Disodium 5’-ribonucleotides (INS 635, E635) is not a single substance but a mixture of two flavour enhancers, disodium 5’-inosinate (INS 631) and disodium 5’-guanylate (INS 627), usually in roughly equal parts. Buying them premixed saves seasoning makers from dosing two powders separately. Some labels shorten the name to “ribotides” or “I+G”.
The mix has little taste alone, but with monosodium glutamate it greatly strengthens the savoury, mouth-filling umami of a seasoning, so less MSG is needed for the same effect. That is why it turns up so often in cheese, pizza, barbecue and seafood flavours.
Because the inosinate part may come from animal sources, the mix is not automatically vegetarian. It is permitted under Codex. Examples on SeekSnack include Lay’s Play 3D Shape Potato Snack Cheese Pizza Flavor and Carada Rice Ball Nori Seaweed.
