4MU-α-L-Arabinofuranoside

4MU-α-L-Arabinofuranoside (4-Methylumbelliferyl-α-L-arabinofuranoside, CAS 77471-44-4) is a fluorogenic substrate optimized for ultrasensitive detection of α-L-arabinofuranosidase (Araf, EC 3.2.1.55) enzymes, where hydrolysis liberates 4-methylumbelliferone (4-MU) with intense blue fluorescence (Ex/Em 360/450 nm, φ=0.63), enabling picomolar enzyme quantification in real-time kinetic assays for plant cell wall degradation and microbial hemicellulase profiling. With molecular formula C15H16O7 (MW 308.29 g/mol), this white crystalline compound features α-L-arabinofuranose—a five-membered ring 6-deoxy sugar from arabinoxylans—α-glycosidically linked at C1 to the 7-position of 4-methylumbelliferone, remaining non-fluorescent until cleaved by fungal (Aspergillus niger Araf51A), bacterial (Bifidobacterium adolescentis), and plant arabinofuranosidases, yielding >2000-fold signal amplification orthogonal to galactosidase/glucosidase probes. Essential for biofuel research targeting hemicellulose hydrolysis (xylan sidechain removal), microbiome functional screening, and diagnostics of carbohydrate metabolism disorders, it supports no-wash 384-well HTS (5-50 μM substrate, pH 4.5-6.0) with linear detection to 10⁻¹² M enzyme, while cell-permeant properties enable live-plant protoplast assays monitoring Araf trafficking during lignocellulosic breakdown. Alkaline termination (0.2M Na₂CO₃) maximizes 4-MU fluorescence for endpoint reads, positioning this furanoside as the gold standard for GH51/GH62 family profiling in biomass conversion and prebiotic arabinooligosaccharide utilization studies.

Appearance

• White to off-white crystalline powder.
• Non-fluorescent; hydrolysis yields blue-fluorescent 4-MU.​

Source

• Chemoenzymatic synthesis: α-L-arabinofuranosyl donor + 4-methylumbelliferone.
• Commercial ≥98% (Sigma-Aldrich M9519).​

Molecular Weight and Structure

• Formula: C15H16O7; MW 308.29 g/mol.
• 7-[(2S,3R,4R,5S)-3,4-Dihydroxy-5-(hydroxymethyl)tetrahydrofuran-2-yl]oxy-4-methyl-2H-chromen-2-one.​

Sugar Specificity

• Highly selective α-L-arabinofuranoside for Araf (GH51/62).
• Negligible activity with arabinopyranosidases.​

Biological Activity

• Fluorogenic substrate; Km 10-50 μM (A. niger Araf).
• Detects fM enzyme concentrations.​

Purity and Microbial Contamination

• ≥98% (HPLC); biochemical grade.
• Synthetic; non-sterile.​

Identity and Quality Control

• [α]D specific rotation verified; InChIKey FAGLTVBWEMHJRP-UHFFFAOYSA-N.
• Fluorescence post-Araf hydrolysis confirmed.​

Shelf Life and Storage

• 3 years −20°C desiccated; DMSO stock 20 mM stable.
• Light-protected.​

Applications

• Hemicellulase assays; biofuel enzyme screening.
• Microbiome Araf profiling.​

Key Characteristics

• Furanoside-specific; >2000x fluorescence gain.
• Furanosyl orthogonal to pyranosides.​

Citation Links

• https://www.chemicalbook.in/product/4-methylumbelliferyl-alpha-l-arabinofuranoside-0249487​
• https://pubchem.ncbi.nlm.nih.gov/compound/14161014​
• https://www.sigmaaldrich.com/IN/en/product/sigma/m9519​
• https://journals.asm.org/doi/10.1128/aem.64.1.43-52.1998​
• https://www.medchemexpress.com/4-methylumbelliferyl-α-l-arabinofuranoside.html​
• https://www.biosynth.com/p/EM09792/77471-44-4-4-methylumbelliferyl-a-l-arabinofuran​
• https://www.cabidigitallibrary.org/doi/pdf/10.5555/20173208666​
• https://www.chemicalbook.com/ChemicalProductProperty_EN_CB0249487.htm​
• https://www.glentham.com/en/products/product/GC9186/ (related MU substrates)
• https://www.creative-enzymes.com/product/4-Methylumbelliferyl-alpha-L-arabinofuranoside