Synthesis and "in Vitro" Trypanocidal Activity Evaluation of Some Organo-iron Compounds

Eight organo-iron ferrocene derivatives and arenocenium salts were prepared and evaluated by "in vitro" assay against one strain of Trypanosoma cruzi (Y). Six of the eight organo-iron compounds assayed, piperazinium diferrocenoate 1, eta(6)-(o-xylene)-eta(5)-(cyclopentadienyl) Iron(II) hexafluorophosphate 3, eta(6)-(mesitylene)-eta(5)-(cyclopentadienyl) iron(II) hexafluorphosphate 5, eta(6)-(durene)-eta(5)-(cyclopentadienyl) iron(II) hexafluorphosphate 6, eta(6)-(rho-chlorotoluene)-eta(5)-(cyclopentadienyl) Iron(II) hexafluorphosphate 7 and eta(6)-(chlorobenzene)-eta(5)-(cyclopentadienyl) iron(II) picrate 8 , were poorly active in the "in vitro" assays. Only two compounds 1,1'-(N-pyperidinocarbonyl) ferrocene 2(IC(50)=2.4 mug/mL) and eta(6)-(o-xylene)-eta(5)(cyclopentadienyl) iron(II) picrate 4 (IC(50)=12.08 mug/mL), were more active. Thus, some of the compounds are promising to be used against Chagas' disease as a prophylactic agents.     

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.     

Interaction of Pd(II) and Pt(II) Amino Acid Complexes With Dinucleotides

The interaction of the dinucleotides d(ApG) and d(ApA) with [Pd(aa)Cl(2)], where aa = L- or D-histidine or the methyl ester of L-histidine, and with [Pt(Met)Cl(2)], where Met = L-methionine was studied by (1)H and (13)C NMR and CD measurements. In the case of the L-histidine and L-histidineOMe, the reaction with d(ApG) appeared to give the bifunctional adducts Pd(L-Histidine)N1(1)N7(2) and Pd(L-HisOMe)N1(1)N7(2), but the behavior with D-histidine suggested the formation of the monofunctional adduct Pd(D-His)N7(2). The reaction of L-histidine with d(ApA) seemed to form the bimetallic adduct (L-His)PdN7(1)N7(2)Pd(L-His). The Pt(II)-L-methionine complex in both reactions with d(ApG) and d(ApA) seemed to yield mainly adducts Pt(L-Met)N7(1)N7(2) but the existence of adducts Pt(L-Met)N1(1)N7(2) cannot be ruled out.     

60]fullerene--metal cluster complexes: novel bonding modes and electronic communication

[60]Fullerene can bind a variety of metal clusters via eta(2)-C(60), mu-eta(2):eta(2)-C(60), and mu(3)-eta(2):eta(2):eta(2)-C(60) pi-type bonding modes. Multiple C(60) additions to a single cluster core have also been demonstrated. Modification of the coordination sphere of cluster moieties has resulted in novel transformation of the coordination mode of the C(60) ligand between pi and sigma (mu(3)-eta(1):eta(1):eta(2)-C(60) and mu(3)-eta(1):eta(2):eta(1)-C(60)) types as well as reversible interconversion between mu(3)-eta(2):eta(2):eta(2)-C(60) and mu-eta(2):eta(2)-C(60). The mu(3)-eta(2):eta(2):eta(2)-C(60) metal cluster complexes show remarkable electrochemical stability and an unusually strong electronic communication between C(60) and metal cluster centers.     

Cooperative enhancement of two-photon absorption based on electron coupling in triphenylamine-branching chromophore

Two novel, triphenylamine derivatives N-(4-(4-(diphenylamino)styryl)phenyl)acetamide and N-(4-(4-(bis-(4-(4-(diphenyl-amino)styryl)phenyl)amino)styryl)phenyl)acetamide were synthesized. The two-photon absorption of N-(4-(4-(bis-(4-(4-(diphenyl-amino)styryl)phenyl)amino)styryl)phenyl) was 17-fold greater relative to N-(4-(4-(diphenylamino)styryl)phenyl)acetamide. Linear absorption spectra, steady-fluorescence and time-resolved fluorescence spectra revealed that electron coupling originating from π-electron delocalization is responsible for the strong cooperative enhancement of TPA within the compounds. This is confirmed by the Lippert-Mataga equation.     

