Fertility Inhibitor Heterobimetallic Complexes of Platinum(II) and Palladium(II): Synthetic, Spectroscopic and Antimicrobial Aspects

Synthetic, spectroscopic and antimicrobial aspects of some fertility inhibitor heterobimetallic complexes have been carried out. These heterobimetallic chelates [M(C(5)H(5)N(3))(2)M(2)'(R)(4)]Cl(2) (M = Pd or Pt and M' = Si, Sn, Ti and Zr) have been successfully synthesinzed via the reaction of M(C(5)H(7)N(3))(2)Cl(2) with group four or fourteen dichlorides in 1:2 stoichiometric proportions. The products were characterized by elemental analyses, molecular weight determinations, magnetic susceptibility measurements, conductance, and IR multinuclear NMR and electronic spectral studies. A square planar geometry has been suggested for all the complexes with the help of spectral data. Conductivity data strongly suggest that chlorine atoms are ionic in nature due to which complexes behave as electrolytes. All the complexes have been evaluated for their antmicrobial effects on different species of pathogenic fungi and bacteria. The testicular sperm density, testicular sperm morphology, sperm motility, density of cauda epididymal spermatozoa and fertility in mating trails and biochemical parameters of reproductive organs have been examined and discussed.     

Synthesis, Characterization and Antifertility Activity of New Unsymmetrical Macrocyclic Complexes of Tin(II)

A new series of unsymmetrical macrocyclic complexes of tin(ll) has been prepared by the template process using bis(3-oxo-2-butylidene)propane-1,3-diamine as precursor. This affords a method to synthesize these complexes with various ring sizes. The tetradentate macrocyclic precursor [N(4)mL] reacts with SnCl(2) and different diamines in a 1:1:1 molar ratio in refluxing methanol to give complexes of the type [Sn(N(4)mL)Cl(2)]. The ring expansion has been achieved by varying the diamine between the two diacetyl amino nitrogen atoms. The macrocyclic precursor and its metal complexes have been characterized on the basis of elemental analysis, molar conductance, molecular weight determinations, IR, (1)H NMR,(13)C NMR, (119)Sn NMR and electronic spectral studies. An octahedral geometry around the metal ion is suggested for these complexes. On the basis of molecular weights and conductivity measurements, their monomeric and non-electrolytic nature has been confirmed. The precursor and complexes have been screened in vitro against a number of pathogenic fungi and bacteria to assess their growth inhibiting potential. The testicular sperm density and testicular sperm morphology, sperm motility, density of cauda epididymal spermatozoa and fertility in mating trails and biochemicals parameters of reproductive organs have been examined and discussed.     

Toxicity, Spectroscopic Characterization and Electrochemical Behaviour of New Macrocclic Complexes of Lead(II) and Palladium(II) Metals

Tetraazamacrocyclie complexes of lead and palladium have been synthesized by the template process using the bis(benzil)ethylenediamine precursor. The tetradentate macrocycle (maL) reacts with PbCl(2), PdCl(2) and different diamines in a 1:1:1 molar ratio in methanol to give several solid complexes of the types [Pb(maL)(R)Cl(2)] and [Pd(maL)(R)]Cl(2) (where R = 2,6-diaminopyridine or 1,2-phenylenediamine). The macrocycle and its metal complexes have been characterized by elemental analysis, molecular weight determinations, molar conductivity, IR, (1)H NMR, (13)C NMR, electronic, mass and electrochemical studies. The macrocyclic ligand coordinates through the four azomethine nitrogen atoms which are bridged by benzil moieties. IR spectra suggest that the pyridine nitrogen is not coordinating. The palladium complexes exhibit tetracoordinated square-planar geometry, whereas a hexacoordinated octahedral geometry is suggested for lead complexes. The macrocycle along with its complexes have been screened in vitro against a number of pathogenic fungi and bacteria to assess their growth inhibiting potential.     

