• Korean Journal of Food Science and Technology
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• v.25 no.3
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• pp.214-219
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• 1993

Properties of the antioxidative fraction isolated from browning reaction product (BRP) that were obtained from 2 M L-ascorbic acid (AsA) solution (adjusted to pH 7.0) by heating for 25 hrs at $85^{\circ}C$ were investigated. Both of dialyzable and nondialyzable fraction isolated from BRP showed antioxidative effect. Dialyzable fraction has stronger antioxidative activity than nondialyzable. Dialyzable fraction was divided into the three fractions (A, B, C) by gel filtration. Among these fractions, the fraction (A) that had the highest reducing power and lowest browning drgree had lowest antioxidative activity. The fraction (C) that had lowest reducing power and highest browning degree showed strongest antioxidative effect. In the UV-visible spectrum of these fractions, the maximum absorption wavelengths of fraction A and B were 266.1 and 257.4nm, respectively, and fraction C showed a weaker absorption peak at 274.8nm. Infrared (IR) spectrum results showed that all fractions (A, B, C) had both hydroxy and carboxylic groups, and fraction B and C had carboxylic ester group.

• YAKHAK HOEJI
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• v.52 no.4
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• pp.241-251
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• 2008

In this study, isolation of antioxidative compounds was performed for development of anti-oxidizing agent. $CHCl_{3}$, $H_{2}O$, 30%, 60% MeOH, MeOH fractions were examined antioxidative activity by DPPH method, TBARS assay, and SOD like activity. It was revealed that 30%, 60% MeOH fractions had significant antioxidative activity. From 30%, 60% MeOH fraction, nine compounds were isolated and elucidated kaempferol $3-O-{\alpha}-L-rhamnopyranosyl$ $(1{\rightarrow}6)-{\beta}-D-glucopyranoside$ (1), quercetin $7-O-{\beta}-D-glucopyranoside$ (II), quercetin $3-O-{\alpha}-L-rhamnopyranosyl$ $(1{\rightarrow}6)$ ${\beta}-D-glucopyranoside(rutin)$ (III), 6-hydroxykaempferol $3-O-{\beta}-D-glucopyranoside$ (lV), kaempferol $3-O-{\beta}-D-glucopyranosyl$ $(1{\rightarrow}2)$ ${\beta}-D-glucopyranoside$ (V), kaempferol $3-O-{\beta}-D-glucopyranoside$ (VI), luteolin (VII), quercetin $3-O-{\beta}-D-glucopyranoside$ (VIII), apigenin $7-O-{\beta}-D-glucuronopyranoside$ (IX) through physicochemical data and spectroscopic methods (Negative FAB-MS, $^1H-NMR$, $^{13}C-NMR$). Entirely, all compounds had similar antioxidative activity, but more OH group had more antioxidative activity.

• Korean Journal of Pharmacognosy
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• v.33 no.4 s.131
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• pp.404-410
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• 2002

Phytochemical examination of Barks of Ulmus macrocarpa has led to the isolation and characterization of two fla-vanonol, taxifolin $7-O-{\beta}-D-glucopyranoside$ (1), taxifolin $3'-0-7-{\beta}-glucopyranoside$ (2), two flavanone eriodictyol $7-O-{\beta}-D-glucopyranoside$ (3), nalingenin $7-O-{\beta}-D-glucopyranoside$ (4), three flavan 3-ol, (+)-catechin (5), (-)-epicatechin (6), (+)-catechin 7-O-{\beta}-D-glucopyranoside (7) and one proanthocyanidin, procyanidin B-1 (8). Antioxidative activity of these compounds was determined by measuring the radical scavenging effect on 1,1-diphenyl-2- picrylhydrazyl (DPPH) radicals . (+)-Catechin (5) , (-)-epicatechin (6), (+)-catechin $7-O-{\beta}-D-glucopyranoside$ (7) and procyanidin B-1 (8) showed significant antioxidative activity.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.211.1-211.1
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• 2003

