5-Deoxy-5-(3,4-dihydro-7,8-dimethyl-2,4-dioxobenzo(g)pteridin-10(2H)-yl)-L-ribonic acid 59224-03-2 7,8-Dimethyl-10-(2,3,4-trihydroxy-4-carboxybutyl)isoalloxazine Vitamin B2 acid