glyoksalaatti

Glyoksalaatti, known in English as glyoxylate, is the two-carbon carboxylate derived from glyoxylic acid. In biochemical contexts the term often refers to the glyoxylate anion or its esters. The molecule contains a carboxyl group and an aldehyde group, making it a reactive α-oxo aldehyde with both oxidizing and carbon‑center chemistry possibilities.

Occurrence and production are greatest in plants, bacteria, and fungi, where glyoxylate appears as a key intermediate in the glyoxylate cycle. In this pathway, isocitrate lyase cleaves isocitrate to produce glyoxylate and succinate; glyoxylate can then combine with acetyl‑CoA via malate synthase to form malate, enabling organisms to convert fatty acids into carbohydrates when growing on two‑carbon substrates. Glyoxylate is also generated by the oxidation of glycolate in various metabolic routes.

Biochemical roles of glyoxylate include transamination to glycine and, in plants and some microbes, further metabolism within amino‑acid and organic‑acid networks. It can be oxidized to oxalate by glyoxylate oxidase, producing hydrogen peroxide as a byproduct. In humans, dysregulation of glyoxylate metabolism is clinically relevant: excess glyoxylate due to deficiencies in alanine:glyoxylate aminotransferase can lead to elevated oxalate and kidney stone formation, a condition known as primary hyperoxaluria type I.

Chemically, glyoxylate and its salts (for example sodium glyoxylate) are used as intermediates in organic synthesis and biochemical studies. They are reactive due to the aldehyde and carboxylate functional groups and should be handled with appropriate safety precautions. Glyoxylate thus occupies a central place in plant and microbial metabolism and in human health considerations related to oxalate synthesis.