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Oxidation and degradation of (epi)gallocatechin gallate (EGCG/GCG) and (epi)catechin gallate (ECG/CG) in alkali solution. Food Chem 2023; 408:134815. [PMID: 36549155 DOI: 10.1016/j.foodchem.2022.134815] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 10/16/2022] [Accepted: 10/28/2022] [Indexed: 11/11/2022]
Abstract
The oxidative decomposition/degradation of two main tea flavanols, EGCG/GCG and ECG/CG, was studied in alkaline solution under ultrasonic-assisted thermal conditions. The study employed HPLC-ESI-ToF-MS to identify the products generated by atmospheric oxygen oxidation and various base-catalyzed reactions. Strong basic condition led to accelerated hydrolysis and oxidation of EGCG/GCG and ECG/CG and yielded gallic acid, de-galloyl flavanols and corresponding o-quinone derivatives. Meanwhile, peroxidation or base-catalyzed cleavage and rearrangement occurred extensively on C- and B-rings of flavanol and generated various simpler aldehydes or acids. Besides, a number of dimers/trimers were produced. This contribution provides empirical proof of oxidative degradation of flavanols under strong alkaline condition. Meanwhile, detailed reaction mechanisms of C-/B-ring degradation and dimerization/polymerization phenomena are proposed to help understand the structural changes of flavanols under strong alkaline conditions.
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Alotaibi B, El-Masry TA, Elekhnawy E, El-Kadem AH, Saleh A, Negm WA, Abdelkader DH. Aqueous core epigallocatechin gallate PLGA nanocapsules: characterization, antibacterial activity against uropathogens, and in vivo reno-protective effect in cisplatin induced nephrotoxicity. Drug Deliv 2022; 29:1848-1862. [PMID: 35708451 PMCID: PMC9225707 DOI: 10.1080/10717544.2022.2083725] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 05/17/2022] [Accepted: 05/23/2022] [Indexed: 12/17/2022] Open
Abstract
Epigallocatechin-3-gallate (EGCG) was isolated from Cycas thouarsii leaves for the first time and encapsulated in aqueous core poly(lactide-co-glycolide) (PLGA) nanocapsules (NCs). This work investigates antimicrobial activity and in vivo reno-protective effects of EGCG-PLGA NCs in cisplatin-induced nephrotoxicity. A double emulsion solvent evaporation process was adopted to prepare PLGA NCs loaded with EGCG. Particle size, polydispersity index (PDI), zeta potential, percent entrapment efficiency (%EE), structural morphology, and in vitro release platform were all studied in vitro. The optimum formula (F2) with particle size (61.37 ± 5.90 nm), PDI (0.125 ± 0.027), zeta potential (-11.83 ± 3.22 mV), %EE (85.79 ± 5.89%w/w), initial burst (36.85 ± 4.79), and percent cumulative release (87.79 ± 9.84) was selected for further in vitro/in vivo studies. F2 exhibited an enhanced antimicrobial activity against uropathogens as it had lower minimum inhibitory concentration (MIC) values and a more significant impact on bacterial growth than free EGCG. Forty male adult mice were randomly allocated into five groups: control vehicle, untreated methotrexate, MTX groups treated with a daily oral dose of free EGCG, placebo PLGA NCs, and EGCG PLGA NCs (F2) for 10 days. Results showed that EGCG PLGA NCs (F2) exerted promising renoprotective effects compared to free EGCG. EGCG PLGA NCs group induced a significant decrease in kidney index, serum creatinine, kidney injury molecule-1 (KIM-1), NGAL serum levels, and pronounced inhibition of NLPR-3/caspase-1/IL/1β inflammasome pathway. It also significantly ameliorated oxidative stress and decreased NFκB, Bax expression levels. Aqueous core PLGA NCs are a promising formulation strategy that provides high polymeric protection and sustained release pattern for hydrophilic therapeutic agents.
