1. Graduate School of Agriculture Kyoto University Kitashirakawa-Oiwakecho, Sakyo-ku Kyoto 606-8501 Japan
2. Graduate School of Pharmaceutical Sciences Kyoto University Yoshida, Sakyo-ku Kyoto 606-8502 Japan
3. Department of Pharmaceutical Chemistry Faculty of Pharmacy, University of Khartoum Alqsr Avenue Khartoum 11111 Sudan