桑椹提取物中酚类化合物的抗氧化及抗糖基化活性分析

利用葡聚糖凝胶层析柱将桑椹提取物分为6 个组分（F1、F2、F3、F4、F5、F6），研究了桑椹中酚类化合物的抗氧化能力和抗糖基化能力。采用Folin-酚法、pH示差法和高效液相色谱法测定各组分总酚、总花色苷含量和酚类化合物成分；通过1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl，DPPH）自由基、2,2’-联氮-二（3-苯并噻唑-6-磺酸）（2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)，ABTS）自由基清除率和亚铁还原能力实验评价各组分抗氧化能力；建立牛血清白蛋白-果糖模拟反应体系和牛血清白蛋白-丙酮醛模拟反应体系评价各组分抗糖基化能力。结果表明：桑椹提取物中检测出5 种酚酸、两种花色苷和两种黄酮类物质；F3的总花色苷含量最高（P＜0.05，（101.10±2.39） mg 矢车菊素-3-葡萄糖苷当量/g），F5的总酚含量最高（P＜0.05，（188.05±2.01） mg 没食子酸当量/g）；F3的抗氧化能力显著高于其他组分（P＜0.05，DPPH自由基清除能力、ABTS＋·清除能力、亚铁还原能力分别为（129.33±5.58）、（194.33±2.48）、（130.44±1.38） mmol Trolox/g），F5的抗糖基化能力显著强于其他组分（P＜0.05，牛血清白蛋白-果糖模拟反应体系和牛血清白蛋白-丙酮醛模拟反应体系中的糖基化抑制率分别为（87.23±0.36）%和（66.99±1.62）%）；桑椹提取物的抗氧化能力、抗糖基化能力分别与总花色苷、总酚含量呈现显著的回归关系（P＜0.05）。

Antioxidant and Antiglycation Activities of Phenolic Compounds Extracted from Mulberry Fruits

The present study aims at evaluating the antioxidant and antiglycation activities of mulberry extracts rich in
phenolics and the relationships between phenolic components and their activities. Mulberry fruit (Morus atropurpurea
Roxb.) extract was separated by Sephadex LH-20 gel filtration column chromatography into six fractions (F1, F2, F3, F4, F5
and F6). Total phenolics and total anthocyanins of different fractions and their main phenolic components were quantified by
Folin-Ciocalteu method, pH differential method and high performance liquid chromatography (HPLC). DPPH and ABTS+
radical scavenging and ferric reducing assays were conducted to evaluate the antioxidant abilities of fractions. Bovine
serum albumin (BSA)-fructose and BSA-methyglyoxal (MGO) models were applied for the measurement of antiglycation
capacity. The results indicated that the extracts contained mainly five phenolic acids (gallic acid, hydroxybenzoic acid,
caffeic acid, p-coumaric acid and o-coumaric acid), two anthocyanins (cyanidin-3-glucoside and cyanidin-3-rutinoside)
and two flavonoids (rutin and quercetin). Fraction F3 contained the highest amount of anthocyanin ((101.10 ± 2.39) mg
cyanidin-3-glucoside/g md, P < 0.05) and F5 was the richest in total phenolic compounds ((188.05 ± 2.01) mg gallic acid
equivalent/g md, P < 0.05). F3 had the highest antioxidant capacity among fractions (P < 0.05, which showed DPPH
and ABTS+ radical scavenging activity of (129.33 ± 5.58) and (194.33 ± 2.48) mmol/g and ferric reducing power of
(130.44 ± 1.38) mmol/g, respectively) while the antiglycation capacity of F5 was the highest (P < 0.05), with percentage
inhibition of (87.23 ± 0.36)% and (66.99 ± 1.62)% in BSA-fructose and BSA-MGO model, respectively. The linear
regression analysis showed that the antioxidant capacity of the extracts was due mostly to anthocyanins and their
antiglycation activity was attributed to total phenolic compounds.