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, cilt.69, ss.348-355, 2013 (SCI İndekslerine Giren Dergi) identifier identifier identifier

  • Cilt numarası: 69
  • Basım Tarihi: 2013
  • Doi Numarası: 10.1016/j.ejmech.2013.08.050
  • Dergi Adı: EUROPEAN JOURNAL OF MEDICINAL CHEMISTRY
  • Sayfa Sayıları: ss.348-355

Özet

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.

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.