Pierre-Jean Robiquet – discoverer Asparagine & Alizarin dye

Pierre-Jean Robiquet – discoverer of Asparagine & Alizarin dye

Category : Personalities
Published by : Data Research Analyst, Worldofchemicals.com

Biography & contributions

Pierre-Jean Robiquet was a French chemist born on January 13, 1780 – April 1840. Robiquet was first person who identified existence of amino acid asparagine and also identified alizarin dye.

Robiquet reported that the elementary composition of alizarin and archil corresponded to the formulas C37H24O10 (today C14H8O4) and C18H22O5 (today, C28H24N2O7) respectively, indicating that these should be considered only approximate because of the difficult of preparing the substances in a sufficiently pure form.

In 1836 Robiquet reported that while working on the formation and properties of gallic acid he had found a large number of remarkable modifications of the acid (Robiquet, 1836).

In addition to the alizarin dyes, Robiquet also studied Prussian blue purple of Cassius and indigo. In 1826 Robiquet proved that morphine had a capacity of saturating acids similar to what it would have if all the nitrogen it contained were in the form of ammonia.

Robiquet isolated and characterized properties of following products like

Narcotine – It is a benzylisoquinoline alkaloid from plants of the Papaveraceae

Codeine – It is an opioid pain medication

Asparagine – It is α-amino acid that is found in many plant proteins

Caffeine – It is a bitter substance found in coffee, tea, soft drinks

Cantharides – It is a powerful irritant vesicant substance

Strychnine - a poisonous alkaloid that is obtained from seeds of the nux vomica tree.

Facts about strychnine

Strychnine is obtained from seeds plants of the genus Strychnos. It is practically insoluble in water and is soluble only with difficulty in alcohol and other common organic solvents. Strychnine has an exceptionally bitter taste. Strychnine has been used in rodent poisons and in smaller doses as a stimulant in veterinary practice. It increases the reflex irritability of the spinal cord, which results in a loss of normal inhibition of the body’s motor cells, causing severe contractions of the muscles; arching of the back is a common symptom of poisoning.

Strychnine rapidly enters the blood, whether taken orally or by injection, and symptoms of poisoning usually appear within 20 minutes. Strychnine is rapidly metabolized by the liver microsomal enzyme system requiring NADPH and O2. Strychnine competes with the inhibitory neurotransmitter glycine resulting in an excitatory state. Strychnine is a neurotoxin which acts as an antagonist of glycine and acetylcholine receptors. It primarily affects the motor nerves in the spinal cord which control muscle contraction.

Facts about codeine

Codeine is the second-most predominant alkaloid in opium. It is an opiate used for its analgesic, antitussive, antidiarrheal, antihypertensive, anxiolytic, antidepressant, sedative and hypnotic properties. Codeine is also used to suppress premature labor contractions, myocardial infarction, and has many other potential and indicated uses. Codeine is used to treat mild to moderate pain and to relieve cough. It is also used to treat diarrhea and diarrhea-predominant irritable bowel syndrome. Codeine is also demethylated by reaction with pyridine to synthesize morphine, which can then be acetylated to make heroin.

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