Biological Active Macrocyclic Diterpenoids from Chinese Drug “Fáng Féng Cáo”; II1. Derivatives of Ovatodiolids and their Cytotoxity2 - Arisawa, M; Nimura, M; Fujita, A; Hayashi, T; Morita, N; Koshimura, S (Planta Medica, 1986)