Synthesis and physiological activity of ureas and amides with carvone residues

The synthesis and herbicidal activity of ureas and amides with carvone residues were examined. (S)-(+)-(1) and (R)-(-)-Carvone(2) were converted to the respectively, primary amines(3) and (4) by oximation and reduction with LiAlH(4). Primary amine derivatives were further converted into the urea and amide compounds (3a) approximately (3e) and (4a) approximately (4e). The herbicidal activity of products (3a) approximately (3e) and (4a) approximately (4e) towards weeds found in a paddy field and field was measured in the pot. Products (3a) showed a particularly strong inhibitory effect on the growth of Amaranthus retroflexus(AR) and Setaria viridis(SV).     

Behaviors of plutonium and neptunium in nitric acid solutions containing hydrazine and technetium ions

The valence behaviors of plutonium and neptunium in the interaction of Pu(IV) and Np(V) with hydrazine and tetravalent uranium in technetium(VII)-containing aqueous nitric acid are reported. At [HNO₃] = 1 mol/l and Pu(IV) and Tc(VII) concentrations of ～0.1 and 0.01–0.2 mol/l, respectively, Pu(IV) is reduced to Pu(III) and is then entirely reoxidized to Pu(IV). Neptunium(V) in 1–3 M HNO₃ undergoes reduction to Np(IV) and then turns back into Np(V). The resulting solution usually contains a mixture of Np(IV) and Np(V). The reduction of Pu(IV) to Pu(III) and the reduction of Np(V) to Np(IV) are accompanied by hydrazine decomposition and by the reduction of most of the Tc(VII) to its lower valence forms. The conversions of Pu(III) into Pu(IV) and of Np(IV) into Np(V) are accompanied by the oxidation of these forms of technetium to Tc(VII). The introduction of diethylenetriaminepentaacetic acid into the reaction system makes Pu(III) more stable against reoxidation into Pu(IV) by reducing the hydrazine decomposition rate, enhances the conversion of Np(V) into Np(IV), and hampers Np(IV) oxidation to Np(V).     

Structure Determination and Anti-Inflammatory Activity of some Purine Complexes

Organomercury(II)-purine derivatives of the type, p-MeOC(6)H(4)HgL(1) (I), p-NO(2)C(6)H(4)HgCl(L(2))(II), p-MeC(6)H(4)HgCl(L(3))(III) and p-NO(2)C(6)H(4)HgCl(L(3))(IV) [ HL(1) = theophylline, L(2) = theobromine, L(3) = caffeine] have been synthesised and characterised on the basis of spectral studies (IR, UV, (1)H & (13)C NMR). The complexes have been screened for anti-inflammatory activity.     

A novel organometallic ReI complex with favourable properties for bioimaging and applicability in solid-phase peptide synthesis

Organometallic complexes possess great potential for imaging applications in biology, due to their kinetic stability and often favourable intrinsic properties. In this work we present a new class of Re(I) -tricarbonyl complexes with a substituted bis(phenanthridinylmethyl)amine (bpm) ligand. The complex Re(CO)(3) (R-bpm) could be conveniently prepared by microwave synthesis from [Re(CO)(3)(H(2)O)(3) ]Br and a suitably substituted bis(phenanthridinylmethyl)amine (R-bpm). Complex 5, with R=CH(2)-CO(2)-CH(3) , was characterized by a single-crystal X-ray structure. Complex 6 (R=CH(2)-C(6)H(4)-CO(2)H) was used in solid-phase peptide synthesis (SPPS) to label the neurotensin(8-13) (NT) fragment N-terminally. The complexes show luminescence emission with large Stokes shifts (λ(ex) =350 nm, λ(em) =570 nm). Cellular uptake and intracellular localization studies in several cell lines demonstrate the utility of the new Re(CO)(3) (R-bpm) complexes for fluorescence imaging and reveal significant differences between the simple methyl ester 5 and the NT bioconjugate 7.     

Pentamethylcyclopentadienyl ruthenium(III) vs hexamethylbenzene ruthenium(II) in sulfur-centered reactivity of their thioether-thiolate and allied complexes

The reactivity features of [Cp*Ru(III){eta(3)-tpdt)}] (7) and [(HMB)Ru(II)(eta(3)-tpdt)] (10) {Cp* = eta(5)-C(5)Me(5); HMB = eta(6)-C(6)Me(6); tpdt = 3-thiapentane-1,5-dithiolate, S(CH(2)CH(2)S(-))(2)} are presented, together with selected aspects of their (eta(3)-apdt) analogues 8 and 11 {apdt = 3-azapentane-1,5-dithiolate, HN(CH(2)CH(2)S(-))(2)}. This account will highlight the differences observed in their reactions with metal fragments of compounds of Ru and groups 10 and 11 in various coordination environments and with alkylating agents, including alpha,omega-dibromoalkanes. The mechanistic pathway of the alkylation of 7 will be discussed in some detail.     