Synthesis, Spectral and Antibacterial Studies of Copper(II) Tetraaza Macrocyclic Complexes

A novel family of tetraaza macrocyclic Cu(II) complexes [CuLX(2)] (where L = N(4) donor macrocyclic ligands) and (X = Cl(-), NO(3) (-)) have been synthesized and characterized by elemental analysis, magnetic moments, IR, EPR, mass, electronic spectra and thermal studies. The magnetic moments and electronic spectral studies suggest square planar geometry for [Cu(DBACDT)]Cl(2) and [Cu(DBACDT)](NO(3))(2) complexes and distorted octahedral geometry to the rest of the ten complexes. The biological activity of all these complexes against gram-positive and gram-negative bacteria was compared with the activity of existing commercial antibacterial compounds like Linezolid and Cefaclor. Six complexes out of twelve were found to be most potent against both gram-positive as well as gram-negative bacteria due to the presence of thio group in the coordinated ligands.     

Txicological Aspects of Newly Designed Macrocyclic Complexes of Iron(II)

Brine shrimp lethality of a new series of 16 to 26-membered macrocycles of iron(II) containing tetraaza groups and prepared by the template condensation reaction of diacarboxylic acids (malonic, succinic, glutaric or adipic) with 2,6-diaminopyridine and diethylenetriamine in 1:2:2 molar ratios have been studied. Structures and bonding of the macrocyclic complexes have been proposed based on elemental analyses, IR, electronic, X-ray and mass spectral studies. An octahedral geometry for these complexes has been proposed as the binding sites are the nitrogen atoms of the macrocycles. The formation of the complexes as [Fe(L(n))Cl(2)] has been established on the basis of the chemical composition. The complexes have also been screened against several microbes.     

Synthetic, Spectroscopic and Biocidal Aspects of Heterobimetallic Complexes Comprising Platinum(II) and a Group Four or Fourteen Element

Heterobimetallic complexes with varying amines have been synthesized by the reaction of [Pt(C(2)H(8)N(2))(2)]Cl(2) with group four or fourteen organometallic dichlorides, viz., R(2)MCl(2) and Cp(2)M'Cl(2) in a 1:2 molar ratio in MeOH (where M=Si or Sn, M'= Ti or Zr and R=Ph or Me). These complexes have been characterized by elemental analysis, molecular weight determinations, magnetic measurements, conductance, IR, (1)H NMR and electronic spectra. The spectral data suggest a square planar geometry for all the complexes. Conductivity data suggest that they behave as electrolytes. These monometallic precursors along with their complexes have been screened in vitro against a number of pathogenic fungi and bacteria to assess their growth inhibiting potential.     

Reactions of Pd(II) and Pt(II) Complexes With Tetraethylthiouram Disulfide

The reactions of tetraethylthiouram disulfide (DTS), an inhibitor of the nephrotoxicity of Pt(II) drugs, an efficient agent in the treatment of chronic alcoholism, in the treatment of HIV infections, AIDS and heavy metal toxicity, and a fungicide and herbicide, with K(2)[PtCl(4)], in ratio 1:1 and 1:2, gave the compounds [PtCl(2)DTS] and [Pt(S(2)CNEt(2))(2)] respectively. The reaction of the complexes K(2)[PdCl(4)], Pd(AcO)(2) and [PdCl(2)(PhCN)(2)], where PhCN = Benzonitrile, with tetraethylthiouram disulfide in ratio 1:1 or 1:2, yielded orange crystals identified as [Pd(S(2)CNEt(2))(2)]. The crystals were suitable for study by X-ray diffraction. The -S-S- bridge in the tetraethylthiouram disulfude molecule was broken and the two molecules of the thiocarbamate derivative were bound to the Pd(II) by the equivalents sulfur atoms. All the compounds were characterized by IR, (1)H and (13)C NMR spectroscopies.     

