R 1305 (OTTO) Riboflavin 5'-phosphate disodium salt Cas 130-40-5 - used as a prosthetic group by oxidoreductase (one and two electron transfer) enzymes such as NADH dehydrogenase, nitric oxide synthase, and nitrilotriacetate monooxygenase. R 1305 (OTTO) Riboflavin 5'-phosphate disodium salt Cas 130-40-5 - used as a substrate to study the specificity and kinetics of FMN phosphohydrolases and to study molecular sensing based gene regulation by riboswitches.