Methionine can favor DNA platination by trans-coordinated platinum antitumor drugs.

In this paper, the inclusion complexation between host and guest in cyclodextrin (CD) chemistry is care fully compared with the coordination interaction between central ion (Mx+) and ligands in coordination chemistry. In viewof the importanceof the concept of the coordinationnumber (CN)ofMx+ in coordination compounds, the inclusion number (IN) is first defined to evaluate the nature of inclusion complexa tion between host and guest in CD supramolecular inclusion complexes. The similarities and differences betweenCNand IN are also discussed. The changes of the number and forms ofwatermolecules both in CD hydrates and in CD crystal inclusion complex hydrates are reviewed.Moreover, this paper emphasizes the distinction between the two forms of CD guest inclusion phenomenon, i.e., inclusion complexation and encapsulation interaction. Furthermore, the present work indicates that though chemical stoichiometric ratio can be used to characterize the inclusion phenomena, IN can better reveal the essence of inclusion phenomena in cyclodextrin chemistry. © 2008 Elsevier B.V. All rights reserved.