Erythorbic acid

Erythorbic acid

Names
IUPAC name D-erythro-Hex-2-enono-1,4-lactone
Systematic IUPAC name (5R)-5-[(1R)-1,2-Dihydroxyethyl]-3,4-dihydroxyfuran-2(5H)-one
Other names D-Araboascorbic acid, Erythorbate, Isoascorbic acid, D-isoascorbic acid
Identifiers
CAS Number	89-65-6  Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:51438  Y
ChemSpider	16736142  Y
ECHA InfoCard	100.001.753
E number	E315 (antioxidants, ...)
PubChem CID	6981
UNII	311332OII1  Y
CompTox Dashboard (EPA)	DTXSID6026537
InChI InChI=1S/C6H8O6/c7-1-2(8)5-3(9)4(10)6(11)12-5/h2,5,7-10H,1H2/t2-,5-/m1/s1 Y Key: CIWBSHSKHKDKBQ-DUZGATOHSA-N Y InChI=1/C6H8O6/c7-1-2(8)5-3(9)4(10)6(11)12-5/h2,5,7-10H,1H2/t2-,5-/m1/s1 Key: CIWBSHSKHKDKBQ-DUZGATOHBV
SMILES OC=1[C@H](OC(=O)C=1O)[C@H](O)CO
Properties
Chemical formula	C6H8O6
Molar mass	176.124 g·mol−1
Density	0.704 g/cm3
Melting point	164 to 172 °C (327 to 342 °F; 437 to 445 K) (decomposes)
Acidity (pKa)	2.1
Hazards
NFPA 704 (fire diamond)	1 1 0
Related compounds
Other cations	Calcium erythorbate, sodium erythorbate, potassium erythorbate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y  verify  (what is  YN ?) Infobox references

Erythorbic acid (isoascorbic acid, D-araboascorbic acid) is a stereoisomer (C5 epimer) of ascorbic acid (vitamin C). ^[1] It is synthesized by a reaction between methyl 2-keto-D-gluconate and sodium methoxide. It can also be synthesized from sucrose or by strains of Penicillium that have been selected for this feature. ^[2] It is denoted by E number E315, and is widely used as an antioxidant in processed foods. ^[3]

Health effects

Clinical trials have been conducted to investigate aspects of the nutritional value of erythorbic acid. One such trial investigated the effects of erythorbic acid on vitamin C metabolism in young women; no effect on vitamin C uptake or clearance from the body was found. ^[4]

A later study found that erythorbic acid is a potent enhancer of nonheme-iron absorption, just like ascorbate. This is thought to be due to it exerting the same iron-reducing and iron-chelating activity as ascorbic acid. Neither of these reactions is mediated by an enzyme, which would confer some chiral selectivity. ^[5] It is twice as effective as ascorbic acid in enhancing non-heme iron absorption. Americans are estimated to ingest 200 mg of erythorbic acid per day, making it a very important factor in understanding iron absorption. ^[6]

Uses

See also: Sodium erythorbate

Since the U.S. Food and Drug Administration banned the use of sulfites as a preservative in foods intended to be eaten fresh (such as salad bar ingredients), the use of erythorbic acid as a food preservative has increased.

It is also used as a preservative in cured meats and frozen vegetables. ^[7] Much like ascorbic acid, it increases nitrosylation of the central iron atom of muscle myoglobin, resulting in the formation of reddish-brown nitrosomyoglobin and the characteristic pink color of nitrosohemochrome or nitrosyl-heme upon cooking. ^[8] Again like ascorbic acid, it reduces the formation of nitrosamines. ^[9]

History

It was first synthesized in 1933 by the German chemists Kurt Maurer and Bruno Schiedt. ^{[10] [11]}

Production

Erythorbic acid is very easily produced by fermentation, being obtainable in just one step compared to ascorbic acid's two. A number of Penicillium naturally produce this chemical from glucose. This is the original process developed in the 1960s, but it has low volumetric efficiency and glucose yield compared to the modern method. ^[8]

Today the industrial process is quite similar to the Reichstein process used for ascorbic acid, only chirally flipped. Microbial fermentation first produces a 2-keto-sugar acid, e.g. by Pseudomonas fluorescens AR4 converting glucose to 2-keto-D-gluconate. Then chemical rearrangement produces the product. ^[8]

Economics

Like ascorbic acid, the production of erythorbic acid is concentrated in China. Its price is less volatile than that of ascorbic acid, making it an attractive alternative in non-nutritive uses in times of high ascorbic acid prices. ^[8]

