Soviet Medical Encyclopedia

Biuret

Biochemistry, Chemistry & Physics

Also known as: Carbamylurea

Historical document, translated for reference. It reflects medical knowledge of the 1920s–30s and is not medical advice.

Summary

This 1930s encyclopedia article describes biuret, an amide of allophanic acid formed by gently heating dry urea. It details its chemical properties, crystal structure, and the characteristic violet-red color reaction with copper sulfate and alkali.

Encyclopedia entry (1928–1936)

BIURET, NH2-CO-NH-CO-NH2, the amide of allophanic acid (HN<OCONH2COOH), which does not exist in a free state. It is formed by the careful heating of dry urea. It forms long needles that are sparingly soluble in cold water; it melts with decomposition at 193°. Its alkaline solution gives a violet-red coloration with copper sulfate, forming a compound consisting of two molecules of biuret, two molecules of caustic alkali, and one molecule of copper oxide.

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Cite this page

“Biuret.” Soviet Medical Encyclopedia. English translation of Bolshaya Meditsinskaya Entsiklopediya, 1st ed. (Moscow, 1928–1936), ed. N. A. Semashko. https://sovietmedicalencyclopedia.pages.dev/article/biuret/