p‑Nitrophenyl‑α‑L‑fucoside

p‑Nitrophenyl‑α‑L‑fucoside (PNP‑α‑L‑Fucoside, CAS 10231‑84‑2) is a synthetic α‑L‑fucosidase‑specific chromogenic substrate in which a 4‑nitrophenyl aglycone is linked via an α‑glycosidic bond to the anomeric carbon of L‑fucose. When hydrolyzed by α‑L‑fucosidases, the glycosidic bond is cleaved to release 4‑nitrophenol and α‑L‑fucose. In mild alkaline buffer (pH ~8–8.5), 4‑nitrophenol ionizes to form a yellow‑colored phenolate anion whose absorbance at 400–420 nm can be monitored continuously, providing a convenient readout of enzyme velocity. PNP‑α‑L‑Fucoside is widely used to characterize α‑L‑fucosidase activity in microbial, plant, and mammalian systems, to study enzyme‑substrate specificity among fucosyl‑glycosides, and to quantify activity in kinetic experiments (Km, Vmax). The compound is water‑soluble, supplied as a high‑purity, crystalline powder, and is suitable for routine biochemical and glycosidase‑related research. Its structure makes it a key tool in glycobiology and glycan‑remodeling studies, especially where terminal α‑L‑fucose removal is under investigation.

Appearance

• Off‑white to pale yellow crystalline powder.
• Forms a clear, colorless solution in aqueous buffer; a yellow color develops only after enzymatic hydrolysis and alkaline adjustment.

Source / synthesis

• Synthetically produced by glycosylation of 4‑nitrophenol with α‑L‑fucopyranose or a protected α‑L‑fucoside derivative, followed by deprotection and crystallization from water or alcohol.
• Commercially manufactured by biochemical‑reagent suppliers (e.g., Chem‑Impex, TCI Chemicals, various ChemicalBook‑linked vendors) as a high‑purity substrate for α‑L‑fucosidase assays.

Molecular weight and structure

• Molecular formula: C12H15NO7C12​H15​NO7​.
• Molecular weight: 285.25 g/mol.
• Structure: 4‑nitrophenyl α‑L‑fucopyranoside, with an α‑glycosidic linkage between the aromatic 4‑nitrophenyl group and the anomeric oxygen of the 6‑deoxy‑L‑galactose (L‑fucose) ring in the pyranose form.

Sugar specificity

• Specifically hydrolyzed by α‑L‑fucosidases and other α‑glycosidases acting on α‑L‑fucosyl linkages.
• Used to distinguish α‑L‑fucosidase activity from other glycosidases in enzyme‑profiling panels, including α‑glucosidases and α‑galactosidases.

Biological activity

• Serves as a chromogenic reporter whose rate of 4‑nitrophenol release under defined pH and temperature reflects α‑L‑fucosidase activity.
• Enables determination of kinetic parameters (Km, Vmax), inhibitor‑IC₅₀, and comparative activity profiling of different glycosidases involved in fucose‑containing glycoconjugate metabolism.

Purity and microbial contamination

• Typically supplied at ≥97–99% purity (e.g., >98% HPLC‑grade) as indicated by supplier data sheets and product‑description pages.
• Described as non‑sterile, research‑grade material suitable for use in standard enzymatic assays under clean‑laboratory conditions.

Identity and quality control

• Identity confirmed by molecular formula, molecular weight, UV‑Vis spectral profile (4‑nitrophenol‑like absorbance), and NMR‑type data consistent with 4‑nitrophenyl‑α‑L‑fucopyranoside.
• Quality‑control includes checks for appearance, solubility, elemental composition, and performance in an α‑L‑fucosidase activity assay (e.g., in spectrophotometric or microplate‑format assays).

Shelf life and storage

• Shelf life is generally 12–24 months when stored as a dry powder at −20 °C in a tightly sealed, light‑protected container, shielded from moisture.
• Aqueous working solutions are best prepared fresh or kept at 4 °C for short periods, as alkaline pH and elevated temperature increase background hydrolysis and absorbance.

Application

• Enzyme‑kinetic assays and specificity studies of α‑L‑fucosidases from bacterial, fungal, and mammalian sources.
• Measurement of α‑L‑fucosidase activity in clinical and diagnostic contexts related to lysosomal‑storage diseases (e.g., fucosidosis).
• Use in glycobiology and glycan‑remodeling experiments, and in inhibitor‑screening and enzyme‑mechanism‑elucidation studies.

Key characteristics

• Colorimetric readout based on 4‑nitrophenol release, enabling spectrophotometric quantification of α‑L‑fucosidase activity.
• Defined α‑L‑fucopyranoside linkage providing selectivity for α‑L‑fucosidases over many other glycosidases.
• Crystalline, stable powder with a known molecular formula and weight, suitable for quantitative enzyme assays and standardized protocols.

Citations

• ChemicalBook – 4‑Nitrophenyl‑α‑L‑fucopyranoside (PNP‑α‑L‑Fucoside, CAS 10231‑84‑2, MF C₁₂H₁₅NO₇, MW 285.25): https://www.chemicalbook.com/ChemicalProductProperty_EN_CB2190439.htm
• Megazyme – 4‑Nitrophenyl‑α‑L‑fucopyranoside (high‑purity substrate for α‑fucosidase, now discontinued but with assay details): https://www.megazyme.com/4-nitrophenyl-alpha-l-fucopyranoside
• Chem‑Impex – 4‑Nitrophenyl‑α‑L‑fucopyranoside product page (applications in enzyme activity assays and glycobiology): https://www.chemimpex.com/products/21604
• TCI Chemicals – 4‑Nitrophenyl‑α‑L‑fucopyranoside (CAS 10231‑84‑2) product and specification page: https://www.tcichemicals.com/IN/en/p/N0392
• Immunomart – p‑Nitrophenyl‑α‑L‑fucoside (PNP‑α‑L‑Fuc) substrate for α‑L‑fucosidase assay: https://immunomart.com/product/p-nitrophenyl-%CE%B1-l-fucoside/
• PubChem – p‑nitrophenyl‑α‑L‑fucoside entry (CAS 10231‑84‑2, CID 82473): https://pubchem.ncbi.nlm.nih.gov/compound/82473
• ScienceDirect overview on α‑L‑fucosidase (context for PNP‑α‑L‑Fucoside use in lysosomal and glycan‑metabolism studies): https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/alpha-l-fucosidase
• ChemExpress – p‑Nitrophenyl‑α‑L‑fucoside (PNP‑α‑L‑Fucoside) product page (China‑based supplier listing): https://www.chemexpress.cn/10231-84-2.htm
• ChemSynlab – Fuc‑α‑1→2‑Gal‑α‑PNP and related PNP‑fucosides, for fucosidase and glycan‑remodeling context: http://www.chemsynlab.com/cn/product/383417-46-7.html
• General glycosidase‑substrate catalog (PNP‑α‑L‑Fucoside and related PNP‑glycosides overview): https://www.chemicalbook.com/ (search for “10231‑84‑2”)