Related compounds

The structurally similar C5 sugar acid, D-erythroascorbic acid, is made by baker's yeast and other fungi, acting as an antioxidant in their own cells. It is made by and has some antioxidant activity in Manduca sexta . ^[12] It has no industrial use, however. ^[8]

References

1. Erythorbic acid and its sodium salt Dr R. Walker, Professor of Food Science, Department of Biochemistry, University of Surrey, England.
2. "Erythorbic acid".
3. Current EU approved additives and their E Numbers, Food Standards Agency
4. Sauberlich, HE; Tamura T; Craig CB; Freeberg LE; Liu T (September 1996). "Effects of erythorbic acid on vitamin C metabolism in young women". American Journal of Clinical Nutrition. 64 (3): 336–46. doi: 10.1093/ajcn/64.3.336 . PMID   8780343.
5. Fidler, MC; Davidsson L; Zeder C; Hurrell RF (January 2004). "Erythorbic acid is a potent enhancer of nonheme-iron absorption". American Journal of Clinical Nutrition. 79 (1): 99–102. doi: 10.1093/ajcn/79.1.99 . PMID   14684404.
6. Hurrell, Richard; Egli, Ines (May 2010). "Iron bioavailability and dietary reference values". The American Journal of Clinical Nutrition. 91 (5): 1461S –1467S. doi:10.3945/ajcn.2010.28674F.
7. Hui YH (2006). Handbook of Food Science, Technology and Engineering. CRC Press. pp. 83–32. ISBN   0-8493-9848-7.
8. Pappenberger, Günter; Hohmann, Hans-Peter (2013). "Industrial Production of l-Ascorbic Acid (Vitamin C) and d-Isoascorbic Acid". Biotechnology of Food and Feed Additives. 143: 143–188. doi:10.1007/10_2013_243.
9. Herrmann, S.S.; Granby, K.; Duedahl-Olesen, L. (May 2015). "Formation and mitigation of N-nitrosamines in nitrite preserved cooked sausages". Food Chemistry. 174: 516–526. doi: 10.1016/j.foodchem.2014.11.101 .
10. See:
    • Maurer, Kurt; Schiedt, Bruno (August 2, 1933). ""Die Darstellung einer Säure C₆H₈O₆ aus Glucose, die in ihrer Reduktionskraft der Ascorbinsäure gleicht (Vorläuf. Mitteil.)" (The preparation of an acid C₆H₈O₆ from glucose, which equals ascorbic acid in its reducing power (preliminary report))". Berichte der Deutschen Chemischen Gesellschaft. 66 (8): 1054–1057. doi:10.1002/cber.19330660807.
    • Maurer, Kurt; Schiedt, Bruno (July 4, 1934). ""Zur Darstellung des Iso-Vitamins C (d-Arabo-ascorbinsäure) (II. Mitteil.)" (On the preparation of iso-vitamin C (d-arabo-ascorbic acid) (2nd report))". Berichte der Deutschen Chemischen Gesellschaft. 67 (7): 1239–1241. doi:10.1002/cber.19340670724.
11. See also:
    • Ohle, Heinz; Erlbach, Heinz; Carls, Herbert (February 7, 1934). ""d-Gluco-saccharosonsäure, ein Isomeres der Ascorbinsäure, I. Mitteil.: Darstellung und Eigenschaften" (d-Gluco-saccharosonic acid, an isomer of ascorbic acid, 1st report: preparation and properties)". Berichte der Deutschen Chemischen Gesellschaft. 67 (2): 324–332. doi:10.1002/cber.19340670235.
    • Baird, D. K.; Haworth, W. N.; Herbert, R. W.; Hirst, E. L.; Smith, F.; Stacey, M. (1934). "Ascorbic acid and synthetic analogues". Journal of the Chemical Society: 63–67. doi:10.1039/JR9340000062.
    • Reichstein, T.; Grüssner, A.; Oppenauer, R. (1934). ""Synthese der Ascorbinsäure und verwandter Verbindungen nach der Oson-Blausäure-Methode"(Synthesis of ascorbic acid and related compounds via the ozone-hydrogen cyanide method)". Helvetica Chimica Acta. 17: 510–520. doi:10.1002/hlca.19340170157.
12. Shao, Yi Yuan.; Seib, Paul A.; Kramer, Karl J.; Van Galen, Dean A. (1 September 1993). "Synthesis and properties of D-erythroascorbic acid and its vitamin C activity in the tobacco hornworm (Manduca sexta)". Journal of Agricultural and Food Chemistry. 41 (9): 1391–1396. doi:10.1021/jf00033a009.