Gluconic acid is an
organic compound with
molecular formula C6H12O7 and condensed
structural formula HOCH2(CHOH)4CO2H. A white solid, it forms the gluconate anion in neutral aqueous solution. 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. Some drugs are injected in the form of gluconates.
Gluconic acid is typically produced by the aerobic oxidation of glucose in the presence of the enzyme
glucose oxidase. The conversion produces
gluconolactone and
hydrogen peroxide. The lactone spontaneously hydrolyzes to gluconic acid in water.[3]
Gluconic acid was first prepared by Hlasiwetz and Habermann in 1870[8] and involved the chemical oxidation of glucose. In 1880, Boutroux prepared and isolated gluconic acid using the glucose fermentation.[9]
Gluconate is also used in building and construction as a concrete admixture (retarder) to slow down the cement hydration reactions, and to delay the cement setting time. It allows for a longer time to lay the concrete, or to spread the cement hydration heat over a longer period of time to avoid too high a temperature and the resulting cracking.[12][13] Retarders are mixed in to concrete when the weather temperature is high or to cast large and thick concrete slabs in successive and sufficiently well-mixed layers.
Gluconic acid aqueous solution finds application as a medium for
organic synthesis.[14]
Medicine
In medicine, gluconate is used most commonly as a biologically neutral carrier of Zn2+, Ca2+, Cu2+, Fe2+, and K+ to treat
electrolyte imbalance.[15]
Calcium gluconate, in the form of a gel, is used to treat burns from
hydrofluoric acid;[16][17] calcium gluconate injections may be used for more severe cases to avoid necrosis of deep tissues, as well as to treat hypocalcemia in hospitalized patients. Gluconate is also an electrolyte present in certain solutions, such as "
plasmalyte a", used for intravenous fluid resuscitation.[18]Quinine gluconate is a salt of gluconic acid and quinine, which is used for
intramuscular injection in the treatment of
malaria.
^Boutroux, L. (1880).
"Sur une fermentation nouvelle du glucose" [On a new fermentation [product] of glucose]. Comptes Rendus de l'Académie des Sciences (in French). 91: 236–238.
^Julie K. Levy, P. Cynda Crawford, Leslie D. Appel, Emma L. Clifford (2008), Comparison of intratesticular injection of zinc gluconate versus surgical castration to sterilize male dogs. American Journal of Veterinary Research Vol. 69, No. 1, Pages 140–143.
doi:
10.2460/ajvr.69.1.140
^Ramachandran, V.S.; Lowery, M.S. (1992). "Conduction calorimetric investigation of the effect of retarders on the hydration of Portland cement". Thermochimica Acta. 195: 373–387.
doi:
10.1016/0040-6031(92)80081-7.
ISSN0040-6031.
^Ma, Suhua; Li, Weifeng; Zhang, Shenbiao; Ge, Dashun; Yu, Jin; Shen, Xiaodong (2015). "Influence of sodium gluconate on the performance and hydration of Portland cement". Construction and Building Materials. 91: 138–144.
doi:
10.1016/j.conbuildmat.2015.05.068.
ISSN0950-0618.
^el Saadi M. S.; Hall A. H.; Hall P. K.; Riggs B. S.; Augenstein W. L.; Rumack B. H. (1989). "Hydrofluoric acid dermal exposure". Vet Hum Toxicol. 31 (3): 243–7.
PMID2741315.
^Roblin I.; Urban M.; Flicoteau D.; Martin C.; Pradeau D. (2006). "Topical treatment of experimental hydrofluoric acid skin burns by 2.5% calcium gluconate". J Burn Care Res. 27 (6): 889–94.
doi:
10.1097/01.BCR.0000245767.54278.09.
PMID17091088.
S2CID3691306.
^
D. Thomas, U. Jaeger, I. Sagoschen, C. Lamberti and K. Wilhelm (2009), Intra-Arterial Calcium Gluconate Treatment After Hydrofluoric Acid Burn of the Hand. CardioVascular and Interventional Radiology, Volume 32, Number 1, pages 155–158
doi:
10.1007/s00270-008-9361-1
^Paul Reznikoff and Walther F. Goebel (1937), The preparation of ferrous gluconate and its use in the treatment of hypochromic anelia in rats. Journal of Pharmacology and Experimental Therapy, volume 59 issue 2, page 182.