1. Faculty of Pharmaceutical Sciences; Okayama University; Okayama Okayama 700-8530 Japan
2. Department of Microbiology, School of Medicine; Fujita Health University; Toyoake Aichi 470-1192 Japan
3. Institute of Pharmacognosy, Faculty of Pharmaceutical Sciences; Tokushima Bunri University; Tokushima Tokushima 770-8514 Japan