Background: Fungal laccase (EC 1.10.3.2) is an important enzyme for catalyzing the oxidation of tea polyphenols during the fermentation of tea. (-)-Epigallocatechin gallate (EGCG) is the main ingredient of tea polyphenols. To a certain extent, the oxidation degree of EGCG reflects the fermentation degree of tea. This study preliminarily optimized the conditions for catalytically oxidizing EGCG by Aspergillus sp. trijbl1112 laccase and systematically analyzed the components and contents of the EGCG oxidation products.
Results: Aspergillus sp. trijbl1112 laccase oxidized EGCG into free catechins, ester catechins, gallic acid and tea pigments. The reaction conditions had a significant impact on the oxidation rate, types and concentrations of the products. At natural pH, 69.29% of EGCG was oxidized when 1 mL of EGCG (1 mmol L(-1) ) was catalyzed by 10 µg of fungal laccase for 150 min at 70 °C. When the EGCG oxidation rate was 69.27%, free catechins ((+)-catechin and (-)-epigallocatechin) and tea pigments (mainly thearubigin and theabrownin) constituted 48.42 and 38.87% of the oxidation products respectively.
Conclusion: The results may provide a theoretical basis for the application of EGCG oxidation using laccase and provide a novel technique for obtaining high production of tea pigments.
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http://dx.doi.org/10.1002/jsfa.7003 | DOI Listing |
Nutrients
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School of Pharmacy, Shaoyang University, Shaoyang 422000, China.
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Department of Chemistry & Biochemistry, Miami University, Oxford, OH 45056, USA.
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Lab of Applied Biocatalysis, School of Food Science and Engineering, South China University of Technology, No. 381 Wushan Road, Guangzhou, Guangdong 510640, China. Electronic address:
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Department of Biomedical, Surgical and Dental Sciences, University of Milan, Via Luigi Vanvitelli 32, 20133, Milan, Italy.
Neurodegenerative diseases (NDs) are caused by progressive neuronal death and cognitive decline. Epigallocatechin 3-gallate (EGCG) is a polyphenolic molecule in green tea as a neuroprotective agent. This review evaluates the therapeutic effects of EGCG and explores the molecular mechanisms that show its neuroprotective properties.
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Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, Hunan 410013, China.
Atherosclerosis (AS) is a prevalent inflammatory vascular disease characterized by plaque formation, primarily composed of foam cells laden with lipids. Despite lipid-lowering therapies, effective plaque clearance remains challenging due to the overexpression of the CD47 molecule on apoptotic foam cells, inhibiting macrophage-mediated cellular efferocytosis and plaque resolution. Moreover, AS lesions are often associated with severe inflammation and oxidative stress, exacerbating disease progression.
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