethanol extract was physically stable and formulated with organoleptic test, homogeneity, viscosity, mechanical test, pH, cycling test, and irritation test. Type M / A cream preparations from ethanol extract of Harendong fruit (Melastoma affine D. Don) have a strong / moderate tyrosinase enzyme inhibitor activity with IC50 values of F1 (1%) of 526,192 ppm, F2 (1.5%) ) amounted to 317,534 ppm and F3  (2%)  amounted  to  128,523  ppm.  Keywords: Foemulation,  stability test, activity test, tyrosinase enzyme, herenong fruit (Melastoma affine G.Don)

scholarly journals Splash mask formulation of tangerine (Citrus reticulata Blanco.) peel extract and turmeric (Curcuma longa L) extract as a whitening agent

2020 ◽  
Vol 6 (3) ◽  
pp. 341
Author(s):  
Framesti Frisma Sriarumtias ◽  
Nurul Auliasari
Keyword(s):  
Kojic Acid ◽  
Curcuma Longa ◽  
Citrus Reticulata ◽  
Tyrosinase Inhibition ◽  
Elisa Method ◽  
Tropical Country ◽  
Citrus Reticulata Blanco ◽  
Whitening Agent ◽  
Tyrosinase Enzyme ◽  
Peel Extract

<p class="abstract"><strong>Background:</strong> Indonesia is a tropical country that is exposed to the sun for 12 hours, one of the harm effects of sunlight which is damage to the skin. The purpose of this study was to determine tyrosinase inhibition of tangerin peel extract (<em>Citrus reticulata Blanco</em>.) from Garut, West Java, Indonesia then develop the splash mask from the extract.</p><p class="abstract"><strong>Methods:</strong> The tangerine peel will be extracted by maceration method. The splash mask formulation containing tangerine peel extract which has a whitening agent. Tyrosinase inhibition determine by ELISA method with tyrosinase enzyme and L-DOPA substrat.<strong></strong></p><p class="abstract"><strong>Results:</strong> The results showed that tangerine peel extract had tyrosinase inhibition with the IC50 of 30.000 ppm, which has less effective than kojic acid with IC50 81,10 ppm. Splash mask containing of 1000x IC50, evaluation carried out for 28 days showed that preparations made pharmaceutically stable.</p><p class="abstract"><strong>Conclusions:</strong> In addition, the whitening agent of tangerine peel extract is in the weak category. It is hoped that this research can increase the value of tangerine peel waste.</p><p> </p>

scholarly journals Potent Microbial and Tyrosinase Inhibitors from Stem Bark of Bauhinia Rufescens (Fabaceae)

2013 ◽  
Vol 8 (10) ◽  
pp. 1934578X1300801 ◽  
Author(s):  
Aminu Muhammad ◽  
Hasnah Mohd Sirat
Keyword(s):  
Kojic Acid ◽  
Stem Bark ◽  
Positive Control ◽  
Inhibition Assay ◽  
Bacterial Strains ◽  
Tyrosinase Inhibition ◽  
Fungal Strains ◽  
Inhibition Concentration ◽  
Tyrosinase Enzyme ◽  
Antimicrobial Assay

The stem bark extracts of Bauhinia rufescens Lam. (Fabaceae) yielded 6-methoxy-7-methyl-8-hydroxydibenz[ b,f]oxepin, α-amyrin acetate, β-sitosterol 3- O-β-D-xylopyranoside, 4-(2′-Hydroxyphenethyl)-5-methoxy-2-methylphenol, menisdaurin and sequoyitol. Their structures were determined using spectroscopic methods and comparisons with the literature data. For the antimicrobial assay Gram-positive and Gram-negative bacterial and fungal strains were tested, while the tyrosinase inhibition assay utilized L-DOPA as a substrate for the tyrosinase enzyme. 6-Methoxy-7-methyl-8-hydroxydibenz[ b,f]oxepin, α-amyrin acetate, β-sitosterol 3- O-β-D-xylopyranoside, menisdaurin and sequoyitol showed weak to moderate activities with minimum inhibition concentration (MIC) values in the range of 112.5–900 μg/mL against all bacterial strains, while the MIC values for the fungal strains were in the range of 28.1–450 μg/mL. In the tyrosinase inhibition assay, α-amyrin acetate was found to be moderately active against tyrosinase with an inhibition of 62% at 0.1 mg/mL. This activity was lower than that of the positive control, kojic acid (85%).

scholarly journals Uji Aktivitas Ekstrak Daun Dan Akar Singawalang (Petiveria alliaceae) Terhadap Penghambatan Tirosinase

