Probing of the combined effect of bisquaternary ammonium antimicrobial agents and acetylsalicylic acid on model phospholipid membranes: differential scanning calorimetry and mass spectrometry studies

2014 ◽  
Vol 10 (12) ◽  
pp. 3155-3162 ◽  
Author(s):  
N. A. Kasian ◽  
V. A. Pashynska ◽  
O. V. Vashchenko ◽  
A. O. Krasnikova ◽  
A. Gömöry ◽  
...  

Qualitatively different membranotropic effects of the individual drugs and complexes formed in their combined use were demonstrated by differential scanning calorimetry.

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4653
Author(s):  
Jakub Herman ◽  
Piotr Harmata ◽  
Michał Czerwiński ◽  
Olga Strzeżysz ◽  
Marta Pytlarczyk ◽  
...  

The synthesis and characterization of new deuterated liquid crystal (LC) compounds based on phenyl tolane core is described in this paper. The work presents an alternative molecular approach to the conventional LC design. Correlations between molecular structure and mesomorphic and optical properties for compounds which are alkyl-hydrogen terminated and alkyl-deuterium, have been drawn. The compounds are characterized by mass spectrometry (electron ionization) analysis and infrared spectroscopy. They show enantiotropic nematic behavior in a broad temperature range, confirmed by a polarizing thermomicroscopy and differential scanning calorimetry. Detailed synthetic procedures are attached. Synthesized compounds show a significantly reduced absorption in the near-infrared (NIR) and medium-wavelength infrared (MWIR) radiation range, and stand as promising components of medium to highly birefringent liquid crystalline mixtures.


2002 ◽  
Vol 80 (11) ◽  
pp. 1469-1480 ◽  
Author(s):  
Karena Thieme ◽  
Sara C Bourke ◽  
Juan Zheng ◽  
Mark J MacLachlan ◽  
Fojan Zamanian ◽  
...  

The novel zirconatetraferrocenylcyclotrisiloxane Cp2Zr(OSiFc2)2O (6), dizirconatetraferrocenylcyclotetrasiloxane [Cp2Zr(OSiFc2)O]2 (7), boratetraferrocenylcyclotrisiloxane (C6H5)B(OSiFc2)2O (8), and diboratetraferrocenylcyclotetrasiloxane [(C6H5)B(OSiFc2)O]2 (9) with ferrocenyl (Fc = Fe(η-C5H4)(η-C5H5)) substituents at silicon have been prepared from the reactions of Cp2Zr(NMe2)2 and PhBCl2 with diferrocenylsilanediol Fc2Si(OH)2 (3) and tetraferrocenyldisiloxanediol [Fc2SiOH]2O (5). The compounds were characterized by mass spectrometry, elemental analysis, UV–vis, IR, Raman, and multinuclear NMR spectroscopy, as well as single crystal X-ray diffraction. Thermogravimetric analysis and differential scanning calorimetry investigation of 6–9 showed that the cycles decompose before they can undergo any thermal ring-opening polymerization. In addition, no polymerization was detected in the presence of either KOSiMe3 or HOTf. The bulky ferrocenyl substituents on the Si atoms are likely to be at least partially responsible for the inability of these heterocycles to undergo ring-opening polymerization. Key words: heterocyclosiloxanes, ferrocenyl.


2017 ◽  
Vol 50 (5) ◽  
pp. 391-402 ◽  
Author(s):  
Federico Karp ◽  
Julio A Luna ◽  
Luciano N Mengatto

In this work, a new recyclable ethylene-vinyl acetate (EVA)-based strip impregnated with amitraz (AMZ) was prepared, characterized, and evaluated for the treatment of Apis mellifera against Varroa destructor. Bees are important for natural pollination, honey, and related goods production. Varroa destructor is currently considered one of the major pests and important efforts around the world are focused on methods for varroasis treatment. The procedure of strips preparation presented in this work consisted of two steps: impregnation and molding of impregnated pellets. Differential scanning calorimetry and gas chromatography–mass spectrometry analyses confirmed that AMZ molecule resisted the impregnation and molding conditions. The strips were sufficiently strong to resist destruction by the bees. The final infestation was lower in the hives treated with AMZ/EVA strips than in those treated with commercial strips. In order to check the possibility of recycling, strips were cut into little pieces and were subjected to total AMZ extraction. Finally, the fragments were exposed to re-impregnation and molding. The strips prepared after the recycling process presented the same shape and AMZ load than fresh strips.


2008 ◽  
Vol 33 (4) ◽  
pp. 61-68 ◽  
Author(s):  
C. T. de Carvalho ◽  
A. B. Siqueira ◽  
E. Y. Ionashiro ◽  
M. Pivatto ◽  
M. Ionashiro

The 2-methoxycinnamylidenepyruvic acid (2-MeO-HCP) was synthesized and characterized for nuclear magnetic resonance (¹H and 13C NMR), mass spectrometry (MS), Infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The application of DSC for purity determination is well documented in literature and is used in the analysis of pure organic compounds. The molecular geometry and vibrational frequencies of 2-MeO-HCP have been calculated.


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