scholarly journals The Oxidation of Equol by Tyrosinase Produces a Unique Di-ortho-Quinone: Possible Implications for Melanocyte Toxicity

2021 ◽  
Vol 22 (17) ◽  
pp. 9145
Author(s):  
Hitomi Tanaka ◽  
Shosuke Ito ◽  
Makoto Ojika ◽  
Tomoko Nishimaki-Mogami ◽  
Kazunari Kondo ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Oxidation Product ◽  
Bovine Serum ◽  
Cellular Proteins ◽  
Cysteine Residues ◽  
Substituted Phenols ◽  
Catalyzed Oxidation ◽  
Human Tyrosinase

Equol (7-hydroxy-3-(4′-hydroxyphenyl)-chroman, EQ), one of the major intestinally derived metabolites of daidzein, the principal isoflavane found in soybeans and most soy foods, has recently attracted increased interest as a health-beneficial compound for estrogen-dependent diseases. However, based on its structure with two p-substituted phenols, this study aimed to examine whether EQ is a substrate for tyrosinase and whether it produces o-quinone metabolites that are highly cytotoxic to melanocyte. First, the tyrosinase-catalyzed oxidation of EQ was performed, which yielded three EQ-quinones. They were identified after being reduced to their corresponding catechols with NaBH4 or L-ascorbic acid. The binding of the EQ-quinones to N-acetyl-L-cysteine (NAC), glutathione (GSH), and bovine serum albumin via their cysteine residues was then examined. NAC and GSH afforded two mono-adducts and one di-adduct, which were identified by NMR and MS analysis. It was also found that EQ was oxidized to EQ-di-quinone in cells expressing human tyrosinase. Finally, it was confirmed that the EQ-oligomer, the EQ oxidation product, exerted potent pro-oxidant activity by oxidizing GSH to the oxidized GSSG and concomitantly producing H2O2. These results suggest that EQ-quinones could be cytotoxic to melanocytes due to their binding to cellular proteins.

scholarly journals INTERACTION OF RUTHENIUM COMPLEX WITH BOVINE SERUM ALBUMIN FOR AMPEROMETRIC DETECTION OF ASCORBIC ACID

Química Nova ◽  
2014 ◽  
Author(s):  
Ronnie Edson da Silva ◽  
Kalil Cristhian Figueiredo Toledo ◽  
Herculys Bernardo Jorge ◽  
Bento Moreira Neto ◽  
Vagner Roberto de Souza ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Ruthenium Complex ◽  
Amperometric Detection

scholarly journals Bovine serum albumin assisted preparation of ultra-stable gold nanoflowers and their selective Raman response to charged dyes

RSC Advances ◽  
2019 ◽  
Vol 9 (48) ◽  
pp. 28228-28233
Author(s):  
Xiaoyu Zhang ◽  
Yandong Han ◽  
Zihao Xing ◽  
Zhenzhen Huang ◽  
Renguo Xie ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
One Pot ◽  
Gold Precursor ◽  
Gold Nanoflowers ◽  
Raman Response

In this work, we demonstrated a facile, one-pot approach for preparation of gold nanoflowers by using tetrachloroauric acid as a gold precursor, ascorbic acid as a reductant, and bovine serum albumin (BSA) as a ligand.

scholarly journals Anti-aggregation effect of Ascorbic Acid and Quercetin on aggregated Bovine Serum Albumin Induced by Dithiothreitol: Comparison of Turbidity and Soluble Protein Fraction Methods

2020 ◽  
Vol 23 (4) ◽  
pp. 129-134
Author(s):  
Amat Rifai ◽  
Mukhammad Asy'ari ◽  
Agustina L. N. Aminin
Keyword(s):  
Ascorbic Acid ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Protein Aggregation ◽  
Soluble Protein ◽  
Bovine Serum ◽  
Disulfide Bonds ◽  
Protein Profile ◽  
Turbidity Method ◽  
Aggregation Activity

Studies on the anti-aggregation of dithiothreitol (DTT) induced - protein is generally determined by the fraction soluble (non-aggregated) protein. While the turbidity method is commonly used in studies of anti-aggregation, in which protein is induced by heat, in this study, both methods are compared in observing the anti-aggregation activity of ascorbic acid and quercetin toward bovine serum albumin induced by DTT. The DTT is a reducing agent for protein disulfide bonds and capable of inducing protein aggregation at physiological pH and temperature. The work was performed by the formation of Bovine Serum Albumin (BSA) aggregates induced by DTT under physiological conditions, which are pH 7.4 and 37°C. The aggregated protein profile was observed using the turbidity method at the end of incubation and measuring the difference of concentration between the fraction of soluble protein before and after incubation. The measurement was carried out using a spectrophotometer UV-Vis. The results indicate that both methods show similar inhibition profiles. The potential inhibition of ascorbic acid (AA) toward BSA protein aggregation induced by DTT increased along with incubation time. While quercetin shows the highest inhibition at 12 hours but decreased at 18 hours, this study reveals that both methods can observe the anti-aggregation activity of ascorbic acid and quercetin.

Binding of ascorbic acid and α-tocopherol to bovine serum albumin: a comparative study

2014 ◽  
Vol 10 (2) ◽  
pp. 326-337 ◽  
Author(s):  
Xiangrong Li ◽  
Gongke Wang ◽  
Dejun Chen ◽  
Yan Lu
Keyword(s):  
Ascorbic Acid ◽  
Bovine Serum Albumin ◽  
Comparative Study ◽  
Serum Albumin ◽  
Bovine Serum

scholarly journals Drug Interactions. I. Binding of Ascorbic Acid and Fatty Acid Ascorbyl Esters to Bovine Serum Albumin

1974 ◽  
Vol 22 (2) ◽  
pp. 385-389 ◽  
Author(s):  
TYOTARO TUKAMOTO ◽  
SHOJI OZEKI ◽  
FUJIO HATTORI ◽  
TAKASHI ISHIDA
Keyword(s):  
Ascorbic Acid ◽  
Fatty Acid ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Drug Interactions ◽  
Bovine Serum ◽  
Ascorbyl Esters

Improvement of an artificial test substrate technique for evaluation of em immunocytochemical labeling

1987 ◽  
Vol 45 ◽  
pp. 762-763
Author(s):  
G. D. Gagne ◽  
M. F. Miller
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Artificial Substrate ◽  
Chemical Fixation ◽  
As If

We recently described an artificial substrate system which could be used to optimize labeling parameters in EM immunocytochemistry (ICC). The system utilizes blocks of glutaraldehyde polymerized bovine serum albumin (BSA) into which an antigen is incorporated by a soaking procedure. The resulting antigen impregnated blocks can then be fixed and embedded as if they are pieces of tissue and the effects of fixation, embedding and other parameters on the ability of incorporated antigen to be immunocyto-chemically labeled can then be assessed. In developing this system further, we discovered that the BSA substrate can also be dried and then sectioned for immunolabeling with or without prior chemical fixation and without exposing the antigen to embedding reagents. The effects of fixation and embedding protocols can thus be evaluated separately.

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