Pyruvic Acid

Pyruvic acid (Brenz-traubensaure), CH₃.CO.COOH, a liquid (crystallizing at low temperatures with a melting point of 13.6°), with an odor resembling acetic acid; boils at 65° (at 10 mm pressure); soluble in alcohol, ether, water. With sodium nitroprusside in the presence of KOH gives a violet coloration; in the presence of NH₄OH it gives a violet-blue coloration, which turns blue upon addition of CH₃COOH; gives the iodoform test. When heated with H₂SO₄, as well as under the influence of yeast, it decomposes into carbonic acid and acetaldehyde; putrefactive bacteria decompose P. k. into CH₃COOH, CO₂, H₂. Upon reduction with sodium amalgam, P. k. yields lactic acid. Discovered by Mörner among the hydrolytic products of the breakdown of various protein substances, but apparently it is a secondary product. P. k. may also serve as a source for the formation of alanine. P. k. and its aldehyde (methylglyoxal) apparently have important biological significance in the processes of fermentation and in the transformation of proteins, fats, and carbohydrates in the animal organism. Pyruvic acid has been found in cancer cells (V. Mendel). It is contained in the blood serum of mammals and in young pea seeds.