2021 ◽  
pp. 189
Author(s):  
Munawarohthus Sholikha ◽  
Nur M, R. ◽  
Nur M, R. ◽  
Mahfudza, A.R.
Keyword(s):  
Kojic Acid ◽  
Root Extract ◽  
Tyrosinase Inhibitor ◽  
Inhibition Activity ◽  
Tyrosinase Inhibition ◽  
Root Extracts ◽  
Activity Test ◽  
Petiveria Alliacea ◽  
Elisa Technique ◽  
Microplate Reader

Tyrosinase is an enzyme that plays a role in the formation of skin pigments from a person because it is involved in the process of melanogenesis. Tyrosinase plays a very important role in the skin depigmentation process, there are several attempts to inhibit the skin depigmentation process, one of which is by inhibiting tyrosinase. Research on the leaves and roots of singawalang (Petiveria alliacea) was conducted to determine the potential as a tyrosinase inhibitor. Leaves and root extracts of singawalang were macerated with ethanol, then tested for identification of secondary metabolites. Singawalang leaves extract contains alkaloids, tannins and terpenoids while singawalang root extract contains alkaloids, flavonoids, tannins and terpenoids. Tyrosinase inhibitory activity used the microplate reader ELISA technique at a wavelength of 492 nm. Tests were carried out on kojic acid as a comparison and L-DOPA as a substrate. The results of the tyrosinase inhibition activity test for the extracts of singawalang leaves, singawalang roots and kojic acid, IC50 were 9.817 mg / mL, 4.987 mg / mL and 0.092 mg / mL, respectively.

The stability of dislocation networks under various oxygen-doping conditions in superconducting Bi2Sr2CaCu2Oy single crystals and their influence on the flux pinning properties

1994 ◽  
Vol 52 ◽  
pp. 802-803
Author(s):  
Y. Feng ◽  
X. Y. Cai ◽  
R. J. Kelley ◽  
D. C. Larbalestier
Keyword(s):  
Single Crystals ◽  
Oxygen Content ◽  
Basal Plane ◽  
Flux Pinning ◽  
Pinning Centers ◽  
Before And After ◽  
Anomalous Peak ◽  
Basal Plane Dislocation ◽  
The Stability ◽  
Further Development

The issue of strong flux pinning is crucial to the further development of high critical current density Bi-Sr-Ca-Cu-O (BSCCO) superconductors in conductor-like applications, yet the pinning mechanisms are still much debated. Anomalous peaks in the M-H (magnetization vs. magnetic field) loops are commonly observed in Bi2Sr2CaCu2Oy (Bi-2212) single crystals. Oxygen vacancies may be effective flux pinning centers in BSCCO, as has been found in YBCO. However, it has also been proposed that basal-plane dislocation networks also act as effective pinning centers. Yang et al. proposed that the characteristic scale of the basal-plane dislocation networksmay strongly depend on oxygen content and the anomalous peak in the M-H loop at ˜20-30K may be due tothe flux pinning of decoupled two-dimensional pancake vortices by the dislocation networks. In light of this, we have performed an insitu observation on the dislocation networks precisely at the same region before and after annealing in air, vacuumand oxygen, in order to verify whether the dislocation networks change with varying oxygen content Inall cases, we have not found any noticeable changes in dislocation structure, regardless of the drastic changes in Tc and the anomalous magnetization. Therefore, it does not appear that the anomalous peak in the M-H loops is controlled by the basal-plane dislocation networks.

Synergistic Effects of Linderanolide B Combined with Arbutin, PTU or Kojic Acid on Tyrosinase Inhibition

2015 ◽  
Vol 16 (12) ◽  
pp. 1120-1126 ◽  
Author(s):  
You-Cheng Hseu ◽  
Kuo-Chen Cheng ◽  
Yi-Chieh Lin ◽  
Chung-Yi Chen ◽  
Hsin-Yu Chou ◽  
...  
Keyword(s):  
Kojic Acid ◽  
Synergistic Effects ◽  
Tyrosinase Inhibition

scholarly journals Enzyme-Site Blocking Combined with Optimization of Molecular Docking for Efficient Discovery of Potential Tyrosinase Specific Inhibitors from Puerariae lobatae Radix

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2612 ◽  
Author(s):  
Haichun Liu ◽  
Yitian Zhu ◽  
Ting Wang ◽  
Jin Qi ◽  
Xuming Liu
Keyword(s):  
Molecular Docking ◽  
Structural Modification ◽  
Enzyme Inhibitors ◽  
Kojic Acid ◽  
Systematic Evaluation ◽  
Tyrosinase Inhibition ◽  
Computational Docking ◽  
Site Blocking ◽  
Leading Compounds ◽  
Positive Results

