Zhang Lu, Tu Zong-cai, Yuan Tao, Ma Hang, Niesen Daniel B, Wang Hui, Seeram Navindra P
Nat Prod Commun. 2015 Nov;10(11):1977-80.
The maple (Acer) genus is a reported source of bioactive (poly)phenols, including gallotannins, but several of its members, such as the sycamore maple (A. pseudoplatanus), remain uninvestigated. Herein, thirty-nine compounds, including a new gallotannin, 1,2,3-tri-O-galloyl-6-O-(p-hydroxybenzoyl)-β-D- glucopyranoside (1), and thirty-eight (2-39) known compounds, consisting of four gallotannins, one ellagitannin, thirteen flavonoids, eight hydroxycinnamic acids, ten benzoic acid derivatives, and two sesquiterpenoids, were isolated from sycamore maple leaves. Their structures were determined based on NMR and mass spectral analyses. The isolates were evaluated for α-glucosidase inhibitory and antioxidant activities. Among the isolates, the gallotannins were the most potent α-glucosidase inhibitors with thirteen-fold more potent activity compared with the clinical drug, acarbose (IC50 = 16-31 vs. 218 µM). Similarly, the gallotannins showed the highest antioxidant activities, followed by the other phenolic sub-classes, while the sesquiterpenoids were inactive.
据报道，枫树属（槭属）植物是生物活性（多）酚类物质的来源，包括没食子鞣质，但该属的一些成员，如英国梧桐（Acer pseudoplatanus），仍未得到研究。本文从英国梧桐叶中分离出39种化合物，其中包括一种新的没食子鞣质1,2,3-三-O-没食子酰基-6-O-（对羟基苯甲酰基）-β-D-吡喃葡萄糖苷（1）以及38种（2 - 39）已知化合物，这些已知化合物包括4种没食子鞣质、1种鞣花单宁、13种黄酮类化合物、8种羟基肉桂酸、10种苯甲酸衍生物和2种倍半萜类化合物。通过核磁共振和质谱分析确定了它们的结构。对分离出的化合物进行了α-葡萄糖苷酶抑制活性和抗氧化活性评估。在这些分离出的化合物中，没食子鞣质是最有效的α-葡萄糖苷酶抑制剂，其活性比临床药物阿卡波糖高13倍（IC50 = 16 - 31 μM对218 μM）。同样，没食子鞣质表现出最高的抗氧化活性，其次是其他酚类亚类，而倍半萜类化合物没有活性。