Synthesis, Characterization and Antiproliferative Activity of the Co(II), Ni(II), Cu(II), Pd(II) and Pt(II) Complexes of 2-(4-Thiazolyl)Benzimidazole (Thiabendazole)

Complexes of 2-(4-thiazolyi)benzimidazole (thiabendazole, THBD) with Co(II), Ni(II), Cu(ll) of general formula ML(2)(NO(3))(2) H(2)O and complexes of Pd(II) and Pt(II) of general formula ML2Cl(2) H(2)O have been obtained and characterized by elemental analyses, IR and far IR spectroscopy and magnetic measurements. The X-ray crystal structure of the copper(II) complex has been determined. The in vitro cell proliferation inhibitory activity of these compounds was examined against human cancer cell lines A 549 (lung carcinoma), HCV-29 T (urinary bladder carcinoma), MCF-7 (breast cancer), T47D (breast cancer), MES-SA (uterine carcinoma) and HL-60 (promyelocytic leukemia). Pt-THBD has been found to exhibit an antileukemic activity of the HL-60 line cells matching that of an arbitrary criterion.     

Chiral platinum(II) metallointercalators with potent in vitro cytotoxic activity

Four platinum(II) metallointercalating complexes of 1,10-phenanthroline (phen) with the chiral ancillary ligands trans-R,R- and trans-S,S-1,2-diaminocyclohexane (R,R- and S,S-dach, respectively), and N,N'-dimethyl-R,R- and N,N'-dimethyl-S,S-1,2-diaminocyclohexane (Me(2)-R,R-dach and Me(2)-S,S-dach, respectively) have been synthesised and characterised. The crystal structure of [Pt(Me(2)-S,S-dach)(phen)](ClO(4))(2)1.5 H(2)O (C(20)H(26)Cl(2)N(4)O(9.5)Pt) has been determined; orthorhombic, space group P2(1)2(1)2(1)(No. 19), a=23.194(8), b=25.131(9), c=8.522(3) A. In vitro cytotoxic assays (IC(50)) in the human bladder cancer cell line 5637 and in the murine leukemia L1210 cell line revealed that [Pt(S,S-dach)(phen)](ClO(4))(2) (0.091 and 0.13 microM, respectively) and [Pt(R,R-dach)(phen)](ClO(4))(2) (0.54 and 1.50 microM, respectively) were more cytotoxic than cisplatin (0.31 and 0.50 microM, respectively) and considerably more cytotoxic than their methylated counterparts, [Pt(Me(2)-R,R-dach)(phen)](ClO(4))(2) and [Pt(Me(2)-S,S-dach)(phen)](ClO(4))(2) (both>23 microM). Chiral discrimination for [Pt(S,S-dach)(phen)](ClO(4))(2) over its R,R-enantiomer was observed in all 13 cancer cell lines investigated. Moreover, [Pt(S,S-dach)(phen)](ClO(4))(2) was more active than cisplatin in all cell lines tested and shows only partial cross-resistance to cisplatin in two cisplatin resistant cell lines.     

Properties of Binuclear Rhodium(II) Complexes and Their Antibacterial Activity

Binuclear rhodium(II) complexes [Rh(2)Cl(2)(mu-OOCR)(2)(N-N)(2)], [Rh(2)(mu-OOCR)(2)(N-N)(2)(H(2)O)(2)](RCOO)(2) and [Rh(2)Cl(2)(mu-OOCCH(3))(terpy)(2)](H(3)O)Cl(2).9H(2)O (R = H, Me, Bu(n), ph, PhCHOH; N-N = 2,2'-bipyridine (bpy), 1,10-phenanthroline (phen), 2,9-dimethyl-1,10-phenanthroline (dmp) and 6,7-dimethyl-2,3- di(2-pyridyl)quinoxaline (dmpq); terpy 2,2':6',2'-terpyridine) have been synthesized and their structure and properties have been studied by electronic, IR and (1)H NMR spectroscopy. Antibacterial activity of these complexes against Staphylococcus aureus and Escherichia coli has been investigated. The most active antibacterial agents against S. aureus were [Rh(2)(OOCPh)(2)(phen)(2)(H(2)O)(2)](2+), [Rh(2)(OOCPh)(2)(dmpq)(2)(H(2)O)(2)](2+), [Rh(2)(OOCBu)(2)(phen)(2)(H(2)O)(2)](2+) and [Rh(2)-(OOCBu)(2)(bpy)(2)(H(2)O)(2)](2+) which were considerably more active than the appropriate nitrogen ligands. The complexes show rather low activity against E. coli.     

