Magenta‑GlcNAc

Magenta‑GlcNAc (CAS 5609‑91‑6), systematically 5‑bromo‑6‑chloro‑3‑indolyl N‑acetyl‑β‑D‑glucosaminide, is a synthetic β‑N‑acetyl‑D‑glucosaminidase‑specific chromogenic substrate in which a 5‑bromo‑6‑chloro‑3‑indoxyl aglycone is linked via a β‑glycosidic bond to N‑acetyl‑D‑glucosamine (GlcNAc). When hydrolyzed by β‑N‑acetyl‑β‑D‑glucosaminidase (NAGase) or related enzymes, the indoxyl moiety is released and undergoes aerial oxidation to form an insoluble magenta‑colored indigo‑type precipitate, enabling clear visual detection of enzyme activity. This substrate is commonly used in selective agar media to screen and identify NAGase‑producing microorganisms (e.g., certain bacteria and yeasts) and in enzyme‑kinetic assays for recombinant or purified NAGases. The magenta color provides good contrast against background pigmentation, making it suitable for phenotypic profiling and multiplex assays. Compared with traditional 4‑nitrophenyl‑N‑acetyl‑β‑D‑glucosaminide, Magenta‑GlcNAc offers a chromogenic, solid‑medium‑compatible readout without the need for UV/Vis spectrophotometry. The compound is compatible with standard microbiological media and biochemical buffers and is supplied as a research‑grade reagent.

Appearance

• Off‑white to pale yellow crystalline or lyophilized powder.
• Fine, free‑flowing texture suitable for accurate weighing and dissolution in aqueous or mixed aqueous‑organic solvents.

Source / synthesis

• Synthetically produced by coupling 5‑bromo‑6‑chloro‑3‑indoxyl with N‑acetyl‑β‑D‑glucosamine under glycosylation conditions to form the N‑acetyl‑β‑D‑glucosaminide derivative.
• Commercially manufactured by specialty enzyme‑substrate and biochemical suppliers (e.g., Biosynth, Hepattack, China‑based and India‑based vendors) as a high‑purity, research‑use‑only reagent.

Molecular weight and structure

• Molecular formula: C16H18BrClN2O6\text{C}_{16}\text{H}_{18}\text{BrClN}_{2}\text{O}_{6}C16H18BrClN2O6.
• Molecular weight: 449.68 g/mol.
• Structure: 5‑bromo‑6‑chloro‑1H‑indol‑3‑yl 2‑acetamido‑2‑deoxy‑β‑D‑glucopyranoside, with a β‑(1→4)‑type linkage between the indole C3‑O and the N‑acetyl‑D‑glucosamine ring.

Sugar specificity

• Specifically hydrolyzed by β‑N‑acetyl‑D‑glucosaminidases (NAGase, EC 3.2.1.52) and related N‑acetyl‑β‑glucosaminide‑cleaving enzymes.
• Shows high selectivity over other β‑glycosidases and minimal cross‑reactivity when used under optimized assay conditions.

Biological activity

• Acts as a chromogenic reporter for NAGase‑mediated hydrolysis of N‑acetyl‑β‑D‑glucosaminyl linkages in glycoproteins, glycolipids, and oligosaccharides.
• Enzymatic cleavage yields 5‑bromo‑6‑chloro‑3‑indoxyl, which oxidizes and dimerizes into a magenta‑colored, water‑insoluble dye, providing a sensitive, low‑background readout for solid‑medium and solution‑based assays.

Purity and microbial contamination

• Typically supplied at ≥98% purity as determined by HPLC or similar analytical methods.
• Certificates of analysis from major suppliers confirm acceptable levels of residual solvents, heavy metals, and non‑sterile, low‑microbial‑contamination status suitable for microbiological and biochemical use.

Identity and quality control

• Identity verified by NMR, HPLC, MS, and elemental analysis, with batch‑specific certificates of analysis provided by manufacturers.
• Quality‑control procedures include checks for appearance, solubility, spectral characteristics (UV/Vis), and performance in a defined NAGase activity assay system.

Shelf life and storage

• Shelf life is generally 12–24 months when stored as a dry powder at –20 °C in a tightly sealed container, protected from moisture and light.
• Aqueous or stock solutions should be prepared immediately before use or stored frozen for short periods to minimize degradation and nonspecific oxidation of the indoxyl moiety.

Application

• Screening and phenotypic differentiation of β‑N‑acetyl‑D‑glucosaminidase‑producing microorganisms on selective agar media.
• Enzyme‑activity assays for recombinant or purified NAGases in solution or immobilized formats.
• Histochemical or cytochemical localization of NAGase activity in tissue sections and cell preparations.

Key characteristics

• High sensitivity and low background due to formation of an insoluble magenta‑colored dye upon β‑N‑acetyl‑D‑glucosaminidase hydrolysis.
• Defined N‑acetyl‑β‑D‑glucosaminide linkage providing selectivity for β‑N‑acetyl‑D‑glucosaminidases over other glycosidases.
• Crystalline, stable powder with a known molecular formula and weight, suitable for quantitative enzyme assays and standardized media formulations.

Citations 

• Biosynth – 5‑Bromo‑6‑chloro‑3‑indoxyl‑N‑acetyl‑β‑D‑glucosaminide (Magenta‑GlcNAc) product page: https://www.biosynth.com/p/B-7020/5609-91-6-5-bromo-6-chloro-3-indoxyl-n-acetyl-be
• Hepattack – Magenta‑GlcNAc product entry (CAS 5609‑91‑6): https://www.hepattack.com/en/product03_cid_213_pid_513.html
• ChemicalBook – 5‑Bromo‑6‑chloro‑3‑indolyl‑N‑acetyl‑β‑D‑glucosaminide CAS 5609‑91‑6 information: https://m.chemicalbook.com/ChemicalProductProperty_EN_CB4228846.htm
• NBInno – article on chromogenic N‑acetyl‑β‑D‑glucosaminidase substrates (context for 4‑nitrophenyl‑type and indolyl‑type NAGase substrates): https://www.nbinno.com/article/biochemicals/4-nitrophenyl-n-acetyl-beta-d-glucosaminide-in-glycosidase-research-cb
• Academia.edu – colorimetric assay methods for N‑acetyl‑β‑D‑glucosaminidase using chromogenic substrates: https://www.academia.edu/98207263/Colorimetric_assays_for_N_Aacetyl_βD_glucosaminidase_andβD_galactosidase_in_human
• GoldBio or similar enzyme‑substrate catalog (Magenta‑GlcNAc‑type β‑GLcNAcase substrates): https://www.goldbio.com/ (search for N‑acetyl‑β‑D‑glucosaminidase substrates)
• General glycosidase‑substrate overview (chromogenic and fluorogenic NAGase substrates): https://www.medchemexpress.com/ (β‑N‑acetyl‑D‑glucosaminidase section)
• PubMed / PMC – NAGase and GlcNAc‑metabolism reviews (for enzyme‑substrate‑mechanism context): https://www.ncbi.nlm.nih.gov/pmc/articles/ (search for “N‑acetyl‑β‑D‑glucosaminidase” or “NAGase”)
• Chemical‑data portal listing for 5‑Bromo‑6‑chloro‑3‑indolyl‑N‑acetyl‑β‑D‑glucosaminide (CAS 5609‑91‑6) physical and spectral properties: https://m.chemicalbook.com/ChemicalProductProperty_EN_CB4228846.htm
• Enzyme‑substrate catalog (X‑ and Magenta‑type N‑acetyl‑glucosaminide substrates overview): https://www.biosynth.com/ (NAGase‑substrate section, including Magenta‑GlcNAc)