Analysis of vibrational spectra of some new E- and Z-4-arylidene-3-isochromanones

Keresztury, Gábor; Holly, S.; István, Krisztina; Sundius, Tom; Lóránd, Tamás

doi:10.1016/j.jbbm.2004.04.012

Cited by 4 publications

(3 citation statements)

References 13 publications

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“…The strongest band of the FT IR spectra belongs to the CO stretching vibrations lying mostly in the region of 1715–1726 cm –1 with the exception of compounds 21 , 29–30 . Similar absorption maxima of the CO stretching were observed at analogous compounds – 11 E – Z (Keresztury et al, 2004). The decreased νCO frequency of the two hydroxyl compounds ( 29–30 ) can be explained with the intermolecular hydrogen bond decreasing the absorption maxima (Silverstein et al, 2015).…”

Section: Resultssupporting

confidence: 77%

Novel Cell Wall Antifungals Reveal a Special Synergistic Activity in pbr1 Mutants Resistant to the Glucan Synthesis Antifungals Papulacandins and Echinocandins

et al. 2019

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A series of 4 - (arylmethylene)-3-isochromanones have been prepared with base-catalyzed Knoevenagel condensation starting from 3-isochromanone and aromatic aldehydes. The outcome of the reaction- the isomeric composition of the products depends on the aromatic aldehyde applied. These reactions afforded mostly the more stable E -diastereoisomer, but some condensations resulted in the Z-diastereoisomer or mixture of the stereoisomers ( 1 – 16 ). The products showed antifungal effect against some pathogenic fungi. We wanted to extend this study and to synthesize a new generation of 4 - (arylmethylene)-3-isochromanones. These condensations led mostly to E -diastereoisomers ( 17 – 30 ). The structure verifications were performed by FT IR, 1 H and 13 C NMR methods. Both the 1 – 16 and the novel 17 – 30 compounds have been screened against the three yeast models, fission yeast Schizosaccharomyces pombe (wild-type, and pbr1-6 and pbr1-8 mutants resistant to specific cell wall synthesis inhibitors), budding yeast Saccharomyces cerevisiae (wild-type and pbr1-1 ) and pathogenic yeast Candida albicans (wild-type, ATCC 26555, 90028 and SC5314). Osmotic protection with sorbitol attenuated the in vivo inhibition in living cells suggesting a cell wall-specific antifungal effect. Moreover, the S. pombe wild-type and mutant strains were tested for their resistant or sensitive in vitro β(1,3)-glucan synthase (GS) activity. We found both in vivo in living cells and in vitro in the enzymatic GS assay a synergistic effect of higher sensitivity of the pbr1 mutants resistant to the specific GS inhibitors papulacandins and echinocandins. These results may provide new insights into new strategies of combined antifungal therapy of GS inhibitors directed against spontaneous mutants resistant to echinocandins.

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Section: Resultssupporting

confidence: 77%

Novel Cell Wall Antifungals Reveal a Special Synergistic Activity in pbr1 Mutants Resistant to the Glucan Synthesis Antifungals Papulacandins and Echinocandins

et al. 2019

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“…Since these calculations are generally done on single, isolated molecules, difficulties may occur with condensed phase spectra of molecular systems having strong intermolecular interactions. Our experience has been very positive with the application of the SQM FF method to condensed phase spectra of weakly interacting molecules, whereas the calculations allowed interpreting fine secondary structural effects as well, e.g., cis−trans isomerism and conformational changes due to hindered internal rotation. − …”

Section: Introductionmentioning

confidence: 99%

“…Our experience has been very positive with the application of the SQM FF method to condensed phase spectra of weakly interacting molecules, whereas the calculations allowed interpreting fine secondary structural effects as well, e.g., cis-trans isomerism and conformational changes due to hindered internal rotation. [5][6][7] Although these methods proved to be quite successful in the case of the most neutral organic molecules, little is known about their applicability to ionic species (charged molecules). Characteristically, the best vibrational analysis published for the acetate anion, CH 3 CO 2 -, has been done by Kakihana et al 8 with the use of an empirical simplified valence force field (SVFF) consisting of 27 independent parameters (harmonic force constants) refined to reproduce a set of 82 observed frequencies of 6 isotopomers of sodium acetate with a root-mean-squares deviation of 3.3 cm -1 .…”

Section: Introductionmentioning

confidence: 99%

Applicability of the SQM Force Field Method to the Vibrational Spectra of Sodium Acetate

2005

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The applicability of the scaled quantum mechanical force field (SQM FF) method to the prediction of the vibrational spectra of a charged molecule has been studied by the example of the acetate ion (CH3CO2-) in sodium acetate for which an efficient empirical valence force field (SVFF) based on observed IR spectra of six isotopomers of sodium acetate is available in the literature. Standard SQM FF calculations done on a free acetate ion at the B3LYP/6-31G level failed to give an acceptable estimation of even the most characteristic features of the observed spectra, which can be exemplified by the gross overestimation of the frequency separation of the nu(a)CO2- and nu(s)CO2- vibrations. In search for a better description, SQM calculations were done for three simple structural models of sodium acetate, testing different QM methods. The results indicate that in addition to taking into account the dielectric field effect of the surrounding medium, incorporation of a Na+ counterion is necessary to achieve a realistic simulation of the IR and Raman spectra. Satisfactory results were obtained with a bidentate Na-acetate complex by the SQM method coupled with a continuum model at the B3LYP/6-31+G level, whereas the use of the Onsager-type spherical cavity model and the polarizable continuum model (PCM) were found preferable over SCI-PCM.

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Analysis of the vibrational spectra of new OH-containing E-4-arylmethylene-3-isochromanones and 3-arylcoumarins

Keresztury

Holly²,

Komlósi

et al. 2006

Journal of Biochemical and Biophysical Methods

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Analysis of vibrational spectra of some new E- and Z-4-arylidene-3-isochromanones

Cited by 4 publications

References 13 publications

Novel Cell Wall Antifungals Reveal a Special Synergistic Activity in pbr1 Mutants Resistant to the Glucan Synthesis Antifungals Papulacandins and Echinocandins

Novel Cell Wall Antifungals Reveal a Special Synergistic Activity in pbr1 Mutants Resistant to the Glucan Synthesis Antifungals Papulacandins and Echinocandins

Applicability of the SQM Force Field Method to the Vibrational Spectra of Sodium Acetate

Analysis of the vibrational spectra of new OH-containing E-4-arylmethylene-3-isochromanones and 3-arylcoumarins

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