Antioxidant flavone glycosides from the leaves of Sasa borealis.
Sasa borealis (Poaceae) is a perennial medicinal plant which is a major source of bamboo leaves in Korea. The n-BuOH extract of S. borealis leaves exhibited significant antioxidant activity against the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and a cytoprotective effect against oxidative damage in HepG2 cells. Bioactivity-guided fractionation by column chromatography led to the isolation of two antioxidative flavonoid C-glycoside derivatives, isoorientin (2) and isoorientin 2"-O-alpha-L-rhamnoside (4) along with tricin 7-O-beta-D-glucopyranoside (1) and apigenin 6-C-beta-D-xylopyranosyl-8-C-beta-D-glucopyranoside (3). Their structures were identified on the basis of chemical and spectroscopic methods. The radical scavenging activity and cytoprotective effect against oxidative damage of all the isolated compounds were also evaluated. Isoorientin (2) and isoorientin 2-O-alpha-L-rhamnoside (4) showed potent free radical scavenging activity with IC50 values of 9.5 and 34.5 microM, respectively, and strong cytoprotective effects against t-BOOH-induced oxidative damage in HepG2 cells, at very low concentrations of 1.1 microM isoorientin and 0.8 microM isoorientin 2-O-alpha-L-rhamnoside. This is the first report of the isolation and antioxidant activity of compounds 2 and 4 from S. borealis.
Park
Hae-Suk
HS
College of Pharmacy and Research Institute of Drug Development, Chonnam National University, Gwangju 500-757, Korea.
Lim
Ju Hee
JH
Kim
Hyun Jung
HJ
Choi
Hyun Jin
HJ
Lee
Ik-Soo
IS
D001713:Biphenyl Compounds / Q000737:chemistry; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D047309:Flavones / Q000302:isolation & purification / Q000494:pharmacology*; D016166:Free Radical Scavengers / Q000302:isolation & purification / Q000494:pharmacology*; D006027:Glycosides / Q000302:isolation & purification / Q000494:pharmacology*; D006801:Humans; D006834:Hydrazines / Q000737:chemistry; D015394:Molecular Structure; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000187:drug effects; D010851:Picrates; D018515:Plant Leaves / Q000737:chemistry; D031787:Sasa / Q000737:chemistry*; D013329:Structure-Activity Relationship; D020122:tert-Butylhydroperoxide / Q000633:toxicity
D001713:Biphenyl Compounds; D047309:Flavones; D016166:Free Radical Scavengers; D006027:Glycosides; D006834:Hydrazines; D010851:Picrates; D020122:tert-Butylhydroperoxide; C004931:1,1-diphenyl-2-picrylhydrazyl