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09:50
Biosynthesis of a Flavonol from a Flavanone by Establishing a One-pot Bienzymatic Cascade
Published on: August 14, 2019
Reduction of hexavalent chromium using naturally-derived flavonoids
Veronica A Okello1, Samuel Mwilu, Naumih Noah
1Department of Chemistry Center for Advanced Sensors & Environmental Systems (CASE), State University of New York, Binghamton, New York 13902, United States.
Environmental Science & Technology
|September 1, 2012
Summary
Quercetin and its derivatives effectively remove toxic chromium(VI) from environmental samples. This novel method offers high efficiency and atom economy, outperforming traditional bioremediation techniques.
Area of Science:
- Environmental Chemistry
- Green Chemistry
- Analytical Chemistry
Background:
- Chromium(VI) is a toxic heavy metal pollutant.
- Natural flavonoids like quercetin can complex with metals, reducing their environmental availability.
- Existing remediation methods can be slow or inefficient.
Purpose of the Study:
- To investigate the removal of chromium(VI) using quercetin (QCR) and its synthetic derivatives, quercetin pentaphosphate (QPP) and quercetin sulfonic acid (QSA).
- To synthesize and characterize QPP and QSA.
- To evaluate the efficiency and performance of QCR, QPP, and QSA in Cr(VI) reduction, including the effect of palladium nanoparticles (PdNPs) and temperature.
Main Methods:
- Synthesis and characterization of QPP and QSA using UV-vis spectroscopy, NMR (H(1), C(13), P(31)), and LC-MS.
- Cr(VI) reduction experiments using QCR, QPP/PdNPs, and QSA/PdNPs.
- Optimization of reaction conditions including catalyst (PdNPs) and temperature.
- Validation of the method in environmental soil samples (BU and BRS).
- Analysis of reaction products using electron paramagnetic resonance spectroscopy.
Main Results:
- QPP and QSA were successfully synthesized and characterized; QPP exhibited high solubility (840 mg/mL) and stability.
- QCR achieved the highest Cr(VI) reduction efficiency (99.8% in 30 min).
- QPP/PdNPs and QSA/PdNPs achieved 96.5% and 91.7% efficiency, respectively.
- PdNPs catalyst increased efficiency by ~36.5%, and temperature increase (25 to 45 °C) improved efficiency by ~46.8%.
- The method was validated in environmental soil samples, showing higher efficiency in BU soil than BRS soil by 16.1%.
- QPP demonstrated the highest % atom economy (94.6%).
Conclusions:
- Quercetin and its derivatives, particularly QCR, are highly effective for rapid Cr(VI) reduction in environmental samples.
- The use of PdNPs and elevated temperatures significantly enhances Cr(VI) reduction efficiency.
- This approach offers a promising, efficient, and atom-economical alternative to conventional bioremediation for chromium contamination.
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