For design of artificial enzymes, it would be of primary importance to assemble plural functional groups in a reaction site. For functionalization of flavin models, there are two methods; (1) covalent functionalization and (2) non-covalent functionalization. As a covalently functionalized flavin, we have synthesized benzodiputeridine(BDP) bearing a bipyridine moiety at 3-position as a metal-binding site(bpy-BDP), and examinated activity of the catalysis. We express the oxidation of mandelic acid(MA) by bpy-BDP in t-BuOH containing Et3N in the presence of zinc ion under anaerobic conditions. Without Zn(2+) or Et3N, the reaction was found not to take place. Kinetic study in the oxidaiton of MA suggests that the reaction proceeds via a ternary complex of Zn(2+) - bpy-BDP - MA.