Synthesis, Spectroscopy and Electrochemistry of New 3-(5-Aryl-4,5-Dihydro-1H-Pyrazol-3-yl)-4-Hydroxy-2H-Chromene-2-One 4, 5 as a Novel Class of Potential Antibacterial and Antioxidant Derivatives

Abstract

Abstract3-((2E)-3(aryl)prop-2-enoyl)-2H-chromen-2-one 3 was synthesized from 4-hydroxy coumarin by refluxing 3-acetyl-4-hydroxy coumarin with aromatic aldehydes in chloroform in the presence of a catalytic amount of piperidine. 3 was converted to pyrazoles 4, 5 by treatment with hydrazine and phenylhydrazine in toluene, respectively. The structures of the new compounds were confirmed by elemental analysis, IR, and multinuclear/multidimensional NMR spectroscopy ( 1 H, 13 C-NMR, NOESY, HMBC) which allowed us to assign the complete network of proton and carbon atoms. All the compounds exhibited one quasireversible redox process. All the newly synthesized compounds were screened for their antibacterial and antioxidant activities. Antimicrobial studies revealed that 3-(5-(2,5-dimethylphenyl)-1-phenyl-4,5-dihydro-1H-pyrazol-3-yl)-4-hydroxy-2H-chromene-2-one 5c showed significant antibacterial activity against Escherichia coli and Pseudomonas Aeruginosa 27853. Furthermore, 3-(5-(aryl)-4,5-dihydro-1H-pyrazol-3-yl)-4-hydroxy-2H-chromene-2-ones 4, 5 showed antioxidant activities of different extents with respect to individual compounds as well as to the antioxidant methods. The 3-(5-(phenyl)-4,5-dihydro-1H-pyrazol-3-yl)-4-hydroxy-2H-chromene-2-ones 4a was found to be the most active antioxidant in the series and more active than trolox which makes the investigated complexes a new promising class of antibacterial compounds.

Coumarins: The Antimicrobial agents

“…22 Furthermore, the pharmacological properties as well as therapeutic applications of coumarins depend upon the pattern of substitution and recently they are reported to possess many pharmacological activities such as antimicrobial activity. In continuation of previous studies [23][24][25][26][27][28][29][30][31][32] on coumarins, herein we are reporting a review for such recent derivatives of coumarins with antioxidant activities.…”

“…Streptomycin was used as standard anti-bacterial drug and ketoconazole as standard antifungal drug. One compound (32) had activity equal to that of standard drug ketoconazole (31.25 µgml -1 ) against M. mucedo. 67 A novel series of 3-[(2'-Substituted benzylidene amino thiazol-4'-yl) amino]coumarins (33a-33b) was prepared by Singh et al and evaluated for antibacterial activity against various bacteria, Staphylococcus aureus 209 P, E. Coli ESS2231, Proteus vulgaris, K. Pneumoniae were used and antifungal activity was performed against Candida albicans ATCC10231 and results were compared with gattifloxacin and ciprofloxacin for antibacterial and fluconazole for antifungal activities respectively and propylene glycol treated group served as control.…”

Bis-Kalkon Türevlerinin Elektrokimyasal Davranışlarının İncelenmesi

“…When the nitro group with electronegative property is attached to a benzene ring, it can delocalize the π-electrons of the ring to compensate for the lack of charge or can prevent the transfer of electrons (Saby et al, 1997;Ju et al, 2010). As expected, the oxidation and reduction potentials of P1 and P2 are strongly influenced by the substituents on the phenylene ring in chalcone derivatives (Al-Ayed, 2011;Erasmus, 2011). The fact that the oxidation peaks of P2 have more negative values compared to P1 could be explained by the electron attracting properties of the NO2 group.…”

“…(Quintana-Espinoza et al, 2006;Jin et al, 2014;Yellepa and Mallapa, 2015). However, much work has not been studied in literature with polar aprotic solvents such as acetonitrile (Al-Ayed, 2011).…”

Recent Advances in the Synthesis of Coumarin Derivatives from Different Starting Materials

“…Many authors have published researches exploring the medicinal properties of coumarins [4,6,12,[35][36][37]. Coumarins possess antimicrobial activity such as antibacterial [38][39][40][41][42][43][44] and antifungal [40,[45][46][47][48]. Numerous coumarin derivatives showed significant antioxidant activity [49][50][51][52][53].…”