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Affiliation(s)
- Badriyah Alotaibi
- Department of Pharmaceutical Sciences, College of Pharmacy, Princess Nourah Bint Abdulrahman University, Riyadh, Saudi Arabia
| | - Thanaa A. El-Masry
- Pharmacology and Toxicology Department, Faculty of Pharmacy, Tanta University, Tanta, Egypt
| | - Engy Elekhnawy
- Pharmaceutical Microbiology Department, Faculty of Pharmacy, Tanta University, Tanta, Egypt
| | - Aya H. El-Kadem
- Pharmacology and Toxicology Department, Faculty of Pharmacy, Tanta University, Tanta, Egypt
| | - Asmaa Saleh
- Department of Pharmaceutical Sciences, College of Pharmacy, Princess Nourah Bint Abdulrahman University, Riyadh, Saudi Arabia
- Department of Biochemistry, Faculty of Pharmacy, Al Azhar University, Cairo, Egypt
| | - Walaa A. Negm
- Pharmacognosy Department, Faculty of Pharmacy, Tanta University, Tanta, Egypt
| | - Dalia H. Abdelkader
- Pharmaceutical Technology Department, Faculty of Pharmacy, Tanta University, Tanta, Egypt
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Yong H, Hu H, Wang Z, Yun D, Kan J, Liu J. Structure, stability and antioxidant activity of dialdehyde starch grafted with epicatechin, epicatechin gallate, epigallocatechin and epigallocatechin gallate. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2022; 102:6373-6386. [PMID: 35535559 DOI: 10.1002/jsfa.12003] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Revised: 04/16/2022] [Accepted: 05/10/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND Catechins, a member of the flavonoids, exist widely in teas, and have health benefits. However, catechins have poor stability, which greatly limits their application. In order to improve the stability of catechins, different catechins including (-)-epicatechin (EC), (-)-epicatechin gallate (ECG), (-)-epigallocatechin (EGC) and (-)-epigallocatechin gallate (EGCG) were conjugated onto dialdehyde starch by acid-mediated coupling method. The structure, stability and antioxidant activity of dialdehyde starch-catechin conjugates were determined. RESULTS Thin-layer chromatography and ultraviolet-visible spectroscopy, fluorescence, nuclear magnetic resonance and infrared spectra revealed that catechins were successfully conjugated onto dialdehyde starch, coupling between 6-H/8-H of catechins' A ring and dialdehyde starch's aldehyde groups. The conjugates presented an amorphous structure and sheet-like and/or blocky morphologies. As compared to dialdehyde starch, the conjugates showed enhanced thermal stability. Furthermore, the stability of catechins in pH 7.4 phosphate-buffered saline was improved after conjugating onto dialdehyde starch. The conjugates exhibited significantly higher antioxidant activities than dialdehyde starch, decreasing in the following order: dialdehyde starch-ECG, dialdehyde starch-EGCG, dialdehyde starch-EC, dialdehyde starch-EGC and dialdehyde starch. CONCLUSION Dialdehyde starch-catechin conjugates have great potential as stable antioxidant agents. © 2022 Society of Chemical Industry.
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Affiliation(s)
- Huimin Yong
- College of Food Science and Engineering, Yangzhou University, Yangzhou, PR China
| | - Huixia Hu
- College of Food Science and Engineering, Yangzhou University, Yangzhou, PR China
| | - Zhihao Wang
- College of Food Science and Engineering, Yangzhou University, Yangzhou, PR China
| | - Dawei Yun
- College of Food Science and Engineering, Yangzhou University, Yangzhou, PR China
| | - Juan Kan
- College of Food Science and Engineering, Yangzhou University, Yangzhou, PR China
| | - Jun Liu
- College of Food Science and Engineering, Yangzhou University, Yangzhou, PR China
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Sudha T, Salaheldin TA, Darwish NHE, Mousa SA. Antitumor/anti-angiogenesis efficacy of epigallocatechin gallate nanoformulated with antioxidant in melanoma. Nanomedicine (Lond) 2022; 17:1039-1053. [DOI: 10.2217/nnm-2021-0362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Aim: Epigallocatechin gallate (EGCG) derived from green tea has poor stability; therefore, to enhance its bioavailability and anticancer efficiency, we synthesized three different nanoformulations. We hypothesized that these three nanoformulations of EGCG (nano-EGCG) would enhance EGCG’s stability and improve its anticancer and antiangiogenic activity against melanoma compared with free EGCG. Methods: We prepared nano-EGCG using a copolymerization method with the UV blocker ZnO and the antioxidants lycopene and olive oil. Results: The different nano-EGCG formulation exhibited improved EGCG stability and greater suppression of melanoma growth than free EGCG. Nanoformulation preparation methods efficiently prevented the loss of EGCG activity and are a favorable approach for the treatment of melanoma. Conclusion: Nano-EGCG formulations had enhanced stability and produced greater suppression of melanoma tumor growth and angiogenesis compared with free EGCG.
