1. Department of Pharmacognosy, Faculty of Pharmacy, University of Ibadan, Ibadan, Nigeria
2. Laboratory of Food Biotechnology, Institute of Biotechnology, Division of Bioresources and Bioenvironmental Sciences, Faculty of Agriculture, Graduate School of Kyushu University, 6-10-1-Hakozaki, Higasshi-ku, Fukuoka-shi 812 8581, Japan
3. Department of Chemistry, University of Alabama in Huntsville, Huntsville AL 35899, USA
4. Department of Plant Sciences and Applied Zoology, Olabisi Onabanjo University, P.M.B. 2002, Ago-Iwoye, Ogun State, Nigeria
5. Department of Chemistry, University of Ibadan, Ibadan, Nigeria