Quinine

The quinine , of C20H24N2O2 chemical formula, is a natural Alcaloïde having properties Antipyrétique, antipaludic and Analgésique. It was used for the prevention of the Paludisme before being supplanted by its derivatives, Quinacrine, Chloroquine, and Primaquine. Quinine can always be used to treat the resistant malaria, and to treat the night Crampe S of the legs. It was also used in a test to treat people infected by the prion S, but success was limited.

Discovered

She was discovered with the Peru. The powder of Quinquina was known, and this as of the 18th century, to cure the third Fièvre . Jesuit S brought back his use by the INCA S to relieve the Malaria. It is only in 1820 that the substance activates was isolated by Joseph Bienaimé Caventou, its structure, it was described only one century later. Quinine inhibits the Protéase which degrades the amino-acid of the Hémoglobine to form the wall of the Mérozoïte S. It inhibits also the polymerization of heme of hemoglobin and thus prevents the reproduction of the Plasmodium S. It inhibits the way of the schizontes and is antipyretic.

However: it is toxic for the Nervous system, one thus sought to synthesize analogues not having this defect:

  • the Chloroquine which is not effective on all plasmodiums.
  • the Méfloquine, more effective but also more toxic.

  • the Artémisinine, nonrelated with quinine, is very active. It is about a sesquiterpenic lactone containing a bridge endopéroxyde and which is resulting from a Chinese Armoise ( Artemisia annua ). It is effective against the shapes of plasmodiums resistant to chloroquine (case of the neuropaludisms in particular) and until now, no resistance of the stocks of Plasmodium to the artémisinine or its derivatives semisynthetic (artéméther, artesunate in particular) appeared.

Employment

The use of quinine in excessive amount can cause the Cinchonisme, of the problems for the fetus in particular deafness and even death.

Quinine is component aromatic of tonic water. According to the tradition, the sour taste of the quinine used against the Paludisme encouraged the colonial British in India to mix it with gin, thus creating the tonic Cocktail Gin.

However, the current gin tonic is very different from drink of this time, in particular because the quinine amount employed is from now on only approximately the quarter of what it was. With the the United States, the authorized maximum amount is of 83 ppm.

In March 2006, of the researchers of the Université of Lille I announced to have developed a new molecule, the ferroquine (SR), by associating the chloroquinine with Fer which attracts the parasite, this new molecule would be up to 30 times more effective than the chloroquinine.

Proportioning

Quinine is a fluorescent molecule . One can thus proportion it by Spectrofluorimétrie.

external bonds

  • toxicological Bank

  • of Inchem
  • Malaria Newspaper

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