Studies on fatty acid esters of flavins: . Crystallization of riboflavin tetrabutyrate and its physiochemicarproperties
Yagi, Kunio; Ohama, Hirobumi; Takahashl, Yoshiya; Okuda, J.
Vitamins kyoto 34(6): 546-549
Afat-soluble derivative of riboflavin, riboflavin-2[image],3[image],4[image],5[image]-tetrabutyrate (B2-But) was crysatllized from methyl alcohol-water solvent system (19 : 5, v/v), and reddish-yellow, rhombic crystals were obtained. Melting point of this re crystallized sample was found at 147-148[degree]C, a little higher than that previously reported. Infrared spectrum of this sample showed that 2[image],3[image],4[image],5[image]-tetrahydroxyl groups of riboflavin disappeared completely and that newly formed ester linkage between alcoholic hydroxyl group and carboxyl group of butyric acid appeared. Spectroscopic properties of B2-But in several solvents were studied, and the molar extinction coefficients were determined. B2~But dissolved in water at low concentration.