Synthesis and Characterization of the Antimicrobial 4-Amino-Decylpyridinium Bromide Cationic Surfactant

Abstract

4-Amino-decylpyridinium bromide (ADPBr), an antimicrobial surface active agent, was synthesized by quaternization of 4-aminopyridine (AP) with decyl bromide (DBr). The reaction was carried out at 1:1.2 molar ratio of reactants (4-aminopyridine and decyl bromide, respectively) at 200°C for 10 min. The maximum yield of the product was 74.6%. The structure of the synthesized product was characterized by using modern analytical techniques, such as FT-IR, 1 H NMR, and 13 C NMR. The antimicrobial activity of the salt was evaluated with minimum inhibition concentration method and showed good activity against gram-negative bacteria. The MIC of the salt was found to be 600 ppm for 2 × 104 CFU/mL of E. coli.

Synthesis, characterization and antimicrobial activity of 4-amino-1-alkyl pyridinium salts

“…In a related study, 4-amino-1-dodecylpyridinium chloride was found to have antimicrobial activity against E. coli and Staphylococcus aureus (Zhao and Sun, 2008). Good antimicrobial activity was observed for 4-aminodecylpyridinium bromide against E. coli, only at very high concentration, 600 ppm (Madaan and Tyagi, 2008).…”

“…These methods have some drawbacks such as the need for protection of free -NH 2 group (Zhao and Sun, 2006) low yield (Obando et al, 2009;Zhao and Sun, 2006) and the use of high temperature (Madaan and Tyagi, 2008). Of late, it is well established that the quaternization on endocyclic nitrogen is easier than exocyclic nitrogen due to higher proton affinity of the endocyclic nitrogen (Pillay et al, 1997;Kas'yan et al, 2005).…”

“…Unlike common antifungal agents, the compound 10 shows good germ tube inhibition activity against C. albicans. The factors controlling antimicrobial activity of the substituted pyridine salts (Madaan and Tyagi, 2008) are the hydrophobicity, adsorbability, surface activity, position of the substituents and electron density of the ammonium nitrogen atom (Vildan et al, 2009). Looking at the structure of these compounds, one can obviously assume that the presence of a polar amino pyridinium head group and the long liphophilic carbon chain could give raise to surfactant like activity.…”

“…Looking at the structure of these compounds, one can obviously assume that the presence of a polar amino pyridinium head group and the long liphophilic carbon chain could give raise to surfactant like activity. This surfactant like character may be helpful in achieving successful penetration into the lipid cell membrane and better biological activity for the compounds (Madaan and Tyagi, 2008).…”

“…A large number of quaternary ammonium and pyridinium salts including some natural products are found to show antibiotic activity, by adsorption on the cell membrane and promoting consequent changes in the cell organization (Madaan and Tyagi, 2008;Parag and Vinod, 2008) of microorganisms such as bacteria, viruses, fungi, protozoa, etc. Bisammonium and bisphosphonium alkanes show antifungal activity by inhibiting the fungal virulence factor, phospholipase B1 (PLB1) (Ng et al, 2006), however, found to be haemolytic even at low concentrations (Vildan et al, 2009;Ng et al, 2007).…”