Structure, isomerization and dimerization processes of narigenin flavonoids

Author(s):  
Ana González Moreno ◽  
Pilar Prieto ◽  
M. Carmen Ruiz Delgado ◽  
Eva Dominguez ◽  
Antonio Heredia ◽  
...  

In this study, theoretical and experimental results on molecular structure and reactivity of the plant flavonoids naringenin chalcone and naringenin are reported. UV-Vis and Raman spectra were recorded and their...

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
I Mamarelis ◽  
V Mamareli ◽  
M Kyriakidou ◽  
O Tanis ◽  
C Mamareli ◽  
...  

Abstract Background The atherosclerotic ascending aorta could represent a potential source of emboli or could be an indicator of atherosclerosis in general with high mortality. The mechanism of aneurysm formation and atherosclerosis of the ascending aorta at the molecular level has not yet been clarified. To approach the mechanism of ascending aortic lesions and mineralization at a molecular level, we used the non-destructive FT-IR, Raman spectroscopy, SEM and Hypermicroscope. Methods Six ascending aorta biopsies were obtained from patients who underwent aortic valve replacement (AVR) cardiac surgery. CytoViva (einst inc) hyperspectral microscope was used to obtain the images of ascending aorta. The samples were dissolved in hexane on a microscope glass plate. The FT-IR and Raman spectra were recorded with Nicolet 6700 thermoshintific and micro-Raman Reinshaw (785nm, 145 mwatt), respectively. The architecture of ascending aorta biopsies was obtained by using scanning electron microscope (SEM of Fei Co) without any coating. Results FT-IR and Raman spectra showed changes arising from the increasing of lipophilic environment and aggregate formation (Fig. 1). The band at 1744 cm–1 is attributed to aldehyde CHO mode due to oxidation of lipids. The shifts of the bands of the amide I and amide II bands to lower are associated with protein damage, in agreement with SEM data. The bands at about 1170–1000 cm–1 resulted from the C-O-C of advanced glycation products as result of connecting tissues fragmentations and polymerization. The spectroscopic data were analogous with the lesions observed with SEM and hypermicroscopic images. Conclusions The present innovate molecular structure analysis showed that upon ascending aorta aneurysm development an excess of lipophilic aggregate formation and protein lesions, changing the elasticity of the aorta's wall. The released Ca2+ interacted mostly with carbonate-terminal of cellular protein chains accelerated the ascending aorta calcifications. Figure 1. FT-IR and Raman spectra Funding Acknowledgement Type of funding source: None


1986 ◽  
Vol 64 (1) ◽  
pp. 142-147 ◽  
Author(s):  
Suzanne Deguire ◽  
François Brisse ◽  
Jacques Ouellet ◽  
Rodrigue Savoie

A stoichiometric complex of formula (COOH)2•2H2O•18-crown-6 has been obtained from oxalic acid and the macrocyclic polyether 18-crown-6. The crystals of the complex have a monoclinic unit cell and belong to the P21/c space group. The components in the adduct are linked through hydrogen bonds in a polymer-like fashion: -crown–H2O–HOOCCOOH–OH2–crown–, where the oxalic acid molecules are present in two distinct disordered orientations. The infrared and Raman spectra of the complex are also reported and interpreted.


1966 ◽  
Vol 44 (7) ◽  
pp. 2686-2692 ◽  
Author(s):  
James E. Griffiths ◽  
Alexander L. Beach

2005 ◽  
Vol 36 (10) ◽  
pp. 932-937 ◽  
Author(s):  
F. H. Tukhvatullin ◽  
A. Jumabaev ◽  
G. Muradov ◽  
H. A. Hushvaktov ◽  
A. A. Absanov

1962 ◽  
Vol 40 (4) ◽  
pp. 658-674 ◽  
Author(s):  
R. J. Gillespie ◽  
E. A. Robinson

The Raman spectra of oleums, i.e. mixtures of sulphur trioxide and sulphuric acid, have been re-examined. Similar measurements on the sulphur trioxide – deuterosulphuric acid (D2SO4) system are also reported. The experimental results and conclusions of previous similar work on oleums are discussed. By comparison of the spectra of oleums with those of the polysulphuryl halides it is shown that the polysulphuric acids H2S2O7 and H2S3O10 are present in this system. The increase in the frequency of the SO2 stretching vibrations with increasing concentration of sulphur trioxide gives evidence for the existence of higher polysulphuric acids such as H2S4O13 at high concentrations of sulphur trioxide. In relatively concentrated oleum, sulphur trioxide monomer and trimer are also present. It is shown that the self-dissociation of liquid H2S2O7 gives mainly molecular H2S2O10 and H2SO4 and not ionic species. The conclusions reached from the interpretation of the Raman spectra of the D2SO4–SO3 system are similar to those arrived at for sulphuric acid oleums. The spectra of solutions of NaHSO4 in oleums were also examined, and are discussed.


1936 ◽  
Vol 9 (1) ◽  
pp. 70-73
Author(s):  
Yoshio Tanaka ◽  
Shû Kambara ◽  
Jirô Noto

Abstract To study the effect of solvents on the elastic properties of vulcanized rubber, the following three points were investigated. 1. The swelling maximum obtained by various mixed solvents. 2. The stress-strain curves of rubber swollen to different degrees. 3. Time-swelling and time-deswelling curves. The spiral theory of molecular structure of rubber proposed by Fikentscher and Mark is utilized to explain the experimental results.


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