Hisatake Hamada

Biomimetic synthesis of α-amino acids from α-keto acids

Abstract Protonated α-imino acids, RC(=NH2+)COOH, were easily reduced to α-amino acids by an acid-stable NADH analogue, 1-benzyl-3-carbamoyl-1,4-dihydroquinoline. This is the first model reaction of NADH-mediated α-amino acid synthesis from α-keto acids.

Coenzyme models. Part 16. Studies of general-acid catalysis in the NADH model reduction

The reduction of trifluoroacetophenone was performed in an aqueous acetate (and analogues) buffer solution with an acid-stable NADH model compound, 1-benzyl-3-carbamoyl-1,4-dihydroquinoline. The resultant Bronsted plots had a slope of -0.20, indicating that the reduction process is general-acid catalysed. This is the first example of general-acid catalysis observed in an NADH model reduction performed in an aqueous system.

Biomimetic reduction of inacivated carbonyl compounds by an acid-stable NADH analogue plus brönsted acid

Abstract The NADH model reduction of inactivated carbonyl compounds was achieved by he combination of an acid-stable NADH analogue and strong proton sources (HCl or benzenesulfonic acid).

Biomimetic reduction of benzoylformic acid by an acid stable NADH analogue : a model reaction of lactate dehydrogenase

Abstract By the use of an acid-stable NADH analogue (3-carbamoyl-N-benzyl-1,4-dihydroquinoline) NADH model reduction of benzoylformic acid in aqueous solution was achieved, for the first time, at pH region where the carboxyl group is undissociated.

Influence of Mg2+ ion on the reduction of N-methylacridinium ion with 1,4-dihydronicotinamide

The reaction of N-benzyl-1,4-dihydronicotinamide and N-methylacridinium ion in the presence of Mg2+ gives a normal secondary isotope effect (kH/kH′= 0·98 ± 0·04) and an identical value (3·7) for the primary isotope effect (kH/kD) and the isotopic partitioning ratio.