COMPARISON OF THE COMPOSITION AND STRUCTURE OF CERTAIN SUBSTANCES ISOLATED FROM THE PLANT PHLOMOIDES NUDA USING THE QUANTUM-CHEMICAL CALCULATION METHOD

Abstract

In this scientific article the structures of the biologically active compounds isolated from the plant Phlomoides nuda growing in the Yangiqo'rg'on district of Namangan region, namely the molecules of ecdysterone, α-ecdysone, 8-O-acetylharpagide, lamiide and pinitol, were optimised by means of the quantum-chemical calculation program Gaussian 98 on the basis of the DFT/B3LYP/3-21G method. Their infrared (IR) vibrational spectra were compared and analysed both experimentally and theoretically. The results showed that the experimental spectra of the molecules correspond to a high degree with the theoretical spectral peaks. In particular, the accuracy of the vibrational modes relating to deformation and valence vibrations confirms the number of rings in the molecules, the presence of C-O, C-H, C-C bonds and the exactness of the structure. The results of this analysis provided the grounds for confirming the chemical structure of the isolated substances on the basis of the formulas presented above.