4,4′-联苯二乙酰丙酮桥联双核镍(Ⅱ)配合物的合成及磁性研究

以4,4′-联苯二乙酰丙酮和二苯甲酰甲烷为原料合成了标题化合物,并用元素分析、电导率、红外光谱、电子光谱和电喷雾质谱对其进行了表征,确定了配合物的组成,研究了配合物在氮气气氛中的热分解行为。其变温磁化率(2~300 K)的测定结果表明,桥联双核Ni2+配合物为铁磁性自旋交换作用,Curie常数C=2.04 cm3.mol-1.K,Weiss常数θ=8.10 K。     

Antibacterial and Antifungal Activity of Zinc(II) Carboxylates With/Without N-Donor Organic Ligands

The antibacterial and antifungal activity of zinc(II) carboxylates with composition Zn(RCOO)(2)*nH(2)O(R =H-, CH(3) (-), CH(3)CH(2)CH(2) (-), (CH(3))(2)CH-, XCH(2) (-), X=Cl, Br, I, n=0 or 2), [ZnX(2)(Nia(+)CH(2)COO(-))(2)](Nia=nicotinamide, X=Cl, Br, I) and [Zn(XCH(2)COO)(2)(Caf)(2)]*2H(2)O (Car=caffeine, X=Cl, Br) is studied against bacterial strains Staphylococcus aureus, Escherichia coli and yeast Candida albicans. The structural types are assigned to the prepared compounds and the influence of (i) carboxylate chain length, (ii) substitution of hydrogen atom of carboxylate by halogen and (iii) presence of N-donor organic ligands on the biological activity is discussed.     

C₇₄ endohedral metallofullerenes violating the isolated pentagon rule: a density functional theory study

Precise studies on M(2)@C(74) (M = Sc, La) series by means of DFT methods have disclosed that certain non-IPR isomers are more stable than the IPR structure. M(2)@C(2)(13295)-C(74) and M(2)@C(2)(13333)-C(74), both of which have two pentagon adjacencies (PA), present excellent thermodynamic stability with very small energy differences. Statistical mechanics calculations on the M(2)@C(74) series reveal that M(2)@C(2)(13295)-C(74) and M(2)@C(2)(13333)-C(74) are quite favoured by entropy effects below 3000 K. Sc(2)@C(74) and La(2)@C(74) series are found to have similar electronic transfer but different electronic structures due to the distinct properties of scandium and lanthanum elements according to Natural Bond Orbital (NBO) analysis in conjunction with orbital interaction diagrams. Investigations of bonding energies reflect quite different influences of the two types of metal atoms to C(74) metallo-fullerenes. Further examinations on C(74) metallo-fullerenes uncover significant stabilization effects of metal atoms acting on PA fragments. Geometrical structures of certain non-IPR cages (from C(72) to C(76)), which exhibit splendid stabilities when encapsulating metallo-clusters, are found to be related by Stone-Wales transformation and C(2) addition. Furthermore, IR spectra and (13)C NMR spectra of M(2)@C(2)(13295)-C(74) and M(2)@C(2)(13333)-C(74) have been simulated to assist further experimental characterization.     

Aspirin analogues as dual cyclooxygenase-2/5-lipoxygenase inhibitors: synthesis, nitric oxide release, molecular modeling, and biological evaluation as anti-inflammatory agents

