Biopterin (also known as L-erythro-biopterin or 6-Biopterin) is an oxidation product of tetrahydrobiopterin. Bioptrrin is an endogenous enzyme cofactor and its accumulation serves as markers of Parkinson's disease, Hyperphenylalaninemia and in addition, it can serve as a non-invasive biomarker for cancer.

Hypoxanthine is a naturally occurring purine derivative and a reaction intermediate in the metabolism of adenosine and in the formation of nucleic acids by the salvage pathway. Hypoxanthine is a necessary additive in the certain cell, bacteria, and parasite cultures as a substrate and nitrogen source. For example, it is commonly a required reagent in malaria parasite cultures, since Plasmodium falciparum requires a source of hypoxanthine for nucleic acid synthesis and energy metabolism.

Epipregnanolone is an epimer of endogenous neurosteroid pregnanolone, it has been shown to antagonize GABAA and NMDA receptors. In addition epipregnanolone inhibits calcium T-currents and stimulates TRPM3 channel. Epipregnanolone displays anesthetic properties. Epipregnanolone has been shown to reduce alcohol self-administration in rats.