Isolation and Structural Determination of Two Novel Phlorotannins from the Brown Alga Ecklonia kurome Okamura, and Their Radical Scavenging Activities oleh Yuko Cho, Keiichi Konoki, Hisatomi Ito, Haruhiko Toyohara, Yi-Chin Lin, Shinya Segawa, Sawako Kondo, Mari Yotsu-Yamashita, Takafumi Uchida