L-(?)-Glucose

L-(?)-Glucose (CAS No.: 921-60-8) is a naturally occurring stereoisomer of D-glucose that serves as a non-metabolizable monosaccharide widely utilized in metabolic and biochemical research. Due to its inability to be efficiently phosphorylated by hexokinase, L-(?)-glucose is not readily used as an energy substrate in mammalian cells, and it exhibits limited transport across the blood–brain barrier, making it a useful control compound for distinguishing metabolic versus osmotic or transport-dependent effects in cellular systems. Functionally, L-(?)-glucose has been reported to modulate metabolic pathways associated with feeding behavior and energy sensing, thereby promoting food intake in experimental models, while also demonstrating potential cognitive effects, including memory enhancement in murine studies through mechanisms that remain to be fully elucidated. In addition, its chemical compatibility with fluorescent detectors enables the development of fluorescent probes for in vitro visualization and characterization of cancer cells, supporting its application in cellular imaging and tumor biology research. Although it lacks intrinsic cytotoxic or enzymatic inhibitory activity, L-(?)-glucose is commonly employed in vitro and in vivo at concentrations tailored to specific experimental paradigms, typically within millimolar ranges for metabolic studies, and serves as a valuable tool in drug discovery and mechanistic investigations involving carbohydrate metabolism, transporter specificity, and non-metabolizable sugar analogs.