Theoretical Study of Morphine and Heroin: Conformational Study in Gas Phase and Aqueous Solution and Electron Distribution Analysis

Abstract

The conformational preferences of morphine and heroin were studied in gas phase and with inclusion of solvent effects. At 298.15 K, three conformers are significant for isolated morphine, all of them displaying antiperiplanar arrangement for the C2-C3-O-H unit, and there is only one significantly populated conformer for heroin. Quantum theory of atoms in molecules analysis of the electron density in their most populated conformers in gas phase indicates that the positive charge is shared among the amino hydrogen, those hydrogens of the methylamino group, and all of the hydrogens attached to the bridgehead carbons. (C) 2010 Wiley Periodicals, Inc. Int J Quantum Chem 110: 2472-2482, 2010