Synthesis, In-vitro antibacterial and antioxidant activity of chalcone derivatives

Abstract

In the face of the emergence of bacteria resistant to common antibacterials and excessive accumulation of free radicals that can cause several diseases, it is important to look for new antibacterials and antioxidants. The goal of this work was to synthesize three chalcones derivatives by the Claisen-Schmidt condensation and then evaluate their antibacterial and antioxidant activities. The structure of these 3 compounds has been determined by NMR (1H and 13C) spectroscopy. The in vitro antibacterial activity assessed by Microdilution methods, was tested against Gram positive bacteria (Staphylococcus aureus and Bacillus subtilis) and gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa) at different concentrations ranging from 7.82 to 1000 µg/mL. All three synthesized chalcones showed good antibacterial activity against gram positive and negative bacteria used with a range of MIC ranging from 62.50 to 1000 µg/mL. However, the (E)-3-(3, 4-dimethoxyphenyl)-1-(2-hydroxyphenyl) prop-2-en-1-one showed excellent activity against Bacillus subtilis with Minimum Inhibitory Concentration (MIC) of 62.5 µg/mL which is similar to that of the standard (Ampicillin) against the same bacterial strain. Antioxidant activity evaluated using 2,2-diphenyl2-picryl- hydrazyle ( DPPH) revealed that all the synthesized chalcones showed an antioxidant activity with IC50 values of 8.22; 6.89 and 3.39 µg/mL for (E)-1-(2-hydroxyphenyl)-3-(4-hydroxyphenyl) prop-2-en-1-one, (E)-1-(2-hydroxyphenyl)-3-(4-methoxyphenyl) prop-2-en-1-one and (E)-3-(3, 4-dimethoxyphenyl)-1-(2-hydroxyphenyl) prop-2-en-1-one, respectively. These values are closer to that of ascorbic acid used as a standard. The results suggest that the synthesized chalcones, especially the (E)-3-(3, 4-dimethoxyphenyl)-1-(2-hydroxyphenyl) prop-2-en-1-one could be used, after in vivo and clinical tests, like antibacterial and antioxidant supplement or even replace current drug therapies.

Synthesis and Preliminary Biological study of New Chalcone Derivatives Containing Isoxazoline Moiety

“…A process that generates hydrogen peroxide in vivo by some oxidase enzymes, and which product hydroxyl radical that in turn can harm the biological systems. The antioxidant potential of some new synthetic compounds have been assigned by its scavenging for the stable (DPPH) free radical [18][19][20].…”

Synthesis, In-vitro Antimalarial Activity and In silico Molecular Docking Study of Amino Chalcone Derivatives from 1-(2-aminophenyl)-3-(4- substituted-phenyl) prop-2-en-1-one and Dihydroquinolone Derivatives

“…The 4 substituted amino chalcones from 1-(2aminophenyl)-3-(4-substituted-phenyl) prop-2-en-1-one have been synthesized by Claisen-Schmidt reaction using Sodium hydroxide (NaOH) as catalyst in anhydrous ethanol according to the method described by Mulula and al 17,18,19 . Whereas, the four substituted Dihydroquinolones were synthesized by intramolecular cyclization of substituted amino chalcones by using 1 mol % phosphomolybdic acid (H3PMo12O40) PMA-SiO2 a reusable catalyst in ethanol according to the literature 33,34 .…”

“…The Chalcones, known as 1,3-diphenylprop-2en-1-one, are the aromatic ketones and the enones that form a variety of biological agents and they considered the main precursors for flavonoids, and isoflavonoids biosynthesis in plants [14][15][16][17][18][19][20][21] . They are widely located in nature (in plants, bacteries, fungi, etc.)…”

“…They are widely located in nature (in plants, bacteries, fungi, etc.) and are generally synthesized in the Laboratory from aromatic aldehydes and aliphatic aldehydes or ketones via the condensation reaction Claisen-Schmidt in the presence of base or acid catalysts [17][18][19][20][21][22] . Chalcones possess several physiological activities (antioxidant, antimalarial, antibacterial, antiulceral, anti-inflammatory, anti-HIV, antiviral, antifungal, antileishmanial, anticancer, antitubercular, antihyperglycemic, carboxygenase inhibitor, and insecticidal) which are generated by the presence of the reactive function α,β-unsaturated keto present in the molecule [23][24][25][26][27][28][29] .…”