Antioxidant constituents and a new triterpenoid glycoside from Flos Lonicerae.
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-.
Choi
Chun-Whan
CW
Faculty of Food Science and Biotechnology, Pukyong National University, Busan 608-737, Korea.
Jung
Hyun Ah
HA
Kang
Sam Sik
SS
Choi
Jae Sue
JS
D000818:Animals; D000975:Antioxidants / Q000737:chemistry; D001713:Biphenyl Compounds; D002855:Chromatography, Thin Layer; D035264:Flowers; D016166:Free Radical Scavengers / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D006027:Glycosides / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D017665:Hydroxyl Radical / Q000737:chemistry; D066298:In Vitro Techniques; D007668:Kidney / Q000187:drug effects / Q000378:metabolism; D031239:Lonicera; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D013058:Mass Spectrometry; D015394:Molecular Structure; D030421:Peroxynitrous Acid / Q000737:chemistry; D010851:Picrates / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism; D012997:Solvents / Q000737:chemistry; D014315:Triterpenes / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology
D000975:Antioxidants; D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D006027:Glycosides; D010851:Picrates; D010936:Plant Extracts; D017382:Reactive Oxygen Species; D012997:Solvents; D014315:Triterpenes; D030421:Peroxynitrous Acid; D017665:Hydroxyl Radical; C004931:1,1-diphenyl-2-picrylhydrazyl