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Affiliation(s)
- Thangirala Sudha
- The Pharmaceutical Research Institute, Albany College of Pharmacy & Health Sciences, Rensselaer, NY 12144, USA
| | - Taher A Salaheldin
- The Pharmaceutical Research Institute, Albany College of Pharmacy & Health Sciences, Rensselaer, NY 12144, USA
| | - Noureldien HE Darwish
- The Pharmaceutical Research Institute, Albany College of Pharmacy & Health Sciences, Rensselaer, NY 12144, USA
| | - Shaker A Mousa
- The Pharmaceutical Research Institute, Albany College of Pharmacy & Health Sciences, Rensselaer, NY 12144, USA
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5
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Xiao Q, Xuan X, Boczkaj G, Yoon JY, Sun X. Photolysis for the Removal and Transformation of Pesticide Residues During Food Processing: A State-of-the-Art Minireview. Front Nutr 2022; 9:888047. [PMID: 35669077 PMCID: PMC9164305 DOI: 10.3389/fnut.2022.888047] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 03/29/2022] [Indexed: 11/13/2022] Open
Abstract
Pesticide residues are of great significant issue that exerted adverse effects on humans. There is a need for effective and non-toxic decontamination of pesticide residues during food processing. In this minireview, the recent advances in the degradation of pesticide residues by photolysis have been firstly described during food processing. The mechanisms of pesticide residues destruction by photolysis were discussed accordingly. Finally, applications of photolysis in the degradation of pesticide residues from beverages, fresh produce, and food rinse waste were also summarized.
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Affiliation(s)
- Qian Xiao
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, China
- Department of Civil Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Xiaoxu Xuan
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, Ministry of Education, School of Mechanical Engineering, Shandong University, Jinan, China
| | - Grzegorz Boczkaj
- Department of Process Engineering and Chemical Technology, Faculty of Chemistry, Gdańsk University of Technology, Gdańsk, Poland
| | - Joon Yong Yoon
- Department of Mechanical Engineering, Hanyang University, Ansansi, South Korea
| | - Xun Sun
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, Ministry of Education, School of Mechanical Engineering, Shandong University, Jinan, China
- Department of Mechanical Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
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6
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Farag MA, Shakour ZTA, Elmassry MM, Donia MS. Metabolites profiling reveals gut microbiome-mediated biotransformation of green tea polyphenols in the presence of N-nitrosamine as pro-oxidant. Food Chem 2022; 371:131147. [PMID: 34808759 DOI: 10.1016/j.foodchem.2021.131147] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 09/11/2021] [Accepted: 09/13/2021] [Indexed: 01/23/2023]
Abstract
The gut microbiome contributes to host physiology and nutrition metabolism. The interaction between nutrition components and the gut microbiota results in thousands of metabolites that can contribute to various health and disease outcomes. In parallel, the interactions between foods and their toxicants have captured increasing interest due to their impact on human health. Taken together, investigating dietary interactions with endogenous and exogenous factors and detecting interaction biomarkers in a specific and sensitive manner is an important task. The present study sought to identify for the first time the metabolites produced during the interaction of diet-derived toxicants e.g., N-nitrosamines with green tea polyphenols, using liquid chromatography electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS). In addition, the metabolic products resulting from the incubation of green tea with a complex gut microbiome in the presence of N-nitrosamine were assessed in the same manner. The quinone products of (epi)catechin, quercetin, and kaempferol were identified when green tea was incubated with N-nitrosamine only; whereas, incubation of green tea with N-nitrosamine and a complex gut microbiome prevented the formation of these metabolites. This study provides a new perspective on the role of gut microbiome in protecting against potential negative interactions between food-derived toxicants and dietary polyphenols.
