Disodium inosinate (E631^[2]) is the disodium salt of inosinic acid with the chemical formula C₁₀H₁₁N₄Na₂O₈P. It is used as a food additive and often found in instant noodles, potato chips, and a variety of other snacks.

Quick Facts Names, Identifiers ...

Disodium inosinate

Names
IUPAC name Disodium 5′-inosinate
Systematic IUPAC name Disodium [(2R,3S,4R,5R)-3,4-dihydroxy-5-(4-oxo-2,3-dihydro-9H-purin-9-yl)oxolan-2-yl]methyl phosphate[1]
Other names Sodium 5′-inosinate Disodium inosin 5′-monophosphate Inosine 5′-(disodium phosphate) Sodium inosinate
Identifiers
CAS Number	4691-65-0  Y Y
3D model (JSmol)	Interactive image Interactive image
ChemSpider	19594 Y
ECHA InfoCard	100.022.860
E number	E631 (flavour enhancer)
PubChem CID	20819
UNII	T2ZYA7KC05 Y
CompTox Dashboard (EPA)	DTXSID4044242
InChI InChI=1S/C10H13N4O8P.2Na/c15-6-4(1-21-23(18,19)20)22-10(7(6)16)14-3-13-5-8(14)11-2-12-9(5)17;;/h2-4,6-7,10,15-16H,1H2,(H,11,12,17)(H2,18,19,20);;/q;2*+1/p-2/t4-,6-,7-,10-;;/m1../s1 Y Key: AANLCWYVVNBGEE-IDIVVRGQSA-L Y InChI=1/C10H13N4O8P.2Na/c15-6-4(1-21-23(18,19)20)22-10(7(6)16)14-3-13-5-8(14)11-2-12-9(5)17;;/h2-4,6-7,10,15-16H,1H2,(H,11,12,17)(H2,18,19,20);;/q;2*+1/p-2/t4-,6-,7-,10-;;/m1../s1 Key: AANLCWYVVNBGEE-IMCBXCBXBI
SMILES C1=NC(=O)C2=C(N1)N(C=N2)C3C(C(C(O3)COP(=O)([O-])[O-])O)O.[Na+].[Na+] [Na+].[Na+].[O-]P([O-])(=O)OC[C@H]3O[C@@H](n1cnc2c1N\C=N/C2=O)[C@H](O)[C@@H]3O
Properties
Chemical formula	C10H11N4Na2O8P
Molar mass	392.171 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Close

Commercial disodium inosinate may either be obtained from bacterial fermentation of sugars or prepared from animal products. The Vegetarian Society reports that production from meat or fish is more widespread,^[3] but the Vegetarian Resource Group reports that all three "leading manufacturers" claim to use fermentation.^[4]

Disodium inosinate is used as a flavor enhancer, in synergy with monosodium glutamate (MSG) to provide the umami taste. It is often added to foods in conjunction with disodium guanylate; the combination is known as disodium 5′-ribonucleotides.

As a relatively expensive product, disodium inosinate is usually not used independently of glutamic acid; if disodium inosinate is present in a list of ingredients, but MSG does not appear to be, it is possible that glutamic acid is provided as part of another ingredient or is naturally occurring in another ingredient like tomatoes, Parmesan cheese, or yeast extract.

Inosinate is naturally found in meat and fish at levels of 80–800 mg/100 g.^[5] It can also be made by fermentation of sugars such as tapioca starch.^[6]

Some sources claim that industrial levels of production are achieved by extraction from animal products, making E631 non-vegetarian.^[3] However, an interview by the Vegetarian Resource Group reports that all three "leading manufacturers" (one being Ajinomoto) claims to use an all-vegetarian fermentation process.^[4] Producers are generally open to providing information on the origin. E631 is in some cases labeled as "vegetarian" in ingredients lists when produced from plant sources.^[7]

In the United States, consumption of added 5′-ribonucleotides averages 4 mg per day, compared to 2 g per day of naturally occurring purines. A review of literature by an FDA committee found no evidence of carcinogenicity, teratogenicity, or adverse effects on reproduction.^[8]

In 2004, disodium inosinate was proposed to be removed from the food additive list by Codex Alimentarius Commission.^[9] This change did not go through: it is still present in the 2009 Codex Alimentarius list.^[10]