1. Département de Chimie Organique; Université de Yaoundé 1; Yaoundé Cameroun
2. Department of Food, Life, and Environmental Science, Faculty of Agriculture; Yamagata University; Tsuruoka Yamagata Japan
3. The United Graduate School of Agricultural Sciences; Iwate University; Morioka Iwate Japan
4. Research and Analytical Center for Giant Molecules, Graduate School of Science; Tohoku University; Sendai Miyagi Japan