ON A NEW FLAVIN MONONUCLEOTIDE PRODUCED BY RHIZOPUS ORYZAE

1. As reported in the previous paper, the RF value of a new flavin mononucleotide, FMN′, in a solvent system of phenol-n-butanol-water (16:3:10) was 0.27, which is higher than that of FMN, 0.18, and lower than that of 4′, 5′-cyclic monophosphate, 0.50. It was further confirmed that FMN′ migrated faster than FMN toward the anode in paper electrophoresis. 2. One mole of NaIO4 was consumed per mole of FMN′. 3. The yellow oxidation product of FMN′ by NaIO4 was chromatographycally different from that of FMN, and more stable than that in the course of oxidation. 4. FMN′ was more stable than FMN against the hydrolysis by 5′- or 3′-nucleotidase or by the cell-free extracts of Aspergillus oryzae. 5. It was suggested that the possible structure of FMN′ might be 3′-, 2′, 5′-cyclic or 2′, 3′-cyclic monophosphate.