Fischer was born in Euskirchen, near Cologne, the son of Laurenz Fischer, a businessman, and his wife Julie Poensgen. After graduating he wished to study natural sciences, but his father compelled him to work in the family business until determining that his son was unsuitable. Fischer then attended the University of Bonn in 1871, but switched to the University of Strasbourg in 1872.[6] He earned his doctorate in 1874 under Adolf von Baeyer[6] with his study of phthaleins.
Fischer remained with Baeyer in Strassburg as an independent research student. In the fall of 1874, he was appointed assistant of the organic laboratory. There in 1875, he discovered and named hydrazines, including unsymmetrical dimethylhydrazine, which became important much later during the Space Race, and phenylhydrazine.[2] The latter compound reacts with carboxylic compounds (aldehydes and ketones) producing crystalline solids. The phenylhydrazones of sugars allowed him to develop his work on the synthesis of sugars and purines, which earned him the Nobel Prize in Chemistry in 1902. Using the phenylhydrazone of piruvic acid, he developed the synthesis of indole.
In 1875, von Baeyer was asked to succeed Justus von Liebig at the University of Munich and Fischer went there with him to become an assistant in organic chemistry. In 1878 Fischer qualified as a "Privatdozent" at Munich, where he was appointed associate professor of analytical chemistry in 1879.[7]
He investigated the derivatives of phenylhydriazines, 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.[8]
He next turned to the fuchsine (then called "rosaniline") magenta dyes, and in collaboration with his cousin Otto Fischer, he published papers in 1878 and 1879 which established that these dyes were derivatives of triphenylmethane. Emil Fischer's next research was concerned with compounds related to uric acid. Here the ground had been broken by von Baeyer, but Fischer greatly advanced the field of knowledge of the purines. In 1881 and 1882 he published papers which established the formulae of uric acid, xanthine, caffeine (achieving the first synthesis), theobromine and some other compounds of this group. After purine itself was isolated, a variety of derivatives were prepared, some of which were patented in view of possible therapeutical applications.[8]
Fischer is particularly noted for his work on sugars. Among his early discoveries related to hydrazine was that phenylhydrazine reacted with sugars to form substances which he named osazones, and which, being highly crystalline and readily formed, served to identify such carbohydrates more definitely than had been previously possible.[8] Later, among other work, he is noted for the organic synthesis of D-(+)-glucose.[9] 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.[8]
In the field of enzymology, Fischer is known for his proposal of "the lock and key" model as a mechanism of substrate binding.[10]
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.[11] 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.[12] 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.[13] 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[14]
Personal life and death
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.[6] Emil Fischer died in Berlin on 15 July 1919 at the age of 66.[5]
^Lichtenthaler, F. W. (1992). "Emil Fischers Beweis der Konfiguration von Zuckern: eine Würdigung nach hundert Jahren". Angewandte Chemie. 104 (12): 1577–1593. Bibcode:1992AngCh.104.1577L. doi:10.1002/ange.19921041204.
Text-book of Physiological Chemistry in Thirty Lectures by Emil Abderhalden, translated by William Thomas Hall and George Defren; published 1908 by Wiley Company, has many technical references to Fischer's work in Chemistry.
