2-Hydroxy-3-methylbutyric acid (2-hydroxyisovaleric acid) is a metabolite found in the urine of patients with phenylketonuria methylmalonic acidemia propionic acidemia 3-ketothiolase deficiency isovaleric acidemia 3-methylcrotonylglycemia 3-hydroxy-3-methylglutaric acidemia multiple carboxylase deficiency glutaric aciduria ornithine transcarbamylase deficiency glyceroluria tyrosinemia type I galactosemia and maple syrup urine disease.

1,2,3,6,7-Pentamethoxyxanthone is a natural product from Polygala tenuifolia.

Guaiacol is a precursor to various flavorants, such as eugenol and vanillin. Its derivatives are used medicinally as an expectorant, antiseptic, and local anesthetic.