1.Synthesis, characterization and antibacterial properties of dihydroxy quaternary ammonium salts with long chain alkyl bromides.
Liu WS1, Wang CH, Sun JF, Hou GG, Wang YP, Qu RJ. Chem Biol Drug Des. 2015 Jan;85(1):91-7. doi: 10.1111/cbdd.12427. Epub 2014 Oct 16.
Five N-methyl-N-R-N,N-bis(2-hydroxyethyl) ammonium bromides (R = -benzyl (chloride, BNQAS), -dodecyl (C12QAS), -tetradecyl (C14QAS), -hexadecyl (C16QAS), -octadecyl (C18QAS)) were prepared based on N-methyldiethanolamine (MDEA) and halohydrocarbon. Five QAS were characterized by FTIR, NMR, and MS. BNQAS, C12QAS, C14QAS, and C16QAS were confirmed by X-ray single-crystal diffraction. Their antibacterial properties indicated good antibacterial abilities against E. coli, S. aureus, B. subtilis, especially C12QAS with the best antibacterial ability (100% to E. coli, 95.65% to S. aureus, and 91.41% to B. subtilis). In addition, C12QAS also displayed the best antifungal activities than BNQAS and C18QAS against Cytospora mandshurica, Botryosphaeria ribis, Physalospora piricola, and Glomerella cingulata with the ratio of full marks. The strategy provides a facile way to design and develop new types of antibacterial drugs for application in preventing the fruit rot, especially apple.
2.Non-toxic O-quaternized chitosan materials with better water solubility and antimicrobial function.
Wang CH1, Liu WS2, Sun JF2, Hou GG3, Chen Q2, Cong W2, Zhao F2. Int J Biol Macromol. 2016 Mar;84:418-27. doi: 10.1016/j.ijbiomac.2015.12.047. Epub 2015 Dec 19.
Five water-soluble O-quaternary ammonium salt-chitosans (QAS-CS) bearing N-methyl-N-R-N, N-bis(2-hydroxyethyl) ammonium bromides (R=-benzyl (chloride, BNQAS-CS), -dodecyl (C12QAS-CS), -tetradecyl (C14QAS-CS), -hexadecyl (C16QAS-CS), -octadecyl (C18QAS-CS)) were prepared, respectively. They were characterized by FTIR, (1)H NMR and elemental analysis. Through chemical modification of O-quaternized chitosans, the water solubility of all QAS-CS was improved distinctly. Their antibacterial properties indicate good antibacterial abilities against gram-positive bacteria and bad against gram-negative bacteria, therein, C12QAS-CS and C14QAS-CS are the best. More importantly, their cytotoxicity was markedly lower than the corresponding QAS monomers by evaluating for AT2 cell line using CCK-8 assay. The strategy provides a facile way to design and develop new types of antibacterial chitosan materials with better water solubility, better antimicrobial ability and lower cytotoxicity for primary additive agent of self-owned intellectual band-aids.
3.Design of triple-shape memory polyurethane with photo-cross-linking of cinnamon groups.
Wang L1, Yang X, Chen H, Gong T, Li W, Yang G, Zhou S. ACS Appl Mater Interfaces. 2013 Nov 13;5(21):10520-8. doi: 10.1021/am402091m. Epub 2013 Oct 17.
A triple-shape memory polyurethane (TSMPU) with poly(ε-caprolactone) -diols (PCL-diols) as the soft segments and diphenyl methane diisocyanate (MDI), N,N-bis (2-hydroxyethyl) cinnamamide (BHECA) as the hard segments was synthesized via simple photo-crosslinking of cinnamon groups irradiated under λ > 280 nm ultraviolet (UV) light. Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance ((1)H-NMR) and ultraviolet-visible absorption spectrum (UV-vis) confirmed the chemical structure of the material. Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) results demonstrated that the photo-crosslinked polymer possessed two transition temperatures, one is due to the melting point of the soft segment PCL-diols, and the other is due to the glass transition temperature. All these contributed to the cross-linked structure of the hard segments and resulted in an excellent triple-shape memory effect.
4.Development of an automated ballast water treatment verification system utilizing fluorescein diacetate hydrolysis as a measure of treatment efficacy.
Akram AC1, Noman S1, Moniri-Javid R2, Gizicki JP1, Reed EA1, Singh SB1, Basu AS2, Banno F1, Fujimoto M1, Ram JL3. Water Res. 2015 Mar 1;70:404-13. doi: 10.1016/j.watres.2014.12.009. Epub 2014 Dec 16.
Methods for verifying ballast water treatments in foreign vessels are needed to protect the Great Lakes from the discharge of live non-native organisms or pathogens. A prototype automated viability test system using fluorescein diacetate (FDA), a membrane permeable fluorogen, to differentiate live from dead bacteria and algae is described. The automated fluorescence intensity detection device (AFIDD) captures cultured algae or organisms in Detroit River water (simulated ballast water) on 0.2 μm filters, backwashes them from the filter into a cuvette with buffer and FDA for subsequent fluorescence intensity measurements, and washes the filters with sterile water for serial automated reuse. Preliminary manual versions of these procedures were also tested. Tests of various buffers determined N,N-Bis(2-hydroxyethyl)-2-aminoethanesulfonic acid, N,N-Bis(2-hydroxyethyl)taurine (BES) and 3-(N-morpholino)propanesulfonic acid (MOPS) at pH 7.0 to be the best buffers, causing the least spontaneous FDA breakdown without inhibiting enzymatic activity.