1. Department of Chemistry, Obafemi Awolowo University, Ile-Ife, Nigeria
2. Department of Biochemistry, Obafemi Awolowo University, Ile-Ife, Nigeria
3. Maradi Integrated Development Program, BP 121, Maradi, Niger Republic
4. CSIRO Forestry and Forest Products, P.O. Box E4008, Kingston, A. C. T. 4008, Australia