home Audience 4 Pyruvic acid and its use as a peeling agent. Aldehyde acids Synthesis of pyruvic acid

Pyruvic acid and its use as a peeling agent. Aldehyde acids Synthesis of pyruvic acid

Nomenclature

Rational. Aldehydo and keto acids can be considered as derivatives of the corresponding fatty acids by replacing an atom N and radical R on acyl. Acylcarboxylic acid.

Systematic. Referred to as a carboxylic acid with the addition of the prefix oxo- and indicating the carbon atom number. (Oxogroup = C = O).

Oxoacids are divided into classes based on the relative position of functional groups, dividing them into a-, b-, g-oxoacids.

General formula

The homologous series begins with glyoxylic acid - (trivial name):

Next in the series is formyacetic acid. Unknown in free state:

3-oxopropanoic acid

Aldehyde acids have all the properties of aldehydes:

1) addition of hydrocyanic acid HCN

2) addition of sodium bisulfite NaSO 3 H

3) replacement of carbonyl oxygen in the reaction with hydroxylamine H 2 N – OH

4) with an ammonia solution of silver oxide - silver mirror reaction

by carboxyl group:

1) formation of salts

2) formation of esters

The first in the homologous series of a-keto acids is pyruvic acid:

Acetylformic acid

2-oxopropanoic acid

t pl = 14 o C, t boil = 165 o C

An intermediate product in lactic and alcoholic fermentation of carbohydrates.

First isolated from the pyrolysis of grape acid.

Salts are pyruvates.

a-keto acids are much stronger than the carboxylic acids from which they can be formed

a-oxo acids are the strongest of the carboxylic acids.

C* is an asymmetric carbon atom and is associated with four different groups.

NAD – nicotinamide adenine dinucleotide – nicotinamide coenzyme

HSCoA – coenzyme A, coenzyme A, pantetheine adenine nucleotide diphosphate. Contained in plant and animal tissues and microorganisms. Acceptor and carrier of acidic residues during biochemical oxidative decarboxylation of keto acids, etc.

Acetomic acid is stronger than acetic acid and is capable of enolization:

Decarboxylation is a general property of carboxylic acids:

in vivo:

Acetoacetic acid is formed during the metabolism of higher fatty acids, during the oxidation of b-hydroxy butyric acid, and accumulates in diabetics.

Of greatest interest is acetoacetic ester (ethyl ester of acetoacetic acid), which is a mixture of two mutually converting isomers: tautomeric transformations:

The equilibrium position depends on temperature, the nature of the solvent, and the conditions of acid and base catalysis:

1) The keto form is more energetically beneficial. When distilling from a quartz vessel in the absence of alkali, the lower boiling enol form is distilled off, which upon standing gradually turns into an equilibrium mixture (the content of the enol form is less than 10%).

2) By freezing, i.e. when a solution of acetaacetic ether in petroleum ether is cooled with liquid air, the keto form crystallizes out with T pl = - 39 o C. But at room temperature it again goes into an equilibrium mixture.

3) influence of pH of the environment.

a) alkaline

October 29, 2016

Pyruvic acid (formula C 3 H 4 O 3) is β-ketopropionic acid. Colorless liquid with the odor of acetic acid; soluble in water, alcohol and ether. It is usually used in the form of salts - pyruvates. Pyruvic acid is found in all tissues and organs and, being a link in the metabolism of carbohydrates, fats and proteins, plays an important role in metabolism. The concentration of pyruvic acid in tissues changes with liver diseases, some forms of nephritis, cancer, vitamin deficiencies, especially with a lack of vitamin B1. Violation of pyruvic acid metabolism leads to acetonuria (see).
See also Biological oxidation.

