Geranyl diphosphate (Geranyl pyrophosphate) is an isoprenoid, an intermediate in the synthesis of cannabinoids, and a substrate for the manufacture of volatile monoterpenes, which can be used by plants to acclimatize.

4-Guanidinobutyric acid is an L-arginine metabolite that has been used in the intestinal transport tranport studies. It has been specifically use to human proton coupled amino acid transporters hPAT1.

2-Oxovaleric acid is a keto acid found in human blood.