Quercitrin quercetin-3-rhamnoside

Quercitrin (= Quercetin-3-rhamnoside) (flavonol O-glycoside) Widespread Polygonum spp. (Polygonaceae), Quercus tinctoria (Fagaceae) ACE (51% inhibition at 300 pM) [76]... 

Flavonols. The most common flavonols (3-hydroxyflavones) include kaempferol (3,5,7,4 -tetrahydroxyflavone), quercetin (3,5,7,3, 4 -pentahydroxyflavone), myricetin (3,5,7,3, 4, 5 -hexahydroxyflavone), quercitrin (quercetin 3-0-rhamnoside), isoquercitrin (quercetin 3-0-glucoside), isorhamnetin (quercetin 3 -methyl ether) and rutin (quercetin... 

Quercetin-3-0-( 2 "-0-galloyl)-P-D-glucoside (flavonol gaflate ester) Quercetin-3-0-( 2 "-0-galloyl)-P-D-rutinoside (flavonol gaflate ester) Quercitrin ( = Quercetin 3-0-rhamnoside 3,5,7,3, 4 -Pentahydroxyflavone) (flavonol O-glycoside)... 

Quercetin glycosides rutin, hyperoside, quercitrin, quercetin-3-O-arabinoside Kaempferol -SJ-O-dirhamnoside, k-3-O-rhamnoside and -3-0-arabinoside... 

In the laboratory of the California Fruit Growers Exchange it was observed that lemon juice dried in the presence of boric acid acquires a brilliant yellow color. The color-reactive substance was identified as quercetin or its 3-L-rhamnoside quercitrin, which can be detected in amounts of 0.002 rag. and 0.004 mg. on treatment with a 1 1 mixture of acetone saturated with boric acid and a 10% solution... 

Preparation. Lemon flavin, a khaki dyestuff obtained from the bark of an oak species (Quercus tinctoria Mich.), provides an excellent source of the sugar. The main constituent of the lemon flavin is the rhamnoside quercitrin, which after hydrolysis, yields the aglycon (quercetin) and L-rhamnose. The lemon flavin is hydrolyzed in boiling dilute acid, and after neutralization of the solution and treatment with a considerable proportion of decolorizing carbon, the sugar crystallizes from the evaporated solution.237... 

Flavonoids were first reported to be AR inhibitors in 1975 [26]. With partially purified rat lens AR, eight of them were tested and three were found to retain activity at 1 x 10" 7 M, the most potent being quercitrin, the 3-L-rhamnoside of quercetin Table 8.4, No. 3), which inhibited AR by 55% at 1 x 10 7 M. At l x 10 " 4 M, it decreased xylitol accumulation by 80% in rat lens incubated in a high-xylose medium [26]. 

The naturally occurring aryl L-rhamnosides include quercitrin, namely, quercetin substituted at C-3. This is a fairly common derivative in plant tissues. - Mono-L-rhamnosides of kaempferol, in which substitution occurs at the hydroxyl groups at C-3 and C-7, are known, and kaemp-feritrin (lespedin, 3,7-di-L-rhamnosylkaempferol) has also been reported. ... 

The main constituent of the lemon flavin is the rhamnoside quercitrin (Chapter X). This glycoside yields after hydrolysis the aglycon (quercetin) and L-rhamnose. 

Also sometimes given incorrectly as quercitin. Quercitrin is the glucoside (3-L-rhamnoside Colour Index, 1971, Cl 75720/Natural Yellow 10) in Quercus velutina Lam. bark. The Colour Index lists quercetin imder Cl 75670/Natural Yellow 10,13/Natural Red 1. 

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