Hermann Emil Fischer

Hermann Emil Louis Fischer (; 9 October 1852 – 15 July 1919) was a German chemist and 1902 recipient of the Nobel Prize in Chemistry. He discovered the Fischer esterification. He also developed the Fischer projection, a symbolic way of drawing asymmetric carbon atoms. He also hypothesized the lock and key mechanism of enzyme action. He never used his first given name, and was known throughout his life simply as Emil Fischer. He obtained his doctorate in 1874 under Adolf von Baeyer

In 1882, he was appointed professor of chemistry at the University of Erlangen and in 1885 at the University of Würzburg. In 1892, he succeeded von Hofmann as professor of chemistry at the Friedrich Wilhelm University of Berlin.

Research He investigated the derivatives of phenylhydrazines, establishing their relation to the diazo compounds, and he noted the readiness with which they entered into combination with other substances, giving origin to a wealth of hitherto unknown compounds. Of such condensation products undoubtedly the most important are the hydrazones, which result from the interaction with aldehydes and ketones. His observations, published in 1886, that such hydrazones, by treatment with hydrochloric acid or zinc chloride, yielded derivatives of indole, the parent substance of indigo, were a confirmation of the views advanced by von Baeyer on the subject of indigo and the many substances related to it. He showed how to deduce the formulae of the 16 stereoisomeric glucoses, and prepared several stereoisomerides, helping to confirm the Le Bel–Van 't Hoff rule of the asymmetric carbon atom.

Fischer was also instrumental in the discovery of barbiturates, a class of sedative drugs used for insomnia, epilepsy, anxiety, and anesthesia. Along with the physician Josef von Mering, he helped to launch the first barbiturate sedative, barbital, in 1904. He next carried out pioneering work on proteins. By the introduction of new methods, he succeeded in breaking down the complex albumins into amino acids and other nitrogenous compounds, the constitutions of most of which were known, and by bringing about the recombination of these units, he prepared synthetic peptides which approximated to the natural products. His research group synthesised the first free dipeptide (Glycine-Glycine) in 1901. By 1906 about 65 peptides of different chain length and amino acid composition had been made by his research group. His researches made from 1899 to 1906 were published in 1907 with the title Untersuchungen über Aminosauren, Polypeptides und Proteine. Three years later the total number of peptides exceeded 100, with the longest being an 18 amino acid peptide containing 15 glycine and three leucine units. The 18 amino acid peptide gave the standard responses to tests for proteins used by physiological chemists - a positive Biuret test, precipitation by inorganic salts and cleavage by proteolytic enzymes

Personal life Fischer married Agnes Gerlach in 1888. She died seven years later, leaving him a widower with three sons. The younger two died during their military service in World War I, but the oldest, Hermann, became an organic chemist. He was Protestant

Honours, awards, and legacy

In 1897 he put forward the idea to create the International Atomic Weights Commission. Fischer was elected a Foreign Member of the Royal Society (ForMemRS) in 1899. He was awarded the 1902 Nobel Prize in chemistry "in recognition of the extraordinary services he has rendered by his work on sugar and purine syntheses." He was elected an International Member of the United States National Academy of Sciences in 1904, an International Honorary Member of the American Academy of Arts and Sciences in 1908, and an International Member of the American Philosophical Society in 1909.

Many names of chemical reactions and concepts are named after him:

Fischer indole synthesis Fischer projection Fischer oxazole synthesis Fischer peptide synthesis Fischer phenylhydrazine and oxazone reaction Fischer–Speier esterification Fischer glycosidation Kiliani–Fischer synthesis

The Fischer–Tropsch process is named after Franz Emil Fischer, who headed the Max Planck Institute for Coal Research in Mülheim an der Ruhr, and is unrelated to Fischer.