5'-Guanylic acid is involved in several metabolic disorders, including AICA-ribosiduria pathway, ?adenosine deaminase deficiency,adenine phosphoribosyltransferase deficiency (aprt), and the 2-hydroxyglutric aciduria pathway.

2-Methoxyestrone is a methoxylated catechol estrogen and the principal metabolite of 2-hydroxyestrone, a nonuterotropic metabolite of estradiol.

2-Hydroxyphenethylamine has been found in human testicle tissue and has also been primarily detected in blood. 2-Hydroxyphenethylamine can be converted into 2-(hydroxymethyl)-4-(1-hydroxy-2-{[6-(4-phenylbutoxy)hexyl]amino}ethyl)phenol.