Homoserine is a more reactive variant of the amino acid serine. In this variant the hydroxyl side chain contains an additional CH2 group which brings the hydroxyl group closer to its own carboxyl group allowing it to chemically react to form a five-membered ring.

N1,N8-Diacetylspermidine is a polyamine found in human urine.N1,N8-Diacetylspermidine can be used as a marker for cancer and malignancy.

γ-Glu-Phe (γ-Glutamylphenylalanine) is a γ-3 glutamyl dipeptide found in sourdough.it is synthesized by Bacillus amyloliquefaciens (GBA) and Aspergillus oryzae (GAO). γ-Glu-Phe or the post-enzymatic reaction mixture enhances the umami intensity of commercial soy sauce and model chicken broth.