'Pyruvic acid' (CH
3COCO
2H) is an
alpha-keto acid which plays an important role in biochemical processes. The
carboxylate anion of pyruvic acid is known as 'pyruvate'.
Chemistry
Pyruvic acid is a colorless liquid with a smell similar to
acetic acid. It is
miscible with water, and soluble in
ethanol and
diethyl ether. In the laboratory, pyruvic acid may be prepared by heating a mixture of
tartaric acid and
potassium hydrogen sulfate, or by the hydrolysis of
acetyl cyanide, formed by reaction of
acetyl chloride with
potassium cyanide:
:CH
3COCl + KCN → CH
3COCN
:CH
3COCN → CH
3COCOOH
Biochemical role
Pyruvate is an important
chemical compound in
biochemistry. It is the output of the metabolism of
glucose known as
glycolysis. One molecule of
glucose breaks down into two molecules of pyruvic acid, which are then used to provide further energy, in one of two ways. Provided that sufficient
oxygen is available, pyruvic acid is converted into
acetyl-coenzyme A, which is the main input for a series of reactions known as the
Krebs cycle. Pyruvate is also converted to
oxaloacetate by an
anaplerotic reaction and then further broken down to
carbon dioxide. These reactions are named after
Hans Adolf Krebs, the biochemist awarded the 1953
Nobel Prize for physiology, jointly with
Fritz Lipmann, for research into metabolic processes. The cycle is also called the
citric acid cycle, because citric acid is one of the intermediate compounds formed during the reactions.
If insufficient oxygen is available, the acid is broken down
anaerobically, creating
lactic acid in animals and
ethanol in plants. Pyruvate from glycolysis is converted by
anaerobic respiration to
lactate using the
enzyme lactate dehydrogenase and the
coenzyme NADH in lactate
fermentation, or to
acetaldehyde and then to ethanol in alcoholic fermentation.
Pyruvic acid is a key intersection in the network of
metabolic pathways. Pyruvic acid can be converted to
carbohydrates via
gluconeogenesis, to
fatty acids or energy through
acetyl-CoA, to the
amino acid alanine and to
ethanol. Therefore it unites several key metabolic processes.
3-bromopyruvate has been studied for potential cancer treatment applications, by Young Hee Ko, Ph.D., at Johns Hopkins University
[1][2], in ways that would support the
Warburg hypothesis.
Pyruvate production by glycolysis
This reaction is not reversible and cannot proceed in the direction of PEP.
===
Pyruvate decarboxylation to acetyl CoA=
Note that decarboxylation is only one of several possible reactions for pyruvate.
Pyruvic acid's role in the origin of life==
Main articles: iron-sulfur world theory
Current evolutionary theory on the
origin of life posits that the first organisms were anaerobic because the atmosphere of prebiotic Earth was almost devoid of oxygen. As such, requisite biochemical materials must have preceded life and recent experiments indicate that pyruvate can be synthesized abiotically. In vitro,
iron sulfide at sufficient pressure and temperature
catalyzes the formation of pyruvic acid. Thus, argues
Günter Wächtershäuser, the mixing of iron-rich crust with hydrothermal vent fluid is suspected of providing the fertile basis for the formation of life.
See also
References
★ George D. Cody, Nabil Z. Boctor, Timothy R. Filley, Robert M. Hazen, James H. Scott, Anurag Sharma, Hatten S. Yoder Jr., "Primordial Carbonylated Iron-Sulfur Compounds and the Synthesis of Pyruvate," ''Science'', ''289'' (5483) (25 August 2000) pp. 1337 - 1340.
[3]
External links
★
<3-bromopyruvate>"Energy Blocker Kills Big Tumors in Rats"
★
"Pyruvate in Cancer Prevention and Treatment"
★
"Young Resercher Stalks Cancer" (with pyruvate)
★
"The cancer cell's "power plants" as promising therapeutic targets: An overview." by Peder Petersen, Johns Hopkins
★
3-BROMOPYRUVIC ACID As a Potent Anticancer Agent Delivered Intraarterially."
★
"Pyruvate" from Malaysian Global Information on Integrated Medicine