Qinpei Wu*a, Claire Simons*b a School of Life Science and Technology, Beijing Institute of Technology, Beijing 100081, P. R. China Fax: +86(10)68913293; e-Mail: qpwu@bit.edu.cn; b Welsh School of Pharmacy, Cardiff University, Cardiff CF10 3XF, UK Fax: +44(29)20876307; e-Mail: simonsc@cardiff.ac.uk;