Isolation and Frontier Molecular Orbital Investigation of Bioactive Quinone-Methide Triterpenoids from the Bark of Salacia petenensis - Setzer, William N; Holland, Michael T; Bozeman, Carey A; Rozmus, Glenn F; Setzer, Mary C; Moriarity, Debra M; Reeb, Sabine; Vogler, Bernhard; Bates, Robert B; Haber, William A (Planta Medica, 2001)