Figure 1: Riboflavin is converted to its biologically active metabolites, flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD).
Riboflavin enters the cell through riboflavin transporters (SLC52A1, SLC52A2, or SLC52A3) and it is converted to FMN by riboflavin kinase. FAD synthase converts FMN to FAD. FMD and FAD are important cofactors for flavoproteins that are involved in multiple cellular processes. Image generated using ChemDraw (PerkinElmer).