Glyoxylic acid

|Section3=

Glyoxylic acid or oxoacetic acid is an organic compound. Together with acetic acid, glycolic acid, and oxalic acid, glyoxylic acid is one of the C2 carboxylic acids. It is a colourless solid that occurs naturally and is useful industrially.

The conjugate base of glyoxylic acid is known as glyoxylate and is the form that the compound exists in solution at neutral pH. Glyoxylate is the byproduct of the amidation process in biosynthesis of several amidated peptides. For the historical record, glyoxylic acid was prepared from oxalic acid electrosynthetically: in organic synthesis, lead dioxide cathodes were applied for preparing glyoxylic acid from oxalic acid in a sulfuric acid electrolyte. Hot nitric acid can oxidize glyoxal to glyoxylic; however this reaction is highly exothermic and prone to thermal runaway. In addition, oxalic acid is the main side product. Also, ozonolysis of maleic acid is effective. fungi, and plants to convert fatty acids into carbohydrates. The glyoxylate cycle is also important for induction of plant defense mechanisms in response to fungi. The glyoxylate cycle is initiated through the activity of isocitrate lyase, which converts isocitrate into glyoxylate and succinate. Research is being done to co opt the pathway for a variety of uses such as the biosynthesis of succinate.

Glyoxylate is produced via two pathways: through the oxidation of glycolate in peroxisomes or through the catabolism of hydroxyproline in mitochondria. In the peroxisomes, glyoxylate is converted into glycine by AGT1 or into oxalate by glycolate oxidase. In the mitochondria, glyoxylate is converted into glycine by AGT2 or into glycolate by glyoxylate reductase. A small amount of glyoxylate is converted into oxalate by cytoplasmic lactate dehydrogenase.

In addition to being an intermediate in the glyoxylate cycle, glyoxylate is also an important intermediate in the photorespiration pathway. Photorespiration is a result of the side reaction of RuBisCO with O2 instead of CO2. While at first considered a waste of energy and resources, photorespiration has been shown to be an important method of regenerating carbon and CO2, removing toxic phosphoglycolate, and initiating defense mechanisms. In photorespiration, glyoxylate is converted from glycolate through the activity of glycolate oxidase in the peroxisome. It is then converted into glycine through parallel actions by SGAT and GGAT, which is then transported into the mitochondria.

Glyoxylate is thought to be a potential early marker for Type II diabetes. AGEs can lead to further complications of diabetes, such as tissue damage and cardiovascular disease. They are generally formed from reactive aldehydes, such as those present on reducing sugars and alpha oxoaldehydes. In a study, glyoxylate levels were found to be significantly increased in patients who were later diagnosed with Type II diabetes. The elevated levels were found sometimes up to three years before the diagnosis, demonstrating the potential role for glyoxylate to be an early predictive marker.

Glyoxylate is involved in the development of hyperoxaluria, a key cause of nephrolithiasis (commonly known as kidney stones). Glyoxylate is both a substrate and inductor of sulfate anion transporter 1 (sat 1), a gene responsible for oxalate transportation, allowing it to increase sat 1 mRNA expression and as a result oxalate efflux from the cell. The increased oxalate release allows the buildup of calcium oxalate in the urine, and thus the eventual formation of kidney stones.

Glyoxylic acid is a component of the Hopkins–Cole reaction, used to check for the presence of tryptophan in proteins.

Glyoxylic acid is one of several ketone and aldehyde containing carboxylic acids that together are abundant in secondary organic aerosols. In the presence of water and sunlight, glyoxylic acid can undergo photochemical oxidation. Several different reaction pathways can ensue, leading to various other carboxylic acid and aldehyde products.

The compound is not very toxic with an for rats of 2500 mg/kg. But a recent experiment shows that it is toxic. See https://karger. com/cnd/article/12/2/112/827730/Acute Kidney Injury following Exposure to.