Structural features and antioxidant activity of tannin from persimmon pulp
Structural features and antioxidant activity of tannin from persimmon pulp
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DOI：
10.1016/j.foodres.2007.11.011
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发表时间：
2008-01-01
影响因子：
8.1
通讯作者：
Wan, Qiong-hong
中科院分区：
文献类型：
--
作者：
Gu, Hai-Feng;Li, Chun-Mei;Wan, Qiong-hong
用1%HCl酸化的甲醇提取柿浆中的酚类化合物，然后在AB-8大孔树脂上纯化。获得的单宁提取物通过截留分子量为10,000 Da的聚砜超滤膜分级成两个部分：低分子量单宁（LMWT）和高分子量单宁（HMWT）。 HPLC-MS分析表明没食子酸是LMWT组分的主要成分之一。通过GPC方法测定HMWT的分子量分布在1.16 x 10(4) Da至1.54 x 10(4) Da范围内，其中分子量为1.28 x 10(4) Da in (M) over bar (n)和1.39 x 10(4) Da in (M) over bar (w)。 HPLC-MS通过HPLC峰面积估计，HMWT的硫解降解产物由(epi)没食子儿茶素、表没食子儿茶素-3-O-没食子酸酯、表儿茶素-3-O-没食子酸酯和未知单体组成，比例为1:73:1。分别使用2-脱氧核糖氧化系统和水杨酸系统的羟自由基清除活性、超氧阴离子清除活性和亚油酸脂质过氧化抑制活性来评价柿单宁的抗氧化特性。 HMWT 在所有测试系统中均以剂量依赖性方式表现出优异的抗氧化活性。 HMWT的抗氧化活性明显强于LMWT和葡萄籽原花青素(GSP)，表明高分子量缩合单宁是柿浆中的主要抗氧化成分。 (C) 2007 Elsevier Ltd. 保留所有权利。
Phenolic compounds from persimmon pulp were extracted with methanol acidified with 1% HCl, and then purified on AB-8 macroporous resin. The tannic extracts obtained were fractionated by polysulfone ultrafiltration membrane with molecular weight cutoff of 10,000 Da into two fractions: low molecular weight tannin (LMWT) and high molecular weight tannin (HMWT). HPLC-MS analysis showed that gallic acid was one of the main components of LMWT fraction. The molecular weight distribution of HMWT was determined to be in the range of 1.16 x 10(4) Da to 1.54 x 10(4) Da, with the molecular weight of 1.28 x 10(4) Da in (M) over bar (n) and 1.39 x 10(4) Da in (M) over bar (w) by GPC method. HPLC-MS showed that the thiolysis degradation products of HMWT consist of (epi) gallocatechin, epigallocatechin-3-O-gallate, epicatechin-3-O-gallate and an unknown monomer with the ratio of 1:73:1 by estimation of the peak area on HPLC. The antioxidant properties of persimmon tannins were evaluated using the hydroxyl radical scavenging activities by 2-deoxyribose oxidation system and salicylic acid system, superoxide anion scavenging activity, and linoleic acid lipid peroxidation inhibition activity, respectively. HMWT exhibited excellent antioxidant activities in all tested systems in a dose-dependent manner. The antioxidant activity of HMWT was significantly stronger than that of LMWT and grape seeds proanthocyanidins (GSP), suggesting that high molecular weight condensed tannins are the major antioxidant composition in persimmon pulp. (C) 2007 Elsevier Ltd. All rights reserved.