title: Xanthine oxidase inhibitory activities and crystal structures of methoxyflavones from Kaempferia parviflora rhizome.
abstract: Kaempferia parviflora (KP), a Zingiberaceae plant, is used as a folk medicine in Thailand for the treatment of various symptoms, including general pains, colic gastrointestinal disorders, and male impotence. In this study, the inhibitory activities of KP against xanthine oxidase (XOD) were investigated. The extract of KP rhizomes showed more potent inhibitory activity (38% at 500 µg/ml) than those of the other Zingiberaceae plants tested. Ten methoxyflavones were isolated from the KP extract as the major chemical components and their chemical structures were elucidated by X-ray crystallography. The structurally confirmed methoxyflavones were subjected to the XOD inhibitory test. Among them, 3,5,7,4',5'-pentamethoxyflavone and 3',4',5,7-tetramethoxyflavone showed inhibitory activities (IC(50) of 0.9 and >4 mM, respectively) and their modes of inhibition are clarified as competitive/non-competitive mixed type. To the best of our knowledge, this is the first report to present the inhibitory activities of KP, 3,5,7,4',5'-pentamethoxyflavone and 3',4',5,7-tetramethoxyflavone against XOD.
authors: Research Institute of Oriental Medicine, Kinki University, 377–2 Ohno-higashi, Osakasayama, Osaka 589–8511, Japan.
authors: Kikuyo
authors: K
authors: Nakao
authors: Kazuya
authors: K
authors: Murata
authors: Takahiro
authors: T
authors: Deguchi
authors: Kimihisa
authors: K
authors: Itoh
authors: Takanori
authors: T
authors: Fujita
authors: Masayuki
authors: M
authors: Higashino
authors: Yuri
authors: Y
authors: Yoshioka
authors: Shin-Ichi
authors: S
authors: Matsumura
authors: Rika
authors: R
authors: Tanaka
authors: Tetsuro
authors: T
authors: Shinada
authors: Yasufumi
authors: Y
authors: Ohfune
authors: Hideaki
authors: H
authors: Matsuda
mesh_terms: D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D047309:Flavones / Q000737:chemistry / Q000494:pharmacology*; D008958:Models, Molecular; D015394:Molecular Structure; D013057:Spectrum Analysis; D014961:X-Ray Diffraction; D014969:Xanthine Oxidase / Q000037:antagonists & inhibitors*; D030521:Zingiberaceae / Q000737:chemistry*
chemical_list: D004791:Enzyme Inhibitors; D047309:Flavones; D014969:Xanthine Oxidase