4-methylcatechol is a metabolite of homoprotocatechuic acid. It is both a substrate and a suicide inhibitor of Catechol 23-dioxygenase. 4-methylcatechol is known to induce the production of brain-derived neurotrophic factor (BDNF). Recent studies have suggested that a lack of brain-derived neurotrophic factor (BDNF) in the limbic system may cause neuropathic pain.

Pimecrolimus, like all ascomycins, is an immunophilin ligand, which binds specifically to the cytosolic receptor, immunophilin macrophilin-12.

GGTI 298 is a geranylgeranyltransferase I inhibitor with ability to arrest human tumor cells in the G1 phase of the cell cycle and induce apoptosis.