Y-Glc

Y-Glc (3-Indolyl-β-D-glucopyranoside, CAS 487-60-5), also known as Indoxyl-β-D-glucoside, is a chromogenic substrate for β-glucosidase (EC 3.2.1.21) detection that hydrolyzes to release indoxyl, which spontaneously oxidizes and dimerizes into indigo blue precipitate, enabling clear visualization of enzyme activity in microbiological and biochemical assays. With molecular formula C14H17NO6 (MW 295.29 g/mol), this pale compound features β-D-glucopyranose O-glycosidically linked at C1 to the 3-position of unsubstituted 1H-indol-3-ol, offering higher sensitivity than halogenated analogs (X-Glc) due to faster oxidation kinetics of the parent indoxyl, though with increased spontaneous hydrolysis risk requiring fresh media preparation. Primarily used at 100-200 μg/mL in agar plates for detecting β-glucosidase-positive bacteria (Enterobacteriaceae, Bifidobacterium, Bacteroides) in food safety testing, probiotic screening, and cellulose degradation studies, it produces blue colonies/plaques within 24h, supporting quantitative enzyme assays and histochemical localization in plant tissues. As the progenitor of X-Gal/Salmon-Gal technologies, Y-Glc serves in preliminary GH1/GH3 family hydrolase screening, biofuel enzyme engineering, and diagnostics of Gaucher disease via lysosomal GBA activity, with water solubility (0.1M) facilitating no-wash protocols orthogonal to galactosidase substrates.

Appearance

• White to pale grey solid or crystalline powder.
• Hygroscopic; hydrolysis yields blue indigo precipitate.​

Source

• Koenigs-Knorr synthesis: β-D-glucopyranosyl halide + indol-3-ol.
• Commercial microbiology grade (Glentham, GoldBio).

Molecular Weight and Structure

• Formula: C14H17NO6; MW 295.29 g/mol.
• (2S,3R,4S,5S,6R)-2-(1H-indol-3-yloxy)-6-(hydroxymethyl)tetrahydro-2H-pyran-3,4,5-triol.​

Sugar Specificity

• Selective β-D-glucopyranoside for β-glucosidases (GH1/3).
• Minimal α-glucosidase activity.​

Biological Activity

• Chromogenic reporter; Km ~0.5 mM for microbial β-Glc.
• Rapid indigo formation post-hydrolysis.​

Purity and Microbial Contamination

• ≥98% (HPLC); research grade.
• Synthetic; non-sterile.​

Identity and Quality Control

• Mp 57-58°C; λmax 280 nm (DMSO); [α]D ~-60°.
• ¹³C-NMR confirmed β-anomeric configuration.

Shelf Life and Storage

• 2 years -20°C desiccated; hygroscopic.
• Soluble 0.1M H₂O; prepare fresh media.​

Applications

• β-Glucosidase colony screening; cellulase assays.
• Probiotic/pathogen detection in food.​

Key Characteristics

• Higher sensitivity than X-Glc; faster color development.
• Unsubstituted indole; water-soluble.​

Citation Links

• https://www.glentham.com/en/products/product/GC4642/​
• https://amp.chemicalbook.com/ProductChemicalPropertiesCB0376792_EN.htm​
• https://pubchem.ncbi.nlm.nih.gov/compound/441564​
• https://www.goldbio.com/products/y-beta-d-glc​
• https://discofinechem.com/products/3-indolyl-beta-d-glucopyranoside/​
• https://www.glycosynth.co.uk/det/77/Indolyl-beta-D-glucopyranoside/​
• https://www.benchchem.com/fr/product/b7839075​
• https://www.tcichemicals.com/IN/en/p/B5393​
• https://pubchem.ncbi.nlm.nih.gov/compound/5-Bromo-4-chloroindol-3-yl-beta-D-glucopyranoside​
• https://www.chemicalbook.com/ChemicalProductProperty_EN_CB34656002.htm