1. Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba R3T 2N2; and Department of Botany, University of Tanta, Egypt
2. Department of Botany, Faculty of Science, University of Tanta, Egypt
3. Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2
4. Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba R3T 2N2