6425. Naringin

Nomenclature

CAS number: 10236-47-2
7-[[2-O-(6-Deoxy-α-l-mannopyranosyl)-β-d-glucopyranosyl]oxy]-2,3-dihydro-5-hydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one; 4′,5,7-trihydroxyflavanone 7-rhamnoglucoside; naringenin-7-rhamnoglucoside; aurantiin.
C27H32O14; mol wt 580.53.
C 55.86%, H 5.56%, O 38.58%.

Description and references

In the flowers of grapefruit trees (Citrus paradisi Macfad, Rutaceae), also in fruit and rind. Most abundant in immature fruit; main bitter component of grapefruit juice. Extraction from grapefruit peel: Zoller, Ind. Eng. Chem. 10, 364 (1918); Pulley, von Loesecke, J. Am. Chem. Soc. 61, 175 (1939); US 2421062; US 2421063 (both 1947 to California Fruit Growers Exchange). Structure: Asahina, Inubuse, C.A. 23, 3475 (1929); cf. also Ber. 61, 1514 (1928); Horowitz, Gentili, Tetrahedron 19, 773 (1963). Solubility data: G. N. Pulley, Ind. Eng. Chem. Anal. Ed. 8, 360 (1936). Review: Kesterson, Hendrickson, Naringin, A Bitter Principle of Grapefruit Bulletin no. 511 (Univ. Florida Agric. Expt. Station, Jan. 1953).

Chemical structure

Properties

When crystallized from water, it contains 6 to 8 mols H2O. mp ≈83°. After drying at 110° to constant weight, it contains 2 mols H2O, mp 171°. Bitter taste (1:10,000 H2O can be tasted). [α]D19 -82° (alcohol). One gram dissolves in 1000 ml water at 40°. At 75° one gram dissolves in 10 ml water. Sol in acetone, alcohol, warm acetic acid.