Pyruvic acid (acidum pyroracemicum) is β-ketopropionic acid. It exists in two tautomeric forms - ketone and enol: CH 3 COCOOH>CH 2>COHCOOH. The keto form (see Keto acids) is more stable. Pyruvic acid is a colorless liquid that smells like acetic acid, d 15 4 = 1.267, melting point 13.6°, boiling point 165° (partially decomposes at 760 mm). Soluble in water, alcohol and ether. It is oxidized by nitric acid to oxalic acid, and by chromic anhydride to acetic acid. As a ketone, P. k. gives hydrazone, semihydrazone, oximes, and as an acid it forms esters, amides and salts - pyruvates. It is most often used in the form of pyruvates.
P. to. is obtained by distillation of tartaric or grape acids using water-removing agents. Its determination is based on reactions with nitroprusside, salicylic aldehyde, and 2,4-dinitrophenylhydrazine, the products of which are colored.
Pyruvic acid is found in all tissues and organs. Human blood normally contains 1 mg%, and urine 2 mg%. P. to. plays an important role in metabolism, being a connecting link in the metabolism of carbohydrates, fats and proteins. In the body, P. is formed as a result of the anaerobic breakdown of carbohydrates (see Glycolysis). Subsequently, under the action of pyruvate dehydrogenase, P. is converted into acetyl-CoA, which is used in the synthesis of fatty acids, acetylcholine, and can also transfer its acyl to oxaloacetic acid for further oxidation to CO 2 and H 2 O (see Biological oxidation) . P. to. also participates in the reactions of transamination and glycogenolysis.
P.'s concentration in tissues changes in a variety of diseases: liver diseases, some forms of nephritis, vitamin deficiencies, cerebrospinal injuries, cancer, etc.
Violation of P.'s metabolism leads to acetonuria.
In pharmacology, pyruvic acid is used to prepare zinchofen.

Source – http://www.medical-enc.ru/15/pyruvic-acid.shtml

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2016-10-29

Medicine is a separate and very important field of human activity, which is aimed at studying various processes in the human body, treating and preventing various diseases. Medicine studies both old and new diseases, develops new treatment methods, medicines and procedures.

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Medicine helps people recover from everyday illnesses, helps in the prevention of various infections, but it also cannot be omnipotent. There are still quite a few different unknown diseases, inaccurate diagnoses, and incorrect approaches to curing the disease. Medicine cannot provide 100% reliable protection and assistance to people. But it’s not just a matter of insufficiently known diseases. Recently, many alternative methods of healing have appeared; the terms correction of chakras and restoration of energy balance are no longer surprising. Such a human ability as clairvoyance can also be used for diagnosis, predicting the course of development of certain diseases and complications.

Are common
Pyruvic acid

Pyruvic-acid-3D-balls.png
Systematic Name	2-oxopropanoic acid
Abbreviations	Pyruvate
Traditional names	α-ketopropionic acid, pyruvic acid, pyruvate
Chem. formula	C3H4O3
Physical properties
Molar mass	88.06 g/mol
Density	1.250 g/cm³
Thermal properties
T. float.	11.8 °C
T. kip.	165 °C
Chemical properties
pKa	2,50
Classification
Reg. CAS number	127-17-3
SMILES
Data are based on standard conditions (25 °C, 100 kPa) unless otherwise stated.

Pyruvic acid- a chemical compound with the formula CH 3 COCOOH, organic keto acid.

Biochemical role

Pyruvates (salts of pyruvic acid) are important chemical compounds in biochemistry. They are the end product of glucose metabolism through the process of glycolysis. One molecule of glucose is converted into two molecules of pyruvic acid. Further metabolism of pyruvic acid is possible in two ways - aerobic and anaerobic.

Under conditions of sufficient oxygen supply, pyruvic acid is converted into acetyl coenzyme A, which is the main substrate for a series of reactions known as the Krebs cycle, or the respiratory cycle, tricarboxylic acid cycle. Pyruvate can also be converted in the anaplerotic reaction to oxaloacetate. Oxaloacetate is then oxidized to carbon dioxide and water. These reactions are named for Hans Adolf Krebs, a biochemist who, together with Fritz Lipmann, received the Nobel Prize in Physiology in 1953 for his research into the biochemical processes of the cell. The Krebs cycle is also called the citric acid cycle, since citric acid is one of the intermediate products of the Krebs cycle reaction chain.

If oxygen is insufficient, pyruvic acid undergoes anaerobic breakdown to form lactic acid in animals and ethanol in plants and fungi. During anaerobic respiration in cells, pyruvate produced by glycolysis is converted to lactate by the enzyme lactate dehydrogenase and NADP in the process of lactate fermentation, or to acetaldehyde and then to ethanol in the process of alcoholic fermentation.

Pyruvic acid is the “crossing point” of many metabolic pathways. Pyruvate can be converted back to glucose through gluconeogenesis, or to fatty acids or energy via acetyl-CoA, the amino acid alanine, or ethanol.

