Theoretical study of structure spectral properties of Tacrine as Alzheimer drug

Tacrine (9-amino-1,2,3,4-tetrahydroacridine) as a reversible inhibitor of acetylcholinesterase (AChE), was the first drug for the symptomatic treatment of Alzheimer’s disease (AD). NMR structure determination still presents some considerable challenges: the method is limited to systems of relatively small molecular mass, data collection times are long, data analysis remains a lengthy procedure, and it is difficult to evaluate the quality of the final structures but calculation of a structure itself has become extremely rapid, and new labeling methods have significantly improved both spectral quality and automated analysis, whilst rigorous standards and data formats afford compatibility of different software packages. In this theoretical study, we used HF and DFT (BLYP, B3LYP) method for chemical shift nucleus magnetic resonance DFT-NMR. The basis set used were 6–31G, 6–31G** and 6-31G++. The results show a reasonably good correlation between calculated and experimental chemical shifts. Agreement of experiment and calculated data suggesting that studies of drug structures can be pursued with some degree of confidence with this level of theory.