Determination of Riboflavin-5'-monosulfate.

As reported previously, FMS* has been synthesized as a coenzyme analogue1 ) and has been found to inhibit D-amino acid oxidase in competition with FAD2)3 )4). On the other hand, it has been observed that FMS has an inhibitory action on the growth of riboflavin requiring bacteria5). From these results, it was supposed that FMS, as an antivitamin B2, disturbs the metabolic pattern in higher animals. To study this antivitamin action of FMS, the effect of its administration to animals may be observed by physiological and nutritional experiments. In this connection, we tried to establish a determination method of FMS in animal tissues. This paper reports a method suitable for the separating micro-determination of flavins including FMS. The principle of the present work is to develope the previously reported method for separating determination of flavins6) so as to be adopted for the samples containing FMS as well as physiologically existing flavins, FAD, FMN and FR.