Rubusuaviins a-f, monomeric and oligomeric ellagitannins from chinese sweet tea and their α-amylase inhibitory activity
Rubusuaviins a-f, monomeric and oligomeric ellagitannins from chinese sweet tea and their α-amylase inhibitory activity
复制标题
DOI：
10.1248/cpb.55.1325
复制
发表时间：
2007-09-01
影响因子：
1.7
通讯作者：
Kouno, Isao
中科院分区：
文献类型：
--
作者：
Li, Haizhou;Tanaka, Takashi;Kouno, Isao
从甜茶（甜茶）的丙酮水提物中分离得到六个新鞣花单宁，命名为甜茶酸悬钩子素（RubussuavissimusS.李）连同七个已知的单宁。Rubuaviin A的化学结构为1-O-没食子酰基-2，3-O-（S）-HHDP-4，6-O-（S）-sanguisorboyl-beta-D-glucopyranose。悬钩子素B、C和E分别是二聚体、三聚体和四聚体鞣花单宁，其中血醇基连接鞣花单宁单元。甜茶素D和F分别是甜茶素C和E的脱没食子酰基衍生物。比较了甜茶苷和相关鞣花单宁对α-淀粉酶活性的抑制作用。在葡萄糖C-1位具有β-没食子酰基的鞣花单宁与α-没食子酰基和去没食子酰基化合物相比显示出更强的抑制作用。这些化合物的分子量对α-淀粉酶活性的抑制并不重要。
Six new ellagitannins herein, rubusuaviins A-F, were isolated from the aqueous acetone extract of Chinese sweet tea (Tien-cha, dried leaves of Rubus suavissimus S. LEE) together with seven known tannins. Rubusuaviin A was characterized as 1-O-galloyl-2,3-O-(S)-HHDP-4,6-O-(S)-sanguisorboyl-beta-D-glucopyranose. Rubusuaviins B, C, and E are dimeric, trimeric, and tetrameric ellagitannins, respectively, in which the sanguisorboyl groups were connected ellagitannin units. Rubusuaviins D and F were desgalloyl derivatives of rubusuaviins C and E, respectively. The inhibition of a-amylase activity by rubusuaviins and related ellagitannins was compared. Ellagitannins with beta-galloyl groups at the glucose C-1 positions showed stronger inhibition compared with the alpha-galloyl and desgalloyl compounds. The molecular weight of these compounds was not important for the inhibition of a-amylase activity.