1. a Department of Chemistry , Lagos State University , Badagry Expressway Ojo, P. M. B. 1087, Apapa, Lagos, Nigeria
2. b Department of Pharmacognosy, Faculty of Pharmacy , University of Ibadan , Ibadan, Nigeria
3. c Faculty of Chemistry , Vinh University , 182, Le Duan, Vinh, Vietnam
4. d Faculty of Chemistry , College of Natural Sciences, Hanoi National University , 19-Le Thanh Tong, Hanoi, Vietnam
5. e Department of Plant Science and Applied Zoology , Olabisi Onabanjo University , P.M. B. 2002, Ago-Iwoye, Ogun State, Nigeria