Cd(II) and Cu(II) complexes of polydentate Schiff base ligands: synthesis, characterization, properties and biological activity

We report the synthesis of the Schiff base ligands, 4-[(4-bromo-phenylimino)-methyl]-benzene-1,2,3-triol (A₁), 4-[(3,5-di-tert-butyl-4-hydroxy-phenylimino)-methyl]-benzene-1,2,3-triol (A₂), 3-(p-tolylimino-methyl)-benzene-1,2-diol (A₃), 3-[(4-bromo-phenylimino)-methyl]-benzene-1,2-diol (A₄), and 4-[(3,5-di-tert-butyl-4-hydroxy-phenylimino)-methyl]-benzene-1,3-diol (A₅), and their Cd(II) and Cu(II) metal complexes, stability constants and potentiometric studies. The structure of the ligands and their complexes was investigated using elemental analysis, FT-IR, UV-Vis, ¹H and ¹³C NMR, mass spectra, magnetic susceptibility and conductance measurements. In the complexes, all the ligands behave as bidentate ligands, the oxygen in the ortho position and azomethine nitrogen atoms of the ligands coordinate to the metal ions. The keto-enol tautomeric forms of the Schiff base ligands A₁-A₅ have been investigated in polar and non-polar organic solvents. Antimicrobial activity of the ligands and metal complexes were tested using the disc diffusion method and the strains Bacillus megaterium and Candida tropicalis.Protonation constants of the triol and diol Schiff bases and stability constants of their Cu²⁺ and Cd²⁺ complexes were determined by potentiometric titration method in 50% DMSO-water media at 25.00 ± 0.02 °C under nitrogen atmosphere and ionic strength of 0.1 M sodium perchlorate. It has been observed that all the Schiff base ligands titrated here have two protonation constants. The variation of protonation constant of these compounds was interpreted on the basis of structural effects associated with the substituents. The divalent metal ions of Cu²⁺ and Cd²⁺ form stable 1:2 complexes with Schiff bases.The Schiff base complexes of cadmium inhibit the intense chemiluminescence reaction in dimethylsulfoxide (DMSO) solution between luminol and dioxygen in the presence of a strong base. This effect is significantly correlated with the stability constants K_CdL of the complexes and the protonation constants K_OH of the ligands; it also has a nonsignificant association with antibacterial activity.     

Studies on the synthesis,characterisation and antimicrobial activity of new Co(II), Ni(II) and Zn(II) complexes of Schiff base derived from ninhydrin and glycine

Summary For the first time, Co(II), Ni(II) and Zn(II) complexes have been synthesized involving an intermediate Schiff base, indane-1,3-dione-2-imine-N-acetic acid the condensed product of ninhydrin and glycine. These coloured complexes were characterised by elemental analysis, molar conductivity, thermogravimetric analyses/differential thermal analysis, infrared, magnetic susceptibility, NMR and electronic spectral studies. Mechanisms for their formation have been proposed. The experimental studies reveal that the complexes possess octahedral stereochemistry whereas the Schiff base behaves as a monobasic tridentate ligand. A molecular structure for the metal complexes is also proposed. A comparative study of the antimicrobial activity of ninhydrin and the corresponding metal complexes againstEscherichia coli, Proteus mirabilis, Staphylococcus aureus andStreptococcus faecalis has been undertaken and the results are discussed.     

Design,synthesis, in vitro anticancer,antioxidant and antibacterial activity; DNA/BSA binding,photoleavage and docking studies of Cu(II) ternary metal complexes

Abstract

Three mononuclear, mixed ligand ternary Cu(II) complexes of 3-((Z)-1-(2-hydroxyphenylimino)ethyl)-4-hydroxy-6-methyl-2H-pyran-2-one (HEHMP) viz; [Cu-(Phen) (HEHMP)] (1a), [Cu-(Bpy)(HEHMP)] (1?b) and [Cu-Bpy(NCS)(HEHMP)] (1c) were synthesized and characterized by data obtained from various spectral techniques. The binding affinities of these complexes with calf thymus DNA (CT-DNA) and bovine serum albumin (BSA) protein were explored by absorption and fluorescence quenching titrations. The results indicated strong affinity of the title compounds to bind with both CT-DNA and BSA. The antioxidant properties of the synthesized compounds evaluated by free-radical scavenging method using spectrophotometric technique indicated their affirmative potential activity. Gel electrophoresis experiments revealed the efficacy of metal complexes in resulting the cleavage of pBR322 supercoiled DNA. In vitro cytotoxicity studies of these complexes evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay against HeLa and MCF-7 cancer cell lines indicated relatively high effectiveness of the complex 1c. Confocal microscopy signified the potential of the complexes to induce apoptosis in HeLa cell lines. In addition, the antibacterial activity of the compounds carried out by disc diffusion method revealed significantly enhanced antibacterial activity in Cu (II) ternary complexes compared to the activity of ligands in unbound form signifying the implicit role of metal ion in inducing lipophilic character.     

