Quantum mechanical study of the inclusion process of adamantanol isomers by l-tryptophan-modified-β-cyclodextrin

Abstract

The complexation processes of 1 and 2-adamantanol with l-tryptophan-β-cyclodextrin have been studied using ab initio Hartree–Fock and density functional theory levels. For the host: guest inclusion processes, the up mode with the OH group of the alcohol oriented towards the secondary rim, is found to be in qualitative agreement with the experimental finding. A molecular recognition mechanism is proposed based on the host: guest relative dipole orientation. For the complex with the 2-Ada isomer the host and guest the dipoles are parallels favoring the interaction energy and. This mechanism can explain the small energy difference for the processes involving the adamantanol isomers and modified cyclodextrins.

Keywords:

• Adamantanol isomers
• Inclusion process
• β-Cyclodextrin
• Molecular recognition

Acknowledgements

W. B. De Almeida, C. S. Nascimento, Jr. and H. F. Dos Santos would like to thank the CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico) and FAPEMIG (Fundação de Amparo a Pesquisa do Estado de Minas Gerais) for financial support and research grants.