Hermann Emil Fischer

For more information on Emil Hermann Fischer, visit Britannica.com.

German organic chemist and biochemist (1852–1919)

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.

(1852-1919) German chemist; established the structures of, and synthesized, many of the sugars; Nobel Prize 1902.

The German chemist Emil Fischer (1852-1919), perhaps the greatest of the organic chemists, is known for his work in the study of pure sugars and proteins.

Emil Fischer was born at Euskirchen, Prussia, on Oct. 9, 1852. After studying chemistry at the University of Bonn for a short time, he transferred to the University of Strassburg and received a doctoral degree in 1874. Fischer moved to Munich that year and spent 8 productive years there. He then went to Erlangen (1882) and to Würzburg (1885) and finished his career as professor of chemistry at the University of Berlin (1892).

Studies of Pure Sugars

Of the many natural products available for man's use, perhaps no group is so important as the carbohydrates. Until 1884, however, no exact scientific study of the carbohydrates had been undertaken, and little was known concerning their chemical constitution or the arrangement of their molecules. Between 1884 and 1900 Fischer successfully determined the inner structure of the sugar group and thus gave scientists the key to an understanding of other carbohydrates.

Fischer's first step in unraveling the mysteries of the sugar group was the discovery in 1875 of phenyl hydrazine, a compound which could be used as a general reagent for separating and isolating sugars. Through the use of phenyl hydrazine and its derivatives, he discovered the presence in sugars of the carbonyl group (=CO). By 1884 he was able to produce crystalline derivatives with various sugars; hitherto, these derivatives had been available only in impure mixtures which almost always were syrups. Fischer was also able to show that the best-known sugars contain six carbon atoms. Differences in the sugars could be detected through their effects, in solution, on polarized light, although not all of them were found to be optically active.

Fischer synthesized some of the known sugars such as fructose and glucose, and he identified 16 stereoisomeric forms of glucose. In addition, he synthesized a number of sugars that do not occur in nature and demonstrated their structural relationships. His work proved to be a vindication of the asymmetry theory of J. H. van't Hoff and J. A. Le Bel; that is, mirror-image molecules do, in fact, exist.

Purine Group

At approximately the same time that Fischer was involved with the analysis and synthesis of sugars, he accomplished a great deal of research on another important group of compounds, the purine group, or purine derivatives. Among the purine derivatives are caffeine, xanthine, theobromine, and uric acid. The Swedish chemist Carl W. Scheele discovered uric acid in 1776, and Justus von Liebig and Friedrich Wohler studied its derivatives in the 1830s. Adolf von Baeyer was also interested in studies of this natural product of tissue waste and succeeded in presenting an orderly arrangement of the purine derivatives. However, the final determination of the structures of the purine group was done by Fischer during his years at the universities of Erlangen and Würzburg. Later, at Berlin, he synthesized xanthine, caffeine, theobromine, adenine, and the parent compound, purine. Before 1900 Fischer and his students had investigated no fewer than 130 purine derivatives. In 1902 he received the Nobel Prize for his work on sugars and purines.

Research in the Proteins

From his previous research, Fischer was led in 1899 to the study of an even more complex group of natural products, the proteins. The proteins themselves are made up of amino acids; therefore the first steps in his research had to be the investigation of the amino acids, and he proceeded with great skill to isolate and identify them.

The difficulties in these researches were such as to discourage any but the most persistent of investigators, for the proteins are noncrystalline, are sensitive to heat, alcohol, and acids, and cannot easily be produced in a pure state. Fischer's basic method was to prepare the esters of amino acids and then distill them fractionally. Once the amino acids were separated, they could be built up into more complex structures, which he called polypeptides. With this method, the number of possible variations was almost unlimited, and it became evident why such a large number of different proteins exist in nature. In this field of study his greatest achievement was perhaps his synthesis in 1907 of a simple, but real protein molecule.

Later Life and Character

Fischer continued to investigate new areas of organic chemistry. His vacations in the Black Forest of Bavaria led him to study the chemical substances in the lichens that were attached to the old evergreens, and he discovered a new group of compounds, the "depsides." He also studied the constitution and synthesis of tanning substances and initiated some research into the composition of fats.

