Quercus tinctoria

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

O-rhamnoside 3,5,7,3, (Polygonaceae), Quercus tinctoria [antibacterial, antimutagenic,... 

Quercetrin (= Quercetin Quercus tinctoria (oak) Yields aglycone Quercetin... 

Quercitrin is the colouring-matter of the dyewood known as quercitron bark, obtained from Quercus tinctoria. 

Quercus tinctoria. Black oak. Quercus tinctoria. W. IV. 444. Cortex. The bark. 

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... 

For example, Douglas-fir bark, Pseudotsuga menziesii, contains up to 5% dihydroquercetin (85) whereas bark of Firms contorta contains between 0 and 2% myricetin (83). Angiosperm barks seem to have rather lesser amounts the recovery of quercetin (8) from bark or Quercus tinctoria of Q phellus does not usually exceed 0.5%. 

Harley (1982) encoimtered a reference to Ackermann s yellow in a treatise on Ackermann s watercolours dated 1801. From the description of the pigment she suggests that it is an early example of a quercitron q.v ) lake (dye derived from Quercus tinctoria on an inorganic base). 

Carlyle (2001) considers the composition to be unclear, alfliough it may have been a cpiercitron lake pigment (lake formed from quercitron, flie inner bark of the oak Quercus tinctoria). 

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