1. Department of Organic Chemistry, School of Pharmacy; Iwaki Meisei University; Iino, Chuodai, Iwaki, Fukushima; 970-8551; Japan
2. Department of Medicinal Chemistry, School of Pharmaceutical Sciences; Kitasato University; Shirokane, Minato-ku, Tokyo; 108-8641; Japan
3. Department of Molecular Design for Medicine, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences; Okayama University; Tsushimanaka, Kita-ku, Okayama-Shi, Okayama; 700-8530; Japan