Antimicrobial, Antifertility and Antiinflammatory Approach to Tetradentate Macrocyclic Complexes of Iron(II) and Manganese(II)

Some antifertility inhibitors of 18 to 24-membered tetraazamacrocyclic complexes of iron(II) and manganese(II) have been synthesised by the template condensation using 1,3-phenylenediamine with malonic acid, succinic acid, glutaric acid and adipic acid. The reaction proceed smoothly to completion. The complexes were characterized by elemental analyses, molecular weight determinations, infrared, electronic, magnetic moment, mössbaur and mass spectral studies. The elemental analyses are consistent with the formation of the complexes [M(N₄L_n)Cl₂] (M = Fe(lI) or Mn(II)). All these complexes are stable and monomeric in nature as indicated by the molecular weight determinations. The spectral studies confirm the octahedral geometry around the central metal atom. The complexes have been screened in vitro against a number of fungi and bacteria to assess their growth inhibiting potential. The testicular sperm density and testicular sperm morphology, sperm motility, density of cauda epididymal spermatozoa and fertility in mating trials and biochemical parameters of reproductive organs have been examined and discussed.     

Synthesis, Characterisation and Anti-Fungal Activities of Some New Copper(II) Complexes of Octamethyl Tetraaza-Cyclotetradecadiene

The ligand Me(8)[14]diene, L, in its free state as well as in the dihydroperchlorate form, L.2HClO(4), coordinates copper(ll) in different salts to yield a series of [CuLX(x)] X(y)(H(2)O)(z) complexes where X = NO(3), ClO(4), NCS, Cl and Br; x and y may have values of 0 or 2 and z = 0, 1 or 2. The complex, [CuL(ClO(4))(2)].2H(2)O is found to undergo axial ligand substitution reactions with SCN(-), NO(3) and Cl(-) to give a variety of substitution derivatives: [CuL(ClO(4))(m) X(n)] where X = NCS, NO(3) and Cl; m = 0 or 1, and n = 1 or 2. The complexes .have been characterised on the basis of analytical, spectroscopic, magnetic and conductance data. The anti-fungal activities of the ligand and its complexes have been investigated against a range of phytopathogenic fungi.     

Different coordination modes of a tripod phosphine in gold(i) and silver(i) complexes

The following gold(I) and silver(I) complexes of the tritertiary phosphine 1,1,1- tris(diphenylphosphinomethyl)ethane, tripod , have been synthesised: Au(3)(tripod)X(3) [X = Cl(1), Br(2), I(3)]; [Au(3)(tripod)(2)Cl(2)]Cl (4); Au(tripod)X [X = Br(5), I(6)]; Ag(3)(tripod) (NO(3))(4) (7), Ag(tripod)NO(3) (8). They were characterized by X-ray diffraction (complexes 2, 3 and 4), (31)P NMR spectroscopy, electrospray and FAB mass spectrometry and infrared spectroscopy. Complexes 2 and 3 show a linear coordination geometry for Au(I), with relatively short Au-P bond distances. Complex 3 has a Au***Au intramolecular distance of 3.326 A degrees , while complex 2 had a short Au***Au intermolecular interaction of 3.048 A degrees . Complexes 4-6 were found by (31)P NMR spectroscopy studies to contain a mixture of species in solution, one of which crystallised as [Au(3)(tripod|)(2)Cl(2)]Cl which was shown by X-ray diffraction to contain both tetrahedral and linear Au(I), the first example of a Au(I) complex containing such a mixture of geometries. The reaction of [Au(3) (tripod)Cl(3)] (1) with tripod led successfully to the formation of [Au(3)(tripod|)(2)Cl(2)](+) and [Au(3)(tripod)(2)Cl(3)](+) and [Au(3)(tripod|)(3)Cl](2+). The silver(I) complexes, 7 and 8 appear to contain linear and tetrahedral Ag(I), respectively.     

