H OH metabolites OH Article Rapid Screening of Proanthocyanidins from the Roots of Ephedra sinica Stapf and its Preventative Effects on Dextran-Sulfate-Sodium-Induced Ulcerative Colitis Mengying Lv 1,2,*,†, Yang Wang 1,2,†, Xiayun Wan 1,2, Bo Han 3, Wei Yu 3, Qiaoling Liang 1,2...