1. Faculty of Biology, Vinh University, 182-Le Duan, Vinh City, Nghe An Province, Vietnam
2. Faculty of Chemistry, Vinh University, 182-Le Duan, Vinh City, Nghe An Province, Vietnam
3. Natural Products Research Unit, Department of Chemistry, Faculty of Science, Lagos State University, Badagry Expressway Ojo, P. M. B. 0001, LASU Post Office, Ojo, Lagos, Nigeria