PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 10939849

[Computational study on antioxidation mechanism of catechins].

M Kurihara·K Kondo·K Fukuhara·M Toyoda·N Miyata
View original source ↗Export metadata ↓

Abstract

All C-H and O-H bond dissociation enthalpies (BDE's) in catechins, (-)-epigallocatechin) were calculated by semi-empirical molecular orbital calculation using the SPARTAN program. The BDE's of benzyl hydrogens (C-2 position in catechins) were found to be quite low. This suggests that abstraction of benzyl hydrogen is crucial step for antioxidative activity. This is corroborated by the reported results of LC/MS and spectrophotometric analysis of reaction intermediates from catechins treated with AAPH.

Explore related subjects

AntioxidantsCatechinFlavonoidsFree Radical ScavengersHydrogen BondingMathematicsJournal ArticleResearch Support, Non-U.S. Gov't

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

M Kurihara, K Kondo, K Fukuhara, M Toyoda, N Miyata. 1999. [Computational study on antioxidation mechanism of catechins].. https://pubmed.ncbi.nlm.nih.gov/10939849/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2026

Efficacy and Safety of Low-Molecular-Weight Collagen Peptide GT for Improving Hair Condition in Individuals with Damaged Hair: A Randomized, Double-Blind, Placebo-Controlled Trial.

Addressing hair damage is essential for maintaining overall hair and scalp health. Previous studies have suggested that low-molecular-weight collagen peptides may support hair follicle biology through regulation of extracellular matrix homeostasis and cellular signaling pathways. In addition, recent preclinical studies have demonstrated that low-molecular-weight fish collagen peptides promote hair regrowth through activation of proliferative signaling and suppression of inhibitory pathways. However, their clinical efficacy in improving hair damage has not been clearly established. In this study, the efficacy and safety of low-molecular-weight collagen peptide GT (LMWCP GT) were evaluated in Korean adults with damaged hair. In a randomized, placebo-controlled trial, individuals aged 19∼60 years without alopecia but with mild to moderate hair damage received LMWCP GT (3 g/day) for 24 weeks. Compared with placebo, the treatment group demonstrated significant improvements in hair gloss, as measured using a gloss meter (SAMBA) and scanning electron microscopy, as well as in hair elasticity, assessed by tensile strength and hair diameter. Subjective evaluations further indicated improvements in overall hair condition, including gloss, elasticity, thickness, texture, fullness, and appearance. In addition, scalp elasticity was significantly increased in the treatment group. No treatment-related adverse events were observed. These findings indicate that daily supplementation with LMWCP GT (3 g/day) for 24 weeks is safe and effective in improving overall hair condition in individuals with damaged hair without alopecia.

Antioxidants↗
PubMed2026

Free polyphenols and multi-omics traits underlying antioxidant variation across Paeonia lactiflora leaf cultivars.

Leaves of Paeonia lactiflora are underutilized by-products with potential as natural antioxidant sources. In this study, 18 cultivars were evaluated for phytochemical composition and in vitro antioxidant capacity. Total phenolic content correlated strongly with DPPH and ABTS activities, and the comprehensive antioxidant index identified 'Coral Charm' and 'Hangshao' as representative high- and low-antioxidant cultivars, respectively. Untargeted metabolomics detected 2677 metabolites and identified 908 differential metabolites between the two cultivars. Targeted phenolic profiling quantified 27 compounds, among which 11 differed significantly between the two cultivars. Catechin and epicatechin were enriched in 'Coral Charm', with contents of 6.62 and 0.397 ng/mg, respectively, compared with 0.012 and 0.002 ng/mg in 'Hangshao'. (+)-Dihydroquercetin was also more abundant in 'Coral Charm', while caffeic acid showed an upward trend. Proteomic analysis identified 423 differentially expressed proteins, mainly associated with secondary metabolite biosynthesis, redox homeostasis, and central carbon metabolism. Integrated analysis identified pyruvate metabolism as the only pathway significantly enriched in both metabolomic and proteomic datasets. Molecular docking predicted favorable binding between representative phenolics and selected proteins. These findings link cultivar-dependent antioxidant variation in peony leaves with free-phenolic accumulation and pathway-level metabolic differences, supporting the selection and utilization of antioxidant-rich peony leaf resources.

Antioxidants↗
PubMed2026

A smartphone-integrated Pt@Cu-HCF nanozyme-based paper sensor for on-site determination of total antioxidant capacity in marine oils.

Total antioxidant capacity (TAC) serves as a key indicator for evaluating the nutritional quality of foods. In this study, we designed a platinum-embedded copper hexacyanoferrate (denoted as Pt@Cu-HCF) nanozyme that exhibits high oxidase-like activity, efficiently catalyzing the oxidation of chromogenic substrates to generate robust colorimetric signals. Antioxidants quench hydroxyl radicals (∙OH) produced during the catalytic process, leading to a concentration-dependent suppression of the color signal. Leveraging this mechanism, a smartphone-integrated, colorimetric paper sensor for on-site TAC quantification was developed, using vitamin E as the calibration standard. The sensor was applied to determine TAC in fish oil, algal oil, and krill oil, demonstrating a linear response range of 9.78-312.5 μM and a limit of detection (LOD) of 6.41 μM. Validation using real-world marine oil samples showed excellent agreement with a commercial assay kit, confirming the reliability and practical applicability of this portable sensor for TAC measurement in complex biological matrices.

Antioxidants↗