Magenta‑GlcA CHX Salt 

Magenta‑GlcA CHX Salt (CAS 144110‑43‑0), systematically 5‑bromo‑6‑chloro‑3‑indolyl β‑D‑glucuronide cyclohexylammonium salt, 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 β‑D‑glucuronic acid and provided as the cyclohexylammonium salt. When hydrolyzed by β‑D‑glucuronidase (EC 3.2.1.31) or GUS‑expressing systems, the indoxyl moiety is released and oxidizes to an insoluble magenta‑red indigo‑type precipitate, enabling clear visual detection of enzyme activity. This salt form is preferred for high‑concentration stock solutions in dimethylformamide (DMF), DMSO, or ethanol, and then diluted into aqueous media for use in bacterial‑colony screening, GUS‑reporter assays, and histochemical staining. The magenta color provides better contrast than X‑GlcA’s blue, improving sensitivity and ease of readout in selective agar plates, tissue sections, and plant‑transformation assays. The compound is supplied as a high‑purity, research‑use‑only reagent compatible with standard microbiological and molecular‑biology buffers.

Appearance

• White to off‑white crystalline powder.
• Free‑flowing solid suitable for preparation of concentrated stock solutions in DMF, DMSO, or ethanol for subsequent dilution into aqueous media.

Source / synthesis

• Synthetically produced by coupling 5‑bromo‑6‑chloro‑3‑indoxyl with β‑D‑glucuronic acid and then converting the free acid into the cyclohexylammonium salt form for improved solubility.
• Commercially manufactured by specialty enzyme‑substrate and biochemical suppliers (e.g., TCI Chemicals, Fisher Scientific, GoldBio) as a high‑purity GUS‑assay reagent.

Molecular weight and structure

• Molecular formula: C20H26BrClN2O7C20​H26​BrClN2​O7​.
• Molecular weight: 521.78–521.79 g/mol.
• Structure: 5‑bromo‑6‑chloro‑1H‑indol‑3‑yl β‑D‑glucopyranuronate esterified as the cyclohexylammonium salt, with the β‑(1→4) linkage between the indole C3‑O and the D‑glucuronic acid ring.

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 glucuronides and glycosaminoglycan‑derived substrates.
• 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, plant‑tissue GUS assays, and histological preparations.

Purity and microbial contamination

• Typically supplied at ≥98% purity as determined by HPLC or similar analytical methods.
• 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; major suppliers provide batch‑specific certificates of analysis.
• Quality‑control checks include appearance, solubility, spectral characteristics, and performance in a defined β‑glucuronidase assay (e.g., E. coli GUS⁺ colonies or plant GUS staining).

Shelf life and storage

• Shelf life is typically 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 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.
• Histochemical and plant‑tissue localization of GUS activity in transgenic and reporter‑gene experiments.

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 with a cyclohexylammonium counterion, providing improved solubility in organic stock solvents.
• Crystalline, stable powder with a known molecular formula and weight, suitable for quantitative GUS assays and standardized media formulations.

Citations

• TCI Chemicals – 5‑Bromo‑6‑chloro‑3‑indolyl‑β‑D‑glucuronide cyclohexylammonium salt (Magenta‑GlcA CHX Salt): https://www.tcichemicals.com/US/en/p/B4128
• Fisher Scientific – 5‑Bromo‑6‑chloro‑3‑indolyl‑β‑D‑glucuronide cyclohexylammonium salt (biochemical‑research grade): https://www.fishersci.com/shop/products/5-bromo-6-chloro-3-indolyl-beta-d-glucuronide-cyclohexylammonium-salt-for-biochemical-research
• GoldBio – Magenta‑β‑D‑glucuronide cyclohexylammonium salt (Magenta‑GlcA CHX) product page: https://www.goldbio.com/products/magenta-beta-d-glucuronide-cyclohexylammonium-salt
• Duche‑fa Direct – Magenta‑GlcA cyclohexylammonium salt overview: https://duchefadirect.com/magenta-glca-cyclohexylammonium-salt/
• ChemicalBook – 5‑Bromo‑6‑chloro‑3‑indolyl‑D‑glucuronide cyclohexylammonium salt (CAS 144110‑43‑0) entry: https://www.chemicalbook.com/ChemicalProductProperty_IN_CB8167628.htm
• CP Lab Safety – 5‑Bromo‑6‑chloro‑3‑indolyl‑β‑D‑glucuronide cyclohexylammonium salt (biochemical‑research product): https://www.calpaclab.com/5-bromo-6-chloro-3-indolyl-beta-d-glucuronide-cyclohexylammonium-salt-for-biochemical-research-100mg-e …
• Smart Science – Magenta‑β‑D‑glucuronide cyclohexylammonium salt catalog entry: https://www.smartscience.co.th/en/product/67035/magenta-%CE%B2-d-glucuronide-cyclohexylammonium-salt
• Sigma‑Aldrich – 5‑Bromo‑6‑chloro‑3‑indolyl‑β‑D‑glucuronide cyclohexylammonium salt (Magenta‑GlcA, Magenta™ glucuronide): https://www.sigmaaldrich.com/US/en/product/sigma/ (search for “5‑Bromo‑6‑chloro‑3‑indolyl‑β‑D‑glucuronide cyclohexylammonium salt” or CAS 144110‑43‑0)
• ChemImpex / similar catalog (Magenta‑GlcA CHX‑salt GUS‑substrate overview): https://www.chemicalbook.com/ (search for CAS 144110‑43‑0)
• General enzyme‑substrate resource (β‑glucuronidase‑substrate catalog): https://www.medchemexpress.com/ (for GUS‑substrate context and assay‑format reference)