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Hydrogen Peroxide Scavenging Activity of Novel Coumarins Synthesized Using Different Approaches.

Al-Amiery AA, Al-Majedy YK, Kadhum AA, Mohamad AB - PLoS ONE (2015)

Bottom Line: The newly synthesized coumarins were characterized by different spectroscopic techniques (FT-IR and NMR) and micro-elemental analysis (CHNS).In vitro antioxidant activities of these compounds were evaluated against hydrogen peroxide and were compared with standard natural antioxidant, vitamin C.Our results reveal that these compounds exhibit excellent radical scavenging activities.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical and Process Engineering, University Kebangsaan Malaysia (UKM), Bangi, Selangor, 43000, Malaysia; Environmental Research Center, University of Technology (UOT), Baghdad, 10001, Iraq.

ABSTRACT
New derivatives of 7-hydroxy-4-methylcoumarin were synthesized using a chemical method and a microwave-assisted method to compare the feasibility, reaction times, and yields of the product. The newly synthesized coumarins were characterized by different spectroscopic techniques (FT-IR and NMR) and micro-elemental analysis (CHNS). In vitro antioxidant activities of these compounds were evaluated against hydrogen peroxide and were compared with standard natural antioxidant, vitamin C. Our results reveal that these compounds exhibit excellent radical scavenging activities.

No MeSH data available.


Suggested mechanism for compound 4 as an antioxidant.
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pone.0132175.g003: Suggested mechanism for compound 4 as an antioxidant.

Mentions: Fig 2 showed that the eight synthesized compounds (1–8) demonstrated a strong scavenging activity against H2O2. At a very low concentration of 250 μg/mL we observed a concentration dependent decrease in H2O2 activity. A very weak inhibitory activity was found in compound 1 and compound 6 (5.33 ± 0.88 and 18.0 ± 1.00). The highest concentration was found at 1000 μg/mL (Fig 2). The best percentage scavenging activity was shown by compound 8 (91.66 ± 1.52), followed by compound 4, 3 and 7 (88.33 ± 1.50; (83.33 ± 1.52 and (82.66 ± 1.52;). However, their activity was not significantly different at 95% confidence interval. vitamin C was used as standard drugs with percentage inhibition of 70.00 ± 2.00. The hydrogen-donating activity, measured utilizing hydrogen peroxide radicals as the hydrogen acceptor, demonstrated that a strong association could be found between the concentration of the coumarin molecule and the rate of inhibition [27]. Using the hydrogen peroxide test, coumarins 1–8 demonstrated their ability to diminish the stable radical. The postulated mechanism for the reaction of coumarin 4 as an antioxidant, as indicated in Fig 3, relies on the mercapto hydrogen atom (bold), which is under the influence of resonance and inductive effects. The resonance effect of the mercapto hydrogen facilitates the release of hydrogen, while the inductive effect pushes the electrons toward a sulfur-free radical, resulting in stability of the molecule.


Hydrogen Peroxide Scavenging Activity of Novel Coumarins Synthesized Using Different Approaches.

Al-Amiery AA, Al-Majedy YK, Kadhum AA, Mohamad AB - PLoS ONE (2015)

Suggested mechanism for compound 4 as an antioxidant.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4492988&req=5

pone.0132175.g003: Suggested mechanism for compound 4 as an antioxidant.
Mentions: Fig 2 showed that the eight synthesized compounds (1–8) demonstrated a strong scavenging activity against H2O2. At a very low concentration of 250 μg/mL we observed a concentration dependent decrease in H2O2 activity. A very weak inhibitory activity was found in compound 1 and compound 6 (5.33 ± 0.88 and 18.0 ± 1.00). The highest concentration was found at 1000 μg/mL (Fig 2). The best percentage scavenging activity was shown by compound 8 (91.66 ± 1.52), followed by compound 4, 3 and 7 (88.33 ± 1.50; (83.33 ± 1.52 and (82.66 ± 1.52;). However, their activity was not significantly different at 95% confidence interval. vitamin C was used as standard drugs with percentage inhibition of 70.00 ± 2.00. The hydrogen-donating activity, measured utilizing hydrogen peroxide radicals as the hydrogen acceptor, demonstrated that a strong association could be found between the concentration of the coumarin molecule and the rate of inhibition [27]. Using the hydrogen peroxide test, coumarins 1–8 demonstrated their ability to diminish the stable radical. The postulated mechanism for the reaction of coumarin 4 as an antioxidant, as indicated in Fig 3, relies on the mercapto hydrogen atom (bold), which is under the influence of resonance and inductive effects. The resonance effect of the mercapto hydrogen facilitates the release of hydrogen, while the inductive effect pushes the electrons toward a sulfur-free radical, resulting in stability of the molecule.

Bottom Line: The newly synthesized coumarins were characterized by different spectroscopic techniques (FT-IR and NMR) and micro-elemental analysis (CHNS).In vitro antioxidant activities of these compounds were evaluated against hydrogen peroxide and were compared with standard natural antioxidant, vitamin C.Our results reveal that these compounds exhibit excellent radical scavenging activities.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical and Process Engineering, University Kebangsaan Malaysia (UKM), Bangi, Selangor, 43000, Malaysia; Environmental Research Center, University of Technology (UOT), Baghdad, 10001, Iraq.

ABSTRACT
New derivatives of 7-hydroxy-4-methylcoumarin were synthesized using a chemical method and a microwave-assisted method to compare the feasibility, reaction times, and yields of the product. The newly synthesized coumarins were characterized by different spectroscopic techniques (FT-IR and NMR) and micro-elemental analysis (CHNS). In vitro antioxidant activities of these compounds were evaluated against hydrogen peroxide and were compared with standard natural antioxidant, vitamin C. Our results reveal that these compounds exhibit excellent radical scavenging activities.

No MeSH data available.