Fu, YingRomero Castro, María JoséSalassa, LucaCheng, XiHabtemariam, AbrahaClarkson, Guy J.Prokes, IvanRodger, AlisonCostantini, GiovanniSadler, Peter J.2025-12-032025-12-032016-05-30Fu, Y., Romero, M. J., Salassa, L., Cheng, X., Habtemariam, A., Clarkson, G. J., Prokes, I., Rodger, A., Costantini, G., Sadler, P. J. (2016). "Os2-Os4 switch controls DNA knotting and anticancer activity", Angew. Chem. Int. Ed. , 55, 8909–89121433-7851https://hdl.handle.net/10347/44209Dinuclear trihydroxido-bridged osmium–arene complexes are inert and biologically inactive, but we show here that linking dihydroxido-bridged OsII–arene fragments by a bridging di-imine to formametallacycle framework results in strong antiproliferative activity towards cancer cells and distinctive knotting of DNA. The shortened spacer length reduces biological activity and stability in solution towards decomposition to biologically inactive dimers. Significant differences in behavior toward plasmid DNA condensation are correlated with biological activityeng© 2016 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited (CC BY 4.0; Attribution 4.0 International: https://creativecommons.org/licenses/by/4.0/). Open access article available at: https://doi.org/10.1002/anie.201602995Attribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/CancerDNAOrganometallicOsmiumSupramolecularjournal article10.1002/anie.2016029951521-3773open access