On the purpose of develcpement of antioxidative compound from natural sources, medicinal plants known to have antioxidant actuvity have been examined concening DPPH radical scavenging activity and SOD-liked activities. Among 8 plants exhibiting the activity, Houttuynia cordata THUNB was selected as resources to search for active compounds due to rareness of study. The antioxidative compounds from Houttuynia cordata THUNB,quercitrin was assayed using a DPPH free radical. The DPPH radical scavenging activity of quercitrin was similar to that of BHA and Ascorbic acid

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.4
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• pp.726-731
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• 2001

To enhance the utilization of chestnut husk discarded in the processing company antioxidative activities and compounds were investigated. Antioxidative activities of solvent fractions from chestnut husk were examined by benzoic acid hydroxylation method ferric thiocyanate method and DPPH test. Ethyl acetate fraction showed strong antioxidative activities comparable to BHA. Active compounds were isolated and purified from ethyl acetate fraction by Sephadex LH-20 column chromatography and preparative HPLC. A major active compound gallic acid was identified by $^{1}$H and $^{13}$ C-NMR. The phenolic acid contents was analyzed by GC and ellagic acid (172.22 mg%) and gallic acid (107.39 mg%) were major phenolic acid of chestnut husk.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.499-499
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• 2002

• Korean Journal of Food Science and Technology
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• v.29 no.1
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• pp.38-43
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• 1997

Free phenolic acids (FPA), soluble phenolic acid esters (SPA) and insoluble-bound phenolic acids (IPA) were extracted from defatted Perillae semen flour and the antioxidative components in FPA extract was separated by column chromatography and HPLC. Total phenolic content of defatted Perillae semen flour was 0.38% as chlorogenic acid and each percent ratio of the content of FPA, SPA and IPA to total phenolic content was 71.1%, 15.8% and 13.1%, respectively. The antioxidative activity was compared by measuring of electron donating ability (EDA) and thiobarbituric acid value (linoleic acid substrates). The FPA extract was showed the highest antioxidative activity among the three kinds of phenolic extracts. The FPA extract showing the highest antioxidative activity was separated by silica gel column chromatography and then the separated fractions were compared in terms of antioxidative activity. The fractions of acetone : methanol (8 : 2) showing the highest antioxidative activity was further separated by HPLC. Five fractions (F-I, F-II, F-III, F-IV and F-V) were observed on the HPLC chromatogram and F-I fraction showed the highest antioxidative activity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.3
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• pp.377-381
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• 2001

Chlorophyll a and b, pheophytin a and b and $\beta$-carotene, crude chlorophylls and carotenoids (CCC) extracts of mustard leaf kimchi were isolated by DEAE-sepharose CL-6B and Sepharose CL-6B colume and TLC. The effects of chlorophyll a and b, pheophytin a and b and $\beta$-carotene on linoleic acid autoxidation were examined by the determination of peroxide value and conjugated dienoic acid content. Among them, chlorophyll a showed greater antioxidative activity than others, followed by chlorophyll b, pheophytin a, pheophytin b and $\beta$-carotene. Degradation of pheophytin b was observed to be slower than others and $\beta$-carotene showed highest degradation level during the autoxidation reaction of linoleic acid.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.496-496
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• 2003

• Natural Product Sciences
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• v.15 no.4
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• pp.241-245
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• 2009

In the course of screening for antioxidant compounds by measuring the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging effect and superoxide quenching activity, methanol extract of Cyperus difformis (Cyperaceae) was found to show potent antioxidant activities. Subsequent activity-guided fractionation of the methanolic extract led to the isolation of three phenolic compounds, rosmarinic acid (1), luteolin (2) and caffeic acid (3). Their structures were elucidated by spectroscopic studies. Three compounds showed the significant antioxidative effects on DPPH and nitric oxide radical scavenging effects, riboflavin and xanthin originated superoxide quenching activities. Among them, compound 3 showed the most significant antioxidative effects on those four antioxidant tests. Compound 3 showed better antioxidative activities than vitamin C.