Fischer , Emil Hermann

(1852–1919) German organic chemist and biochemist

The son of a successful businessman from Euskirchen, now in Germany, Fischer joined his father's firm on leaving school (1869) but left in 1871 to study chemistry with August Kekulé at Bonn. He was not happy with the chemistry instruction there and came close to abandoning chemistry for physics. In 1872, however, he moved to Strasbourg to study with Adolf von Baeyer. Here, he gained his doctorate in 1874 for work on phthaleins. The same year he made the vital discovery of phenylhydrazine, a compound that was later to prove the vital key for unlocking the structures of the sugars.

Fischer became Baeyer's assistant and together they moved to Munich (1875). At Munich, working with his cousin, Otto Fischer, he proved that the natural rosaniline dyes are derivatives of triphenylmethane. In 1879 Fischer became assistant professor of analytical chemistry and soon after became financially independent. He was then professor at Erlangen (1882), Würzburg (1885), and Berlin (1892).

Fischer has some claim to be called the father of biochemistry. He carried out extremely comprehensive work in three main fields: purines, sugars, and peptides, the last two effectively founding biochemistry on a firm basis of organic chemistry. The work on purines, begun in 1882, resulted in the synthesis of many important compounds, including the alkaloids caffeine and theobromine, and purine itself (1898). Fischer's early structures were incorrect but from 1897 the correct structures were used.

In 1884 Fischer discovered that phenylhydrazine produces well-defined crystalline compounds with sugars, thus affording a reliable means of identification. In 1887 he synthesized first fructose (from acrolein dibromide) and later mannose and glucose. By 1891 he was able to deduce the configurations of the 16 possible aldohexoses, which he represented in the form of the famous Fischer projection formulae.

In 1899 Fischer turned to amino acids and peptides and devised a peptide synthesis that eventually produced a polypeptide containing 18 amino acids (1907). Fischer's other work included the first synthesis of a nucleotide (1914), the ‘lock-and-key’ hypothesis of enzyme action, work on tannins, and attempts to prepare very high-molecular-weight compounds. He was awarded the 1902 Nobel Prize for chemistry for his work on purines and sugars.