Inosinate (IMP)

Monograph number: 05000

Title: Inosinic Acid

CAS Registry Number:  131-99-7

CAS Name: 5'-Inosinic acid

Additional Names:  5-inosinic acid ; muscle inosinic acid; t-inosinic acid; hypoxanthine riboside-5-phosphoric acid; IMP

Molecular Formula: C₁₀H₁₃N₄O₈P

Molecular Weight: 348.21

Percent Composition: C 34.49%, H 3.76%, N 16.09%, O 36.76%, P 8.90%

Literature References: Prepn from meat extract: Levene, Bass, Nucleic Acids (New York, 1931) p 229; from dried sardines: Yoshida, Kageyama, JP 56 732 (1956 to Ajinomoto), C.A. 51, 3870b (1957). Structure: Levene, Bass, op. cit., pp 187-192; Bredereck, Ber. 66, 198 (1933); Levene, Tipson, J. Biol. Chem. 111, 313 (1935). Also prepd from muscle by enzymatic deamination of muscle adenylic acid: Ostern, Biochem. Z. 254, 65 (1932); by hydrolysis of inosine triphosphate: Kleinzeller, Biochem. J. 36, 729 (1942). Studies on the enzymatic synthesis: Greenberg, J. Biol. Chem. 190, 611 (1951); Korn et al., ibid. 217, 875 (1955). Microbial fermentation method using mutant strains of Micrococcus glutamicus: Kinoshita et al., US 3232844 (1966 to Kyowa).

Properties: Syrup, solidifies to a glass when dried over H₂SO₄. Agreeable sour taste. pK₁ = 2.4; pK₂ = 6.4. Absorption spectrum: Kalckar, J. Biol. Chem. 167, 445 (1947). Freely sol in water, in formic acid; very sparingly sol in alcohol, ether. On boiling with acid hydrolyzes to 1 mol H₃PO₄, 1 mol hypoxanthine, 1 mol D-ribose.

Derivative Type: Disodium salt dihydrate

Molecular Formula: C₁₀H₁₁N₄Na₂O₈P.2H₂O

Molecular Weight: 428.20

Percent Composition: C 28.05%, H 3.53%, N 13.08%, Na 10.74%, O 37.36%, P 7.23%

Properties: Barely sol in alcohol, ether, acetone; soly in water at 20° about 13 g/100 ml. Kawasaki, New Food Ind. 3, no. 1, 17 (1961).

Derivative Type: Barium salt

Molecular Formula: C₁₀H₁₁BaN₄O₈P

Molecular Weight: 483.52

Percent Composition: C 24.84%, H 2.29%, Ba 28.40%, N 11.59%, O 26.47%, P 6.41%

Properties: Hemipentadecahydrate, lustrous leaflets. Becomes anhydr at 100° in vacuo. [α]_D20 -18.5° (0.3 g of anhydr Ba salt in 10 ml of 2.5% HCl).

Use: Its salts as flavor intensifiers, like sodium glutamate. Examples of mixtures of sodium inosinate and sodium glutamate or other salts: Toi et al., US 3109741 (1963 to Ajinomoto).