Inclusion of molybdenocene dichloride (Cp2MoCl2) in 2-hydroxypropyl- and trimethyl-β-cyclodextrin: Structural and biological properties

Abstract

Organometallic-cyclodextrin inclusion compounds were obtained by the treatment of molybdenocene dichloride (Cp 2 MoCl 2 ) with the modified cyclodextrins (CDs) heptakis-2,3,6-tri-O-methyl-b-CD (TRIMEB) and 2-hydroxypropyl-b-CD (HPbCD) in aqueous solution. The products were isolated by liophilisation and characterised in the solid-state by powder XRD, thermogravimetric analysis, Raman and FTIR spectroscopy, and 13 C CP MAS NMR spectroscopy. The results are consistent with inclusion of Cp 2 MoCl 2 , rather than hydrolysis products such as [Cp 2 Mo(H 2 O)X] + (X = Cl, OH) or [Cp 2 Mo(H 2 O) 2 ] 2+ . The pure non-included metallocene Cp 2 MoCl 2 and its inclusion compounds with unmodified b-CD, TRIMEB and HPbCD were screened for their potential antiproliferative and cytotoxic activity, in both human cancer and healthy cell lines. Inclusion in CD was found to enhance the cytotoxic effect of Cp 2 MoCl 2 , with the TRIMEB adduct displaying the highest anti-tumour activity, along with the lowest toxicity towards non-neoplastic cells.

Cyclodextrins improve the antimicrobial activity of the chloride salt of Ruthenium(II) chloro-phenanthroline-trithiacyclononane

“…Although such a feature is somewhat uncommon for TRIMEB Fig. 3 Laboratory X-ray diffraction patterns and packing mode schematics for b-CD (bottom), the guest 2 (middle) and compound 4 (top) compounds with metal guests, a similar behavior was observed in some of our previous work with TRIMEB adducts of metallocenes (M = Mo, Nb) (Pereira et al 2007;Braga et al 2005Braga et al , 2001. This same behavior was observed in the TRIMEBÁ[Ru( [9] aneS 3 )bpyCl]Cl adduct , thus suggesting that it may be a characteristic of TRIMEB-encapsulated Ru(II) trithyacyclononane polypyridyl complexes.…”

“…Recent work on CD inclusion of the compounds Cp 2 MCl 2 (Cp = cyclopentadienyl, M = Nb, Mo) (Pereira et al 2007;Braga et al 2005Braga et al , 2001 showed an enhanced antitumoral action, in particular for TRIMEBÁCp 2 MoCl 2 (Braga et al 2005). b-CD was also shown to enhance the cytotoxic activity of trans Pt(dipyridine)Cl 2 by improvement of its aqueous solubility (Horvath et al 2008).…”

Structural studies on supramolecular adducts of cyclodextrins with the complex [Ru([9]aneS3)(bpy)Cl]Cl

“…Suitable guests include transition-metal complexes and organometallic compounds bearing hydrophobic ligands such as cyclopentadienyl (Cp = g 5 -C 5 H 5 ) and g 6 -arene groups [4][5][6], capable of docking into the host cavity by non-covalent bonding (either van der Waals or charge-transfer interactions). We have explored the protecting and bio-delivery properties of these hosts to enhance the activity of antitumour metal compounds such as ferrocene derivatives [7] and metallocene dihalides, in particular Cp 2 MCl 2 (Cp = cyclopentadienyl, M = Nb, Mo) [8][9][10]. In particular, cytotoxic assays carried out for pure and included molybdenocene dichloride showed a higher activity upon encapsulation, in particular when using permethylated b-cyclodextrin (TRIMEB) [9].…”

“…We have explored the protecting and bio-delivery properties of these hosts to enhance the activity of antitumour metal compounds such as ferrocene derivatives [7] and metallocene dihalides, in particular Cp 2 MCl 2 (Cp = cyclopentadienyl, M = Nb, Mo) [8][9][10]. In particular, cytotoxic assays carried out for pure and included molybdenocene dichloride showed a higher activity upon encapsulation, in particular when using permethylated b-cyclodextrin (TRIMEB) [9]. We have also used cyclodextrin encapsulation to modulate the activity of carbonyl organometallics such as CpFe(CO) 2 X (X = Cl, CN) [11][12][13], Cp 0 Mo(g 3 -C 3 H 5 )(CO) 2 [14], CpMo(LL)(CO) 2 (L = 2 Â CH 3 CN or LL = 2,2 0 -bis-imidazole) [15] and CpMo(CO) 3 CH 2 CONH 2 [16].…”

“…For this purpose, some of us have developed a series of Ru(II) complexes with the face-capping ligand trithyacyclononane ( [9]aneS 3 ) and planar aromatic amines suitable for DNA intercalation [17]. The crystal structures of these compounds were found to be largely stabilised by hydrogen bonding interactions and the coordinated planar aromatic amines exhibit p-stacking arrangements which mimic the structure of polypyridyl complexes intercalated with DNA.…”