Antioxidant constituents and a new triterpenoid glycoside from Flos Lonicerae

• Published in: Archives of pharmacal research 2007, 30(1), , pp.1-7
• Main Authors: Choi, Chun-Whan, Jung, Hyun Ah, Kang, Sam Sik, Choi, Jae Sue
• Format: Article
• Language: English
• Subjects: Animals; Antioxidants - chemistry; Biphenyl Compounds; Chromatography, Thin Layer; Flowers; Free Radical Scavengers - chemistry; Free Radical Scavengers - isolation & purification; Free Radical Scavengers - pharmacology; Glycosides - chemistry; Glycosides - isolation & purification; Glycosides - pharmacology; Hydroxyl Radical - chemistry; In Vitro Techniques; Kidney - drug effects; Kidney - metabolism; Lonicera; Magnetic Resonance Spectroscopy; Male; Mass Spectrometry; Molecular Structure; Peroxynitrous Acid - chemistry; Picrates - chemistry; Plant Extracts - chemistry; Plant Extracts - pharmacology; Rats; Rats, Wistar; Reactive Oxygen Species - metabolism; Solvents - chemistry; Triterpenes - chemistry; Triterpenes - isolation & purification; Triterpenes - pharmacology; 약학
• ISSN: 0253-6269; 1976-3786
• DOI: 10.1007/BF02977770

As a component of our continuing investigations into herb-derived antioxidant agents, we have evaluated the antioxidant effects of Flos Lonicerae (Lonicera japonica flowers), via 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, total reactive oxygen species (ROS), hydroxyl radical (*OH), and peroxynitrite (ONOO-) assays. Among the methanolic extract and the dichloromethane, ethyl acetate, n-butanol, and water fractions, the EtOAc fraction of Flos Lonicerae exhibited marked scavenging/inhibitory activities, as follows: IC50 values of 4.37, 27.58 +/- 0.71, 0.47 +/- 0.05, and 12.13 +/- 0.79 microg/mL in the DPPH, total ROS, ONOO-, and *OH assays, respectively. Via a bioactivity-guided fractionation approach, a new triterpenoid glycoside, oleanolic acid 28-O-alpha-L-rhamnopyranosyl-(1-->2)-[beta-D-xylopyranosyl(1-->6)]-beta-D-glucopyranosyl ester (12), along with eleven known compounds, including chrysoeriol (1), luteolin (2), 5-hydroxymethyl-2-furfural (3), caffeic acid (4), protocatechuic acid (5), chrysoeriol 7-O-beta-D-glucopyranoside (6), isorhamnetin 3-O-beta-D-glucopyranoside (7), kaempferol 3-O-beta-D-glucopyranoside (8), quercetin 3-O-beta-D-glucopyranoside (9), hederagenin 3-O-alpha-L-arabinopyranoside (10), and luteolin 7-O-beta-D-glucopyranoside (11), were isolated from the EtOAc fraction. The structures of isolated compounds 1-12 were elucidated via spectroscopic analyses. Compound 12 was isolated from a natural source for the first time. Compounds 2, 4, 5, 7, 9, and 11 evidenced marked scavenging activities, with IC50 values of 2.08-11.76 microM for DPPH radicals, and 1.47-6.98 microM for ONOO-.