Synthesis, antibacterial and antioxidant activities of new 1-alkyl-4-(1-alkyl-4-oxo-1,4-dihydroquinolin-2-yl)pyridinium bromides.
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 (C₅-C₁₅) 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 μg/mL). They also showed good antioxidant activities in DPPH scavenging (SC₅₀: 45-133 μg/mL) and ferric reducing/antioxidant power (14-141 μM 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.
Department of Chemistry, Faculty of Science, Karadeniz Technical University, 61080 Trabzon, Turkey. Electronic address: nuran_yayli@hotmail.com.
Nuran
N
Kahriman
Büşra
B
Yaylı
Ayça
A
Aktaş
Zeynep
Z
Iskefiyeli
Fatih Şaban
FŞ
Beriş
Nurettin
N
Yaylı
D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D000975:Antioxidants / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D001713:Biphenyl Compounds / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D016166:Free Radical Scavengers / Q000737:chemistry; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D010851:Picrates / Q000737:chemistry; D011726:Pyridinium Compounds / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D015363:Quinolones / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D013329:Structure-Activity Relationship
D000900:Anti-Bacterial Agents; D000975:Antioxidants; D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D010851:Picrates; D011726:Pyridinium Compounds; D015363:Quinolones; C004931:1,1-diphenyl-2-picrylhydrazyl
1,4′-Diazaflavone; Antibacterial activity; Antioxidant activity; Microwave; N,N′-Dialkyl-1,4′-diazaflavonium bromide; Quinoline nucleus