8034. Quercetin

Nomenclature

CAS number: 117-39-5
2-(3,4-Dihydroxyphenyl)-3,5,7-trihydroxy-4H-1-benzopyran-4-one; 3,3′,4′,5,7-pentahydroxyflavone; meletin; sophoretin; cyanidenolon 1522.
C15H10O7; mol wt 302.24.
C 59.61%, H 3.33%, O 37.06%.

Description and references

The aglucon of quercitrin, of rutin, and of other glycosides. Widely distributed in the plant kingdom, esp in rinds and barks, in clover blossoms and in ragweed pollen. Isoln from Rhododendron cinnabarinum Hook, Ericaceae: Rangaswami et al., Proc. Indian Acad. Sci. 56A, 239 (1962), C.A. 58, 9414a (1963). Structure: Underhill et al., Can. J. Biochem. Physiol. 35, 219 (1957). Biosynthesis: Watkin et al., ibid. 229; Grisebach, Biochem. J. 85, 3p (1962); Patschke et al., Z. Naturforsch. 21b, 201 (1966). Synthesis: Shakhova et al., Zh. Obshch. Khim. 32, 390 (1962), C.A. 58, 1426f (1963). Metabolism: Nakagawa et al., Biochim. Biophys. Acta 97, 233 (1965). Toxicity data: M. Sullivan et al., Proc. Soc. Exp. Biol. Med. 77, 269 (1951). See also Bioflavonoids.

Chemical structure

Derivative

Dihydrate.

Nomenclature

CAS number: 6151-25-3

Properties

Yellow needles from dil alcohol. Becomes anhydr at 95-97°. When anhydr dec 314°. uv max (alc): 258, 375 nm (log ε 2.75, 2.75). One gram dissolves in 290 ml abs alc, in 23 ml boiling alc. Soluble in glacial acetic acid; in aq alkaline solns with yellow color. Practically insol in water. Alcoholic solns taste very bitter. LD50 orally in mice: 160 mg/kg (Sullivan).

Derivative

Pentabenzyl ether.

Nomenclature

CAS number: 13157-90-9
3,3′,4′,5,7-Pentakis(benzyloxy)flavone; penta-O-benzylquercetin; Parietrope (Marcofina).
C50H40O7; mol wt 752.85.
C 79.77%, H 5.36%, O 14.88%.

Description and references

Prepn: Chopin, Chadenson, C. R. Seances Acad. Sci. Ser. C 263, 729 (1966); Binovic, DE 2122514 (1972 to Biosedra), C.A. 76, 113072n (1972).

Properties

Crystals, mp 123-125°. uv max (chloroform): 249, 343 nm (log ε 4.43, 4.14).

Derivative

3-β-d-Galactoside hemipentahydrate.

Nomenclature

Hyperin; hyperoside.
C21H20O12.2 1/2 H2O; mol wt 509.41.
C 49.51%, H 4.95%, O 45.54%.

Description and references

From Acacia melanoxylon R. Br., Leguminosae: Falco, de Vries, Naturwissenschaften 51, 462 (1964).

Properties

Yellow needles from ethanol, dec 227-230°. [α]D20 -83° (c = 0.2 in pyridine). uv max: 259, 364 nm (log ε 4.31, 4.39).

Therapeutic Category

Capillary protectant.

Keywords

Vasoprotectant