During World War I Fischer held a position as scientific adviser to the German government, with the task of organizing industrial chemical production for the war effort. He increased the ammonia supply from coke ovens, stimulated the production of the synthetic nitric acid industry, and attempted to organize the production of "synthetic" food. He also worked closely with the German dye industry but never accepted any of the lucrative industrial posts offered to him.

As a professor at Berlin, Fischer found himself called upon for many duties outside teaching and research. He was several times president and vice president of the German Chemical Society and was a member of the Prussian Academy of Sciences. Because of the pressure of these outside activities, he sought to establish private research facilities and to turn over his teaching duties to younger men. In this effort he helped to found the Kaiser Wilhelm Institute for Chemistry and the Kaiser Wilhelm Institute for Carbon Research.

Fischer was a scientist of great talent, imagination, and energy who spent his life in dedication to his field. He married Agnes Gerlach, the daughter of an anatomy professor at Erlangen, in 1885; they had three sons. Agnes Fischer died in 1892.

During the war Fischer suffered from ill health, first from chemical poisoning and then from cancer. He tried unsuccessfully to treat the disease with various chemicals and died on July 15, 1919. One of his colleagues, the Nobel Prize winner Richard Willstätter, said of Fischer's life and character, "He was the unmatched classicist, master of organic-chemical investigation with regard to analysis and synthesis, as a personality a princely man."

Further Reading

A sympathetic biographical essay on Fischer can be found in Burckhardt Helferich's contribution to Eduard Farber, ed., Great Chemists (1961). A brief account of Fischer's work is included in J. R. Partington, A Short History of Chemistry (1937; 3d ed. rev. 1957), and in Alexander Findlay, A Hundred Years of Chemistry (1937; 3d ed. 1965).

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Emil Fischer
Hermann Emil Fischer
Born	9 October 1852(1852-10-09) Euskirchen, Germany
Died	15 July 1919 (aged 66) Berlin, Germany
Nationality	Germany
Fields	Chemistry
Institutions	University of Munich (1875-81) University of Erlangen (1881-88) University of Würzburg (1888-92) University of Berlin (1892-1919)
Alma mater	University of Bonn University of Strasbourg
Doctoral advisor	Adolf von Baeyer
Doctoral students	Alfred Stock Otto Diels Otto Ruff Walter A. Jacobs Ludwig Knorr Oskar Piloty Julius Tafel
Known for	Study of sugars & purines
Notable awards	Nobel Prize for Chemistry (1902)

Hermann Emil Fischer (9 October 1852 - 15 July 1919) was a German chemist and recipient of the Nobel Prize for Chemistry in 1902. He is known for inventing the Fischer esterification.

Contents 1 Biography 1.1 Early years 1.2 Academic career 1.3 Research work 1.4 Personal life 2 Honours, awards, and legacy 3 See also 4 Notes 5 References 6 External links

Biography

Early years

Fischer was born in Euskirchen, near Cologne, the son of a businessman. 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 1872, but switched to the University of Strasbourg in 1872. He earned his doctorate in 1874 with his study of phthalein and was appointed to a position at the university.

Academic career

In 1885 von Baeyer was asked to succeed Liebig at the University of Munich and Fischer went there with him to become an assistant in organic chemistry.

In 1888 Fischer qualified as a Privatdozent at Munich, where he was appointed Associate Professor of Analytical Chemistry in 1879. In the same year he was offered, but refused, the Chair of Chemistry at Aix-la-Chapelle.

In 1891 he was appointed Professor of Chemistry at the University of Erlangen and in 1883 he was asked by the Badische Anilin- und Soda-Fabrik to direct its scientific laboratory. Fischer, however, whose father had now made him financially independent, preferred academic work.

In 1898 he was asked to become Professor of Chemistry at the University of Würzburg and here he remained until 1892, when he was asked to succeed A. W. Hofmann in the Chair of Chemistry at the University of Berlin. Here he remained until his death in 1919.

Research work

Fischer's early discovery of phenylhydrazine and its influence on his later work have already been mentioned. 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 oxyproline. 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 Fourneau, the synthesis of the dipeptide, glycyl-glycine and in that year he also published his work on the hydrolysis of casein. Amino acids occurring in nature were prepared in the laboratory and new ones were discovered. His synthesis of the oligopeptides culminated in an octodecapeptide, which had many characteristics of natural proteins. This and his subsequent work led to a better understanding of the proteins and laid the foundations for later studies of them.