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Notes

An excerpt characterizing pyruvic acid

Prince Andrei headed towards the door from behind which voices were heard. But just as he wanted to open the door, the voices in the room fell silent, the door opened of its own accord, and Kutuzov, with his aquiline nose on his plump face, appeared on the threshold.
Prince Andrei stood directly opposite Kutuzov; but from the expression of the commander-in-chief’s only seeing eye it was clear that thought and concern occupied him so much that it seemed to obscure his vision. He looked directly at the face of his adjutant and did not recognize him.
- Well, have you finished? – he turned to Kozlovsky.
- Right this second, Your Excellency.
Bagration, a short man with an oriental type of firm and motionless face, a dry, not yet old man, followed the commander-in-chief.
“I have the honor to appear,” Prince Andrei repeated quite loudly, handing over the envelope.
- Oh, from Vienna? Fine. After, after!
Kutuzov went out with Bagration onto the porch.
“Well, prince, goodbye,” he said to Bagration. - Christ is with you. I bless you for this great feat.
Kutuzov's face suddenly softened, and tears appeared in his eyes. He pulled Bagration to him with his left hand, and with his right hand, on which there was a ring, apparently crossed him with a familiar gesture and offered him his plump cheek, instead of which Bagration kissed him on the neck.
- Christ is with you! – Kutuzov repeated and walked up to the carriage. “Sit down with me,” he said to Bolkonsky.
– Your Excellency, I would like to be useful here. Let me stay in the detachment of Prince Bagration.
“Sit down,” said Kutuzov and, noticing that Bolkonsky was hesitating, “I need good officers myself, I need them myself.”
They got into the carriage and drove in silence for several minutes.
“There is still a lot ahead, there will be a lot of things,” he said with an senile expression of insight, as if he understood everything that was happening in Bolkonsky’s soul. “If one tenth of his detachment comes tomorrow, I will thank God,” added Kutuzov, as if speaking to himself.
Prince Andrei looked at Kutuzov, and he involuntarily caught his eye, half an arshin away from him, the cleanly washed assemblies of the scar on Kutuzov’s temple, where the Izmail bullet pierced his head, and his leaking eye. “Yes, he has the right to talk so calmly about the death of these people!” thought Bolkonsky.
“That’s why I ask you to send me to this detachment,” he said.
Kutuzov did not answer. He seemed to have already forgotten what he had said and sat thoughtful. Five minutes later, smoothly rocking on the soft springs of the stroller, Kutuzov turned to Prince Andrei. There was no trace of excitement on his face. With subtle mockery, he asked Prince Andrei about the details of his meeting with the emperor, about the reviews he had heard at court about the Kremlin affair, and about some common women he knew.

Kutuzov, through his spy, received news on November 1 that put the army he commanded in an almost hopeless situation. The scout reported that the French in huge numbers, having crossed the Vienna bridge, headed towards Kutuzov’s route of communication with the troops coming from Russia. If Kutuzov had decided to stay in Krems, then Napoleon’s army of one and a half thousand would have cut him off from all communications, surrounded his exhausted army of forty thousand, and he would have been in Mack’s position near Ulm. If Kutuzov had decided to leave the road that led to communications with troops from Russia, then he would have had to enter without a road into the unknown lands of the Bohemian
mountains, defending themselves from superior enemy forces, and abandoning all hope of communication with Buxhoeveden. If Kutuzov had decided to retreat along the road from Krems to Olmutz to join forces with troops from Russia, then he risked being warned on this road by the French who had crossed the bridge in Vienna, and thus being forced to accept battle on the march, with all the burdens and convoys, and dealing with an enemy three times his size and surrounding him on both sides.
Kutuzov chose this last exit.
The French, as the spy reported, having crossed the bridge in Vienna, were marching in an intensified march towards Znaim, which lay on Kutuzov’s retreat route, more than a hundred miles ahead of him. To reach Znaim before the French meant to have great hope of saving the army; to allow the French to warn themselves in Znaim would probably mean exposing the entire army to a disgrace similar to that of Ulm, or to general destruction. But it was impossible to warn the French with their entire army. The French road from Vienna to Znaim was shorter and better than the Russian road from Krems to Znaim.

Pyruvic acid (formula C 3 H 4 O 3) is α-ketopropionic acid. Colorless liquid with odor; soluble in water, alcohol and. It is usually used in the form of salts - pyruvates. Pyruvic acid is found in all tissues and organs and, being a link in the metabolism of fats and proteins, plays an important role in metabolism. The concentration of pyruvic acid in tissues changes with liver diseases, some forms of nephritis, cancer, vitamin deficiencies, especially with deficiency. Violation of pyruvic acid metabolism leads to acetonuria (see).