E628 (Dipotassium guanylate) is a chemical compound, nucleotide, dipotassium salt of guanylic acid.

It appears as a whitish crystalline powder. 

What it is used for and where

Food

Ingredient listed in the European food additives list as E628 as a flavour enhancer to improve the taste of food or drink (1).

Safety

In the minimum quantities in which it is included in food or cosmetics, it is of no concern. Check for cumulative intake.

• Molecular Formula   C₁₀H₁₂K₂N₅O₈P
• Molecular Weight      439.40 g/mol
• CAS  3254-39-5
• UNII   R87C8160YV 
• EC Number    221-849-5     226-914-1

References_____________________________________________________________________

(1) Parmar, K. and Patel, J., 2019. Recent Trends Used in Functional Food and Nutraceuticals Industries for Modulation of Flavors for Improving Sensory Perception. In Flavor Development for Functional Foods and Nutraceuticals (pp. 167-175). CRC Press.