cis-4-Hydroxy-L-proline is an inhibitor of the synthesis and extracellular deposition of collagen. cis-4-Hydroxy-L-proline could inhibit fibroblast growth by preventing the deposition of triple-helical collagen on the cell layer.

Glutaric acid is a simple five-carbon linear dicarboxylic acid. Glutaric acid is naturally produced in the body during the metabolism of some amino acids including lysine and tryptophan. Glutaric acid may cause irritation to the skin and eyes. When present in sufficiently high levels glutaric acid can act as an acidogen and a metabotoxin.

Oxoadipic acid is a key metabolite of the essential amino acids tryptophan and lysine.Important metabolite between the TCA cycle and lysine biosynthesis. Of interest for research on mitochondrial metabolite transporters.