title: Isolation and characterization of a new steroid derivative as a powerful antioxidant from Cleome arabica in screening the in vitro antioxidant capacity of 18 Algerian medicinal plants.
abstract: Hydromethanolic extracts from 18 Algerian medicinal plants were screened for their phenolic contents and radical scavenging activities. The phenolic extract of Cleome arabica (Capparaceae) was found to be the most active one. Purification of this extract by semi-preparative high performance liquid chromatography led to the isolation and identification of new steroid derivative. The structure of the active principle is proposed as (17-(4-hydroxy-1,5-dimethylhexyl)-2,3,7-(acetyloxy) gona-1,3,5(10)-trien-15-ol). Compared to six other standard antioxidants which were ascorbic acid, α-tocopherol, Trolox, (+) catechin, p-coumaric acid and gallic acid, the isolated compound was found to be significantly more active in the radical scavenging assay using 2,2-diphenyl-1-picrylhydrazyl (DPPH). Similar results were obtained in the hemolysis assay. The antioxidant capacities of the methanolic extract of C. arabica and its principle compound indicate that this plant may be an important source of chemopreventive and chemotherapeutic natural products activity.
authors.affiliation: Laboratoire des Sciences Fondamentales, Université Amar Telidji, Laghouat, BP37G Laghouat, Algeria. djeridane_O@yahoo.fr
authors.forename: Amar
authors.initials: A
authors.lastname: Djeridane
authors.forename: Mohamed
authors.initials: M
authors.lastname: Yousfi
authors.forename: Jean Michel
authors.initials: JM
authors.lastname: Brunel
authors.forename: Pierre
authors.initials: P
authors.lastname: Stocker
mesh_terms: D000462:Algeria; D000975:Antioxidants; D001713:Biphenyl Compounds; D002138:Calibration; D002851:Chromatography, High Pressure Liquid; D031485:Cleome / Q000737:chemistry*; D016166:Free Radical Scavengers / Q000737:chemistry / Q000494:pharmacology; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D009682:Magnetic Resonance Spectroscopy; D010636:Phenols / Q000737:chemistry / Q000494:pharmacology; D010851:Picrates; D010946:Plants, Medicinal / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013256:Steroids / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D010636:Phenols; D010851:Picrates; D013256:Steroids; C004931:1,1-diphenyl-2-picrylhydrazyl