Bismuth(III) complexes derived from non-steroidal anti-inflammatory drugs and their activity against Helicobacter pylori.

The formation of bismuth(III) complexes of carboxylates and benzoates derived from the 1 : 3 reaction of BiPh(3) with the common non-steroidal anti-inflammatory drugs (NSAIDs) ketoprofen, naproxen, ibuprofen, mefenamic acid, diflunisal, 5-chlorosalicylic acid, fenbufen, sulindac, tolfenamic acid and flufenamic acid, has been achieved using both solvent-free and solvent-mediated methods. The thermochemical profiles of the solvent-free reactions were studied using DSC-TGA. All reactions produced the tris-substituted complexes of general formula BiL(3), with the complexes derived from ketoprofen and sulindac having an additional single bismuth bound H(2)O molecule in the inner coordination sphere. The complexes are stable in air over a period of six months, do not undergo significant decomposition when suspended overnight in water, but decompose in 1 M HCl solution to release the free acid form of the NSAID. All ten complexes show excellent in vitro activity against Helicobacter pylori with MIC values of > or = 6.25 microg mL(-1).