title: Anti-complement activity of constituents from the stem-bark of Juglans mandshurica.
abstract: Four known flavonoids and two galloyl glucoses isolated from the stem-bark of Juglans mandshurica (Juglandaceae), namely taxifolin (1), afzelin (2), quercitrin (3), myricitrin (4), 1,2,6-trigalloylglucose (5), and 1,2,3,6-tetragalloylglucose (6), were evaluated for their anti-complement activity against complement system. Afzelin (2) and quercitrin (3) showed inhibitory activity against complement system with 50% inhibitory concentrations (IC(50)) values of 258 and 440 microM. 1,2,6-Trigalloylglucose (5) and 1,2,3,6-tetragalloylglucose (6) exhibited anti-complement activity with IC(50) values of 136 and 34 microM. In terms of the evaluation of the structure-activity relationship of 3,5,7-trihydroxyflavone, compounds 2, 3, and 4 were hydrolyzed with naringinase to give kaempferol (2a), quercetin (3a), and myricetin (4a) as their aglycones, and these were also tested for their anti-complement activity. Of the three aglycones, kaempferol (2a) exhibited weak anti-complement activity with an IC(50) value of 730 microM, while quercetin (3a) and myricetin (4a) were inactive in this assay system. Among the compounds tested, 1,2,3,6-tetragalloylglucose (6) showed the most potent anticomplement activity (IC(50), 34 microM).
authors.affiliation: Laboratory of Immunomodulator, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Korea.
authors.forename: Byung-Sun
authors.initials: BS
authors.lastname: Min
authors.forename: Sun-Young
authors.initials: SY
authors.lastname: Lee
authors.forename: Jung-Hee
authors.initials: JH
authors.lastname: Kim
authors.forename: Joong-Ku
authors.initials: JK
authors.lastname: Lee
authors.forename: Tae-Jin
authors.initials: TJ
authors.lastname: Kim
authors.forename: Dong-Hee
authors.initials: DH
authors.lastname: Kim
authors.forename: Young-Ho
authors.initials: YH
authors.lastname: Kim
authors.forename: Hyouk
authors.initials: H
authors.lastname: Joung
authors.forename: Hyeong-Kyu
authors.initials: HK
authors.lastname: Lee
authors.forename: Norio
authors.initials: N
authors.lastname: Nakamura
authors.forename: Hirotsugu
authors.initials: H
authors.lastname: Miyashiro
authors.forename: Masao
authors.initials: M
authors.lastname: Hattori
mesh_terms: D000818:Animals; D003169:Complement Inactivator Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D003165:Complement System Proteins / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D031324:Juglans; D008297:Male; D024301:Plant Bark; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D018547:Plant Stems; D012756:Sheep
chemical_list: D003169:Complement Inactivator Proteins; D010936:Plant Extracts; D003165:Complement System Proteins