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Several bioconjugates of ferrocene with biological compounds such as aminoacid esters and related species have been prepared by reaction of chlorocarbonyl ferrocene with the corresponding amino acid ester (histidine methyl ester, tryptophan methyl ester, methionine methyl ester and lysine ethyl ester) or histamine or prolinamide in the presence of NEt(3). The reaction of the tryptophan or prolinamide ferrocene conjugates with [Au(acac)(PR(3))] (acac=acetylacetonate) results in the substitution of the proton of the cyclic NH groups by the fragment AuPR(3)(+) affording the complexes [Au(FcCO-tryptophan-OMe)(PR(3))] or [Au(FcCO-prolinamide)(PR(3))] (Fc=ferrocenyl group). The reaction of FcCO-Met-OMe with [Au(OTf)(PR(3))] (OTF=trifluoromethysulfonate) or [Au(C(6)F(5))(3)(OEt(2))] yields the gold(I) or gold(III) derivatives [Au(FcCO-Met-OMe)(PR(3))]OTf or [Au(C(6)F(5))(3)(FcCO-Met-OMe)], respectively. Cytotoxicity studies towards several cancer lines such as MCF-7, HeLa or NIE-115 have been performed. The ferrocene bioconjugates show no activity whereas the gold complexes exhibit antiproliferative effect. Preliminary studies of interaction of compounds with cells were carried out with the goal of increasing our knowledge on the mechanism of action of these potential drugs., (Copyright © 2011 Elsevier Inc. All rights reserved.)

A new phosphine ligand bearing a thiophene moiety, C4H3SNHCOCH2CH2PPh2 (L), has been prepared by reaction of the aminophosphine Ph2PCH2CH2NH2 with thiophenecarbonylchloride in the presence of triethylamine. The coordination behavior towards gold(I), gold(III) and silver(I) species has been studied and several metal compounds of different stoichiometry have been achieved, such as [AuL2]OTf, [AuXL] (X = Cl, C6F5), [Au(C6F5)3L], [AgL2]OTf or [Ag(OTf)L]. Additionally, the reactivity of the chloride gold(I) species with biologically relevant thiolates was explored, thus obtaining the neutral thiolate compounds [AuL(SR)] (SR = 2-thiocitosine, 2-thiolpyridine, 2-thiouracil, 2-thionicotinic acid, 2,3,4,6-tetra-6-acetyl-1-thiol-β-d-glucopyranosato or thiopurine). The antitumor activity of the compounds was measured by the MTT method in several cancer cells and the complexes exhibit excellent cytotoxic activity. [ABSTRACT FROM AUTHOR]