Pierre Jean Robiquet

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Pierre Robiquet
Kingdom of France
Died29 April 1840(1840-04-29) (aged 60)
OccupationChemist

Pierre Jean Robiquet (13 January 1780 – 29 April 1840) was a French chemist. He laid founding work in identifying amino acids, the fundamental building blocks of proteins. He did this through recognizing the first of them, asparagine, in 1806, in the industry's adoption of industrial dyes, with the identification of alizarin in 1826, and in the emergence of modern medications, through the identification of codeine in 1832, an opiate alkaloid substance of widespread use with analgesic and antidiarrheal properties.

Robiquet was born in Rennes. He was at first a pharmacist in the French armies during the French Revolution years, and became a professor at the École de pharmacie in Paris, where he died.

Notable scientific achievements were among other things his isolation and characterization of properties of

Orcin (1829), amygdalin (1830), as well as codeine
(1832). Some of these discoveries were made in collaboration with other scientists.

Academic titles and distinctions

Registered Pharmacist (1808), lecturer in chemistry at the

Académie des Sciences (1833), one of the founders and first President of the Société de Prévoyance des Pharmaciens
see [6](1820).

Distinguished with the order of the

Légion d'Honneur
(1830).

Discovery of asparagine, the first amino acid ever identified

In the fall of 1805, Robiquet, then a young help working in the laboratory of Louis Nicolas Vauquelin, started analyses, with what rudimentary methods were then available, with asparagus juice. After a number of operations he obtained a crystallized white matter, which he and Vauquelin tried to characterize in 1806 as day by day their attempts found it to be some kind of new "chemical principle" with hitherto unknown properties, nothing like well known mineral salts classically obtained in the 18th century. Duly convinced this is something completely new, they call this matter "asparagin", after the asparagus plant they extracted it from. Asparagine will turn out to be one of the 22 amino acids that build-up all living matter on earth, the first ever identified and understood as belonging to a new class of molecules. Progress in isolating the other amino acids was very slow, with less than a handful in total during the whole 19th century.

Discovery of various dyes

Even until the middle of 19th century, all dyes used for colouring cloth were natural substances, many of which were expensive and labour-intensive to extract. Furthermore, many lacked stability through washing or exposure to sunlight, or fastness.

For instance, the colour purple, which had been a mark of aristocracy and prestige since ancient times in Rome, the Middle East and Egypt, was especially expensive and difficult to produce—the dye used, known as Tyrian purple, was made from the glandular mucus of certain molluscs. Its extraction was variable and complicated, and dependent on the availability of the very specific type of shell (actually two types, now known the one as Bolinus brandaris, and the other as Hexaplex trunculus, nowadays classified within two different genders) from which it was extracted.

Another type of natural red dye used from times immemorial was obtained from

Corinth. In the Middle Ages, Charlemagne encouraged madder cultivation. It grew well in the sandy soils of the Netherlands and became an important part of the local economy. By 1804, the English dye maker George Field had introduced new techniques known as lake
madder, that extended the use of the tincture to paints.

Robiquet obtained from madder root two distinct molecules with dye properties, the one producing a magnificent red, that he called alizarin, which proved as well extremely stable, and another, of less stable properties, that he called purpurin.

Some 30 years later in April 1856, William Henry Perkin, then a mere youngster working as assistant at the Royal College of Chemistry in London within a team intent on research over the synthesis of quinine, a potent drug, discovered a process that obtained a purple dye (which he called mauveine) from aniline, which in turn could be easily obtained from coal tar; over the next ten years Perkin set up the first industrial model of molecules obtained through synthesis from coal tar and his success had prompted intense research from numerous teams all over Europe on coal tar by-products, while he himself pursued such a work on top of his industrial activity.

Thus it came that in 1868, in turn alizarin was proved to be obtainable from

Carl Gräbe and Carl Theodore Liebermann
, both working in Germany for the BASF company; unfortunately Perkin missed the patent priority by one single day, alizarin's extraordinary properties made it become the first really mass industry-produced dye and enabled the rise of BASF to first rank in the chemistry industry world.

Discovery and industrialization of codeine

elixirs (a number of them, very popular in England since the beginning of the 18th century), and health or even death hazards to users from improper preparation or improper use were frequent.

The isolation of codeine by Robiquet from opium's several active components while working on refined morphine extraction processes, opened the path to the elaboration of a new generation of specific antitussive and antidiarrheal potions of much safer use, based on codeine only, which became immediately extremely popular.

Codeine is nowadays by far the most widely used opiate in the world and very likely even the most commonly used drug overall according to numerous reports over the years by organizations such as the World Health Organization and its League of Nations predecessor agency and others. It is one of the most effective orally-administered opioid analgesics and has a wide safety margin. It is from 8 to 12 percent of the strength of morphine in most people; differences in metabolism can change this figure as can other medications, depending on its route of administration.

