Inosine monophosphate

Structural formula
General
Surname	Inosine monophosphate
other names	Inosine 5'-monophosphate Inosinic acid Inosinate E  630
Molecular formula	C 10 H 13 N 4 O 8 P
External identifiers / databases
CAS number 131-99-7 4691-65-0 (disodium salt) 352195-40-5 (disodium salt hydrate) EC number 205-045-1 ECHA InfoCard 100.004.588 PubChem 797 ChemSpider 775 DrugBank DB04566 Wikidata Q255933
properties
Molar mass	348.21 g mol −1
Physical state	firmly
pK s value	2.4
safety instructions
GHS labeling of hazardous substances no GHS pictograms H and P phrases H: no H-phrases P: no P-phrases
Toxicological data	12 g kg −1 ( LD 50 ,  mouse ,  oral ) 16 g kg −1 ( LD 50 ,  rat ,  oral )
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Inosine monophosphate ( IMP ) is a nucleotide and the phosphoric acid ester of the nucleoside inosine . IMP is a central intermediate of the purine metabolism in all living things.

properties

Colorless syrup with a pleasant meaty taste ( umami ). When dried over sulfuric acid, the syrup turns into a glassy mass.

physiology

IMP is a central intermediate product in the biosynthesis of the purine nucleotides AMP and GMP and is fully interconvertible with both substances.

biosynthesis

The biosynthesis takes place either de novo in 11 steps from α-D-ribose-5-phosphate - the last reaction step is the formylation and cyclization of AICAR - or much more efficiently via the salvage pathway directly from hypoxanthine . Catalyzing enzymes are the AICAR Formyltransferase / IMP cyclase or the hypoxanthine-guanine phosphoribosyltransferase .

IMP is also created when AMP is broken down by deamination using AMP deaminase and by reducing GMP using GMP reductase .

metabolism

IMP is the starting material for the synthesis of AMP (via adenylosuccinate) and GMP (via xanthosine 5'-monophosphate (XMP)). If there is an excess of nitrogen, it is broken down into uric acid via inosine in four steps and excreted in the urine.

use

Inosine monophosphate, like the disodium, dipotassium and calcium salts, is used as a flavor enhancer ( E 630, E 631, E 632 and E 633). Despite the low inherent taste, inosine monophosphate has a pronounced effect as a flavor enhancer. When inosine monophosphate is used together with glutamate , the taste-enhancing effect of glutamate is considerably increased due to synergistic effects. Inosine monophosphate is widely used as a flavor enhancer in the form of the sodium salt in the food industry, e.g. B. in soup and sauce products as well as canned meat. Inosine monophosphate was detected in meat extract as early as 1847 by Justus von Liebig , who also mentioned the flavor-enhancing effect of inosine monophosphate.

Individual evidence

1. ↑ Entry on E 630: Inosinic acid in the European database for food additives, accessed on August 11, 2020.
2. ↑ ^{a b c d} data sheet inosine monophosphate from Sigma-Aldrich , accessed on June 11, 2011 ( PDF ).
3. ↑ ^{a b} Entry on inosine monophosphate in the ChemIDplus database of the United States National Library of Medicine (NLM) .
4. ↑ ^{a b} entry on inosine 5′-monophosphate. In: Römpp Online . Georg Thieme Verlag, accessed on December 22, 2014.
5. ↑ D'Eustachio / reactome: 5'-phosphoribosyl-5-aminoimidazole-4-carboxamide (AICAR) + 10-formyltetrahydrofolate ⇒ 5'-phosphoribosyl-5-formaminoimidazole-4-carboxamide (FAICAR) + tetrahydrofolate  ( page no longer available , Search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.   .
6. ↑ Jassal / reactome: 5'-phosphoribosyl-5-formaminoimidazole-4-carboxamide (FAICAR) ⇔ inosine 5'-monophosphate + H2O  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.   .
7. ↑ reactome: Hypoxanthine + PRPP ⇒ IMP + PPi  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.   .
8. ↑ reactome: adenosine 5'-monophosphate (AMP) + H ₂ O ⇒ inosine 5'-monophosphate (IMP) + NH ₄ ⁺ (L isoform)  ( page no longer available , search in web archives )  Info: The link was automatically defective marked. Please check the link according to the instructions and then remove this notice.   .
9. ↑ D'Eustachio / reactome: inosine 5'-monophosphate + L-aspartate + GTP ⇒ adenylosuccinate + guanosine 5'-diphosphate + orthophosphate  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.   .
10. ↑ D'Eustachio / reactome: inosine 5'-monophosphate (IMP) + NAD + + H2O ⇒ xanthosine 5'-monophosphate (XMP) + NADH + H +  ( page no longer available , search in web archives )  Info: The link was automatically identified as defective marked. Please check the link according to the instructions and then remove this notice.   .
11. ↑ reactome: inosine 5'-monophosphate (IMP) + H2O ⇒ inosine + orthophosphate  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.   .

Web links

Wikibooks: Biochemistry and Pathobiochemistry: Purine Metabolism  - Learning and Teaching Materials

• reactome: IMP (cytosol) (all reactions at a glance)