1. Chemistry, School of Environmental & Life Sciences The University of Newcastle 1 University Drive Callaghan NSW 2308 Australia
2. Experimental Therapeutics Group, Department of Medical Oncology Calvary Mater Hospital Edith Street Waratah NSW 2298 Australia
3. Present address: Department: School of Science and Health Western Sydney University Locked Bag 1797 Penrith South DC NSW 2750 Australia