[Show abstract][Hide abstract] ABSTRACT: Total of 3 water-soluble quaternary-based chitin/chitosan derivatives, which have an identical molecular weight and anion, were synthesized and characterized. Their antibacterial activities against Salmonella cholerae-suis and Bacillus subtilis were evaluated in vitro. The polysaccharides exhibited the antibacterial efficiency. Their minimum inhibitory concentration (MIC) values vary from 0.02 to 20.48 mg/mL, and their minimum bactericidal concentration (MBC) values vary from 0.08 to 40.96 mg/mL against S. cholerae-suis and B. subtilis, respectively. Futhermore, the extent of Bacillus subtilis cells damage was examined via transmission electron microscopy (TEM) to show how N,N,N-trimethylchitosan (TMC) gradually destroyed and killed B. subtilis cells when they were treated with TMC. One of those quaternary polymers, O-([2-hydroxy-3-trimethylammonium])propyl chitin (OHT-chitin), which can be directly and easily synthesized from chitin in bulk quantities, also was demonstrated its antibacterial activity. These water soluble quaternary-based chitin/chitosan derivatives that have antibacterial effect should be potentially used as antimicrobial agents in many fields.
Practical Application: The main practical application behind the investigation and evaluation antibacterial activity of 3 water-soluble quaternary-based chitin/chitosan derivatives could be potentially used as antimicrobial agents in many fields. These polysaccharides represent a renewable source of natural biodegradable polymers and meet with the emergence of more and more food safe problems.
[Show abstract][Hide abstract] ABSTRACT: Quaternary amino groups were introduced into chitin and chitosan to obtain O-(2-hydroxy-3-trimethylammonium)propyl chitin (OHT-chitin) and N-(2-hydroxy-3-trimethylammonium)propyl chitosan (NHT-chitosan). They were characterized by FTIR spectra, and GPC. The molecular weight Mw of OHT-chitin and NHT-chitosan were 8986 and 9723 with polydispersity of 1.01 and 1.02, respectively. Their antioxidant activities in vitro were further studied. It was found that β-carotene-linoleic acid values of OHT-chitin and NHT-chitosan at 0.8 mg/mL were up to 91% and 96%, while that of chitosan was 40%. Based on photobleaching of α,α-diphenyl-β-picrylhydrazyl (DPPH) at 326 nm, the DPPH inhibitory activity of OHT-chitin and NHT-chitosan was 30.9% and 31.9% at 5 mg/mL, whereas chitosan only gave 4.8%. It was also exhibited that OHT-chitin and NHT-chitosan had better antioxidant activity than chitosan according to the reducing power as well as H2O2 scavenging activity.
[Show abstract][Hide abstract] ABSTRACT: The title compound, [PdBr(C(3)H(5))(C(9)H(8)N(2))], was synthesized by the reaction of the allyl-palladium(II) bromide dimer and 1-phenyl-1H-imidazole. The Pd atom is coordinated by one allyl group [in η(3) mode, the central CH group of the allyl group is disordered over two sets of sites in a 0.668 (5):0.332 (5) ratio], one bromide anion and a 1-phenyl-1H-imidazole ligand. Intra-molecular face-to-face π-π stacking inter-actions occur between adjacent phenyl or imidazole groups, with centroid-centroid distances in the range 3.877 (1)-3.6596 (6) Å, forming a supra-molecular chain along .