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Affiliation(s)
- Mohamed A Farag
- Pharmacognosy Department, College of Pharmacy, Cairo University, Cairo, Egypt; Department of Chemistry, School of Sciences & Engineering, American University in Cairo, New Cairo, Egypt.
| | - Zeinab T Abdel Shakour
- Laboratory of Phytochemistry, Egyptian Drug Authority (Former; National Organization for Drug Control and Research), Cairo, Egypt
| | - Moamen M Elmassry
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Mohamed S Donia
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA.
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Peng Y, Dai S, Lu Y, Xiong L, Huang J, Liu Z, Gong Y. Theanine Improves High-Dose Epigallocatechin-3-Gallate-Induced Lifespan Reduction in Caenorhabditis elegans. Foods 2021; 10:foods10061404. [PMID: 34204441 PMCID: PMC8235257 DOI: 10.3390/foods10061404] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 06/14/2021] [Accepted: 06/15/2021] [Indexed: 01/15/2023] Open
Abstract
Epigallocatechin-3-gallate (EGCG) is the most abundant polyphenol in green tea. Our previous report showed that induced hormesis was a critical determinant for the promotion of a healthy lifespan in Caenorhabditis elegans. In the present study, we investigated the anti-aging effects of the main active ingredients in green tea. We found that galloylated catechins (EGCG and epicatechin gallate) could extend the lifespan of C. elegans, while their metabolites (gallic acid, epicatechin, and epigallocatechin) could not. Interestingly, the combination with theanine, not caffeine, could alleviate the adverse effects induced by high-dose EGCG, including the promotion of lifespan and locomotor ability. This was due to the attenuation of the excess production of reactive oxygen species and the activation of DAF-16. These findings will facilitate further studies on the health benefits of tea active components and their interactions.
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Affiliation(s)
- Yuxuan Peng
- National Research Center of Engineering and Technology for Utilization of Botanical Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha 410128, China; (Y.P.); (Y.L.); (L.X.)
- College of Physical Education, Hunan City University, Yiyang 413002, China
| | - Shen Dai
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha 410128, China; (S.D.); (J.H.)
| | - Yan Lu
- National Research Center of Engineering and Technology for Utilization of Botanical Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha 410128, China; (Y.P.); (Y.L.); (L.X.)
| | - Ligui Xiong
- National Research Center of Engineering and Technology for Utilization of Botanical Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha 410128, China; (Y.P.); (Y.L.); (L.X.)
| | - Jianan Huang
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha 410128, China; (S.D.); (J.H.)
| | - Zhonghua Liu
- National Research Center of Engineering and Technology for Utilization of Botanical Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha 410128, China; (Y.P.); (Y.L.); (L.X.)
- Collaborative Innovation Center of Utilization of Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha 410128, China
- Correspondence: (Z.L.); (Y.G.); Tel.: +86-158-741-84082 (Y.G.)
| | - Yushun Gong
- National Research Center of Engineering and Technology for Utilization of Botanical Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha 410128, China; (Y.P.); (Y.L.); (L.X.)
- Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha 410128, China; (S.D.); (J.H.)
- Correspondence: (Z.L.); (Y.G.); Tel.: +86-158-741-84082 (Y.G.)
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Dai J, Jiang C, Chai Y, Wang C, Chen H, Liu X. Photolysis kinetics of cartap and nereistoxin in water and tea beverages under irradiation of simulated sunlight and ultraviolet under laboratory conditions. Food Chem 2021; 355:129595. [PMID: 33774224 DOI: 10.1016/j.foodchem.2021.129595] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 03/07/2021] [Accepted: 03/08/2021] [Indexed: 01/27/2023]
Abstract
Cartap applied widely in agricultural crops and tea plants is readily degraded into nereistoxin, resulting in a longer residual period and higher exposure risk to humans. The photolysis kinetics of cartap and nereistoxin in water and tea beverages was firstly investigated to explore the effect and mechanism of pesticide residue removal. Cartap and nereistoxin could be effectively photolyzed by ultraviolet and their photolysis rate increased with light intensity increasing. The photolysis percentage of cartap and nereistoxin in different solutions under ultraviolet irradiation of 200 W mercury lamp reached 81.8%-100.0% within 6 h. Relative to water solution, the water-soluble components in tea had an inhibition effect on the photodegradation of cartap and nereistoxin. This research provided a reference for the development of effective methods for the removal of cartap and its metabolite in water and tea beverages.
