Gluconic acid, also known as D-gluconic acid, D-gluconate or (2R,3S,4R,5R)-2,3,4,5,6-pentahydroxyhexanoic acid (also named dextronic acid), is the C1-oxidized form of D-glucose where the aldehyde group has become oxidized to the corresponding carboxylic acid.  Gluconic acid belongs to the class of organic compounds known as sugar acids and derivatives. Sugar acids and derivatives are compounds containing a saccharide unit which bears a carboxylic acid group. In aqueous solution, gluconic acid exists in equilibrium with the cyclic ester glucono delta-lactone. Gluconic acid occurs naturally in fruit, honey, kombucha tea and wine. The salts of gluconic acid are known as "gluconates". Gluconic acid, gluconate salts, and gluconate esters occur widely in nature because such species arise from the oxidation of glucose. Gluconic acid exists in all living species, ranging from bacteria to plants to humans. The metabolism of gluconate is well characterized in prokaryotes where it is known to be degraded following phosphorylation by gluconokinase. Glucokinase activity has also been detected in mammals, including humans (PMID: 24896608). Gluconic acid is produced in the gluconate shunt pathway. In the gluconate shunt, glucose is oxidized by glucose dehydrogenase (also called glucose oxidase) to furnish gluconate, the form in which D-gluconic acid is present at physiological pH. Subsequently, gluconate is phosphorylated by the action of gluconate kinase to produce 6-phosphogluconate, which is the second intermediate of the pentose phosphate pathway. This gluconate shunt is mainly found in plants, algae, cyanobacteria and some bacteria, which all use the Entner‚ÄìDoudoroff pathway to degrade glucose or gluconate; this generates 2-keto-3-deoxygluconate-6-phosphate, which is then cleaved to generate pyruvate and glyceraldehyde 3-phosphate. Glucose dehydrogenase and gluconate kinase activities are also present in mammals, fission yeast, and flies. Gluconic acid has many industrial uses. It is used as a drug as part of electrolyte supplementation in total parenteral nutrition. It is also used in cleaning products where it helps cleaning up mineral deposits. Gluconic acid or Gluconic acid is used to maintain the cation-anion balance on electrolyte solutions. In humans, gluconic acid is involved in the metabolic disorder called the transaldolase deficiency. Gluconic acid has been found to be a metabolite in Aspergillus (Hugo Vanden Bossche, D.W.R. Mackenzie and G. Cauwenbergh. Aspergillus and Aspergillosis, 1987).