In the search for substances, other than glutamic acid, betaine, and potassium chloride that might be obtained from Steffens waste, a quantity of concentrated waste, sp. gr. 1.4, was diluted with an equal volume of water, boiled with a small amount of activated carbon, and filtered. A precipitate which formed on cooling was identified as I-tyrosine. Though it had been found in beet molasses, it is apparently the first time that tyrosine has been obtained from Steffen's waste. In 1846, Justus von Liebig discovered tyrosine in cheese (3). Since then it has been found in many substances containing proteins. v. Lippman (4) 1884 obtained tyrosine from beet sugar molasses. His method involved the use of alcohol, sulphuric acid, basic lead acetate, and hydrogen sulphide. No yield was given. Our method is much simpler.
Proceedings of the Iowa Academy of Science
©1940 Iowa Academy of Science, Inc.
Bartow, Edward and Wetzstein, Harland L.
"Preparation of Tyrosine from Steffen's Waste,"
Proceedings of the Iowa Academy of Science, 47(1), 193-195.
Available at: https://scholarworks.uni.edu/pias/vol47/iss1/37