Purpurogallin

• CAS: 569-77-7
• Catalog Number: ACM569777-2
• Category: Main Products
• Molecular Weight: 220.18
• Molecular Formula: C11H8O5
• Synonyms: 2,3,4,6-Tetrahydroxy-5H-benzocyclohepten-5-one
• Appearance: Brown powder

Case Study

Purpurogallin as a Chelating Agent in the Synthesis of Hybrid Alumina Adsorbents for Heavy Metal Removal

Mahmoud M. E, et al. Journal of Hazardous Materials, 2010, 176(1-3), 906-912.

This study demonstrates the experimental application of purpurogallin in the synthesis of three distinct types of alumina-based adsorbents-acidic, neutral, and basic-each physically immobilized with purpurogallin to enhance their metal-binding efficacy.
The synthetic procedure involves dissolving 2.2 g of purpurogallin (~10.0 mmol) in 300 mL of cold ethyl alcohol, followed by the incorporation of 10.0 ± 0.1 g of alumina. After a 6-hour stirring process, the resulting purpurogallin-immobilized alumina adsorbents (I-III) were recovered via filtration, sequentially washed with ethanol and diethyl ether, and dried at 60 °C. This simple yet efficient physical adsorption strategy yielded hybrid materials with high surface coverage and excellent physicochemical stability.
Experimental evaluation revealed that the hybrid adsorbents exhibited exceptional thermal resistance up to 350 °C and acid stability in the pH range of 2-7. More notably, their metal ion adsorption capacity ranged from 420 to 590 μmol g⁻¹ for Cr(III), Fe(III), and Cu(II), highlighting their strong selectivity and capacity. These properties were particularly pronounced at trace metal concentrations (μg mL⁻¹ to ng mL⁻¹), affirming the critical role of the alumina matrix and purpurogallin's chelation efficiency. Field validation using underground water samples confirmed their practical utility, achieving metal recovery rates of 92-100% (±1-3%).

Purpurogallin is Used for the Synthesis of Silica Gel-Bound Extractor for Iron(III) Selective Adsorption

Mahmoud M. E, et al. Analytica Chimica Acta, 2001, 450(1-2), 239-246.

Purpurogallin was utilized as a reactive phenolic ligand in the synthesis of a silica gel-bound purpurogallin (SGBP) solid-phase extractor, designed for selective binding of Fe(III) ions. The synthesis protocol involved a stepwise surface functionalization strategy, beginning with the activation of commercial silica gel particles using concentrated hydrochloric acid under reflux for 4 hours. This treatment introduced reactive silanol groups essential for subsequent silanization.
The activated silica gel was thoroughly washed with distilled water to remove residual acid and dried at 150 °C. Surface amination was then performed by suspending 20.0 g of activated silica in 150 mL of dry toluene, followed by the addition of 20.0 mL of 3-aminopropyltrimethoxysilane. The mixture was refluxed under stirring for 6 hours, allowing the covalent anchoring of aminopropyl groups onto the silica surface. The resulting silica-bound aminopropyl phase was isolated by filtration, washed successively with ethanol and diethyl ether, and dried at 70 °C.
To immobilize purpurogallin, 10.0 g of the aminated silica gel was mixed with 10.0 mmol (2.20 g) of purpurogallin in 150 mL of dry toluene. This mixture was refluxed for 8 hours to facilitate coupling between the phenolic hydroxyl groups of purpurogallin and the terminal amines on the silica surface. The final SGBP product was filtered, extensively washed to remove unreacted reagents, and dried at 70 °C.Elemental analysis and metal probe testing confirmed effective immobilization with surface coverage values of ~0.46-0.49 mmol g⁻¹.

Purpurogallin Is Used for the Application of Neuroprotection Against Cerebral Ischemia/Reperfusion Injury

Li X, et al. International Immunopharmacology, 2022, 111, 109057.

Purpurogallin (PPG) has demonstrated significant neuroprotective potential in the context of cerebral ischemia/reperfusion (I/R) injury. In a controlled study, PPG was evaluated through both in vivo and in vitro experimental models, including C57/B6 mice subjected to middle cerebral artery occlusion/reperfusion (MCAO/R) and oxygen-glucose deprivation/reoxygenation (OGD/R) models using BV2 microglia and HT22 hippocampal neurons.
PPG treatment notably reduced endoplasmic reticulum (ER) stress markers and neuroinflammatory mediators, while enhancing neuronal viability and reducing apoptosis. Western blotting and ELISA analyses confirmed the downregulation of pro-inflammatory cytokines and ER stress proteins. Functional assays such as mNSS, water maze tests, and TTC staining revealed improvements in neurological function and decreased cerebral infarct volumes and edema in MCAO/R mice.
Mechanistically, PPG exerted its protective effects by inhibiting the TLR4/NF-κB signaling pathway in both microglial and neuronal populations. These findings strongly support the application of Purpurogallin as a therapeutic candidate for attenuating cerebral I/R injury through modulation of ER stress and neuroinflammation.

Purpurogallin as a Potent Mixed-Type Inhibitor of Xanthine Oxidase: Spectroscopic and Docking Evidence

Wang J, et al. Journal of Molecular Structure, 2021, 1228, 129772.

Purpurogallin demonstrates strong inhibitory activity against xanthine oxidase (XO), a key enzyme in purine metabolism and uric acid production. In enzymatic assays, purpurogallin displayed a reversible, mixed-type inhibition with an IC₅₀ of 5.60 μM. This product is used for the application of XO inhibition, explored through a suite of experimental spectroscopic techniques.
Fluorescence titration experiments revealed static quenching, indicating the formation of a stable complex between purpurogallin and XO, driven primarily by hydrogen bonding and van der Waals interactions. Synchronous fluorescence further indicated microenvironmental polarity shifts around tyrosine and tryptophan residues. Circular dichroism analysis highlighted conformational modulation of XO upon binding, with a notable increase in α-helix content and corresponding reductions in β-sheet and random coil structures. Molecular docking confirmed that purpurogallin interacts specifically with XO's molybdenum cofactor domain, forming stable hydrogen bonds with residues Arg880, Thr1010, Val1011, and Glu1261. These findings underscore purpurogallin's experimental utility in mechanistic enzymology and its promise as a lead compound in the development of novel XO inhibitors for therapeutic intervention in hyperuricemia and gout.

Custom Q&A

What is the IUPAC name of the keyword?

The IUPAC name of the keyword is 2,3,4,6-tetrahydroxybenzo[7]annulen-5-one.

What is the CAS number of the keyword?

The CAS number of the keyword is 569-77-7.

What is the molecular weight of the keyword?

The molecular weight of the keyword is 220.18 g/mol.

What is the molecular formula of the keyword?

The molecular formula of the keyword is C11H8O5.

What are the synonyms of the keyword?

The synonyms of the keyword include 2,3,4,6-tetrahydroxy-5H-benzo[7]annulen-5-one, MLS000738105, SMR000393869, CHEMBL66953, and CHEBI:8647.

What is the role of the keyword?

The keyword has multiple roles, including being an antibacterial agent, an antioxidant, an EC 1.17.3.2 (xanthine oxidase) inhibitor, and a protective agent.

What is the natural product in which the keyword is found?

The natural product in which the keyword is found is Quercus.

What is the InChIKey of the keyword?

The InChIKey of the keyword is WDGFFVCWBZVLCE-UHFFFAOYSA-N.

How many hydrogen bond donor counts does the keyword have?

The keyword has 4 hydrogen bond donor counts.

What is the topological polar surface area of the keyword?

The topological polar surface area of the keyword is 98Ų.