Abstract
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.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Acylation
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Biphenyl Compounds
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Camellia / chemistry*
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Carbohydrate Conformation
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Flavonoids / chemistry*
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Flavonoids / isolation & purification
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Free Radical Scavengers / chemistry*
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Glucosides / chemistry*
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Glucosides / isolation & purification
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Glycosides / chemistry
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Glycosides / isolation & purification
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Hydrolysis
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Kaempferols / chemistry*
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Kaempferols / isolation & purification
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Magnetic Resonance Spectroscopy
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Picrates / chemistry*
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Quercetin / analogs & derivatives*
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Quercetin / chemistry
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Quercetin / isolation & purification
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Saponins / chemistry
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Spectrophotometry, Infrared
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Spectrophotometry, Ultraviolet
Substances
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Biphenyl Compounds
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Flavonoids
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Free Radical Scavengers
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Glucosides
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Glycosides
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Kaempferols
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Picrates
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Saponins
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kaempferol 3-O-(2(G)-(E)-coumaroyl-3(G)-O-beta-D-glucosyl-3(R)-O-beta-D-glucosylrutinoside)
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quercetin 3-O-(2(G)-(E)-coumaroyl-3(G)-O-beta-D-glucosyl-3(R)-O-beta-D-glucosylrutinoside)
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Quercetin
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1,1-diphenyl-2-picrylhydrazyl