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Affiliation(s)
- Jinxia Dai
- Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China; Graduate School of Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Changling Jiang
- Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China; Graduate School of Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yunfeng Chai
- Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China; Key Laboratory of Tea Quality and Safety & Risk Assessment, Ministry of Agriculture, Hangzhou 310008, China
| | - Chen Wang
- Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China; Key Laboratory of Tea Quality and Safety & Risk Assessment, Ministry of Agriculture, Hangzhou 310008, China
| | - Hongping Chen
- Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China; Key Laboratory of Tea Quality and Safety & Risk Assessment, Ministry of Agriculture, Hangzhou 310008, China.
| | - Xin Liu
- Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China; Key Laboratory of Tea Quality and Safety & Risk Assessment, Ministry of Agriculture, Hangzhou 310008, China.
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9
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Abstract
Catechin exhibits numerous physiological characteristics. In this study, we determined the photosensitivity of catechin to various lights under alkaline conditions, and the mechanisms by which catechin generates free radical species and polymerizes via a photoreaction. In addition to this, the application of catechin photolysis was investigated. A solution of catechin is transparent, but turns yellowish under blue light illumination (BLI) in neutral or weak alkaline solutions. When catechin is subjected to BLI, a dimeric catechin (proanthocyanidin) and a superoxide anion radical (O2•−) are generated in a photolytic reaction. When ascorbic acid or gallic acid is added to catechin and the mixture is subjected to BLI at alkaline pH, fewer catechin dimers and less O2•− are produced, because both acids inhibit the photosensitive oxidation of catechin. When AlCl3 is added to catechin and the mixture is subjected to BLI at pH 8, a photolytic reaction is suppressed by AlCl3, and AlCl3 acts as a catalyst for the disconnection of proanthocyanidin during photolysis. Under alkaline conditions, catechin generates O2•− via photosensitive oxidation, which suppresses the growth of Acinetobacter baumannii (A. baumannii) by at least 4 logs, and deactivates its multi-drug-resistant strain. This study shows that catechin photolysis is a process of oxidation, and that it can be safely applied as a tool for environmental applications.
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Mittal A, Singh A, Benjakul S, Prodpran T, Nilsuwan K, Huda N, Caba KDL. Composite films based on chitosan and epigallocatechin gallate grafted chitosan: Characterization, antioxidant and antimicrobial activities. Food Hydrocoll 2021. [DOI: 10.1016/j.foodhyd.2020.106384] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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11
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Catechin Photolysis Suppression by Aluminum Chloride under Alkaline Conditions and Assessment with Liquid Chromatography-Mass Spectrometry. Molecules 2020; 25:molecules25245985. [PMID: 33348758 PMCID: PMC7766431 DOI: 10.3390/molecules25245985] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 12/08/2020] [Accepted: 12/14/2020] [Indexed: 11/17/2022] Open
Abstract
Tea is rich in catechins and aluminum. In this study, the process of catechin photolysis was applied as a model for examining the effects of aluminum chloride (AlCl3) on the structural changes of catechin and the alteration of aluminum complexes under blue light irradiation (BLI) at pH 8 using liquid chromatography and mass spectrometry techniques. Additionally, the effects of anions on catechin upon the addition of AlCl3 and treatment with BLI were also studied. In this study, when 1 mM catechin was treated with BLI, a superoxide anion radical (O2•-) was generated in an air-saturated aqueous solution, in addition to forming a dimeric catechin (proanthocyanidin) via a photon-induced redox reaction. The relative percentage of catechin was found to be 59.0 and 95.7 for catechin treated with BLI and catechin upon the addition of 1 mM AlCl3 treated with BLI, respectively. It suggested that catechin treated with BLI could be suppressed by AlCl3, while AlCl3 did not form a complex with catechin in the photolytic system. However, under the same conditions, it was also found that the addition of AlCl3 inhibited the photolytic formation of O2•-, and reduced the generation of proanthocyanidin, suggesting that the disconnection of proanthocyanidin was achieved by AlCl3 acting as a catalyst under treatment with BLI. The influence of 1 mM fluoride (F-) and 1 mM oxalate (C2O42-) ions on the photolysis of 1 mM catechin upon the addition of 1 mM AlCl3 and treatment with BLI was found to be insignificant, implying that, during the photolysis of catechin, the Al species were either neutral or negatively charged and the aluminum species did not form a complex with anions in the photolytic system. Therefore, aluminum, which is an amphoteric species, has an inherent potential to stabilize the photolysis of catechin in an alkaline conditions, while suppressing the O2•- and proanthocyanidin generation via aluminum ion catalysis in the catechin/Al system under treatment with BLI.
