Publications by authors named "Gerhard Rubner"

With the aim to design new biologically active bioinorganic drugs of aspirin, whose mode of action is based on the inhibition of the cyclooxygenase(COX) enzymes, derivatives of Zeise's salt were synthesized in this structure-activity relationship study. Surprisingly, not only these Zeise-aspirin compounds but also Zeise's salt itself showed high inhibitory potency against COX enzymes in in vitro assays. In contrast, potassium tetrachloroplatinate and cisplatin did not influence the enzyme activity at equimolar concentrations.

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Metalcarbonyl complexes with ligands derived from acetylsalicylic acid demonstrated high cytotoxic potential against various tumor cell lines and strong inhibition of the cyclooxygenase enzymes COX-1 and 2. In this study we tried to achieve comparable effects with [alkyne]silver or copper trifluoromethanesulfonate complexes which are more hydrophilic then the uncharged metalcarbonyl derivatives. All compounds were evaluated for growth inhibition against breast (MCF-7, MDA-MB 231) and colon cancer (HT-29) cell lines and for COX-1 and COX-2 inhibitory effects at isolated isoenzymes.

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A series of C5-substituted licofelone ([2,2-dimethyl-6-(4-chlorophenyl)-7-phenyl-2,3-dihydro-1H-pyrrolizin-5-yl]acetic acid) derivatives were developed by a parallel synthesis approach and investigated for cytotoxicity against MCF-7 and MDA-MB-231 cells as well as for anti-inflammatory potency in vitro and in vivo. Dependent on the C5-substituent, the compounds showed high selectivity for MCF-7 cells. Especially 2-oxoethyl benzoate derivatives were inactive at the MDA-MB-231 cell line and as active as 5-FU at MCF-7 cells.

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[(μ(4)-η(2))-(Prop-2-ynyl)-2-acetoxybenzoate]dicobalthexacarbonyl (Co-ASS), a derivative of aspirin (ASS), demonstrated high growth-inhibitory potential against various tumor cells with interference in the arachidonic acid cascade as probable mode of action. The significance of the kind of metal and cluster was verified in this structure-activity study: Co(2)(CO)(6) was respectively exchanged by a tetrameric cobalt-, trimeric ruthenium-, or trimeric ironcarbonyl cluster. Furthermore, the metal binding motif was changed from alkyne to 1,3-butadiene.

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[(Prop-2-ynyl)-2-acetoxybenzoate]dicobalthexacarbonyl (Co-ASS), a derivative of the nonsteroidal anti-inflammatory drug aspirin(®) (ASS), demonstrated high cytotoxic potential against various tumor cells. The [acetylene]Co(2)(CO)(6) cluster strongly increased the biological effects compared to aspirin(®). In this study we evaluated the use of [cyclopentadienyl]metalcarbonyl as cytotoxic moiety with a broader series of metals: molybdenum, manganese, cobalt and rhodium.

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