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.
Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, Taiwan.
Viola Szu-Yuan
VS
Lee
Chiy-Rong
CR
Chen
Yun-Wen
YW
Liao
Jason Tze-Cheng
JT
Tzen
Chi-I
CI
Chang
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