HERMANN EMIL LOUIS FISCHER FRS FRSE FCS (9 October 1852 – 15 July
1919) was a German chemist and 1902 recipient of the Nobel Prize in
* 1 Biography
* 1.1 Early years * 1.2 Academic career * 1.3 Research * 1.4 Personal life
* 2 Honours, awards, and legacy * 3 References * 4 External links
Fischer was born in
In 1878 Fischer qualified as a Privatdozent at
In 1881 he was appointed Professor of
In 1885 he was asked to become Professor of
In 1875 Fischer discovered phenylhydrazine while working in Stassburg with von Baeyer. (This compound would play a critical role in Fischer's later research on sugars.) While he was at Munich, Fischer continued to work on the hydrazines and, working there with his cousin Otto Fischer, who had followed him to Munich, he and Otto worked out a new theory of the constitution of the dyes derived from triphenylmethane , proving this by experimental work to be correct.
At Erlangen, Fischer studied the active principles of tea , coffee and cocoa , namely, caffeine and theobromine , and established the constitution of a series of compounds in this field, eventually synthesizing them.
The work, however, on which Fischer's fame chiefly rests, was his studies of the purines and the sugars . This work, carried out between 1882 and 1906 showed that various substances, little known at that time, such as adenine , xanthine , in vegetable substances, caffeine and, in animal excrement, uric acid and guanine , all belonged to one homogeneous family and could be derived from one another and that they corresponded to different hydroxyl and amino derivatives of the same fundamental system formed by a bicyclic nitrogenous structure into which the characteristic urea group entered. This parent substance, which at first he regarded as being hypothetical, he called purine in 1884, and he synthesized it in 1898. Numerous artificial derivatives, more or less analogous to the naturally occurring substances, came from his laboratory between 1882 and 1896.
In 1884 Fischer began his great work on the sugars, which transformed the knowledge of these compounds and welded the new knowledge obtained into a coherent whole. Even before 1880, the aldehyde formula of glucose had been indicated, but Fischer established it by a series of transformations such as oxidation into aldonic acid and the action of phenylhydrazine which he had discovered and which made possible the formation of the phenylhydrazones and the osazones . By passage to a common osazone, he established the relation between glucose, fructose and mannose , which he discovered in 1888. In 1890, by epimerization between gluconic and mannonic acids, he established the stereochemical and isomeric nature of the sugars, and between 1891 and 1894 he established the stereochemical configuration of all the known sugars and exactly foretold the possible isomers, by an ingenious application of the theory of the asymmetrical carbon atom of Van't Hoff and Le Bel, published in 1874. Reciprocal syntheses between different hexoses by isomerization and then between pentoses , hexoses, and heptoses by reaction of degradation and synthesis proved the value of the systematics he had established. His greatest success was his synthesis of glucose, fructose and mannose in 1890, starting from glycerol .
This monumental work on the sugars, carried out between 1884 and 1894, was extended by other work, the most important being his studies of the glucosides .
Between 1899 and 1908 Fischer made his great contributions to
knowledge of the proteins . He sought effective analytical methods of
separating and identifying the individual amino acids , discovering a
new type, the cyclic amino acids: proline and hydroxyproline . He also
studied the synthesis of proteins by obtaining the various amino acids
in an optically active form in order to unite them. He was able to
establish the type of bond that would connect them together in chains,
namely, the peptide bond , and by means of this he obtained the
dipeptides and later the tripeptides and polypeptides . In 1901 he
discovered, in collaboration with
Ernest Fourneau , the synthesis of
the dipeptide, glycylglycine , and in that year he also published his
work on the hydrolysis of casein .
In addition to his work in the fields already mentioned, Fischer also studied the enzymes and the chemical substances in the lichens which he found during his frequent holidays in the Black Forest , and also substances used in tanning and, during the final years of his life, the fats . In 1890, he also proposed a "Lock and Key Model" to visualize the substrate and enzyme interaction. Though, later studies did not support this model in all enzymatic reactions.
Fischer is noted for his work on sugars among other work the organic synthesis of (+) glucose and purines (including the first synthesis of caffeine ).
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.
At the age of 18, before he went to the University of Bonn, Fischer
suffered from gastritis , which attacked him again towards the end of
his tenure of the Chair at Erlangen and caused him to refuse a
tempting offer to follow
He was particularly happy at Würzburg where he enjoyed walks among the hills and he also made frequent visits to the Black Forest. His administrative work, especially when he went to Berlin, revealed him as a tenacious campaigner for the establishment of scientific foundations, not only in chemistry, but in other fields of work as well. His keen understanding of scientific problems, his intuition and love of truth and his insistence on experimental proof of hypotheses , marked him as one of the truly great scientists of all time.
In 1888 Fischer married Agnes Gerlach, daughter of Joseph von Gerlach , Professor of Anatomy at Erlangen. His wife died seven years after their marriage. They had three sons, one of whom was killed in World War I ; another committed suicide at the age of 25 as a result of compulsory military training . In 1919 in Berlin, Fischer, like his son, committed suicide. The oldest son, Hermann Otto Laurenz Fischer, was Professor of Biochemistry in the University of California at Berkeley from 1948 until his death in 1960.
HONOURS, AWARDS, AND LEGACY
Fischer was made a Prussian Geheimrat (Excellenz), and held honorary
doctorates of the Universities of Christiania, Cambridge (England),
Manchester and Brussels. 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 also
awarded the Prussian Order of Merit and the Maximilian Order for Arts
and Sciences. In 1902 he was awarded the Nobel Prize in
Many names of chemical reactions and concepts are named after him:
Fischer indole synthesis
When Fischer died in 1919, the Emil Fischer Memorial Medal was instituted by the German Chemical Society . Fischer–Tropsch process is named after Franz Emil Fischer a chemist who was no relation, head of the Max Planck Institute for Coal Research in Muelheim.
* ^ A B "Fellows of the Royal Society". London:
Royal Society .
Archived from the original on 2015-03-16.
* ^ Horst Kunz (2002). "Emil Fischer – Unequalled Classicist,
Master of Organic
* Nobel Lecture