Synthesis, antibacterial and antioxidant activities of new 1-alkyl-4-(1-alkyl-4-oxo-1,4-dihydroquinolin-2-yl)pyridinium bromides


KAHRİMAN N., Yayli B., Aktas A., Iskefiyeli Z., Beris F. Ş. , YAYLI N.

EUROPEAN JOURNAL OF MEDICINAL CHEMISTRY, vol.69, pp.348-355, 2013 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 69
  • Publication Date: 2013
  • Doi Number: 10.1016/j.ejmech.2013.08.050
  • Title of Journal : EUROPEAN JOURNAL OF MEDICINAL CHEMISTRY
  • Page Numbers: pp.348-355
  • Keywords: Microwave, 1,4 '-Diazaflavone, Quinoline nucleus, N,N '-Dialkyl-1,4 '-diazaflavonium bromide, Antibacterial activity, Antioxidant activity, MICROWAVE-ASSISTED SYNTHESIS, SOLVENT-FREE SYNTHESIS, N-ALKYL DERIVATIVES, CORRESPONDING 2-ARYL-2,3-DIHYDROQUINOLIN-4(1H)-ONES, ANTIMICROBIAL PROPERTIES, FUNCTIONALIZED FLAVONES, BIOLOGICAL-ACTIVITIES, TEA POLYPHENOLS, CYCLIZATION, FACILE

Abstract

New 1-alkyl-4-(1-alkyl-4-oxo-1,4-dihydroquinolin-2-yl)pyridinium bromides (3aek) were synthesized
from 1,40-diazaflavone [2-pyridin-4-ylquinolin-4(1H)-one] and evaluated for antibacterial and antioxidant
activities. A rapid one-pot preparation of 1,40-diazaflavone (2) was done from 20-amino substituted
chalcone (1) by intramolecular Michael addition using solvent-free microwave heating. New N,N0-dialkyl
substituted (C5eC15) 1,40-diazaflavonium bromides were synthesized from compound 2 with corresponding
alkyl halides. Compounds 3aek were active against six bacteria (MIC: 7.8e500.0 mg/mL). They
also showed good antioxidant activities in DPPH scavenging (SC50: 45e133 mg/mL) and ferric reducing/
antioxidant power (14e141 mM TEAC) tests. The biological activities decreased as alkyl chain length
increased. The reason behind the obvious negative effect of alkyl chain elongation is unclear and requires
investigations about the intermolecular interactions of these pyridinium salts with bioassay
components.

New 1-alkyl-4-(1-alkyl-4-oxo-1,4-dihydroquinolin-2-yl)pyridinium bromides (3a k) were synthesized from 1,4'-diazaflavone [2-pyridin-4-ylquinolin-4(1H)-one] and evaluated for antibacterial and antioxidant activities. A rapid one-pot preparation of 1,4'-diazaflavone (2) was done from 2'-amino substituted chalcone (1) by intramolecular Michael addition using solvent-free microwave heating. New N,N'-dialkyl substituted (C-5-C-15) 1,4'-diazaflavonium bromides were synthesized from compound 2 with corresponding alkyl halides. Compounds 3a k were active against six bacteria (MIC: 7.8-500.0 mu g/mL). They also showed good antioxidant activities in DPPI-1* scavenging (SC50: 45-133 mu g/mL) and ferric reducing/antioxidant power (14-141 p.M TEAC) tests. The biological activities decreased as alkyl chain length increased. The reason behind the obvious negative effect of alkyl chain elongation is unclear and requires investigations about the intermolecular interactions of these pyridinium salts with bioassay components. (C) 2013 Elsevier Masson SAS. All rights reserved.