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12
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Docampo-Palacios ML, Alvarez-Hernández A, de Fátima Â, Lião LM, Pasinetti GM, Dixon RA. Efficient Chemical Synthesis of (Epi)catechin Glucuronides: Brain-Targeted Metabolites for Treatment of Alzheimer's Disease and Other Neurological Disorders. ACS OMEGA 2020; 5:30095-30110. [PMID: 33251444 PMCID: PMC7689943 DOI: 10.1021/acsomega.0c04512] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 10/26/2020] [Indexed: 05/03/2023]
Abstract
Grape seed extract (GSE) is rich in flavonoids and has been recognized to possess human health benefits. Our group and others have demonstrated that GSE is able to attenuate the development of Alzheimer's disease (AD). Moreover, our results have disclosed that the anti-Alzheimer's benefits are not directly/solely related to the dietary flavonoids themselves, but rather to their metabolites, particularly to the glucuronidated ones. To facilitate the understanding of regioisomer/stereoisomer-specific biological effects of (epi)catechin glucuronides, we here describe a concise chemical synthesis of authentic standards of catechin and epicatechin metabolites 3-12. The synthesis of glucuronides 9 and 12 is described here for the first time. The key reactions employed in the synthesis of the novel glucuronides 9 and 12 include the regioselective methylation of the 4'-hydroxyl group of (epi)catechin (≤1.0/99.0%; 3'-OMe/4'-OMe) and the regioselective deprotection of the tert-butyldimethylsilyl (TBS) group at position 5 (yielding up to 79%) over the others (3, 7 and 3' or 4').
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Affiliation(s)
- Maite L. Docampo-Palacios
- BioDiscovery
Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76203, United States
- . Phone: +1-214-601-5892. Fax: +1-580-224-6692
| | - Anislay Alvarez-Hernández
- BioDiscovery
Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76203, United States
| | - Ângelo de Fátima
- Department
of Chemistry, Universidade Federal de Minas
Gerais, Belo Horizonte, MG 31270-901, Brazil
| | - Luciano Morais Lião
- Institute
of Chemistry, Universidade Federal de Goiás, Goiânia, GO 74690-900, Brazil
| | - Giulio M. Pasinetti
- Department
of Psychiatry, The Mount Sinai School of
Medicine, New York, New York 10029, United States
| | - Richard A. Dixon
- BioDiscovery
Institute and Department of Biological Sciences, University of North Texas, Denton, Texas 76203, United States
- . Phone: +1-940-565-2308
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13
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Taslimi P, Kocyigit UM, Tüzün B, Kirici M. Biological effects and molecular docking studies of Catechin 5-O-gallate: antioxidant, anticholinergics, antiepileptic and antidiabetic potentials. J Biomol Struct Dyn 2020; 40:2489-2497. [PMID: 33146092 DOI: 10.1080/07391102.2020.1840440] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Parham Taslimi
- Department of Biotechnology, Faculty of Science, Bartin University, Bartin, Turkey
| | - Umit M. Kocyigit
- Department of Basic Pharmaceutical Sciences, Division of Biochemistry, Faculty of Pharmacy, Sivas Cumhuriyet University, Sivas, Turkey
| | - Burak Tüzün
- Department of Chemistry, Faculty of Science, Sivas Cumhuriyet University, Sivas, Turkey
| | - Mahinur Kirici
- Department of Chemistry, Faculty of Arts and Sciences, Bingol University, Turkey
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