Cocaine Hydrochloride Structure in Solution Revealed by Three Chiroptical Methods

0478538 - ÚOCHB 2018 RIV DE eng J - Journal Article
Fagan, P. - Kocourková, L. - Tatarkovič, M. - Králík, F. - Kuchař, M. - Setnička, V. - Bouř, Petr
Cocaine Hydrochloride Structure in Solution Revealed by Three Chiroptical Methods.
ChemPhysChem. Roč. 18, č. 16 (2017), s. 2258-2265. ISSN 1439-4235. E-ISSN 1439-7641
R&D Projects: GA ČR(CZ) GA16-05935S; GA MŠMT(CZ) LTC17012
Institutional support: RVO:61388963
Keywords : analytical methods * circular dichroism * density functional calculations * Raman spectroscopy * structure elucidation
OECD category: Physical chemistry
Impact factor: 2.947, year: 2017

Structure and flexibility of natural compounds determine their biological activity. In the present study, electronic circular dichroism (ECD), vibrational circular dichroism (VCD), and Raman optical activity (ROA) spectra of cocaine hydrochloride in aqueous solutions were measured and related to the structure with the aid of density functional theory (DFT) computations. Additional measurements in deuterated environment made assignment of vibrational bands easier. The results suggest that the prevalent cocaine conformation in solution differs from that adopted in hydrochloride crystal. The spectroscopic results and computational analysis are consistent with X-ray structures of known cocaine-receptor complexes, in which the compound adopts a variety of conformations. All three kinds of chiroptical spectra exhibited significantly greater conformational sensitivity than unpolarized absorption or Raman scattering. The ROA technique provided the largest number of well-resolved bands, bearing rich structural information.
Permanent Link: http://hdl.handle.net/11104/0274636