Bower, Justin; Drysdale, Martin; Hebdon, Richard; Jordan, Allan; Lentzen, Georg; Matassova, Natalia; Murchie, Alastair; Powles, Jenifer; Roughley, Stephen Bioorganic and Medicinal Chemistry Letters, 2003, vol. 13, # 15 p. 2455 - 2458 doi: 10.1016/S0960-894X(03)00495-5