Euler-Chelpin, Hans Karl August Simon von (1873–1964)

German biochemist who defined the structure of the yeast coenzyme, the nonprotein part of the yeast enzyme zymase that interlocks with the zymase and affects how it functions. He was awarded the Nobel Prize for Chemistry in 1929 for his work on the fermentation of sugar, and fermentative enzymes.

Arthur Harden discovered in 1904 the presence of nonprotein coenzymes that interlock with an enzyme and affect how it functions. Euler-Chelpin, who studied fermentation – a process that requires the presence of a yeast enzyme called zymase – showed that vitamins A and B activate zymase. This discovery led him to define the structure of the yeast coenzyme, which he called diphosphopyridine nucleotide, today known as NAD. NAD is composed of a nucleotide similar to that found in nucleic acids.

Euler-Chelpin was born in Augsburg, Germany, to Swedish parents. He received a cosmopolitan education in biochemistry, moving between the universities of Berlin, Strasbourg, and Göttingen. After studying at the Pasteur Institute in Paris, he moved to Sweden, where he lectured in physical chemistry at the University of Stockholm and later became a professor of chemistry. In 1929, he was appointed director of the Institute for the Biochemistry of Vitamins.