Reactions of organic disulfides and gold(i) complexes

Gold-thiolate/disulfide exchange reactions of (p-SC(6)H(4)Cl)(2) with Ph(3)PAu(SC(6)H(4)CH(3)), dppm(AuSC(6)H(4)CH(3))(2), and dppe(AuSC(6)H(4)CH(3)) (2) were investigated. The rate of reactivity of the gold-thiolate complexes with (p-SC(6)H(4)Cl)(2) is: dppm(AuSC(6)H(4)CH(3))(2)> dppe(AuSC(6)H(4)CH(3))(2)>Ph(2)PAu (SC(6)H(4)CH(3)). This order correlates with conductivity measurements and two ionic mechanisms have been evaluated. (1)H NMR experiments demonstrate that in the reaction of dppm(AuSC(6)H(4)CH(3))(2) with (p-SC(6)H(4)Cl)(2), the mixed disulfide, ClC(6)H(4)SSC(6)H(4)CH(3), forms first, followed by the formation of (p-SC(6)H(4)CH(3))(2). The rate law is first order in (pp-SC(6)H (4)Cl)(2) and partial order in dppm(AuSC(6)H(4)CH(3))(2). Results from electrochemical and chemical reactivity studies suggest that free thiolate is not involved in the gold-thiolate/disulfide exchange reaction. A more likely source of ions is the dissociation of a proton from the methylene backbone of the dppm ligand which has been shown to exchange with D(2)O. The implications of this are discussed in terms of a possible mechanism for the gold-thiolate/disulfide exchange reaction.     

Synthesis, Characterization and Antiviral Properties of Pd(II) Complexes With Penciclovir

With the aim to improve and extend the antiviral activity of the antiherpic drug penciclovir, to a wider spectrum of viruses, we have synthesized and characterized new binary and ternary complexes of Pd(II) of formulae cis-(pen)(2)PdCl(2) and cis,[(nucl)(2)Pd(pen)(2)]Cl(2), where nucl = guanosine, inosine, cytidine or penciclovir. The characterization was mainly based on IR and (1)H NMR spectroscopy, and the results showed that in all prepared complexes, penciclovir coordinates to the metal through N7. The far-i.r. spectrum of the complex cis-(pen)(2)PdCl(2) confirmed the cis- geometry around Pd(II). All the prepared complexes were markedly active against HSV-1 and HSV-2 strains, but not against thymidine kinase-deficient HSV-1 strains.     

Ternary Complexes of cis-(NH(3))(2)PtCl(2) (cis-DDP) With Guanosine (guo), Cytidine (cyd) and the Aminoacids Glycine (gly), L-Alanine (ala), L-2-Aminobutyric Acid (2-aba), L-Norvaline (nval) and L-Norleucine (nleu)

The ternary complexes of formulae cis-[(NH(3))(2)Pt(nucl)(amac)]NO(3), where nucl = guo and cyd (guanosine and cytidine) and amac = the deprotonated aminoacids glycine (gly), L-alanine (ala), L-2-aminobutyric acid (2-aba), L-norvaline (nval) and L-norleucine (nleu), were prepared from the reactions of the binary chelated ones cis-[(NH(3))(2)Pt(nucl)(amac)]NO(3) with the nucleosides.They were characterized by (1)H, (13)C and (195)Pt NMR and IR spectra, together with elemental analysis and conductivity measurements. The aminoacids coordinate with Pt(II) in the ternary complexes with their terminal -NH(2) groups, guo through N(7) and cyd through N(3). Ligand-ligand hydrophobic interactions were also observed in the ternary complexes and were stronger with longer aliphatic chains of the aminoacids. The (3)E sugar conformation increased by 5-7% in the ternary systems, as compared to the free nucleosides, while the percentage of the gg conformation remained almost constant and the one of the anti conformation of the sugar increased also slightly. Finally, the h conformer around the C(alpha)-C(beta) bonds of the aminoacids reached a maximum in the binary systems and decreased again considerably in the ternary ones.     

