Synthesis and direct comparison of the anticancer activities of phomopsolides D and E and two 7-oxa-/7-aza-analogues.

The synthesis of two stable phomopsolide natural products (D and E) and two analogues is presented. The cytotoxicities of these four compounds are surveyed and compared across a panel of NCI-cancer cell lines. This analysis found moderate cytotoxicities (2-50 μM) for the majority of the cell lines with phomopsolide D being more active than phomopsolide E and the 7-oxa analogue being commensurately more active than the 7-aza analogue.