Marine sponge polyketide inhibitors of protein tyrosine kinase

The marine polyketide natural product, halenaquinone, was shown to be an irreversible inhibitor of pp60 v-src, the oncogenic protein tyrosine kinase encoded by the Rous sarcoma virus. This compound had an IC 50 of approximately 1.5 μM against pp60 v-src and also inhibited the ligand-stimulated kinase activity of the human epidermal growth factor receptor with an IC 50 of approximately 19 μM. Halenaquinone blocked the proliferation of a number of cultured cell lines, including several transformed by oncogenic protein tyrosine kinases. Halenaquinol, xestoquinone, halenaquinol sulfate, and several simple synthetic quinone analogs were also shown to inhibit pp60 v-src.