Studies on fatty acid esters of flavins: V Crystallization of riboflavin tetrabutyrate and its physicochemical properties
Yagi, Kunio; Ohama, Hirobumi; Takahashi, Yoshiya; Okuda, J.
J Vitaminol osaka 13(3): 191-196
A fat-soluble derivative of riboflavin, riboflavin-2[image],3[image],4[image],5[image]-tetrabutyrate [R-BUT] was crystallized from methyl alcohol-water mixture (19:5 v/v), and reddish yellow, rhombic crystals were obtained. Melting point of this recrystallized sample was 147-148[degree] which is a little higher than previously reported. Infrared spectrum of this sample showed that 2[image],3[image],4[image],5[image]-tetrahydroxyl groups of riboflavin completely disappeared and that newly formed ester linkages between alcoholic hydroxyl group and carboxyl group of butyric acid appeared. Absorption and fluorescence spectra of R-BUT were studied in water, ethyl alcohol and carbon tetrachloride, and molar extinction coefficients were determined. It was found that R-BUT is soluble in water at low concentration.