title: Anticomplement and antioxidant activities of new acetylated flavonoid glycosides from Centaurium spicatum.
abstract: In addition to the three acetylated flavonol glycosides, quercetin 3- O-[(2,3,4-triacetyl-alpha-rhamnopyranosyl)-(1-->6)]-beta-galactopyranoside, quercetin 3- O-[(2,3,4-triacetyl-alpha-rhamnopyranosyl)-(1-->6)]-3-acetyl-beta-galactopyranoside, and quercetin 3- O-[(2,3,4- triacetyl-alpha-rhamnopyranosyl)-(1-->6)]-4-acetyl-beta-galactopyranoside, which have recently been isolated from Centaurium spicatum (L.) Fritsch (Gentianaceae), a new pentaacetylated flavonoid glycoside was isolated from the same plant. Structure elucidation, especially the localization of the acetyl groups, and complete (1)H- and (13)C-NMR assignments, was carried out using one- and two-dimensional NMR methods, including (1)H- and (13)C-NMR, DEPT-135 and DEPT-90, and gradient-assisted experiments such as DQF-COSY, TOCSY, HSQC and HMBC. The structure of the new flavonoid glycoside was established as quercetin 3- O-[(2,3,4-triacetyl-alpha-rhamnopyranosyl)-(1-->6)]-3,4-diacetyl-beta-galactopyranoside. The anticomplement and antioxidant activities of these compounds were evaluated. The triacetylated flavonoid glycoside showed the highest activity in the two assays.
authors.affiliation: Pharmaceutical Sciences Department, NRC, Dokki, Cairo, Egypt. shahat@uia.ua.ac.be
authors.forename: Abdelaaty A
authors.initials: AA
authors.lastname: Shahat
authors.forename: Paul
authors.initials: P
authors.lastname: Cos
authors.forename: Nina
authors.initials: N
authors.lastname: Hermans
authors.forename: Sandra
authors.initials: S
authors.lastname: Apers
authors.forename: Tess
authors.initials: T
authors.lastname: De Bruyne
authors.forename: Luc
authors.initials: L
authors.lastname: Pieters
authors.forename: Dirk Vanden
authors.initials: DV
authors.lastname: Berghe
authors.forename: Arnold J
authors.initials: AJ
authors.lastname: Vlietinck
mesh_terms: D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology*; D001713:Biphenyl Compounds; D029966:Centaurium; D003169:Complement Inactivator Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005419:Flavonoids / Q000008:administration & dosage / Q000494:pharmacology*; D006027:Glycosides / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D020128:Inhibitory Concentration 50; D008517:Phytotherapy; D010851:Picrates / Q000737:chemistry; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D003169:Complement Inactivator Proteins; D005419:Flavonoids; D006027:Glycosides; D010851:Picrates; D010936:Plant Extracts; C012749:anticomplement; C004931:1,1-diphenyl-2-picrylhydrazyl