Namely
Propanediol (1,3-propanediol) is a natural humectant, used in many formulations. It has excellent sensory characteristics and is environmentally sustainable. It can be made from the fermentation of corn sugar, or synthetically.
Propanediol (1,3-propanediol) and propylene glycol (1,2-propanediol) share the same empirical formula (C3H8O2), but their molecular structure is different.