D-蜜二糖,D-Melibiose monohydrate

Melibiose is a disaccharide consisting of one glucose and one galactose molecule. It is found in certain types of honey, and several plants and microorganisms. It has garnered significant scientific interest due to its unique physical and chemical properties, making it suitable for various applications in research and industry. This paper will explore the definition, background, synthesis, characterization, analytical methods, biological properties, toxicity, safety, applications, current state of research, potential implications, limitations, and future directions of melibiose.

Definition and Background

Melibiose is a disaccharide made of a glucose molecule and a galactose molecule, linked by a β(1→6) glycosidic bond. It was first isolated from honey by French chemist Louis Henry in 1857, and later described by German chemist Emil Fischer in 1895. It is also referred to as galactosyl-glucose, α-D-galactopyranosyl-(1→6)-D-glucose, or 6-O-α-D-galactopyranosyl-D-glucose.

Physical and Chemical Properties

Melibiose is a white to off-white crystalline powder, with a sweet taste. It is soluble in water, slightly soluble in ethanol, and insoluble in ether and chloroform. It has a molecular weight of 342.30 g/mol, a melting point of 100-105°C, and a specific rotation of +140.5°. Melibiose is less soluble than sucrose and other disaccharides, making it useful in the purification of enzymes and proteins.

Synthesis and Characterization

Melibiose can be synthesized from lactose using an enzyme called melibiase, which cleaves lactose into glucose and galactose. It can also be synthesized by chemical means, using methyl α-galactoside and α-D-glucopyranosyl bromide. Melibiose can be characterized using various techniques such as nuclear magnetic resonance (NMR) spectroscopy, X-ray crystallography, and mass spectrometry.

Analytical Methods

Several analytical methods are available to detect the presence of melibiose, including thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), and capillary electrophoresis (CE). These methods can identify and quantify melibiose in complex mixtures, making it suitable for use in various research fields.

Biological Properties

Melibiose has been found to have several biological properties, including prebiotic effects, immunomodulatory effects, and antibacterial activity. It has been shown to promote the growth of beneficial gut bacteria such as bifidobacteria and lactobacilli, and enhance the immune response in humans and animals. Melibiose has also been found to exhibit antibacterial activity against various pathogenic bacteria, including Escherichia coli, Salmonella typhimurium, and Staphylococcus aureus.

Toxicity and Safety in Scientific Experiments

Melibiose has been found to be nontoxic and safe for use in scientific experiments. It has been approved by the Food and Drug Administration (FDA) as a Generally Recognized As Safe (GRAS) substance, and is commonly used as a food additive. However, caution should be taken when administering high doses of melibiose, as it may cause gastrointestinal discomfort and diarrhea in some individuals.

Applications in Scientific Experiments

Melibiose has several applications in scientific experiments, including as a carbon source for microorganisms, a substrate for enzyme assays, a cryoprotectant for cells and tissues, and a marker for mammalian cell differentiation. It is also used in the production of other chemicals such as 3-hydroxypropionic acid, an important intermediate in the production of biodegradable plastics.

Current State of Research

The current state of research on melibiose is focused on its potential as a prebiotic, an immunomodulatory agent, and an antibacterial agent. Several studies have demonstrated its ability to promote the growth of beneficial gut bacteria, enhance the immune response, and inhibit the growth of pathogenic bacteria. Further research is warranted to explore its potential in other areas such as cancer therapy and metabolic disorders.

Potential Implications in Various Fields of Research and Industry

Melibiose has potential implications in various fields of research and industry, including the food industry, biotechnology, and medicine. It can be used as a food additive to promote gut health and enhance the nutritional value of food products. In biotechnology, it can be used as a substrate for enzyme assays and in the production of biodegradable plastics. In medicine, it has potential as an antibacterial agent and as a cryoprotectant for cells and tissues.

Limitations and Future Directions

Despite its potential, melibiose has some limitations that need to be addressed. It is less soluble than other disaccharides, making it less suitable for certain applications. Further research is needed to explore its potential in other areas such as cancer therapy and metabolic disorders. Future directions for research on melibiose include exploring its mechanism of action as a prebiotic and immunomodulatory agent, and investigating its potential use in combination with other drugs for the treatment of various diseases.

Conclusion

Melibiose is a disaccharide consisting of a glucose molecule and a galactose molecule, with unique physical and chemical properties that make it suitable for various applications in research and industry. It has several biological properties, and has been found to be safe and nontoxic for use in scientific experiments. Further research is needed to explore its potential in various fields, and to address its limitations.

Title: Melibiose

CAS Registry Number: 585-99-9

CAS Name: 6-O-a-D-Galactopyranosyl-D-glucose

Additional Names: 6-(a-D-galactosido)-D-glucose

Molecular Formula: C12H22O11

Molecular Weight: 342.30

Percent Composition: C 42.11%, H 6.48%, O 51.41%

Literature References: Prepd from raffinose by fermentation with top yeast which removes the fructose: Hudson, Harding, J. Am. Chem. Soc. 37, 2734 (1915); Fletcher, Diehl, ibid. 74, 5774 (1952). Structure: Haworth, Leitch, J. Chem. Soc. 113, 188 (1918); Charlton et al., ibid. 1926, 99; Charlton et al., ibid. 1927, 1527; Haworth et al., ibid. 3146; Levene, Jorpes, J. Biol. Chem. 86, 403 (1930). Synthesis: Helferich, Bredereck, Ann. 465, 166 (1928).

Derivative Type: Dihydrate

Properties: Monoclinic crystals from water or dil alcohol. mp 84-85°. Shows mutarotation. [a]D20 +111.7° ® +129.5° (c = 4). One gram dissolves in 0.4 ml water, 8.5 ml methanol, 220 ml abs alcohol. Dilute acids hydrolyze melibiose to D-glucose and D-galactose. Also split by emulsin and by bottom yeast. Reduces Fehling's soln. 3.5 g melibiose dihydrate are about as sweet as 1.0 g sucrose.

Melting point: mp 84-85°

Optical Rotation: [a]D20 +111.7° ® +129.5° (c = 4)

COA:

Product name :D-Melibiose; 6-O-α-D-Galactopyranosyl-D-glucose

CAS: 585-99-9       M.F. : C₁₂H₂₂O₁₁        M.W. : 342.30

D-Melibiose anhydrous is a disaccharide that is used as an excipient in the pharmaceutical industry. It has been shown to be an active enzyme, which may be due to its ability to sequester galactose. D-Melibiose anhydrous has a redox potential of -0.2 V, indicating that it has a high number of oxidizable groups. The molecular weight of this sugar is 324.14 g/mol, and it has a polarizability of 0.16 D, which classifies it as a polyol with hydrogen bonding properties. This sugar is not soluble in water but can be dissolved in ethanol or propylene glycol. D-Melibiose anhydrous also has carbohydrate properties and may be considered a sugar alcohol because it contains six carbon atoms and one oxygen atom.

Reference:

1. Wäckers FL, J. Chem. Ecol. 1999, Vol25, No12, 2863-2877