Disodium 5'-ribonucleotides, E number E635, is a flavor enhancer which is synergistic with glutamates in creating the taste of umami. It is a mixture of disodium inosinate (IMP) and disodium guanylate (GMP) and is often used where a food already contains natural glutamates (as in meat extract) or added monosodium glutamate (MSG). It is primarily used in flavored noodles, snack foods, chips, crackers, sauces and fast foods. It is produced by combining the sodium salts of the natural compounds guanylic acid (E626) and inosinic acid (E630).
Guanylates and inosinates are possibly animal derived. They are produced from meat or maybe fish or could be from a non-animal source. These additives are very likely to be vegan if the product indicates that it is vegetarian.
A mixture of 98% monosodium glutamate and 2% E635 has four times the flavor enhancing power of monosodium glutamate (MSG) alone.E635 is animal free when the ribotide version.
It is recommended that no food containing disodium ribonucleotides should be consumed by gout and asthma sufferers.[medical citation needed] However, the concentrations used are generally so low that no effects are to be expected.