1. School of Pharmacy, Kaohsiung Medical College, Kaohsiung, Taiwan 807, Republic of China, Ta-Jen Pharmaceutical Junior College, Ping Tung Hsieng, Taiwan 907, Republic of China, Institute of Chinese Pharmaceutical Science, China Medical College, Taichung, Taiwan 404, Republic of China, and Department of Microbiology and Immunology, National Cheng Kung University, Tainan, Taiwan 701, Republic of China