COMBINED MOLECULAR MECHANICS, MOLECULAR DYNAMICS AND QUANTUM MECHANICAL STUDY OF (1)-MULTIFIDENE STRUCTURE AND CONFORMATION

Molecular mechanics, molecular dynamics and quantum mechanical tools have been used to explore the conformational space of (þ)(3S,4S)-multifidene bioactive compounds. All the computations have been performed in the absence and presence of the solvent, simulated by the explicit introduction of a number of water molecules or by the polarized continuum model (PCM). Three conformational minima, both in vacuo and in water (simulated by PCM tool), have been confirmed at ab initio level of theory (B3LYP and MP2). All minima lie in a very narrow range of energy, and the interconversion between them is possible with a small amount of energy expense.