Surfactant-cobalt(III) complexes: synthesis, critical micelle concentration (CMC) determination, DNA binding, antimicrobial and cytotoxicity studies

A new class of surfactant-cobalt(III) complexes, cis-[Co(bpy)₂(C₁₁H₂₃NH₂)Cl]²⁺ (1) and cis-[Co(phen)₂(C₁₁H₂₃NH₂)Cl]²⁺ (2) (bpy = 2,2′-bipyridyl, phen = 1,10-phenanthroline), have been synthesized and characterized. The critical micelle concentration (CMC) values of these complexes in aqueous solution were obtained from conductance measurements. The specific conductivity data (at 298, 308, 318 and 328 K) served for the evaluation of the temperature-dependent CMC and the thermodynamics of micellization . The interaction between these complexes and calf thymus DNA in aqueous solution was investigated adopting electronic absorption spectroscopy, emission spectroscopy and viscosity measurements. Results suggest that the two complexes can bind to DNA via groove binding, van der Waals interactions and/or electrostatic interactions. The complexes showed moderate antibacterial and antifungal activities against certain selected microorganisms. The cytotoxic activity of the complexes on HBL-100 human breast cancer cells was determined adopting MTT assay and specific staining techniques, which revealed that the viability of the cells thus treated was significantly decreased and the cells succumbed to apoptosis as seen in the changes in the nuclear morphology and cytoplasmic features. Furthermore, the influence of complexes on normal cell lines from green monkey kidney was also determined and the results indicate that the effect is small on inhibition of viability.     

Self-assembled synthesis, characterization and antimicrobial activity of zinc(II) salicylaldimine complexes

One-pot metal promoted reactions between salicylaldehyde and 4-methyl-1,3-phenylenediamine in the presence of metal salts acting as template agents yield zinc(II) salicylaldimine complexes containing N,N′-bis(salicylidene)-4-methyl-1,3-phenylenediamine (H₂L) as a result of the [2 + 1] Schiff base condensation. The complexes of formula [Zn(HL)Cl(H₂O)₂] · C₂H₅OH and [Zn(H₂L)₂Cl(NO₃)(H₂O)] · CH₃OH were characterized as powder solids and in solution by spectroscopic methods (IR, ¹H and ¹³C NMR, FAB-MS, ESI-MS, UV-Vis), thermogravimetric and elemental analysis, potentiometry, and tested for antimicrobial activity against Staphylococcusaureus in a minimum inhibitory concentration (MIC) experiment. In these two powder solid species, the salicylaldimine, formed in a self-assembly process, acts in two different coordination modes: as monodeprotonated bidentate chelator with an N,O donor set or as a neutral monodentate using exclusively oxygen as the donor atom without involving the nitrogen atoms in the coordination. However, crystals of these two complexes are isomorphous, with 1:2 metal:ligand stoichiometry, and display the latter, relatively rare coordination pattern. In solution, the presence of a 1:1 complex of monodeprotonated state is only detected. The complexes exhibit antimicrobial activity against S.aureus.     

Palladium(II) complexes of quinolinylaminophosphonates: synthesis, structural characterization, antitumor and antimicrobial activity

Three types of palladium(II) halide complexes of quinolinylaminophosphonates have been synthesized and studied. Diethyl and dibutyl [α-anilino-(quinolin-2-ylmethyl)]phosphonates (L1, L2) act as N,N-chelate ligands through the quinoline and aniline nitrogens giving complexes cis-[Pd(L1/L2)X₂] (X═Cl, Br) (1-4). Their 3-substituted analogues [α-anilino-(quinolin-3-ylmethyl)]phosphonates (L3, L4) form dihalidopalladium complexes trans-[Pd(L3/L4)₂X₂] (5-8), with trans N-bonded ligand molecules only through the quinoline nitrogen. Dialkyl [α-(quinolin-3-ylamino)-N-benzyl]phosphonates (L5, L6) give tetrahalidodipalladium complexes [Pd₂(L5/L6)₃X₄] (9-12), containing one bridging and two terminal ligand molecules. The bridging molecule is bonded to the both palladium atoms, one through the quinoline and the other through the aminoquinoline nitrogen, whereas terminal ligand molecules are coordinated each only to one palladium via the quinoline nitrogen. Each palladium ion is also bonded to two halide ions in a trans square-planar fashion. The new complexes were identified and characterized by elemental analyses and by IR, UV-visible, ¹H, ¹³C and ³¹P nuclear magnetic resonance and ESI-mass spectroscopic studies. The crystal structures of complexes 1-4 and 6 were determined by X-ray structure analysis. The antitumor activity of complexes in vitro was investigated on several human tumor cell lines and the highest activity with cell growth inhibitory effects in the low micromolar range was observed for dipalladium complexes 11 and 12 derived from dibutyl ester L6. The antimicrobial properties in vitro of ligands and their complexes were studied using a wide spectrum of bacterial and fungal strains. No specific activity was noted. Only ligands L3 and L4 and tetrahalidodipalladium complexes 9 and 11 show poor activities against some Gram positive bacteria.     

