Cytotoxic Alkaloids from the Flowers of Senna spectabilis - Sriphong, Lawan; Sotanaphun, Uthai; Limsirichaikul, Siripan; Wetwitayaklung, Penpan; Chaichantipyuth, Chaiyo; Pummangura, Sunibhond (Planta Medica, 2003)