title: Chlorinated iridoid glucosides from Veronica longifolia and their antioxidant activity.
abstract: From Veronica longifolia were isolated three chlorinated iridoid glucosides, namely, asystasioside E (6) and its 6-O-esters 6a and 6b, named longifoliosides A and B, respectively. The structures of 6a and 6b were proved by analysis of their spectroscopic data and by conversion to the catalpol ester verproside (5a) or to catalpol (5), respectively. The configuration of the previously known vanilloyl analogue, urphoside B, was shown to be the 6β-epimer (6c) of the structure originally reported. Longifoliosides A (6a) and B (6b) were found to exhibit radical-scavenging activity against nitric oxide, superoxide, and 2,2-diphenyl-1-picrylhydrazyl radicals.
authors.affiliation: Department of Chemistry, The Technical University of Denmark, DK-2800, Lyngby, Denmark. srj@kemi.dtu.dk
authors.forename: Søren R
authors.initials: SR
authors.lastname: Jensen
authors.forename: Charlotte H
authors.initials: CH
authors.lastname: Gotfredsen
authors.forename: U Sebnem
authors.initials: US
authors.lastname: Harput
authors.forename: Iclal
authors.initials: I
authors.lastname: Saracoglu
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D001713:Biphenyl Compounds / Q000494:pharmacology; D004952:Esters; D005858:Germany; D005960:Glucosides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D006843:Hydrocarbons, Chlorinated / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D039823:Iridoids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D015394:Molecular Structure; D009569:Nitric Oxide / Q000378:metabolism; D010851:Picrates / Q000494:pharmacology; D013481:Superoxides / Q000494:pharmacology; D032264:Veronica / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D004952:Esters; D005960:Glucosides; D006843:Hydrocarbons, Chlorinated; D039823:Iridoids; D010851:Picrates; C552993:asystasioside E; D013481:Superoxides; D009569:Nitric Oxide; C004931:1,1-diphenyl-2-picrylhydrazyl