jean de dieu tamokou departments of biochemistry, university of dschang, cameroon jules roger kuiate departments of biochemistry, university of dschang, cameroon mathieu tene chemistry, faculty of sciences, university of dschang, cameroon timothée julbelin kenla nwemeguela chemistry, faculty of sciences, university of dschang, cameroon pierre tane chemistry, faculty of sciences, university of dschang, cameroon