Title: Fuscin
CAS Registry Number: 83-85-2
CAS Name: 9,10-Dihydro-5-hydroxy-4,8,8-trimethyl-2H,4H-benzo[1,2-b:4,3-c¢]dipyran-2,6(8H)-dione
Molecular Formula: C15H16O5
Molecular Weight: 276.28
Percent Composition: C 65.21%, H 5.84%, O 28.96%
Literature References: Antibacterial pigment produced by the fungus Oidiodendron fuscom Robak: Michael, Biochem. J. 42, XL; 43, 528 (1948). Derivatives and degradation products: Birkinshaw et al., ibid. 48, 66 (1951). Structure and synthesis: Birch, Chem. Ind. (London) 1955, 682; Barton, Hendrickson, J. Chem. Soc. 1956, 1028. Alternate synthesis: Pyuskyulev et al., Tetrahedron 29, 2849 (1973). Biosynthesis: Birch, Ciba Found. Symp. Quinones Electron Transp. 1960, 233; Birch et al., J. Chem. Soc. 1965, 1231.
Properties: Orange-colored, diamond-shaped plates from alc, mp 230°. uv max: 355, 283 nm (e 27,600; 1000). Practically insol in water, petr ether. Sol in chloroform, acetone, ethyl acetate, acetic acid, ether, benzene. Slightly sol in cold ethanol, more sol in hot ethanol. Dissolves in aq solns of alkali hydroxides and pyridine with an intense purple color. Easily reduced by hydrosulfite or other reducing agents to the colorless dihydrofuscin, C15H18O5, mp 206°, which is also found in the metabolic soln from the fungus grown on Czapek-Dox medium.
Melting point: mp 230°; mp 206°
Absorption maximum: uv max: 355, 283 nm (e 27,600; 1000)
Status: This monograph has been retired and is no longer subject to revision or update.
Fusel Oil Fusidic Acid Gabapentin Gabexate Gaboxadol

Micrograph showing lipofuscin, in brown/yellow, in a liver biopsy with ground glass hepatocytes; H&E stain

Lipofuscin is the name given to finely granular yellow-brown pigment granules[1] composed of lipid-containing residues of lysosomal digestion. It is considered to be one of the aging or "wear-and-tear" pigments, found in the liver, kidney, heart muscle, retina, adrenals, nerve cells, and ganglion cells. It is specifically arranged around the nucleus, and is a type of lipochrome.