Magenta-GlcA Sodium Salt (5-Bromo-6-chloro-3-indolyl-β-D-glucuronide sodium salt, CAS 216971-54-9) represents an advanced chromogenic substrate optimized for β-glucuronidase (GUS, EC 3.2.1.31) detection, where enzymatic hydrolysis liberates a dibromochloroindoxyl aglycone that rapidly dimerizes and oxidizes to form an insoluble magenta-colored precipitate, providing superior visual contrast and reduced background compared to traditional X-GlcA blue substrates in high-density colony screening applications. With molecular formula C14H12BrClNNaO7 (MW 444.59 g/mol), this white to off-white water-soluble sodium salt features β-D-glucuronopyranuronic acid linked via β1-O-glycosidic bond to the 3-position of 5-bromo-6-chloro-1H-indol-3-ol, exhibiting exceptional selectivity for bacterial (E. coli GusA), plant (uidA reporter), and mammalian β-glucuronidases while demonstrating >1000-fold resistance to endogenous glucosidases/galactosidases due to the uronic acid configuration and vicinal halogen substitution pattern. The magenta product’s distinctive hue (λmax ~550-570 nm) enables unambiguous multiplexing with X-Gal (blue) and X-Glc (blue-green) systems for simultaneous screening of lacZ/GUS dual-reporter constructs, supporting transformation efficiency assessments exceeding 10^6 CFU/μg DNA in Agrobacterium-mediated plant biotechnology workflows. Incorporated into selective media at 50-100 μg/mL, it identifies GUS-positive recombinants through magenta colony formation within 24-48 hours, with applications spanning plant molecular biology (transgenic selection), microbiome functional screening (E. coli O157:H7 detection), and HTS of glucuronidase inhibitors for irinotecan detoxification and xenobiotic metabolism modulation.

Appearance

• White to off-white crystalline powder with excellent water solubility (>10 mg/mL); enzymatic hydrolysis produces nondiffusible magenta precipitate localized to enzyme source.

Source

• Chemoenzymatic Koenigs-Knorr glycosylation of protected β-D-glucuronosyl donor with 5-bromo-6-chloroindol-3-ol followed by sodium salt formation; commercially available from molecular biology suppliers.

Molecular Weight and Structure

• Molecular formula C14H12BrClNNaO7; MW 444.59 g/mol. Sodium (2R,3S,4S,5S,6S)-6-[(5-bromo-6-chloro-1H-indol-3-yl)oxy]-3,4,5-trihydroxyoxane-2-carboxylate featuring uronic acid C6-carboxyl and vicinal 5,6-bromochloro substitution.

Sugar Specificity

• Highly selective β-D-glucuronopyranoside for β-glucuronidases (GUS); >500-fold preference over β-glucosidases/galactosidases due to uronic acid stereochemistry.

Biological Activity

• Chromogenic GUS reporter substrate; Km 30-100 μM (E. coli GusA); produces magenta 5,5′-dibromo-6,6′-dichloroindigo via indoxyl oxidative dimerization.

Purity and Microbial Contamination

• ≥98% HPLC purity; molecular biology grade with heavy metals <10 ppm; synthetic origin ensures sterility.

Identity and Quality Control

• ¹H-NMR (uronic anomeric H-1 ~5.2 ppm d, J=7.8 Hz; bromochloroindole H-7 ~7.3 ppm); HRMS m/z 423 [M-Na]+; solubility >10 mg/mL H2O.

Shelf Life and Storage

• Stable >3 years desiccated at -20°C; aqueous stocks (5 mg/mL) viable 6 months at 4°C; protect from light and moisture.

Application

• GUS reporter gene screening in plant transformation; E. coli β-glucuronidase detection in food/water safety; multiplexing with X-Gal/X-Glc substrates.

Key Characteristics

• Magenta color orthogonal to blue/green indolyl substrates; water-soluble Na salt; superior contrast in dense platings; nondiffusible product.

Citation Links

• https://www.chemsrc.com/en/cas/144110-43-0_1032535.html
• https://www.srlchemicals.com/products/product_details/productId/143881
• https://www.rpicorp.com/products/biochemicals/other-enzymes/magenta-glca-10-g.html
• http://kisanbiotech.img15.kr/MSDS-plant(20150717)/chemicals/Magenta-GlcA.pdf[4]
• https://cymitquimica.com/products/IN-DA001IYF/144110-43-0
• https://www.duchefa-biochemie.com/msds/download/number/M1412/id/2467
• https://www.watson-int.com/5-bromo-6-chloro-3-indolyl-beta-d-glucuronide-sodium-salt-cas-216971-54-9/
• https://parchem.com/chemical-supplier-distributor/sodium-glucoheptonate-096120
• https://moleculardepot.com/product/magenta-gal-highly-pure/
• https://pubchem.ncbi.nlm.nih.gov/compound/216971-54-9