1. Laboratory of Natural Products, Institute of Bioscience, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia, Departments of Biotechnology and Chemistry, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia, and Food Chemistry, Graduate School of Human Life Science, Osaka City University, 3-3-138, Sugimoto, Sumiyoshi, Osaka, Japan