flavin-adenine-dinucleotide and 2--3--4--5--tetraacetylriboflavin

Chlorine gas or electropositive chlorine reagents are used to prepare chlorinated aromatic compounds, which are found in pharmaceuticals, agrochemicals, and polymers, and serve as synthetic precursors for metal-catalyzed cross-couplings. Nature chlorinates with chloride anions, FAD-dependent halogenases, and O2 as the oxidant. A photocatalytic oxidative chlorination is described based on the organic dye riboflavin tetraacetate mimicking the enzymatic process. The chemical process allows within the suitable arene redox potential window a broader substrate scope compared to the specific activation in the enzymatic binding pocket.

Topics: Biomimetic Materials; Catalysis; Chlorine; Coloring Agents; Flavin-Adenine Dinucleotide; Halogenation; Hydrocarbons, Aromatic; Hydrolases; Light; Oxidation-Reduction; Oxygen; Riboflavin

The inhibition of glycogen phosphorylase b from rabbit skeletal muscles by the derivatives of riboflavin, FMN, FAD, and 2', 3', 4', 5'-tetraacetylriboflavin substituted in positions 6 and 8 of the isoalloxazine part of the flavin molecule is found to be cooperative (the Hill coefficient, h, exceeds 1.0). The modification of the flavin molecule slightly changes the value of the Hill coefficient, but results in the increase of the "half-saturation" concentration [I]0.5.

Topics: Animals; Binding Sites; Flavin Mononucleotide; Flavin-Adenine Dinucleotide; Flavins; Kinetics; Muscle, Skeletal; Phosphorylases; Rabbits; Riboflavin; Swine