[1] Univ Fed Pelotas, Dept Quim Organ, BR-96010900 Pelotas, RS, Brazil
[2] Fundacao Oswaldo Cruz, Inst Tecnol Farmacos Farmanguinhos, BR-21041250 Rio De Janeiro, Brazil
[3] CHEMSOL, Aberdeen AB155NY, Scotland
[4] Univ Fed Santa Maria, Dept Quim, BR-97105900 Santa Maria, RS, Brazil