Inosinic acid, also known as inosine monophosphate (IMP), is a nucleotide derivative consisting of the purine base hypoxanthine attached to a ribose sugar that is phosphorylated at the 5' position. It occurs naturally in muscle tissue and is a key intermediate in purine nucleotide metabolism. In the food industry, IMP is widely used as a flavor enhancer due to its strong umami taste, often synergizing with glutamic acid to intensify savory flavors. It is the disodium salt form (E631) that is commonly added to processed foods. Chemically, it is stable under acidic conditions but can hydrolyze in strong alkali. IMP plays a role in energy transfer and is involved in the regulation of cellular metabolism. Its presence contributes to the taste profile of aged meats and fermented products.