Structural determination and DPPH radical-scavenging activity of two acylated flavonoid tetraglycosides in oolong tea (Camellia sinensis).
Two major acylated flavonoid tetraglycosides were isolated from the methanol extract of oolong tea. Their structures were elucidated by spectroscopic methods as quercetin 3-O-[2(G)-(E)-coumaroyl-3(G)-O-beta-D-glucosyl-3(R)-O-beta-D-glucosylrutinoside] (1) and kaempferol 3-O-[2(G)-(E)-coumaroyl-3(G)-O-beta-D-glucosyl-3(R)-O-beta-D-glucosylrutinoside] (2). Compounds 1 and 2 exhibited scavenging activity against DPPH radical with EC(50) values of 30.5 and 487.2 microM, respectively.
Lee
Viola Szu-Yuan
VS
Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, Taiwan.
Chen
Chiy-Rong
CR
Liao
Yun-Wen
YW
Tzen
Jason Tze-Cheng
JT
Chang
Chi-I
CI
D000215:Acylation; D001713:Biphenyl Compounds; D028244:Camellia / Q000737:chemistry*; D002236:Carbohydrate Conformation; D005419:Flavonoids / Q000737:chemistry* / Q000302:isolation & purification; D016166:Free Radical Scavengers / Q000737:chemistry*; D005960:Glucosides / Q000737:chemistry* / Q000302:isolation & purification; D006027:Glycosides / Q000737:chemistry / Q000302:isolation & purification; D006868:Hydrolysis; D044949:Kaempferols / Q000737:chemistry* / Q000302:isolation & purification; D009682:Magnetic Resonance Spectroscopy; D010851:Picrates / Q000737:chemistry*; D011794:Quercetin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000302:isolation & purification; D012503:Saponins / Q000737:chemistry; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet
D001713:Biphenyl Compounds; D005419:Flavonoids; D016166:Free Radical Scavengers; D005960:Glucosides; D006027:Glycosides; D044949:Kaempferols; D010851:Picrates; D012503:Saponins; C530118:kaempferol 3-O-(2(G)-(E)-coumaroyl-3(G)-O-beta-D-glucosyl-3(R)-O-beta-D-glucosylrutinoside); C530117:quercetin 3-O-(2(G)-(E)-coumaroyl-3(G)-O-beta-D-glucosyl-3(R)-O-beta-D-glucosylrutinoside); D011794:Quercetin; C004931:1,1-diphenyl-2-picrylhydrazyl