The interaction of three tissue-clearing agents (1,2-1,3-propanediol, 1,2-ethanediol) with the collagen mimetic peptide ((GPH)3)9 was studied by applying the method of classical molecular dynamics. The complete conformational analysis of the clearing agents under study was performed using the DFT/B3LYP/6-311+G method (d, p), the most energetically favorable spatial configurations were determined, the values of the Mulliken atomic charges were calculated which were used for the simulation. The research showed that there is a good correlation between the time of the hydrogen binding of a clearing agent with a collagen peptide and the potential of optical clearing. The paper also discusses that the interaction of the tissue-clearing agents with a collagen peptide in a water solution results in the 6% average enlargement of the distance between the alpha peptide chains. It has been suggested that such changes in a collagen structure can affect the refraction index and as a consequence the optical clearing of a biotissue. The dependences of the average distance changing between the alpha chains of a collagen peptide and the concentration of clearing agents in water solution were determined.
Experimental FT-IR spectra of lemon peel are registered in the 650 - 3800 cm-1 range. The influence of peel artificial and natural dehydration on its vibrational spectrum is studied. The colored outer surface of lemon peel is proved not to have a significant impact on FT-IR spectrum. It is determined that only dehydration processes affect the FT-IR vibrational spectrum of the peel when a lemon is stored for 28 days under natural laboratory conditions. Polymer molecule models for dietary fibers, such as cellulose, hemicellulose, pectin, lignin, as well as hesperidin – flavonoid glycoside, and free moisture cluster are developed within the framework of DFT/B3LYP/6-31G(d) theoretical method. By implementing supramolecular approach, modeling of the vibrational FT-IR spectrum of lemon peel is carried out and its detailed theoretical interpretation is presented.
The calculations of the geometrical parameters, frequencies of normal fluctuations and intensity in IR-spectrums of some metalloforbids (Mg-, Zn-, Cu-, Fe-e and Ni-forbid) have been performed by the matrix isolation technique B3LYP/6-311+G (d, p). In this article the absorption bands in IRspectra sensitive to the nature of the metal’s central ion were defined too. The correlations between the force of the interaction of the central ion of the metal with porphyrin macrocycle and the series of changes in the structural parameters have been established.
This article describes the algorithm and the creation of programs for the input process automate the scaling factors of quantum mechanical force fields calculated in the natural coordinates using abinitio methods and the density functional theory (DFT-methods).