Maltose monohydrate-13C12 is the 13C labeled isotope of Maltose monohydrate. Maltose monohydrate is a disaccharide composed of two glucose molecules linked together. Maltose monohydrate is an endogenous metabolic product in plants, yeast, or bacteria, and it participates in carbon source storage and metabolism. Maltose monohydrate is a key core metabolite and main transport form in the temporary starch degradation, carbon output, and subsequent sucrose synthesis metabolism of the night chloroplast. In X. dendrorhous, maltose can act as a sugar donor and is converted into isomaltulose by alpha-glucosidase. Maltose monohydrate can act as a osmotic agent, supporting continuous capillary ultrafiltration and preventing severe metabolic disorders.