Synthesis, Characterisation and Antifungal Activities of Some New Copper(II) Complexes of Isomeric 3,5,7,7,10,12,14,14-Octamethyl-1,4,8,11-Tetraazacyclotetradecanes

Three isomeric Me(8)[14]anes, L(A), L(B) and L(C), undergo complexation with copper(II) salts to form a series of [CuLX(n)(H(2)O)(x)]X(y).(H(2)O)(z) complexes where L = L(A), L(B) and L(C); X = Cl, Br, NO(3); n, x, y and z may have values of 0, 1 or 2. The complexes have been characterised on the basis of analytical, spectroscopic, magnetic and conductance data. Further, the X-ray crystal structure of one complex, [CuL(B)(OH(2))(2)](NO(3))(2), has been determined. The antifungal activity of all three isomeric ligands and their complexes has been investigated against a range of phytopathogenic fungi.     

Symmetric 1,1'-Dimethylferrocene-Derived Amino Acids: Their Synthesis, Characterization, Ligational and Biological Properties With Cu(II), Co(II) and Ni(II) Ions

Some novel symmetric 1,1'-dimethylferrocene derived amino acids have been prepared by the reaction of 1,1'-ferrocenedimethyldichloride with amino acids (glycine, alanine, phenylalanine and tyrosine). Their Cu(II), Co(II) and Ni(II) complexes, of the type [M(L)] where [M = Cu(II) and L = L(1)-L(5)] and [M(L)Cl(2)] where [M-Co(II)and Ni(II), L = L(1)-L(5)] have been prepared. The dicarboxylic acids and their metal complexes were characterized by their physical, analytical and spectral data. The [M(L)] complexes showed a square planar geometry whereas an octahedral geometry was observed for [M(L)Cl(2)] complexes. The title dicarboxylic acids and their metal complexes have also been screened for their antibacterial activity.     

Herceptin-platinum(II) binding complexes: novel cancer-cell-specific agents

We report a new series of Herceptin-platinum(II) binding complexes, Her-nLPt(II) (Her denotes Herceptin; L denotes diamino ligands and L=L1-L4; n=1, 5, or 10). Solution chemistry studies have shown that these complexes are stable under physiological conditions (pH 7.4 in PBS). The platinum(II) compound L1Pt(II)Cl(2) inhibits the growth of a panel of human cancer cell lines at sub-micromolar concentrations. Remarkable cancer-cell-specific cytotoxicity was observed with Her-nL1Pt(II) (n=1, 5, 10) toward Her2/neu-overexpressing cancer cells (SK-BR-3 and SK-OV-3) over normal fibroblast cells. Annexin V apoptosis assays in SK-BR-3 and low-Her2/neu-expressing MCF-7 breast cancer cells further confirmed the critical role of Herceptin with this cancer-cell-specific agent. It was also found that the L1Pt(II)Cl(2) complex is an efficient regulator of the apoptotic genes Bcl-2 in the treated SK-BR-3 cells. Also, enhanced regulatory effects were observed in Her-10L1Pt(II). Taken together, this study suggests a new approach for the development of mAb-platinum(II)-based targeting agents for the treatment of human cancers.     

Binding of Platinum(II) to Some Biologicaly Important Thiols

The reactions between [Pt(terpy)Cl(+) and thiols, such as glutathione, L-cysteine, D-penicillamine and thioglycolic acid have been Studied by conventional UV-VIS spectrophotometry and H NMR spectroscopy. The second-ordero rate constants, K(2), are similar for these four thiols, varying between 1.06 x 10(-2) and 6.10 x 10(+3) M(-1) s(-1) at 25( degrees )C. The activation entropies have large negative values between -100 and -200 J mol(-1) which are compatible with an associative A mechanism. However, L-methionine, as thioether ligand, is unreactive under the same experimental conditions. The obtained results have been analyzed in relation to the antitumor activity and toxicity of platinum(II) complexes.