CNP-α-Glc

CNP-α-Glc (2-Chloro-4-nitrophenyl-α-D-glucopyranoside, CAS 119047-14-2) is a synthetic chromogenic substrate optimized for quantitative spectrophotometric detection of α-glucosidase (EC 3.2.1.20) activity, where enzymatic hydrolysis cleaves the α-glycosidic bond to release 2-chloro-4-nitrophenolate anion, exhibiting strong yellow absorbance at 400-420 nm (ε ≈ 18,000 M⁻¹cm⁻¹) for real-time kinetic assays with high sensitivity down to pM enzyme concentrations. With molecular formula C12H14ClNO8 (MW 335.69 g/mol), this pale yellow solid features α-D-glucopyranose linked via C1-O to the 2-chloro-4-nitrophenyl aglycone, where the ortho-chloro and para-nitro substituents synergistically enhance leaving group acidity (pKa ~7.2) and electron withdrawal, accelerating hydrolysis rates by 20-30% over unsubstituted 4-nitrophenyl-α-Glc while maintaining strict anomeric specificity for α-glucosidases from sources including human maltase-glucoamylase, bacterial SucB/SacC, and fungal amyloglucosidases. Widely employed in 96/384-well plate formats at 0.1-2 mM for high-throughput screening (HTS) of α-glucosidase inhibitors targeting diabetes (acarbose analogs), Pompe disease diagnostics (GAA deficiency), and starch/glycogen degradation pathway analysis, its aqueous solubility (>50 mM, pH 6.5-8.0) supports continuous-rate assays without organic solvents, while orthogonality to β-glucosidase substrates (CNPG-β-Glc) enables selective profiling of GH13/31 family enzymes in complex mixtures. The released chromophore’s pH-dependent color shift (yellow at pH>8, orange at pH 6-7) facilitates endpoint verification, positioning CNP-α-Glc as a superior alternative to pNP-α-Glc for inhibitor SAR studies, enzyme engineering, and food industry maltase quantification.

Appearance

• Pale yellow to off-white crystalline powder.
• Hydrolysis yields intense yellow solution (λmax 405 nm).

Source

• Koenigs-Knorr synthesis: protected α-D-glucopyranosyl bromide + 2-chloro-4-nitrophenol.
• Commercial analytical grade (MedChemExpress, Hepattack >98%).

Molecular Weight and Structure

• Formula: C12H14ClNO8; MW 335.69 g/mol.
• (2R,3S,4R,5R,6S)-2-(2-chloro-4-nitrophenoxy)-6-(hydroxymethyl)tetrahydro-2H-pyran-3,4,5-triol.​

Sugar Specificity

• Highly selective α-D-glucopyranoside for α-glucosidases (GH13/31).
• 1000x preference over β-glucosidases.​

Biological Activity

• Chromogenic substrate; Km 0.1-0.5 mM (maltase-glucoamylase).
• No intrinsic bioactivity; quantitative at 405 nm.​

Purity and Microbial Contamination

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

Identity and Quality Control

• ¹H-NMR (anomeric α-H 5.4 ppm d, J=3.5 Hz); HRMS m/z 336 [M+H]+.
• Absorbance verification post-acid hydrolysis.​

Shelf Life and Storage

• 3+ years -20°C desiccated; aqueous stocks stable 1 month 4°C.
• Light/moisture protected.​

Applications

• α-Glucosidase HTS inhibitor screening; diabetes diagnostics.
• Starch digestion assays, enzyme kinetics.

Key Characteristics

• Superior kinetics to pNP-α-Glc; 405 nm detection.
• Aqueous soluble; α-specific.​

Citation Links

• https://www.benchchem.com/product/b014266​
• https://www.hepattack.com/en/product03_cid_217_pid_566.html​
• https://pubchem.ncbi.nlm.nih.gov/compound/119047-14-2​
• https://www.medchemexpress.com/2-chloro-4-nitrophenyl-α-d-glucopyranoside.html​
• https://www.chemicalbook.com/ChemicalProductProperty_EN_CB61091708.htm​
• https://pubs.acs.org/doi/10.1021/acs.chemrev.3c00811​
• https://cdn.caymanchem.com/cdn/insert/16527.pdf​
• https://moleculardepot.com/product/2-chloro-4-nitrophenyl-α-d-glucopyranoside-high-purity/​
• https://www.chemicalbook.com/ChemicalProductProperty_EN_CB620216113.htm​
• http://www.hepattack.com/en/product03_cid_217_pid_566.html