Plant Anticancer Agents, XLVI. Cytotoxic Casbane-Type Constituents of Agrostistachys hookeri

Abstract

In addition to the previously characterized agrostistachin [1], three additional cytotoxic macrocyclic casbane-type diterpenes were isolated from a CHCl3 extract of Agrostistachys hookeri, by bioactivity-guided fractionation using the P-388 lymphocytic leukemia cell culture system. These novel compounds, 14-dehydroagrostistachin [2], 17-hydroxyagrostistachin [3], and agroskerin [4], were identified by spectral data comparison to agrostistachin and demonstrated ED50 values of 2.8, 0.8, and 1.4 .mu.g/ml, respectively, with cultured P-388 cells.