D-(+)-Melibiose

D-(+)-Melibiose

D-(+)-Melibiose is a disaccharide composed of one galactose and one glucose unit linked by an α(1→6) glycosidic bond. It is a reducing sugar that plays a significant role in various biological processes and is commonly used in microbiological studies.

Chemical Properties

• CAS Number: 585-99-9
• MDL No.: MFCD00198191
• Catalog Number: A831945
• EINECS: 209-568-6
• Molecular Formula: C₁₂H₂₄O₁₂
• Molecular Weight: 360.31 g/mol
• Boiling Point: 662.8 ± 55.0 °C at 760 mmHg
• Melting Point: 182 °C (dec.) (lit.)
• Flash Point: 354.6 ± 31.5 °C
• Density: Not specified (typically around 1.68 g/cm³)
• Appearance: White powder
• Storage Conditions: Store at 2–8 °C for long-term stability (months).
• Refractivity: 1.652

Physical Characteristics

Melibiose appears as a white crystalline powder and is soluble in water, making it suitable for various laboratory applications. Its melting point of approximately 182°C indicates its thermal stability, while its high boiling point suggests that it can withstand elevated temperatures without decomposing.

Biological Significance

1. Microbial Metabolism:
   • Melibiose serves as a carbon source for certain bacteria, particularly Saccharomyces pastorianus, which can metabolize melibiose, differentiating it from other species like Saccharomyces cerevisiae that cannot.
2. Role in Gene Regulation
   • It acts as an effector molecule that can activate the lac operon by binding to the repressor protein, facilitating the expression of genes involved in lactose metabolism.
3. Prebiotic Potential:
   • Melibiose may have prebiotic effects, promoting the growth of beneficial gut bacteria and contributing to gut health.
4. Research Applications:
   • Used in studies investigating carbohydrate interactions and the effects of sugar on microbial growth and metabolism.

Synthesis and Purification

D-(+)-Melibiose can be synthesized enzymatically or extracted from natural sources. It can be purified through crystallization techniques, often involving water or ethanol to achieve high purity levels.

Safety Profile

While D-(+)-melibiose is generally regarded as safe for laboratory use, standard safety protocols should be followed when handling this compound. Personal protective equipment (PPE) should be used to minimize exposure.

Conclusion

D-(+)-Melibiose (CAS No. 585-99-9) is an important disaccharide with applications in microbiology, biochemistry, and nutrition. Its role as a substrate for specific microorganisms and its function in gene regulation make it valuable for research and industrial applications.

Citations:

1. https://www.chemicalbook.com/ChemicalProductProperty_EN_CB1322130.htm
2. https://goldbio.com/product/7158/d-melibiose-monohydrate
3. https://pubchem.ncbi.nlm.nih.gov/compound/Melibiose
4. https://pubchem.ncbi.nlm.nih.gov/compound/440658
5. https://en.wikipedia.org/wiki/Melibiose
6. https://omanchem.com/product/D-MELIBIOSE-PURISS-99
7. https://www.medchemexpress.com/d-melibiose.html
8. https://www.lobachemie.com/Carbohydrates-04545/D-MELIBIOSE-CASNO-66009-10-7.aspx

FAQs about Melibiose:

Is melibiose a disaccharide?

Yep! It’s a tag team made of galactose and glucose. Two sugars, one bond—classic disaccharide vibes.

Is melibiose a reducing sugar?

It is! One of its sugar units still has a free end (an aldehyde group) that can react, which officially puts it in the “reducing sugar” club. Not all disaccharides get that honor.