Edinburgh Research Explorer

Oxovanadium(IV) Cyclam and Bicyclam Complexes: Potential CXCR4 Receptor Antagonists

Research output: Contribution to journalArticlepeer-review

Related Edinburgh Organisations

Open Access permissions

Open

Documents

  • Download as Adobe PDF

    Rights statement: Copyright © 2010 by the American Chemical Society. All rights reserved.

    Accepted author manuscript, 902 KB, PDF document

http://pubs.acs.org/doi/full/10.1021/ic9020614
Original languageEnglish
Pages (from-to)1122-1132
Number of pages11
JournalInorganic Chemistry
Volume49
Issue number3
DOIs
Publication statusPublished - 1 Feb 2010

Abstract

Metal complexation can have a major influence on the antiviral and coreceptor binding properties of cyclam and bicylam macrocycles. We report the synthesis of the vanadyl cyclam complexes [(VO)-O-(IV)(cyclam)SO4] (1) and [(VO)-O-(IV)(cyclam)CI]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 center dot CH3OH center dot 1.5H(2)O show short V=O bonds (1.6093(19) and 1.599(3) angstrom. respoctively) 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 SO42- (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 (IIIB)) and HIV-2 (ROD) strains with IC50 values in the range 1-5 mu M for 3 and 0.1-0.3 mu M 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 center dot center dot center dot 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.

    Research areas

  • HUMAN-IMMUNODEFICIENCY-VIRUS, RAY-ABSORPTION-SPECTROSCOPY, VANADIUM COMPOUNDS, MACROCYCLIC POLYAMINES, HIV, RECOGNITION, SYSTEMS, 1,4,8,11-TETRAAZACYCLOTETRADECANE, METALLOCYCLAMS, DERIVATIVES

Download statistics

No data available

ID: 547777