Isolation and structure of the cytostatic lignan glycoside phyllanthostatin A

An unusual cytostatic (PS ED50 4 micrograms/ml) lignan ester has been isolated from the Central American tree Phyllanthus acuminatus and designated phyllanthostatin A [1]. Separation of an MeOH extract of the root by size exclusion chromatography, high speed counter-current distribution, and semipreparative hplc afforded glycoside 1 in 0.007% yield. In solution, phyllanthostatin A was slowly transformed into justicidin B [4]. The structure of lignan glycoside 1 was determined by hrfabms and 2D-nmr spectroscopy.