Reduced amino acid Schiff base containing ruthenium(III) complexes: Synthesis,characterization, DNA interaction,and in vitro cytotoxicity

A number of reduced amino Schiff base ligands and corresponding ruthenium(III) complexes were designed and prepared based on the fact that amino acids not only possess multiple coordinate atoms but also improve the solubility of drugs in the body. The interaction of the complexes with calf thymus DNA was analyzed with spectroscopic methods of ultraviolet‐visible absorption spectra, DNA competitive binding with ethidium bromide, circular dichroism spectra, and DNA melting experiments, and DNA viscosity measurements, indicating that the complexes bind to DNA primarily in the grooving mode. With respect to the ligands, the cytotoxicity in vitro of the complexes against Hela, A549, and MCF‐7 cells was much enhanced, with most of the IC₅₀ values less than 50 μM or even comparable with those of cisplatin.     

DNA binding affinity and antioxidative activity of copper(II) and zinc(II) complexes with a novel hesperetin Schiff base ligand

A hesperetin Schiff base ligand (H₄L) and its complexes, [H₃CuL·OAc]·H₂O and [H₃ZnL·OAc]·2H₂O, have been synthesized and characterized on the basis of elemental analysis, molar conductivity, ¹H NMR, mass spectra, UV-Vis spectra and IR spectra. The binding of these two complexes and the ligand to DNA has been investigated by ultraviolet absorption spectroscopy, fluorescence spectroscopy and viscosity measurements. The experiments indicate that all the compounds can bind to DNA through an intercalative mode and the complexes intercalate into DNA more deeply than that of the ligand. In addition, the antioxidative activity was also determined. The 50% inhibition obtained for the ligand and its complexes demonstrates that, compared to the ligand, the complexes exhibit higher antioxidative activity in the suppression of and HO.     

Sugar interaction with metal ions: synthesis,spectroscopic, and structural analysis of Zn(II), Cd(II), and Hg(II) complexes,containing d-glucuronate anion

Interaction between D-glucuronic acid and Zn(II), Cd(II), and Hg(II) metal ion salts has been studied in solution and solid complexes of the type M(D-glucuronate)X · nH₂O and M(D-glucuronate)₂·nH₂O, where M = Zn(II), Cd(II), and Hg(II), X = Cl⁻ or Br⁻, and n = 0–2 were isolated and characterized. Spectroscopic and other evidence indicated that in the metal-halide-sugar complexes the Zn(II) and Cd(II) ions bind to two D-glucuronate moieties via 06, 05 of the carboxyl oxygen atoms of the first and 04, 06' of hydroxyl and carbonyl groups of the second as well as to two H₂O molecules, whereas in the corresponding M(D-glucuronate)₂ · nH₂O salts, the metal ions are bonded to two sugar anions through 06 and 06' of the ionized carboxyl groups and two water molecules, resulting in a six-coordination around each metal cation. The Hg(II) ion binds to 06 and 05 oxygen atoms of a sugar anion and to a halide anion or water molecule, in the Hg(D-glucuronate)X·nH₂O compounds, while in the corresponding metal-glucuronate salt mercury is bonded to 06 and 06' of the two glucuronate anions with four-coordination around the Hg(II) ion. The β-anomer sugar conformation is predominant in the free acid and in these series of metal-sugar complexes.     

