Bioscience, Integrated Center for Sciences, Ehime University, Shitsukawa, Toon, Ehime, Japan.
J Agric Food Chem. 2011 Aug 24;59(16):8646-54. doi: 10.1021/jf201679q. Epub 2011 Aug 1.
Polyphenolic compounds from chestnut astringent skin (CAS) were purified by dialysis, using Diaion HP-20 and Sephadex LH-20 columns. During purification, specific α-amylase inhibitory activities were increased about 3.4-fold, and the 50% inhibition value was 5.71 μg/mL in the Sephadex LH-20 fraction (SE-fraction). The SE-fraction contained about 67% of the total polyphenols, 57.3% of the flavanol-type tannins, and 51.3% of the procyanidins. Strong antioxidant activity was observed in the SE-fraction. Oral administration of the SE-fraction in rats fed corn starch significantly suppressed an increase in blood glucose levels. The SE-fraction contained gallic acid and ellagic acid. The MALDI-TOF spectrum showed a peak series exhibiting a mass increment of 288 Da, reflecting the variation in the number of catechin/epicatechin units. Our results suggest CAS contains polyphenols with strong α-amylase inhibitory activity. The data also suggest CAS polyphenols might be oligomeric proanthocyanidins with gallic acid and ellagic acid.
栗木单宁皮中的多酚化合物（CAS）经透析、Diaion HP-20 和 Sephadex LH-20 柱纯化。在纯化过程中，特定的α-淀粉酶抑制活性增加了约 3.4 倍，Sephadex LH-20 级分（SE 级分）的 50%抑制值为 5.71 μg/mL。SE 级分含有约 67%的总多酚、57.3%的黄烷醇型单宁和 51.3%的原花青素。SE 级分表现出强烈的抗氧化活性。在给予淀粉喂养大鼠 SE 级分的口服给药中，明显抑制了血糖水平的升高。SE 级分含有没食子酸和鞣花酸。MALDI-TOF 谱显示出一系列峰，其质量增量为 288 Da，反映了儿茶素/表儿茶素单元数量的变化。我们的结果表明，CAS 含有具有强α-淀粉酶抑制活性的多酚。数据还表明，CAS 多酚可能是具有没食子酸和鞣花酸的低聚原花青素。
