Simultaneous quantification and validation of new peroxynitrite scavengers from Artemisia iwayomogi

Context: Artemisia iwayomogi Kitamura (Compositae) has been very widely used for the treatment of acute or chronic hepatitis, jaundice, and gastritis. In the course of our continuing efforts to identify and quantify peroxynitrite scavengers from Compositae plants, Artemisia iwayomogi was used in this study. Objective: The present study was aimed to identify and quantify the peroxynitrite scavengers of Artemisia iwayomogi. Materials and methods: Silica gel and ODS were used for column chromatography. The isolated compounds were quantified using an HPLC equipped with a Capcell Pak C18 column (5 mu m, 250 mm x 4.6 mm i.d.), and the method was validated for the quality control. Peroxynitrite (ONOO-)-scavenging activities of the compounds and extracts were evaluated on the measurement of highly fluorescent rhodamine 123 converted from non-fluorescent dihydrorhodamine (DHR)-123 under the presence of peroxynitrite. Results: Based on the spectroscopic evidences, a new compound, 2 ''-O-caffeoylrutin (2 ''-O-trans-caffeic acid ester of quercetin 3-O-alpha-L-rhamnopyranosyl(1--> 6)-beta-D-glucopyranoside) was isolated and determined together with patuletin 3-O-glucoside, scopolin, scopoletin, rutin, 3,4-dicaffeoylquinic acid, and chlorogenic acid. All of them were potent peroxynitrite scavengers (IC50 <= 1.88 mu g/mL). Discussion and conclusion: The peroxynitrite scavengers were mainly distributed in the EtOAc fraction rather than the ether and BuOH fractions. The 70% MeOH extract exhibited a high peroxynitrite-scavenging activity. Through the validation, the present HPLC method was verified to be sufficiently sensitive, accurate, precise, and stable. Therefore, this method can be used for the quality control of Artemisia iwayomogi.