红背山麻杆叶的化学成分研究(Ⅲ)——奎宁酸类化合物（英文）

Chemical constituents from the leaves of Alchornea trewioides(Ⅲ). Quinic acids

红背山麻杆作为一种常用的传统中药材,它常常被用来治疗前列腺、腰腿痛、炎症等疾病,它的化学成分及抗氧化活性已有研究报道。为了继续研究红背山麻杆的化学成分,以掌握其物质基础,对新鲜叶子80%丙酮提取物水萃取部位,利用凝胶、MCI及Toyopearl Butyl-650C柱色谱进行分离、纯化得到5个奎宁酸类化合物。根据化合物的波谱数据分析鉴定为3-O-咖啡酰基奎宁酸（1）、4-O-咖啡酰基奎宁酸（2）、5-O-咖啡酰基奎宁酸（3）、4-O-galloylquinic acid（4）、5-O-galloylquinic acid（5）。化合物1~5均为首次从本属植物中分离得到。通过抗氧化能力指数检测（ORAC法）,所有的化合物均表现出较强的抗氧化活性。

Alchornea trewioides is a kind of Traditional Chinese Medicine,which was used to treat prostate gland,shigella,lumbocrural pain,inflammation and other diseases in China,and its chemical constituents and antioxidation activity have been reported.To continue invested the chemical composition and master the material basis of A.trewioides,80% acetone extracts of the fresh leaves of A.trewioides was successively separated by Sephadex LH-20,MCI gel CHP 20 P,and Toyopearl Butyl-650 Ccolumn chromatography to yield five quinic acids.Their structures were elucidated spectroscopic analyses as：3-O-caffeoylquinic acid（1）,4-O-caffeoylquinic acid（2）,5-O-caffeoylquinic acid（3）,4-O-galloylquinic acid（4）,and 5-O-galloylquinic acid（5）.Compounds 1-5 were isolated from the Alchornea for the first time.Oxygen radical absorbance capacity（ORAC）of the all compounds were also compared and compounds 1-5 were observed to show the strongest antioxidation activity.