pNP (para-Nitorophenyl) Glycoseides are a class of compounds widely used in sugar chemistry and biochemistry research. These glycosides are composed of a sugar part (such as glucose, galactose, etc.) connected to a p-nitrophenyl part through a glycosidic bond. Due to their unique optical properties, they have important applications in enzyme activity determination and reaction kinetics research. pNP glycosides are used as marker compounds to help study sugar metabolic pathways and the functions of related enzymes. In the process of new drug development, pNP glycosides can be used to screen compounds that target glycosidase activity.