4-guanidinobutanoate

4-guanidinobutanoate (CAS No.: 463-00-3) is an endogenous guanidino-containing metabolite closely associated with L-arginine metabolism and nitrogen handling pathways, and is commonly detected as a urinary metabolite in mammalian systems. Functionally, this compound is characterized by its guanidino moiety, which contributes to its involvement in biochemical processes linked to nitric oxide biosynthesis, nitrogen metabolism, and the regulation of urea cycle homeostasis. It has been widely utilized as a biochemical probe to investigate the role of guanidino compounds in amino acid metabolic networks and to elucidate alterations in metabolic flux under physiological and pathological conditions. In transporter biology, 4-guanidinobutanoate has been employed in studies of intestinal absorption mechanisms, particularly as a substrate model for human proton-coupled amino acid transporters such as hPAT1, supporting its relevance in membrane transport and metabolite uptake research. While precise potency metrics are not consistently defined, its biological activity is generally explored in vitro within low micromolar to millimolar concentration ranges depending on assay design and system sensitivity. This compound is therefore valuable in cell-based assays, metabolic profiling studies, and transporter function analyses, with experimental concentrations selected according to specific study objectives and model systems to enable mechanistic insights into amino acid metabolism and related regulatory pathways.