[1] Univ Chile, Dept Quim Organ & Fisicoquim, Fac Ciencias Quim & Farmaceut, Santiago 1, Chile
[2] Pontificia Univ Catolica Chile, Fac Quim, Dept Farm, Santiago 22, Chile
[3] Univ Chile, Dept Bioquim & Biol Mol, Fac Ciencias Quim & Farmaceut, Santiago 1, Chile
[4] Univ Chile, Unidad Graf Mol, Dept Quim Inorgan & Analit, Fac Ciencias Quim & Farmaceut, Santiago 1, Chile