William C. Rose; Nutritionist Who Found Amino Acids

William C. Rose, who helped lay the foundation for modern nutritional research by discovering amino acids, has died at 98.

Rose, a 1966 National Medal of Science winner, died Sept. 25 in Urbana, University of Illinois spokesman Keay Davidson said.

He had taught biochemistry at Illinois from 1922 to 1955, when he retired.

In a 1931 speech, Rose predicted the discovery of an element in proteins that is an essential constituent of diet. Within a year, he isolated one amino acid, threonine, and established that it was essential for diet in rats.

The discovery led to identification of other essential amino acids and “laid the foundation for all modern nutritional studies relating to proteins and amino acids,” said Lowell P. Hager, head of the University of Illinois department of biochemistry.

Rose had been trying to create a synthetic diet and took shortcuts to produce amino acids, using human hair. But the rats did not grow, and Rose established that the diet lacked threonine.

From that point, he proved that there were eight amino acids essential in a rat’s diet.