A glycine ruthenium trithiacyclononane complex and its molecular encapsulation using cyclodextrins

The complex Ru([9]aneS₃)(gly)Cl (gly = glycine) was obtained from the reaction of the precursor Ru([9]aneS₃)dmsoCl₂ with glycine and encapsulated into native β-CD, a hydroxypropylated derivative HPβCD, and the methylated cyclodextrins TRIMEB and CRYSMEB. All four inclusion compounds were obtained with a 1:1 host:guest stoichiometry and characterised in the solid-state by powder X-ray diffraction, thermogravimetric analysis (TGA), and ¹³C{¹H} CP/MAS NMR and FTIR spectroscopies. The cytostatic and antiproliferative activity of the complex Ru([9]aneS₃)(gly)Cl and its four CD inclusion compounds was tested on the human osteosarcoma MG-63 cell line and the results compared to the inhibitory effect exerted by the pure cyclodextrins.