title: Biotransformation of 4,5-O-dicaffeoylquinic acid methyl ester by human intestinal flora and evaluation on their inhibition of NO production and antioxidant activity of the products.
abstract: 4,5-O-Dicaffeoylquinic acid methyl ester (1) was anaerobically incubated with human intestinal flora and four biotransformation products (2-5) were obtained. Their structures were elucidated as 3,4-O-dicaffeoylquinic acid methyl ester (2), 3-hydroxyphenylpropionic acid (3), trans-caffeic acid (4) and 3,4-dihydroxyphenylpropionic acid (5) on the basis of their spectroscopic data. Using high-performance liquid chromatography equipped with a diode array detector, chromatographic separation of 1-5 was performed on an analytical C18 column. The time course of the biotransformation was studied to probe into the biotransformation mechanism of 1 by human intestinal flora. In addition, the inhibitory activity of the parent compound 1 and its four main biotransformation products 2-5 on the inhibition of nitric oxide production induced by lipopolysaccharide in macrophage cell line RAW 264.7 and their DPPH free radical-scavenging activity in cell-free bioassay system were estimated.
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs (Peking University), Department of Natural Medicines, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China. xwyang@bjmu.edu.cn
authors.forename: Xiu-Wei
authors.initials: XW
authors.lastname: Yang
authors.forename: Nan
authors.initials: N
authors.lastname: Wang
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Wei
authors.initials: W
authors.lastname: Xu
authors.forename: Shuai
authors.initials: S
authors.lastname: Wu
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D001711:Biotransformation; D006801:Humans; D007422:Intestines / Q000382:microbiology*; D057230:Limit of Detection; D009569:Nitric Oxide / Q000096:biosynthesis*; D011801:Quinic Acid / Q000031:analogs & derivatives* / Q000493:pharmacokinetics
chemical_list: C508224:4,5-o-dicaffeoylquinic acid methyl ester; D000975:Antioxidants; D011801:Quinic Acid; D009569:Nitric Oxide