茶葉カテキン類の抗酸化作用について  [in Japanese] Antioxidative activity of tea leaf catechins.  [in Japanese]

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Author(s)

Abstract

(1) (-)-エピカテキン(EC), (-)-エピガロカテキン(EGC),(-)-エピカテキンガレート(ECg), (-)-エピガロカテキンガレート(EGCg)のラードにおける抗酸化作用を調べた.ラードにおける抗酸化力は等重量濃度で比べた場合, ECg<EC<EGCg<EGCとなり, BHAおよび<i>dl</i>-α-トコフェロールよりも強い抗酸化作用を示した.また等モル濃度で比べた場合はEC<ECg<EGC<EGCgとなり,構造式との相関関係があるように思われる.<br> (2) EGCgとアミノ酸を併用したラードはEGCgのみのものに比べると,むしろPOVを上げるもののほうが多く, 19種アミノ酸のうちL-メチオニンのみがわずかに相乗作用を示した.リンゴ酸,酒石酸およびクエン酸が相乗作用を示した.またL-アスコルビン酸およびトコフェロールもEGCgと強い相乗作用を示した.<br> (3) リノール酸に対してもEGCgは抗酸化作用を示したが,その強さはラードにおけるそれよりも弱かった.また水添加リノール酸に対しても抗酸化作用を示し,油系のみならず,水系においても抗酸化作用を発現することがわかった.<br> (4) カテキン混合物(総カテキン含量約72%)は,ラードにおいてはEGCg単独の抗酸化力と同等の効力を示した,またこれはトコフェロール含有の市販サラダ油に対しても顕著な抗酸化作用を発揮することが明らかになった.

Instant green tea was extracted with chloroform and ethyl acetate to obtain a crude catechin mixture. The four main tea catechin components (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECg) and (-)-epigallocatechin gallate (EGCg) were isolated from the crude catechin by HPLC and purified. The antioxidative effects of the four catechins were tested by the active oxygen method (AOM) at 97.8°C on lard. The antioxidative activity increased in molarity in the following order: EC<ECg<EGC<EGCg. This implies that their activities were related to their structural formula.<br> The synergism of EGCg with 19 amino acids, several organic acids and tocopherol was tested on lard by AOM at 97.8°C or 60°C. Among amino acids tested only L-methionine showed slight synergism, whereas most of the others showed accelerated oxidation. Tocopherol and several organic acids including L-ascorbic acid showed a remarkable synergistic effect. EGCg also acted as an antioxidant in the linoleic acid system but its activity was milder than in the lard system. In addition, the antioxidative activity of EGCg was demonstrated in a system where linoleic acid was solubilized in a large amount of water. EGCg had an antioxidative activity in both the oil and aqueous system. The crude catechin mixture showed a similar antioxidative effect as EGCg in the lard system and was also effective in commercial salad oil.

Journal

  • Nippon Nōgeikagaku Kaishi

    Nippon Nōgeikagaku Kaishi 59(2), 129-134, 1985

    Japan Society for Bioscience, Biotechnology, and Agrochemistry

Cited by:  55

Codes

  • NII Article ID (NAID)
    130001221884
  • NII NACSIS-CAT ID (NCID)
    AN00196191
  • Text Lang
    JPN
  • Article Type
    Journal Article
  • ISSN
    0002-1407
  • NDL Article ID
    3021178
  • NDL Source Classification
    PC1;PC8
  • NDL Source Classification
    ZR7(科学技術--農林水産--農産)
  • NDL Call No.
    Z18-335
  • Data Source
    CJPref  NDL  J-STAGE 
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