Synthesis and antimicrobial activity testing of quaternary ammonium silane compounds.

With increasing health awareness of the pathogenic effects of disease-causing microorganisms, interest in and use (of medical textiles, disinfectants in medical devices, etc.) of antimicrobial substances have increased in various applications, such as medical textiles and disinfectants (alcohol-based and nonalcoholic), in medical devices There are several concerns with alcohol-based disinfectants, such as surface deformation of medical devices due to high alcohol content and damage to skin tissue caused by lipid and protein denaturation of cell membranes. Quaternary ammonium compounds (quats) were preferred because they have the potential to prepare water-based disinfectants. In this study, novel (3-chloropropyl)triethoxysilane (CPTMO) and (3-chloropropyl)triethoxysilane (CPTEO) based quaternary ammonium silane compounds (silane-quats) were developed using quats with carbon chain lengths of C12, C14, C16 and C18. Titration (ASTM D2074) was used to calculate the yield of the synthesis and the structures of the products were characterised by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (13C NMR, 1H NMR) and gas chromatography-mass spectrometry (GC-MS).The in vitro antimicrobial activity of the synthesized samples was evaluated against Gram-positive (Staphylococcus aureus (S. aureus), Enterococcus hirae (E. hirae)) and Gram-negative (Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa)) bacteria and fungi (Candida albicans (C. albicans), Aspergillus brasiliensis (A. brasiliensis)) using the minimum inhibitory concentration (MIC) test. According to MIC tests, the silane-quats with the highest antimicrobial effects were dimethylhexadecyl[3-(trimethoxysilyl)propyl]ammonium chloride (SQ3), which had an MIC of < 16 µg/ml (ppm) against E. coli, S. aureus, E. hirae, C. albicans, and A. brasiliensis and 32 µg/ml against P. aeruginosa. The MIC test results also showed antimicrobial activity at least 2 times greater than that of the commercially available disinfectant benzalkonium chloride (BAC). Findings suggest that SQ3 (C16) holds promise as an effective medical disinfectant, presenting a novel approach to combating microbial infections in healthcare settings.

Alcohol-free synthesis, biological assessment, in vivo toxicological evaluation, and in silico analysis of novel silane quaternary ammonium compounds differing in structure and chain length as promising disinfectants.

Quaternary ammonium compounds (QACs) are commonly used as disinfectants for industrial, medical, and residential applications. However, adverse health outcomes have been reported. Therefore, biocompatible disinfectants must be developed to reduce these adverse effects. In this context, QACs with various alkyl chain lengths (C12-C18) were synthesized by reacting QACs with the counterion silane. The antimicrobial activities of the novel compounds against four strains of microorganisms were assessed. Several in vivo assays were conducted on Drosophila melanogaster to determine the toxicological outcomes of Si-QACs, followed by computational analyses (molecular docking, simulation, and prediction of skin sensitization). The in vivo results were combined using a cheminformatics approach to understand the descriptors responsible for the safety of Si-QAC. Si-QAC-2 was active against all tested bacteria, with minimal inhibitory concentrations ranging from 13.65 to 436.74 ppm. Drosophila exposed to Si-QAC-2 have moderate-to-low toxicological outcomes. The molecular weight, hydrophobicity/lipophilicity, and electron diffraction properties were identified as crucial descriptors for ensuring the safety of the Si-QACs. Furthermore, Si-QAC-2 exhibited good stability and notable antiviral potential with no signs of skin sensitization. Overall, Si-QAC-2 (C14) has the potential to be a novel disinfectant.