730. Apigenin

Nomenclature

CAS number: 520-36-5
5,7-Dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one; 4′,5,7-trihydroxyflavone; 2-(p-hydroxyphenyl)-5,7-dihydroxychromone; pelargidenon 1449.
C15H10O5; mol wt 270.24.
C 66.67%, H 3.73%, O 29.60%.

Description and references

The aglucon of apiin and of apigenin-7-glucoside. From apiin by boiling with acids, from apigenin-7-glucoside by enzymatic hydrolysis with emulsin or by boiling with 15% H2SO4. Isoln and structure: Czajkowski et al., Ber. 33, 1992 (1900); Schmid, Waschkau, Monatsh. Chem. 49, 83 (1928); Baker et al., J. Chem. Soc. 1963, 1477. Synthesis: Hutchins, Wheeler, ibid. 1939, 91; Farooq et al., Arch. Pharm. 292, 792 (1959).

Chemical structure

Properties

Yellow needles from aqueous pyridine, mp 345-350°. uv max (ethanol): 269, 340 nm (ε 18,800; 20,900). Practically insoluble in water; moderately sol in hot alcohol. Sol in dil KOH with intense yellow color.

Use

Has been used to dye Cr mordanted wool yellow. The color is fast to soap.