Analogues of aspirin were synthesized through an efficient one-step reaction in which the carboxyl group was replaced by an ethyl ester, and/or the acetoxy group was replaced by an N-substituted sulfonamide (SO(2)NHOR(2):R(2) =H, Me, CH(2)Ph) pharmacophore. These analogues were designed for evaluation as dual cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) inhibitors. In vitro COX-1/COX-2 isozyme inhibition studies identified compounds 11 (CO(2) H, SO(2)NHOH), 12 (CO(2)H, SO(2)NHOCH(2)Ph), and 16 (CO(2)Et, SO(2)NHOH) as highly potent and selective COX-2 inhibitors (IC(50) range: 0.07-0.7 μM), which exhibited appreciable in vivo anti-inflammatory activity (ED(50) range: 23.1-31.4 mg kg(-1)). Moreover, compounds 11 (IC(50) =0.2 μM) and 16 (IC(50) =0.3 μM), with a sulfohydroxamic acid (SO(2)NHOH) moiety showed potent 5-LOX inhibitory activity. Furthermore, the SO(2)NHOH moiety present in compounds 11 and 16 was found to be a good nitric oxide (NO) donor upon incubation in phosphate buffer at pH 7.4. Molecular docking studies in the active binding site of COX-2 and 5-LOX provided complementary theoretical support for the experimental biological structure-activity data acquired.     

Synthesis of the Sulphonate and Phosphonate Derivatives of Mercaptoacetyltriglycine. X-Ray Crystal Structure of Na(2)[ReO(Mercaptoacetylglycylglycylaminomethanesulphonate)].3H(2)O

Mercaptoacetyltriglycine forms complexes with (186/188)Re and (99m)Tc radionuclides that are useful in nuclear medicine because they are substrates of the renal anion transport system. However, the renal clearance of [MO(MAG(3))](2-)(MAG(3) = penta-anionic form of mercaptoacetyltriglycine, M = Re, Tc) complexes are less than ideal. Organic sulphonates are also transported by the renal anion transport system and phosphonates are similar to sulphonates in size and shape. In an effort to develop new ligands that form Re and Tc complexes and have improved renal clearances compared to [MO(MAG(3))](2-) complexes, the sulphonate and phosphonate derivatives of mercaptoacetyltriglycine were synthesized. The dianion [ReO(MAG(2)-AMS)](2-) (MAG(2)-AMS = penta-anionic form of mercaptoacetylglycylglycylaminomethanesulphonic acid) was prepared for characterization by exchange reaction of ReOCl(3)(Me(2)S)(OPPh(3)) and isolated as the disodium salt. The structure of Na(2)[ReO(MAG(2)-AMS)].3H(2)O (6) was determined by X-ray diffraction. The coordination geometry is pseudo square pyramidal, with the nitrogen and sulfur donor atoms forming a square base and the oxo ligand at the apex. The deprotonated sulphonate group has a syn conformation with respect to the oxo ligand. The renal clearances of [(99m)TcO(MAG(2)-AMS)](2-) and [(99m)TcO(MAG(2)-AMP)](3-) were similar in rats and suggest that the difference in total charge between the SO(3) (-) and PO(3) (2-) groups is not important to renal clearance. However, their renal clearances were 40-50% less than that of [(99m)TcO(MAG(3))](2-) suggesting that the size and shape of the large tetrahedral SO(3) (-) and PO(3) (2-) groups of [(99m)TcO(MAG(2)-AMS)](2-) and [(99m)TcO(MAG(2)-AMP)](3-) inhibit recognition by the renal transport system compared to the small planar CO(2) (-) group of [(99m)TcO(MAG(3))](2-).     

Interaction of Some Non-Platinum Metal Anticancer Complexes With Nucleotides and DNA and The Two-Pole Complementary Principle (TPCP) Arising Therefrom

The binding modes of some non-platinum metal anticancer complexes, Cp(2)TiCl(2), Cp(2)ZrCl(2), (CH(3))(2)SnCl(2), (C(2)H(5))(2)SnCl(2), (C(2)H(5))(2)SnCl(2)(phen) (phen=Phenanthroline) and cis-Ru(II)Cl(2)(DMSO)(3) (DMSO) (cis-RDT) with nucleotides and DNA in aqueous solution at physiological pH values were investigated by various modern techniques. 5'-dGMP with Cp(2)TiCl(2) or cis-RDT forms chelate complexes in which both N(7) and phosphate of dGMP bind to the metal center. Whereas Cp(2)ZrCl(2) and all the diorganotin compounds can bind dGMP only via the phosphate group. The investigations of the interactions between Cp(2)TiCl(2) or (C(2)H(5))(2)SnCl(2) and DNA indicate that there are two types of binding sites on DNA for Cp(2)TiCl(2), i.e., the base nitrogen rings and the phosphate group, while (C(2)H(5))(2)SnCl(2) can bind to DNA only via the phosphate group. At last, by carefully comparing and analysing the binding modes-activity relationships of the above anticancer complexes and other non-platinum and platinum anticancer complexes, a hypothesis named "Two-Pole Complementary Principle" was put forward.     