Enzyme inhibitors from natural products are becoming an attractive target for drug discovery and development; however, separating enzyme inhibitors from natural-product extracts is highly complex. In this study, we developed a strategy based on tyrosinase-site blocking ultrafiltration integrated with HPLC-QTOF-MS/MS and optimized molecular docking to screen tyrosinase inhibitors from Puerariae lobatae Radix extract. Under optimized ultrafiltration parameters, we previously used kojic acid, a known tyrosinase inhibitor, to block the tyrosinase active site in order to eliminate false-positive results. Using this strategy, puerarin, mirificin, daidzin and genistinc were successfully identified as potential ligands, and after systematic evaluation by several docking programs, the rank of the identified compounds predicted by computational docking was puerarin > mirificin > kojic acid > daidzin ≈ genistin, which agreed with the results of tyrosinase-inhibition assays. Structure-activity relationships indicated that C-glycosides showed better tyrosinase inhibition as compared with O-glycosides, with reduced inhibition achieved through the addition of glycosyl, which provides ideas about the screen of leading compounds and structural modification.

Investigation of tyrosinase inhibition by some 1,2,4 triazole derivative compounds: in vitro and in silico mechanisms

2018 ◽  
Vol 44 (4) ◽  
pp. 473-481
Author(s):  
Elif Ayazoglu Demir ◽  
Ahmet Colak ◽  
Aylin Kalfa ◽  
Ahmet Yasar ◽  
Olcay Bekircan ◽  
...  
Keyword(s):  
Critical Role ◽  
Docking Studies ◽  
Biosynthesis Pathway ◽  
Mushroom Tyrosinase ◽  
Tyrosinase Inhibitor ◽  
Effective Inhibitor ◽  
Tyrosinase Inhibition ◽  
Triazole Derivative

Abstract Background Tyrosinase plays a central role in the biosynthesis pathway of melanin pigment. Melanin protects human skin against radiation and its unusual levels cause some skin disorders such as pregnancy scar, oldness spots and melanoma. Tyrosinase has also been linked to Parkinson’s and other neurodegenerative diseases. In addition, melanin plays a critical role as a defense molecule for insects during wound healing and is important for their life. Therefore, determination of inhibitor molecules for tyrosinase has a promising potential for therapies of some diseases and is an alternative method for keeping insects under control. Material and methods In this study, 1-hepthyl-3-(4-methoxybenzyl)-4H-1,2,4-triazole-5-one derivative (A6, A8, A15) and 3-(4-chlorophenyl)- 5-(4-methoxybenzyl)-4H-1,2,4-triazole (B5, B9, B13) derivative compounds were evaluated in terms of their potential for mushroom tyrosinase inhibition. IC50 values of these six molecules were determined. Results It was seen that B9 molecule was the most effective inhibitor. Docking studies also nearly supported this end result. Tyrosinase inhibition type and Ki value were found to be uncompetitive and 370.7±0.3 μM, respectively, in the presence of B9 compound. Conclusion These results suggest that B9 compound is a potential tyrosinase inhibitor.

scholarly journals Synthesis of Novel Compounds as New Potent Tyrosinase Inhibitors

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Hooshang Hamidian
Keyword(s):  
Kojic Acid ◽  
Azo Compounds ◽  
The Novel ◽  
Mushroom Tyrosinase ◽  
Reference Standard ◽  
Tyrosinase Inhibition ◽  
H Nmr ◽  
Ft Ir ◽  
Tyrosinase Inhibitors ◽  
C Nmr

In the present paper, we report the synthesis and pharmacological evaluation of a new series of azo compounds with different groups (1-naphthol, 2-naphthol, andN,N-dimethylaniline) and trifluoromethoxy and fluoro substituents in the scaffold. All synthesized compounds (5a–5f) showed the most potent mushroom tyrosinase inhibition (IC50values in the range of 4.39 ± 0.76–1.71 ± 0.49 µM), comparable to the kojic acid, as reference standard inhibitor. All the novel compounds were characterized by FT-IR,1H NMR,13C NMR, and elemental analysis.

Stability of the Professional Development Assessment

1997 ◽  
Vol 84 (3_suppl) ◽  
pp. 1373-1374
Author(s):  
Jack Kasar
Keyword(s):  
Professional Development ◽  
Occupational Therapy ◽  
Professional Behaviors ◽  
The Stability ◽  
Development Assessment ◽  
Further Development

The Professional Development Assessment was constructed and pilot-tested with 76 students in three occupational therapy programs. A comparison of pretest and posttest scores yielded a significant correlation of .48, supporting the stability of responding over 1 to 2 years and suggesting usefulness of further development for evaluation of professional behaviors in students.

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