Estudo espectroscópico experimental e teórico da acetilbergenina

Abstract

The study of plants of the Amazon has attracted attention due to biological activities proven by empirical use of their communities. Pharmacological research of plants found in nature has a breakthrough with the use of computer modeling. This type of study decreases the time to design a product and enables better analysis of the molecule that already has analyzed its biological activity. The acetilbergenin was synthesized from bergenin extracted from the bark of Endopleura uchi whose extract is used by Amazonian community to treat infections and several biological activities have been proven among them: anti-ulcerogenic, hepatoprotection, anti-HIV, inhibiting obesity antioxidant, antimicrobial and so on. But the bergenin has little lipoficidade and is poorly absorbed by the human gastrointestinal tract. The study demonstrated acetilbergenin greater biological effect and more effective with respect to bergenin. This study expands the information of molecule 3, 4, 8, 10, 11-penta-O acetilbergenin through theoretical calculations and UV / VIS spectra. The UV / Visible spectra of acetilbergenin (3, 4, 8, 10, 11-penta-O acetilbergenine) were convoluted in three different environments: vacuum, ethanol, and water using excitation energies and transition intensities calculated with quantum chemical methods. An experimental UV / Visible spectrum of the molecule in ethanol was comapred with corresponding theoreticaly simulated spectrum. Hartree-Fock method was used to optimized molecular geometry. The Density Functional Theory Time Dependent (DFTTD) with the basis set 6-31G* was used to calculate excitation energies and accompanying intensities of the molecule. Solvent effects of the UV/ Visible spectra and other molecular properties such as atomic charge were studied. The results of theoretical calculations were consistent with experimental data allows the analysis of the UV spectrum. A comparison of the three theoretical spectra of three different solvents shows that the three spectra have three bands A, B and C. The relative intensity of the band C in ethanol and water is very low in comparison with the same in the simulation in vacuo. The HOMO and LUMO are localized on the aromatic ring which shows how the region photoactive molecule acetilbergenin.