title: Antioxidant activity-guided phytochemical investigation of Artemisia gmelinii Webb. ex Stechm.: isolation and spectroscopic challenges of 3,5-O-dicaffeoyl (epi?) quinic acid and its ethyl ester.
abstract: Although Artemisia gmelinii Webb. ex Stechm. has long been used in south and south-east Asia to treat many kinds of inflammatory diseases, up until now its bioactivity-coupled phytochemical characterization has not been reported. We identified one fraction of the methanolic extract of A. gmelinii as a hit in our antioxidant screening (DPPH) campaign. In order to identify the active radical scavenger components of the extract, a DPPH-HPLC spiking assay was carried out. Out of six detected known compounds caffeic acid and scopoletin had already been identified in the plant, but four of them, namely chlorogenic acid, 4-O-caffeoylquinic acid, luteolin-7-O-glucoside, and apigenin-7-O-glucoside are first described here. Moreover, the two most active compounds of the mixture, 3,5-O-dicaffeoylquinic acid (7) and its ethyl ester derivative (8) were isolated with preparative HPLC. The spectroscopic identification of 7 and 8 presented a surprising challenge due to literature ambiguities. These questions are discussed in detail.
authors.affiliation: Compound Profiling Laboratory, Gedeon Richter Plc., H-1475 Budapest, Hungary.
authors.forename: Arpád
authors.initials: A
authors.lastname: Könczöl
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Béni
authors.forename: Márta Meszlényi
authors.initials: MM
authors.lastname: Sipos
authors.forename: Attila
authors.initials: A
authors.lastname: Rill
authors.forename: Viktor
authors.initials: V
authors.lastname: Háda
authors.forename: Judit
authors.initials: J
authors.lastname: Hohmann
authors.forename: Imre
authors.initials: I
authors.lastname: Máthé
authors.forename: Csaba
authors.initials: C
authors.lastname: Szántay
authors.forename: György Miklós
authors.initials: GM
authors.lastname: Keseru
authors.forename: György Tibor
authors.initials: GT
authors.lastname: Balogh
mesh_terms: D019306:Artemisia / Q000737:chemistry*; D001713:Biphenyl Compounds / Q000737:chemistry*; D002726:Chlorogenic Acid / Q000031:analogs & derivatives* / Q000302:isolation & purification / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D016166:Free Radical Scavengers / Q000302:isolation & purification* / Q000494:pharmacology; D005609:Free Radicals / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D010851:Picrates / Q000737:chemistry*; D035261:Plant Components, Aerial / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization; D013329:Structure-Activity Relationship
chemical_list: C572400:3,5-dicaffeoylquinic acid ethyl ester; D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D005609:Free Radicals; D010851:Picrates; D010936:Plant Extracts; D002726:Chlorogenic Acid; C004931:1,1-diphenyl-2-picrylhydrazyl; C100434:3,5-dicaffeoylquinic acid