Metal Complexes of Biologically Important Ligands, CXXV [1]. Palladium(II) and Platinum(II) Complexes of Quinine Derivatives and in vitro Tests
Roland Hubel
a, Tomas Jelinek
b, and Wolfgang Beck
aaDepartment Chemie der Ludwig-Maximilians-Universit¨at, Butenandtstr.5-13, Haus D, D-81377 M¨unchen
bAbteilung f¨ur Infektions- und Tropenmedizin, Medizinische Klinik, Klinikum Innenstadt, Ludwig-Maximilians-Universit¨at, Leopoldstr. 5, D-80802 M¨unchen
Reprint requests to Prof. Dr. W. Beck. Fax: +49 (0)89/2180 7866.
E-mail: wbe@cup.uni-muenchen.de
Dedicated to Professor Rolf Huisgen on the occasion of his 80thbirthday Z. Naturforsch.55 b,821–833 (2000); received March 13, 2000
Quinine Derivatives, Palladium, Platinum
Several quinine substituted derivatives at the C(9)-O position (1-7) have been obtained from quinine and N-protected glycine chloride, chlorocarbonyl ferrocene, phenylisocyanate, dicarboxylic acid dichlorides or trimesinic trichloride. From these only the glycine derivative 1 showed significant antimalarial activity in in vitro tests against Plasmodium falciparum isolates. The quinine derivatives were used as ligands and from chloro bridged palladium and platinum complexes Cl(R3P)M(-Cl)2M(PR3)Cl (M = Pd, Pt) di-, tri-, tetra- and hexa- metallic compounds8-21with coordination both of the aliphatic and aromatic N-atoms were synthesized. Protection of the tertiary N atom by protonation gave the quinoline complexes 22-25. Using a stoichiometric ratio metal/ligand = 1/1 it could be shown that the coordination of metal ions at the quinoline N-atom is by far preferred. A titanium(IV) complex 36 is formulated as [Ti(quinine)3Cl]Cl3with quinine as a zwitterionic ligand.
