ngamgwe fotsing rosine department of organic chemistry, faculty of science, twas research unit, university of yaoundé 1, p. o. box 812, yaoundé, cameroon raoul yakam department of clinical research, university of bern, murtenstrasse 35, ch-3010bern, switzerland jean rodolphe chouna department of chemistry, faculty of science, university of dschang, p. o. box 67, dschang, cameroon christian lanz department of clinical research, university of bern, murtenstrasse 35, ch-3010bern, switzerland julien furrer department of chemistry and biochemistry, university of bern, freiestrasse 3, ch-3012 berne, switzerland stefan schürch department of chemistry and biochemistry, university of bern, freiestrasse 3, ch-3012 berne, switzerland

Rosine Fotsing Ngamgwe Raoul Yankam Jean Rodolphe Chouna Christian Lanz Julien Furrer Stefan Schürch Marcel Kaiser Bruno Ndjakou Lenta Silvère Ngouela Etienne Tsamo Rudolf Brenneisen

Bruno LENTA, Christian Lanz, Etienne Tsamo, Jean Rodolphe Chouna, Julien Furrer, Marcel Kaiser, Ngamgwe Rosine, Raoul Yakam, Rudolf Brenneisen, Silvère Ngouela, Stefan Schürch,

Bruno LENTA, Christian Lanz, Etienne Tsamo, Jean Rodolphe Chouna, Julien Furrer, Marcel Kaiser, Ngamgwe Rosine, Raoul Yakam, Rudolf Brenneisen, Silvère Ngouela, Stefan Schürch,