Riboflavin Functions In Several Different Enzyme Systems. Two Derivatives, Riboflavin 5' Phosphate (flavin Mononucleotide [FMN]) And Riboflavin 5' Adenosine Diphosphate (flavin Adenine Dinucleotide [FAD]) Are The Coenzymes That Unite With Specific Riboflavin Linus Pauling Institute Oregon State University Glutathione: The Master Antioxidant Core Med Science The Activation of Cytochrome P450 2C9 Is Facilitated by the Coenzyme Forms of Vitamin B2 Elemental Selenium and Vitamin B2 (riboflavin) are essential for glutathione use and recycling. Selenium is really low in Australian soils, and people are commonly deficient. Signs of low B2 are blood