Title: Oxovanadium(IV) cyclam and bicyclam complexes: potential CXCR4 receptor antagonists
Authors: Ross, Allison ×
Soares, Dinesh C
Covelli, Danielle
Pannecouque, Christophe
Budd, Laura
Collins, Anna
Robertson, Neil
Parsons, Simon
De Clercq, Erik
Kennepohl, Pierre
Sadler, Peter J #
Issue Date: Feb-2010
Publisher: American Chemical Society
Series Title: Inorganic Chemistry vol:49 issue:3 pages:1122-1132
Abstract: Metal complexation can have a major influence on the antiviral and coreceptor binding properties of cyclam and bicyclam macrocycles. We report the synthesis of the vanadyl cyclam complexes [V((IV))O(cyclam)SO(4)] (1) and [V((IV))O(cyclam)Cl]Cl (2) and the analogous xylylbicyclam sulfato (3) and chlorido (4) complexes. The X-ray crystal structures of 1.1.33CH(3)OH and 2.CH(3)OH.1.5H(2)O show short V=O bonds (1.6093(19) and 1.599(3) A, respectively) with monodentate sulfate H-bonded to ring NH groups for 1, but a long V-Cl bond (2.650(12) A) for 2. The solid-state structures of 3 and 4 were compared to those of 1 and 2 using vanadium K-edge extended X-ray absorption fine structure (EXAFS) data. These suggested that complex 4 was oligomeric and contained bridging chlorido ligands. Electron paramagnetic resonance (EPR) studies suggested that the SO(4)(2-) (from 1) and Cl(-) (from 2) ligands are readily substituted by water in solution, whereas these remain partially bound for the V(IV) xylylbicyclam complexes 3 and 4. The vanadyl xylylbicyclam complexes were highly active against HIV-1 (III(B)) and HIV-2 (ROD) strains with IC(50) values in the range 1-5 microM for 3 and 0.1-0.3 microM for 4; in contrast the vanadyl cyclam complexes 1 and 2 were inactive. The factors that contribute to the activity of these complexes are discussed. Studies of vanadyl cyclam docked into a model of the human CXCR4 coreceptor revealed that the coordination of vanadium to the carboxylate of Asp171 may be accompanied by H-bonding to the macrocycle and an attractive V=O...H interaction involving the backbone Trp195 alpha-carbon proton of CXCR4. In addition, hydrophobic interactions with Trp195 are present. Both ring configuration and the xylyl linker may play roles in determining the higher activity of the bicyclam complexes.
ISSN: 0020-1669
Publication status: published
KU Leuven publication type: IT
Appears in Collections:Laboratory of Virology and Chemotherapy (Rega Institute)
× corresponding author
# (joint) last author

Files in This Item:
File Description Status SizeFormat
2010011.pdf Published 1635KbAdobe PDFView/Open Request a copy

These files are only available to some KU Leuven Association staff members


All items in Lirias are protected by copyright, with all rights reserved.

© Web of science