While codeine can still be directly extracted from opium, its original source, most codeine is nowadays synthesized from morphine through the process of O-methylation.

Sundry researches in pharmacology; missing by a hair's breadth the identification of the benzoyl radical in 1830

Robiquet has analysed the chemical byproducts that could be obtained from a variety of plants: asparagus, madder root, as already mentioned, with the important associated discoveries, and also others, which mostly helped in consolidating the existence of some molecules in a wide range of plants. Thus, in 1809, Robiquet extracts from

asparagin, which it will be indeed proven to be in 1828 by Plisson.[1]

Robiquet likewise analysed a variety of animal tissues. Thus in 1810, he isolated from

Lytta vesicatoria
belongs in the Lytta genus, is rich of several thousands of species)

In fact, even back into the days of the early classical period civilizations of the western Mediterranean, some types of flies from Spain had a reputation for inducing aphrodisiac effects when used in preparations after having been desiccated. Cantharidin has never been proven to provide such collateral benefits, whereas Robiquet demonstrated it had very definite toxic and poisonous properties comparable in degree to that of the most violent poisons known in the 19th century, such as strychnine.[2]

This particular study, that demonstrated, as early as in 1810, the possibility to separate, using "energetic" methods, a simple "principle" that was the actual effective fraction of a traditional natural compound obtained by "soft" methods has been exemplary for the burgeoning community of chemists in the early 19th century, and will prompt very rapidly a flurry of similar attempts that will yield within a few decades an incredible number of molecules from an ever growing number of research groups throughout Europe, and soon in the trail, in the US. In the frame of that same investigation, Robiquet in addition evidences the presence of uric acid within insects feeding on plant tissues.

Over a period of some fifteen years, Pierre Robiquet will also conduct a series of investigations on

1,2-dichloroethane
), which they will try to promote as a reinvigorating medicine.

In 1830, together with

Justus Liebig
, these two got all the credit for this breakthrough result that was opening an entirely new branch for the industry of chemicals with wide-ranging applications.

Amygdalin and related molecules have been used throughout the 19th (promoted by

Sloan-Kettering Cancer Institute that amygdalin
(often sold under the brand name of "Laetrile") could be toxic as it breaks down in the body to form cyanide.

Main published works

See also

Notes

  1. ^ http://www.ibiblio.org/herbmed/eclectic/kings/glycyrrhiza.html[dead link]
  2. ^ Expériences sur les cantharides, Robiquet, Annales de Chimie, 1810, vol. 76, pp. 302–322.
  3. ^ Recherches sur la nature de la matière huileuse des chimistes hollandais, Robiquet, Colin, Annales de Chimie et de Physique, 1816, vol. 1, pp. 337–45

References

  • Baumann E (1884). "Über cystin und cystein". Z Physiol Chem. 8 (4): 299–305. Retrieved 28 March 2011.
  • Braconnot HM (1820). "Sur la conversion des matières animales en nouvelles substances par le moyen de l'acide sulfurique". Annales de Chimie et de Physique. Série 2. 13: 113–125.
  • Moertel CG, Ames MM, Kovach JS, Moyer TP, Rubin JR, Tinker JH (February 1981). "A pharmacologic and toxicological study of amygdalin". JAMA. 245 (6): 591–594.
    PMID 7005480
    .
  • Moertel CG, Fleming TR, Rubin J (January 1982). "A clinical trial of amygdalin (Laetrile) in the treatment of human cancer". N. Engl. J. Med. 306 (4): 201–206.
    PMID 7033783
    .

Sources

External links

  • [1] Origines de la "Société de Prévoyance des Pharmaciens"
  • [2] La codéine : Pierre ROBIQUET (1780–1840)
  • [3] La Création de l'Ecole de Pharmacie
  • [4] Académie Nationale de Pharmacie
Curiosity items about Pierre Robiquet at today's "École de Pharmacie" in Paris

The "Ecole de Pharmacie", nowadays the "Faculté de Pharmacie" (University of pharmaceutical sciences) of Paris, stands 4, avenue de l'Observatoire, Paris 5eme

  • Portrait by Devouge, Salle des Actes; visit [5] and go to portrait n°48
  • One of the many figurehead medallions that adorn the walls of the inner court of the building represents Pierre Robiquet (along with other famed pharmacists and chemists such as Chaptal, Houel, Fourcroy, Antoine de Jussieu, Caventou et Pelletier, Brongniart, Newton, Lavoisier, Berthollet, Dumas, Bernard...) (visit [6] Société d'Histoire de la Pharmacie and [7] Les médaillons de la Faculté de Pharmacie de Paris)