Peroxidase Can Perform the Hydroxylation Step in the “Oxidative Cascade” during Oxidation of Tea Catechins

Verloop, Annewieke J.W.; Vincken, Jean‐Paul; Gruppen, Harry

doi:10.1021/acs.jafc.6b03029

Cited by 32 publications

(16 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Natural fermentation of catechin can take place with the peroxidase enzyme present naturally in tea leaves and oxygen in the atmosphere. , Because of the related chemical structure between luteolin and catechin, here, we have explored the possibility to polymerize luteolin by mimicking the natural environment in tea leaves. We explored the roles of oxidative enzyme horseradish peroxidase (HRP), oxidizing agent H 2 O 2 , and the PEG template.…”

Section: Resultsmentioning

confidence: 99%

Polymerized Luteolin Nanoparticles: Synthesis, Structure Elucidation, and Anti-Inflammatory Activity

et al. 2021

View full text Add to dashboard Cite

Luteolin is an anti-inflammatory flavonoid commonly found in many edible plants. The compound is popularly consumed as a supplement regardless of its poor water solubility (27.8 μg/mL at 25 °C) and low bioavailability. Here, mild one-pot polymerization of luteolin into water-dispersible nanospheres, with an average dry size of 234.8 ± 101.6 nm, an aqueous size distribution of 379.1 ± 220.5 nm (PDI = 0.338), an average ζ-potential of −36.2 ± 0.2 mV, and an 89.3 ± 4.8% yield, is described. The nanospheres consist of polymerized luteolin (polyluteolin) with a weight-average molecular mass of around 410000 Da. The chemical structure of polyluteolin is identified through 1H–1H correlated spectroscopy (COSY), 1H–13C heteronuclear single-quantum coherence (HSQC), and 1H–13C heteronuclear multiple-bond correlation (HMBC) NMR spectroscopic analyses of the oligomers, and a polymerization mechanism is proposed. Unlike luteolin that showed both dose-dependent anti-inflammatory activity and cytotoxicity when tested in lipopolysaccharide-stimulated macrophages, the polyluteolin nanoparticles possess dose-dependent anti-inflammatory activity without causing cell death even at high concentrations.

show abstract

Section: Resultsmentioning

confidence: 99%

Polymerized Luteolin Nanoparticles: Synthesis, Structure Elucidation, and Anti-Inflammatory Activity

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Peroxidase (POD) can also catalyze the oxidation of o-diphenols to their quinones in the presence of peroxide, such as hydrogen peroxide (H 2 O 2 ), which are formed by the effect of PPO on certain flavanols. In fresh tea leaves, some POD activity is more than five times higher than that of PPO and has been found to increase during the manufacturing process of black tea [22]. At the beginning step of black tea processing, PPO is inhibited by heating, whereas POD remains active to a certain extent.…”

Section: Benzotroplone Derivates In Teamentioning

confidence: 99%

Enzymatic Oxidation of Tea Catechins and Its Mechanism

Abudureheman

Dai

et al. 2022

Molecules

View full text Add to dashboard Cite

Tea (Camellia sinensis, Theaceae) is one of the most widely consumed beverages in the world. The three major types of tea, green tea, oolong tea, and black tea, differ in terms of the manufacture and chemical composition. Catechins, theaflavins, and thearubigins have been identified as the major components in tea. Other minor oligomers have also been found in tea. Different kinds of ring fission and formation elucidate the major transformed pathways of tea catechins to their dimers and polymers. The present review summarizes the data concerning the enzymatic oxidation of catechins, their dimers, and thearubigins in tea.

show abstract

“…4) At the world level, black tea production has increased annually by 3.0% and green tea by 5.4% percent over the past decade in response to perceived health benefits. 1,5,6) Green tea is produced by steaming or pan-frying fresh tea leaves immediately after harvesting to inactivate the leaf enzymes including polyphenol oxidase. Therefore, the composition of green tea polyphenols is similar to those of fresh leaves, and (−)-epigallocatechin (1), (−)-epicatechin (3), and their galloyl esters (2 and 4, respectively) are the major polyphenols (Figs.…”

Section: Introductionmentioning

confidence: 99%

Production Mechanisms of Black Tea Polyphenols

Tanaka

Matsuo

2020

Chem. Pharm. Bull.

View full text Add to dashboard Cite

Black tea accounts for 70-80% of world tea production, and the polyphenols therein are produced by enzymatic oxidation of four tea catechins during tea fermentation. However, only limited groups of dimeric oxidation products, such as theaflavins, theasinensins, and theacitrins, have been isolated from black tea and chemically characterized. This is largely because of the complexity and heterogeneity of the oxidation products. To determine structures and production mechanisms of uncharacterized black tea polyphenols, in vitro model fermentation experiments using pure catechins and polyphenol oxidase have been applied, and basic oxidation mechanisms have been established. Contemporary methods, such as LC-MS, are also effective to identify catechin oxidation products in black tea. Despite ongoing efforts, almost 60% of the solids in black tea infusion remain uncharacterized. These compounds include the so-called thearubigins, which are a heterogeneous mixture of uncharacterized catechin oxidation products with oligomeric structures. This review summarizes the current knowledge of the production mechanisms of representative black tea polyphenols and presents recent progress in characterization of thearubigins.

show abstract

Peroxidase Can Perform the Hydroxylation Step in the “Oxidative Cascade” during Oxidation of Tea Catechins

Cited by 32 publications

References 34 publications

Polymerized Luteolin Nanoparticles: Synthesis, Structure Elucidation, and Anti-Inflammatory Activity

Polymerized Luteolin Nanoparticles: Synthesis, Structure Elucidation, and Anti-Inflammatory Activity

Enzymatic Oxidation of Tea Catechins and Its Mechanism

Production Mechanisms of Black Tea Polyphenols

Contact Info

Product

Resources

About