2016-99-1Relevant articles and documents
Highly efficient stabilisation of meta-ethynylpyridine polymers with amide side chains in water by coordination of rare-earth metals
Makida, Hiroki,Abe, Hajime,Inouye, Masahiko
, p. 1700 - 1707 (2015)
An amphiphilic meta-ethynylpyridine polymer with chiral amide side chains was developed. The polymer was prepared by sequential Sonogashira reactions, and the product was soluble in polar and apolar solvents. The additive effects of metal salts on the polymer were examined in water and aqueous EtOH on the basis of UV-vis and CD spectra. The enhancement of the positive Cotton effect and hypochromism around 360 nm occurred by the addition of various metal salts, indicating the coordination of the cations to the amide side chains of the polymer to stabilise the helical structure. Among them, rare-earth metal salts, especially Sc(OTf)3 showed more efficient additive effects probably because of its strong coordination ability even in water. Positive cooperativity was observed for the coordination of Sc(OTf)3 to the polymer in aqueous EtOH.
The influence of alkyl chains on the performance of DSCs employing iron(ii) N-heterocyclic carbene sensitizers
Becker, Mariia,Constable, Edwin C.,Housecroft, Catherine E.,Wyss, Vanessa
supporting information, p. 16961 - 16969 (2021/12/10)
The photovoltaic performances of DSCs employing two new iron(ii) N-heterocyclic carbene (NHC) sensitizers are presented. The presence of n-butyl side chains had a significant impact on DSC performace. The improvement in DSC performance up to 0.93-0.95% was observed for a new heteroleptic sensitizer bearing one carboxylic acid anchoring group. The photovoltaic performance was remarkably affected by sensitization time and by a presence/absence of coadsorbent on the semiconductor surface. The highest photoconversion efficiencies (PCE) were achieved for DSCs sensitized over 17.5 hours without addition of coadsorbents. However, for a shorter dipping time of 4 hours, the presence of chenodeoxycholic acid improved the PCE from 0.46% (no coadsorbents) to 0.74%, respectively. The performance of DSCs based on a new homoleptic complex bearing two n-butyl side chains and a carboxylic acid anchor on each NHC-ligand was improved from 0.05 to 0.29% via changes in dye-bath concentration and sensitization time. The changes in the dye load on the semiconductor surface depending on the sensitization conditions were confirmed using solid-state UV-Vis spectroscopy and thermogravimetric analysis. Electrochemical impedance spectroscopy was used to gain information about the processes occurring at the different interfaces in the DSCs. The impedance response was strongly affected by the immersion time of the photoanodes in the dye-bath solutions. In the case of the homoleptic iron(ii) complex, a Gerischer impedance was observed after 17.5 hours immersion. Shorter dipping times resulted in a decrease in the resistance in the system. For the heteroleptic complex, values of the chemical capacitance and electron lifetime were affected by the immersion time. However, the diffusion length was independent of sensitization conditions. This journal is
Discovery of dap-3 polymyxin analogues for the treatment of multidrug-resistant gram-negative nosocomial infections
Magee, Thomas V.,Brown, Matthew F.,Starr, Jeremy T.,Ackley, David C.,Abramite, Joseph A.,Aubrecht, Jiri,Butler, Andrew,Crandon, Jared L.,Dib-Hajj, Fadia,Flanagan, Mark E.,Granskog, Karl,Hardink, Joel R.,Huband, Michael D.,Irvine, Rebecca,Kuhn, Michael,Leach, Karen L.,Li, Bryan,Lin, Jian,Luke, David R.,Macvane, Shawn H.,Miller, Alita A.,McCurdy, Sandra,McKim, James M.,Nicolau, David P.,Nguyen, Thuy-Trinh,Noe, Mark C.,O'Donnell, John P.,Seibel, Scott B.,Shen, Yue,Stepan, Antonia F.,Tomaras, Andrew P.,Wilga, Paul C.,Zhang, Li,Xu, Jinfeng,Chen, Jinshan Michael
, p. 5079 - 5093 (2013/07/26)
We report novel polymyxin analogues with improved antibacterial in vitro potency against polymyxin resistant recent clinical isolates of Acinetobacter baumannii and Pseudomonas aeruginosa. In addition, a human renal cell in vitro assay (hRPTEC) was used to inform structure-toxicity relationships and further differentiate analogues. Replacement of the Dab-3 residue with a Dap-3 in combination with a relatively polar 6-oxo-1-phenyl-1,6-dihydropyridine-3- carbonyl side chain as a fatty acyl replacement yielded analogue 5x, which demonstrated an improved in vitro antimicrobial and renal cytotoxicity profiles relative to polymyxin B (PMB). However, in vivo PK/PD comparison of 5x and PMB in a murine neutropenic thigh model against P. aeruginosa strains with matched MICs showed that 5x was inferior to PMB in vivo, suggesting a lack of improved therapeutic index in spite of apparent in vitro advantages.
