Homovanillic acid (CAS No 306-08-1) is a biochemical marker primarily used in neurochemistry research It originates as a major metabolite of dopamine formed through the enzymatic degradation pathway involving monoamine oxidase and catechol-O-methyltransferase This compound is significant in studying dopamine metabolism and related neurological disorders such as Parkinson s disease and schizophrenia In vitro activities of homovanillic acid are typically observed in the nanomolar to low micromolar range depending on assay conditions It is commonly employed in experiments using cell models to understand dopaminergic function and in animal studies to evaluate neurological health Additionally its presence is measured in various biofluids for clinical research into nervous system disorders Experimental concentrations typically depend on the specific research design allowing adjustments tailored to the targeted pathways and models under investigation