title: Anti-complementary activity of protostane-type triterpenes from Alismatis rhizoma.
abstract: Four protostane-type triterpenes, alisol B 23-acetate (1a), alisol C 23-acetate (2a), alisol B (3a), and alisol A 24-acetate (4a), were isolated from the rhizome of Alismatis plantago-aquatice L. var. orientale Samuelson (Alismataceae) and eleven protostane derivatives (compounds 1-11) were obtained by selective modification from alisol B 23-acetate (1a). These compounds were investigated for their anti-complement activity against the classical pathway of the complement system. Alisol B (3a) and alisol A 24-acetate (4a) exhibited anti-complement activity with IC50 values of 150 and 130 microM. Among the synthetic derivatives, the tetrahydroxylated protostane triterpene (9) showed moderate inhibitory activity with IC50 value of 97.1 microM. Introduction of an aldehyde group at C-23 (10; IC50 value, 47.7 microM) showed the most potent inhibitory effect on the complement system in vitro.
authors.affiliation: Laboratory of Immunomodulator, Korea Research Institute of Bioscience, Biotechnology, P.O. Box 115, Yusong, Daejeon 305-333, Korea.
authors.forename: Sang Myung
authors.initials: SM
authors.lastname: Lee
authors.forename: Jung Hee
authors.initials: JH
authors.lastname: Kim
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Ren Bo
authors.initials: RB
authors.lastname: An
authors.forename: Byung Sun
authors.initials: BS
authors.lastname: Min
authors.forename: Hyouk
authors.initials: H
authors.lastname: Joung
authors.forename: Hyeong Kyu
authors.initials: HK
authors.lastname: Lee
mesh_terms: D034901:Alismataceae; D003169:Complement Inactivator Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D003165:Complement System Proteins; D006801:Humans; D020128:Inhibitory Concentration 50; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D027343:Rhizome; D014315:Triterpenes / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D003169:Complement Inactivator Proteins; D010936:Plant Extracts; D014315:Triterpenes; D003165:Complement System Proteins