STRUCTURAL ASPECTS OF COPPER(Il) FENAMATES
Marian Koman and Milan Melnik
Department of Inorganic Chemistry, Slovak Technical University, Radlinského 9, 812 3l Bratislava, Slovak Republic
Fenamates ( salicylic, niflumic, flufenamic ) constitue an important group of analgesics which are believed to act through inhibition of prostaglandin biosynthesis, like other anti-inflammatory analgesics [1]. It is known that some druqs act via chelation [2] or via the inhibition of metalloenzymes [3], but little is known about the modífication of activity of most drugs when their ligating potential is utilized. The interaction of the copper(II) atom, which plays a vital role in a number of quite different biological processes, with therapeutically administered drugs is a subject of considerable interest.
In order to better understand some aspects of copper(II) atom - drug interaction, we have studied here the complexation of flufenamic acid (fluH), niflumic acid (nifH) and mefanamic acid (mefH) in the presence of 3 - pyridylcarbinol [ronicol ] (ron), 2,6 - dimethanolpyridyl ( 2,6 - dmph ), N,N- diethylnicotinamide ( Et2nia ) and coffeine ( cof ). The compounds Cu(mef)2(Et2nia)2(H2O)24, Cu(fluf)2(ron)25, Cu(f luf)2(Et2nia)2(H2O)26, Cu(fluf)2(cof)0.5(H2O)0.57, Cu(nif)2(ron)28, Cu(nif)2(Et2nia)29, Cu(nif)2(2,6-dmpy)210, were studied by X - ray analysis.
The X - ray analysis data show that the compound Cu(fluf)2(cof)0.5(H2O)0.57 is dimeric; Cu(fluf)2(ron)25 and Cu(nif)2(ron)28 are polymeric and other compounds are monomeric of structure.
There are several differences, as well as relationships between Cu - O (carboxylate) bond distances from mono-, throught di- to polymeric species, which will be discussed.