Magenta‑GlcA

Magenta‑GlcA (CAS 144110‑42‑9), systematically 5‑bromo‑6‑chloro‑3‑indolyl β‑D‑glucuronide, is a synthetic β‑D‑glucuronidase‑specific chromogenic substrate in which a 5‑bromo‑6‑chloro‑3‑indoxyl aglycone is linked via a β‑glycosidic bond to D‑glucuronic acid. When hydrolyzed by β‑D‑glucuronidase (EC 3.2.1.31) or GUS‑expressing systems, the indoxyl moiety is released and undergoes aerial oxidation to form an insoluble magenta‑red indigo‑type precipitate, enabling clear visual detection of enzyme activity. This substrate is commonly used in selective culture media for identification of β‑glucuronidase‑positive bacteria such as certain E. coli strains, and in GUS‑reporter assays to detect the expression of β‑glucuronidase genes in recombinant systems. The magenta color provides good contrast compared with X‑GlcA’s blue, improving sensitivity and readability in complex samples. Magenta‑GlcA is compatible with standard microbiological media and biochemical buffers, and is provided as a high‑purity research‑grade reagent for microbiology, histochemistry, and molecular biology applications.

Appearance

• White to off‑white crystalline or lyophilized powder.
• Free‑flowing, fine‑particle solid suitable for accurate weighing and dissolution in aqueous‑organic solvents (often used as a cyclohexylammonium salt in concentrated stock solutions).

Source / synthesis

• Synthetically produced by coupling 5‑bromo‑6‑chloro‑3‑indoxyl with β‑D‑glucuronic acid to form the β‑D‑glucuronide derivative.
• Commercially manufactured by specialty enzyme‑substrate and biochemical suppliers (e.g., Hepattack, shopMedVet, Sapphire Bioscience) as a research‑use‑only or GUS‑assay‑grade reagent.

Molecular weight and structure

• Molecular formula: C14H13BrClNO7\text{C}_{14}\text{H}_{13}\text{BrClNO}_{7}C14​H13​BrClNO7​.
• Molecular weight: 422.61 g/mol.
• Structure: 5‑bromo‑6‑chloro‑1H‑indol‑3‑yl 6‑carboxy‑β‑D‑glucopyranuronic acid (β‑D‑glucuronide of 5‑bromo‑6‑chloro‑3‑indolyl, with the glucuronide in the (2S,3S,4S,5R,6R) configuration).

Sugar specificity

• Specifically hydrolyzed by β‑D‑glucuronidases (GUS, EC 3.2.1.31) and β‑glucuronide‑cleaving enzymes.
• Shows high selectivity over other β‑glycosidases, making it ideal for detection of β‑glucuronidase activity in bacteria and plant systems.

Biological activity

• Acts as a chromogenic reporter for β‑glucuronidase‑mediated hydrolysis of β‑D‑glucuronosyl linkages in glycosaminoglycans and glucuronides.
• Enzymatic cleavage releases 5‑bromo‑6‑chloro‑3‑indoxyl, which oxidizes and dimerizes into a magenta‑red, water‑insoluble dye, enabling sensitive detection in bacterial colonies, tissue sections, and enzyme‑activity assays.

Purity and microbial contamination

• Typically supplied at ≥98% purity as determined by HPLC or TLC.
• Supplier certificates of analysis indicate low residual solvents, acceptable heavy‑metal content, and non‑sterile, low‑microbial‑contamination status suitable for microbiological and biochemical use.

Identity and quality control

• Identity confirmed by NMR, HPLC, MS, and elemental analysis, with batch‑specific certificates provided by major manufacturers.
• Quality‑control checks include appearance, solubility, spectral characteristics, and assay performance in a defined β‑glucuronidase system (e.g., E. coli GUS⁺ colonies).

Shelf life and storage

• Shelf life is usually 12–24 months when stored as a dry powder at –20 °C in a tightly sealed, desiccated container, protected from moisture and light.
• Stock solutions (often in DMF or DMSO) 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 identification of β‑glucuronidase‑positive bacteria (e.g., certain E. coli strains) on selective agar media.
• GUS‑reporter assays for detection of β‑glucuronidase gene expression in bacterial, yeast, and plant systems.
• Histological and cytological localization of β‑glucuronidase activity in tissues and cultured cells.

Key characteristics

• High sensitivity and low background due to formation of an insoluble magenta‑red dye upon β‑glucuronidase hydrolysis.
• Defined β‑D‑glucuronide linkage providing selectivity for β‑D‑glucuronidases over other glycosidases.
• Crystalline, stable powder with a known molecular formula and weight, suitable for quantitative microbiological and enzyme‑assay applications.

Citations

• ChemicalBook – 5‑Bromo‑6‑chloro‑3‑indolyl‑β‑D‑glucuronide (Magenta‑GlcA): https://www.chemicalbook.com/ChemicalProductProperty_EN_CB01231726.htm
• Hepattack – Magenta‑GlcA product page: https://www.hepattack.com/en/product03_cid_213_pid_511.html
• BLDpharm – 5‑Bromo‑6‑chloro‑3‑indolyl‑β‑D‑glucuronide (CAS 144110‑42‑9) listing: https://www.bldpharm.com/products/144110-42-9.html
• Sapphire Bioscience – 5‑Bromo‑6‑chloro‑3‑indolyl‑β‑D‑glucuronide catalog entry: https://www.sapphirebioscience.com/product/NS05997602/5-bromo-6-chloro-3-indolyl-b-d-glucuronide
• InAlcoPharm – 5‑Bromo‑6‑Chloro‑3‑Indolyl‑β‑D‑Glucuronide product page: https://www.inalcopharm.com/cart.php?m=product_detail&p=13
• ShopMedVet – Magenta‑GlcA (chromogenic substrate for β‑D‑glucuronidase): https://www.shopmedvet.com/product/124848
• AG Scientific – Magenta‑GlcA cyclohexylammonium salt product: https://agscientific.com/products/biochemicals/substrates/additional-substrates/magenta-glca-1-g.html
• GoldBio – Magenta‑β‑D‑glucuronide cyclohexylammonium salt (Magenta‑GlcA‑CHX) page: https://www.goldbio.com/products/magenta-beta-d-glucuronide-cyclohexylammonium-salt
• TCI Chemicals – 5‑Bromo‑6‑chloro‑3‑indolyl‑β‑D‑glucuronide cyclohexylammonium salt (CAS 144110‑43‑0, same chromophore system): https://www.tcichemicals.com/IN/en/p/B4128
• DiscoFine Chemicals – Magenta‑Glucuronide (Magenta‑GlcA‑type cyclohexylammonium salt) description: https://discofinechem.com/products/magenta-glucoronide/