Abstract
Nekoflavin (NF), isolated from cat's choroids, was identified with chemically synthesized 7α-hydroxyriboflavin. NF was extracted from cat's choroids with water, purified by successive column chromatographies and finally converted to the acetate form. The UV absorption spectrum of NF was very similar to that of riboflavin and the molecular weight of the acetate form was 602. From these facts NF was deduced to be either 7α-hydroxy- or 8α-hydroxyriboflavin (7α or 8αHORF), which were isolated from human urine by Ohkawa et al. The author chemically synthesized 7αHORF from N-acetyl-o-toluidine through 7-cyano-7-demethylriboflavin and 7α-aminoriboflavin. The synthesized acetate of 7αHORF was coincident with the acetate of NF in melting point, molecular weight, and UV absorption and ^1H-NMR spectrum. The free form of 7αHORF was coincident with natural NF in UV absorption sepctrum and also with 7αHORF in human urine in spectra of UV absorption and ^1H-NMR reported by Ohkawa et al.