Controlled growth of SnO₂@Fe₂O₃ double-sided nanocombs as anodes for lithium-ion batteries

A novel heterostructure is developed by grafting 1D SnO(2) nanorods onto both sides of pre-grown 2D Fe(2)O(3) nanoflakes, forming a comb-like rather than tree-like branched nanostructure. The SnO(2) nanorod branches are determined to grow along the [001] direction on the (±001) planes of Fe(2)O(3) nanoflakes. The resulting SnO(2)@Fe(2)O(3) nanocombs show stabilized cycling performance and improved volumetric energy density compared to pristine Fe(2)O(3) nanoflakes presumably due to the integration of SnO(2) branches as well as the 3D hierarchical structural features.     

Anionic Pd(0) and Pd(II) intermediates in palladium-catalyzed Heck and cross-coupling reactions

The anions of PdCl(2)L(2) and Pd(OAc)(2), precursors of palladium(0) used in cross-coupling and Heck reactions, play a crucial role in these reactions. Tricoordinated anionic complexes Pd(0)L(2)Cl(-) and Pd(0)L(2)(OAc)(-) are the effective catalysts instead of the usually postulated Pd(0)L(2) complex. The anion ligated to the palladium(0) affects the kinetics of the oxidative addition to ArI as well as the structure and reactivity of the arylpalladium(II) complexes produced in this reaction. Thus, pentacoordinated anionic complexes are formed, ArPdI(Cl)L(2)(-) or ArPdI(OAc)L(2)(-), the precursor of neutral trans-ArPd(OAc)L(2), instead of the usually postulated trans-ArPdIL(2) complex (L = PPh(3)).     

Synthesis and Anti-Candida Activity of Cobalt(II) Complexes of Benzene-1,2-Dioxyacetic Acid (bdoaH(2)). X-Ray Crystal Structures of [Co(bdoa)(H(2)O)(3)] 3.5H(2)O and {[CO(phen)(3)](bdoa)}(2)24H(2)O (phen = 1,10-Phenanthroline)

Co(CH(3)CO(2))(2)4H(2)O reacts with benzene-1,2-dioxyacetic acid (bdoaH(2)) to give the Co(2+) complexes [Co(bdoa)(H(2)O)(3)]H(2)O (1a) and [Co(bdoa)(H(2)O)(3)] 3.5H(2)O (1b). Subsequent reaction of 1a with 1,10- phenanthroline produces [CO(phen)(3)] bdoa10H(2)O (2a) and {[CO(phen)(3)](bdoa)}(2)24H(2)O (2b). Molecular structures of 1b and 2b were determined crystallographically. In 1b the bdoa(2-)- ligates the metal by two carboxylate oxygens and two ethereal oxygens, whereas in 2b the bdoa(2-) is uncoordinated. The Mn(2+) and Cu(2+) complexes [Mn(bdoa)(phen)(2)]H(2)O (3) and [Cu(pdoa)(imid)(2)] (4) were also synthesised, 1a-4 and other metal complexes of bdoa H(2) (metal = Mn(2+), Co(2+) ,Cu(2+), Cu(+) ) were screened for their ability to inhibit the growth ofhe yeast Candida albicans. Complexes incorporating the 1,10-phenanthroline ligand were the most active.     

11βHSD1抑制剂1-(4-三氟甲氧基苯甲酰基)-4-(4-甲氧基苯甲酰基)哌啶的合成研究

以4-甲氧羰基哌啶盐酸盐(1)和对三氟甲氧基苯甲酰氯(2)为起始原料,在三乙胺的作用下以92.7%的收率制得1-(4-三氟甲基苯甲酰基)-4-甲氧羰基哌啶(3);化合物(3)在羰基二咪唑与N,O-二甲基羟胺盐酸盐(4)作用下,以89.9%的收率制得1-(4-三氟甲氧基苯甲酰基)-4-(N-甲基-N-甲氧基羰基)哌啶(5);化合物(5)和4-甲氧基苯基溴化镁(6)偶联,以60.1%的收率制得化合物1-(4-三氟甲氧基苯甲酰基)-4-(4-甲氧基苯甲酰基)哌啶(7)。三步反应总收率50.0%。