L-(+)-Cystathionine

L-(+)-Cystathionine (CAS No.: 56-88-2) is a nonprotein sulfur-containing thioether intermediate formed from serine and homocysteine in the transsulfuration pathway, serving as a key precursor in cysteine biosynthesis and a critical indicator of sulfur amino acid metabolic status. Widely expressed in mammalian tissues, including the brain, this metabolite is closely associated with cellular redox balance and metabolic homeostasis, and its deficiency is linked to disorders such as cystathioninuria. Functionally, L-(+)-Cystathionine has been shown to mitigate homocysteine-induced, mitochondria-dependent apoptosis in vascular endothelial cells, including human umbilical vein endothelial cells, primarily through stabilization of mitochondrial function and preservation of cellular viability. These effects implicate modulation of mitochondrial integrity and oxidative stress pathways as central mechanisms underlying its biological activity, supporting its relevance in cardiovascular protection and endothelial dysfunction research. Although specific potency metrics such as IC50 or EC50 values are not well established, experimental studies typically employ concentrations in the micromolar range depending on model systems and assay conditions. As a biologically active metabolite, L-(+)-Cystathionine is broadly utilized in in vitro cell-based assays and metabolic studies, as well as in vivo models investigating sulfur amino acid metabolism, oxidative stress, and cardiovascular pathophysiology, making it a valuable tool compound in biomedical research and early-stage drug discovery.