PURPOSE: To prepare a reduced NAD (nicotinamide adenine dinucleotide) using only a small amount of enzyme, in high yield, by reacting NAD with formic acid in the presence of formate-dehydrogenase while evacuating and removing the produced CO2 gas from the reaction system.
CONSTITUTION: NAD is reacted with formic acid in a buffer solution having a pH of about 7.5, in the presence of formate-dehydrogenase at 20W50°C for 1W2 hours under a reduced pressure, while removing the produced CO2 gas from the system. After the completion of the reaction, the enzyme is precipitated by adding an alcohol (vol. ratio of the reaction mixture to the alcohol is 1 to 2), and the filtrate is added with an alcohol until alcohol concentration reaches 90W93%. The objective reduced NAD can be obtained as precipitate in an yield of as high as 95%.
OKA OSAMU
KOUKAWARA ISAMU
HORIO BUICHI