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^[1] and purines (including the first synthesis of caffeine).

Personal life

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 Victor Meyer at the Federal Technical University at Zurich and to take a year's leave of absence before he went, in 1888, to Würzburg. Throughout his life he was well served by his excellent memory, which enabled him, although he was not a naturally good speaker, to memorize manuscripts of lectures that he had written.

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. Sadly his wife died seven years after their marriage. They had three sons, one of whom was killed in World War I; another took his own life at the age of 25 as a result of compulsory military training. In 1919 in Berlin, Fischer, like his son, took his own life.^[2] The oldest son,^[3] 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

Monument to Hermann Emil Fischer in Berlin

Fischer was made a Prussian Geheimrat (Excellenz), and held honorary doctorates of the Universities of Christiania, Cambridge (England), Manchester and Brussels. 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 Chemistry for his work on sugar and purine syntheses.

Many consider Fischer to be the most brilliant chemist who ever lived, as his numerous contributions to science, especially chemistry and biochemistry. 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 reduction
• Fischer-Speier esterification
• Fischer glycosidation

When Fischer died in 1919, the Emil Fischer Memorial Medal was instituted by the German Chemical Society.

Note that the Fischer-Tropsch process is named after Franz Emil Fischer a chemist who was no relation, head of the Institut fuer Kohlenforschung in Muelheim.

See also

• List of chemists

Notes

1. ^ Fischer, Emil (1890). "Synthese des Traubenzuckers". Berichte der deutschen chemischen Gesellschaft 23: 799–805. doi:10.1002/cber.189002301126. 
2. ^ "Emil Fischer". The Notable Names Database. 2008. http://www.nndb.com/people/703/000091430/. Retrieved 2008-09-18. 
3. ^ Poster next to bust of Fischer, Biosciences Library, UC Berkeley

References

• Horst Kunz (2002). "Emil Fischer - Unequalled Classicist, Master of Organic Chemistry Research, and Inspired Trailblazer of Biological Chemistry". Angewandte Chemie International Edition 41: 4439–4451. doi:10.1002/1521-3773(20021202)41:23<4439::AID-ANIE4439>3.0.CO;2-6. 

External links

• Nobel Lecture Syntheses in the Purine and Sugar Group from Nobelprize.org website
• Biography Biography from Nobelprize.org website
• Eminent Chemists of Our Time By Benjamin Harrow pages 216-239, published 1920 by Von Nostrand Company at books.google.com.
• 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.
• American Journal of Diseases of Children 1911 volume 2 by the American Medical Association also refers to Fischer's work.
•  "Fischer, Emil". Encyclopædia Britannica (11th ed.). 1911.  Short biography.
• An Introduction to the History of Medicine: With Medical Chronology by Fielding Hudson Garrison‎, page 708 refers to Fischer and Merings discovery of the drugs veronal(1904) and proponal(1905), published 1921 by Saunders Company.
• 1914 Year Book of the American Pharmaceutical Association, page 438 abstracts Fischer and Strauss's work on Phenol-Glucosides - Synthetic Production from Berlin d.D Chem. Germany, page 45(1912) No. 12.

v • d • e Nobel Laureates in Chemistry Jacobus van 't Hoff (1901) · Emil Fischer (1902) · Svante Arrhenius (1903) · William Ramsay (1904) · Adolf von Baeyer (1905) · Henri Moissan (1906) · Eduard Buchner (1907) · Ernest Rutherford (1908) · Wilhelm Ostwald (1909) · Otto Wallach (1910) · Marie Curie (1911) · Victor Grignard / Paul Sabatier (1912) · Alfred Werner (1913) · Theodore Richards (1914) · Richard Willstätter (1915) · Fritz Haber (1918) · Walther Nernst (1920) · Frederick Soddy (1921) · Francis Aston (1922) · Fritz Pregl (1923) · Richard Zsigmondy (1925) Complete roster · 1901–1925 · 1926–1950 · 1951–1975 · 1976–2000 · 2001–present

Persondata
NAME	Fischer, Hermann Emil
ALTERNATIVE NAMES	Fischer, Emil
SHORT DESCRIPTION	German Chemist
DATE OF BIRTH	9 October 1852
PLACE OF BIRTH	Euskirchen, Germany
DATE OF DEATH	15 July 1919
PLACE OF DEATH	Berlin, Germany

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