title: Angiotensin converting enzyme inhibitors from Cuscuta japonica Choisy.
abstract: Bioassay-guided fractionation of the EtOAc-soluble extract of Cuscuta japonica afforded 3,5-Di-O-caffeoylquinic acid (1). methyl 3,5-Di-O-caffeoylquinate (2). 3,4-Di-O-caffeoylquinic acid (3). and methyl 3,4-Di-O-caffeoylquinate (4). Purification of these compounds was conducted with the application of various chromatographic methods. The structures of the compounds were elucidated on the basis of MS and NMR data analysis. Compounds 1-4 inhibited the angiotensin I converting enzyme activity in a dose-dependent manner. Compounds 1-4 showed the 50% inhibitory concentration values of 596, 483, 534, and 460 micro M, respectively. The presence of these active components may be responsible, at least in part, for the antihypertensive action of traditional crude drug Cuscuta Semen.
authors.affiliation: Professional Graduate School of Oriental Medicine, Wonkwang University, Iksan, Chonbuk 570-749, Republic of Korea.
authors.forename: Hyuncheol
authors.initials: H
authors.lastname: Oh
authors.forename: Dae-Gill
authors.initials: DG
authors.lastname: Kang
authors.forename: Sunyoung
authors.initials: S
authors.lastname: Lee
authors.forename: Ho-Sub
authors.initials: HS
authors.lastname: Lee
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D034182:Cuscuta; D004305:Dose-Response Relationship, Drug; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008517:Phytotherapy; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology*; D011801:Quinic Acid / Q000031:analogs & derivatives*; D012639:Seeds
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D010936:Plant Extracts; D011801:Quinic Acid