Isolation and structure of whiskey polyphenols produced by oxidation of oak wood ellagitannins
Isolation and structure of whiskey polyphenols produced by oxidation of oak wood ellagitannins
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DOI：
10.1021/jf8012713
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发表时间：
2008-08-27
影响因子：
6.1
通讯作者：
Kouno, Isao
中科院分区：
文献类型：
--
作者：
Fujieda, Miho;Tanaka, Takashi;Kouno, Isao
从日本威士忌酒中分离得到3种新的酚类化合物，分别命名为威士忌单宁A、B和羧基鞣花酸，沿着没食子酸、鞣花酸、短叶苏木素羧酸、3种没食子酰葡萄糖、酚葡萄糖的没食子酰酯、2，3-（S）-六羟基联苯酰葡萄糖和Castacrenin B。威士忌单宁A和B是主要橡木鞣花单宁Castalagin的氧化产物，其中Castalagin的葡萄糖C-1位上的连苯三酚环被氧化成环戊烯酮部分。这些单宁来源于橡木桶生产中所含的鞣花单宁;然而，在威士忌中没有检测到原始橡木鞣花单宁。为了检验威士忌单宁是否在制桶过程中产生，对Castalagin的热解产物进行了研究。分离出脱氢Castalagin和一种新的具有异香豆素结构的酚羧酸三内酯，沿着有Castacrenin F和鞣花酸。然而，在产品中未检测到威士忌单宁。
Three new phenolic compounds named whiskey tannins A and B and carboxyl ellagic acid were isolated from commercial Japanese whiskey, along with gallic acid, ellagic acid, brevifolin carboxylic acid, three galloyl glucoses, a galloyl ester of phenolic glucoside, 2,3-(S)-hexahydroxydiphenoylglucose, and castacrenin B. Whiskey tannins A and B were oxidation products of a major oak wood ellagitannin, castalagin, in which the pyrogallol ring at the glucose C-1 position of castalagin was oxidized to a cyclopentenone moiety. These tannins originated from ellagitannins contained in the oak wood used for barrel production; however, the original oak wood ellagitannins were not detected in the whiskey. To examine whether the whiskey tannins were produced during the charring process of barrel production, pyrolysis products of castalagin were investigated. Dehydrocastalagin and a new phenolcarboxylic acid trislactone having an isocoumarin structure were isolated, along with castacrenin F and ellagic acid. However, whiskey tannins were not detected in the products.