Copper(II), cobalt(II) and nickel(II) complexes of lapachol: synthesis,DNA interaction,and cytotoxicity

Three novel copper(II), cobalt(II), and nickel(II) complexes of lapachol (Lap) containing 110-phenanthroline (phen) ligand, [M(Lap)₂(phen)] (M=Cu(II), 1, Co(II), 2, and Ni(II), 3), have been synthesized and characterized using, elemental analysis and spectroscopic studies. Their interactions with calf thymus DNA (CT DNA) were investigated using viscosity, thermal denaturation, circular dichorism, fluorescence quenching, and electronic absorption spectroscopy. The DNA cleavage abilities of 1–3 have been studied, where cleavage activity of copper complex 1 is more than the complexes 2 and 3. The in vitro cytotoxic potential of the complexes 1–3 against human cervical carcinoma (HeLa), human liver hepatocellular carcinoma (HepG-2), and human colorectal adenocarcinoma (HT-29) cells indicated their promising antitumor activity with quite low IC₅₀ values in the range of .15–2.41 μM, which are lower than those of cisplatin.     

Interaction of Fe(III) with herbicide-carboxylato ligands. Di-, tri- and tetra-nuclear compounds: Structure, antimicrobial study and DNA interaction

The iron complexes with the phenoxyalkanoic acids 2,3-D = 2,3-dichlorophenoxyacetic acid, 3,4-D = 3,4-dichlorophenoxyacetic acid, 2,4,5-T = 2,4,5-trichlorophenoxyacetic acid, and mcpa = 2-chloro-4-methyl-phenoxyacetic acid, in the presence or not of a nitrogen donor heterocyclic ligand, py = pyridine, bipy = 2,2′ bipyridine, phen = 1,10-phenanthroline, were prepared and characterized.The interaction of Fe(III) with phenoxyalkanoic acids and bipy or phen leads to dinuclear neutral complexes, while the presence of py favors tetranuclear neutral forms. The crystal structures of [Fe₂OCl₂(mcpa)₂(bipy)₂] · 0.25(bipy) · 0.8MeCN (1a), and {[Fe₄O₂(mcpa)₆Cl₂(py)₄] · 2MeCN} (3a), have been determined. DNA-Fe(III) complex interaction studies suggest that iron complexes promote the hydrolytic cleavage of double stranded DNA that seems to be oxygen independent, while pDNA shows cross-linking with many molecules of the iron clusters. Antibacterial screening data showed that the presence of chelating agents, bipy or phen, increased the efficiency of iron complexes.     

Synthesis,spectral studies,DNA binding,photocleavage, antimicrobial and anticancer activities of isoindol Ru(II) polypyridyl complexes

Abstract

Three new Ru(II) polypyridyl complexes [Ru(phen)₂CIIP]²⁺ (1) {CIIP = 2-(5-Chloro-3a H-Isoindol-3-yl)-1H-Imidazo[4,5-f][1, 10]phenantholine} (phen = 1, 10 phenanthroline), [Ru(bpy)₂CIIP]²⁺ (2) (bpy = 2, 2′ bipyridine) and [Ru(dmb)₂CIIP]²⁺ (3) (dmb = 4, 4′-dimethyl 2, 2′ bipyridine) were synthesized and characterized by different spectral methods. The DNA-binding behavior of these complexes was investigated by absorption, emission spectroscopic titration and viscosity measurements, indicating that these three complexes bind to CT-DNA in an intercalative mode, but binding affinities of these complexes were different. The DNA-binding constants K_b of complexes 1, 2 and 3 were calculated in the order of 10⁶. All three complexes cleave pBR322 DNA in photoactivated cleavage studies and exhibit good antimicrobial activity. Anticancer activity of these Ru(II) complexes was evaluated in MCF7 cells. Cytotoxicity by MTT assay showed growth inhibition in a dose dependent manner. Cell cycle analysis by flow cytometry data showed an increase in Sub G1 population. Annexin V FITC/PI staining confirms that these complexes cause cell death by the induction of apoptosis.     

Design,synthesis, MTT assay,DNA interaction studies of platinum(II) complexes

The square planar Pt(II) complexes of the type [Pt(Lⁿ)(Cl₂)] (where Lⁿ = L^1?3 = thiophene-2-carboxamide derivatives and L^4?6 = thiophene-2-carbothioamide derivatives) have been synthesized and characterized by physicochemical and various spectroscopic studies. MIC method was employed to inference the antibacterial potency of complexes in reference to free ligands and metal salt. Characteristic binding constant (K_b) and binding mode of complexes with calf thymus DNA (CT-DNA) were determined using absorption titration (0.76–1.61 × 10⁵ M^?1), hydrodynamic chain length assay and fluorescence quenching analysis, deducing the partial intercalative mode of binding. Molecular docking calculation displayed free energy of binding in the range of –260.06 to –219.63 kJmol^?1. The nuclease profile of complexes towards pUC19 DNA shows that the complexes cleave DNA more efficiently compared to their respective metal salt. Cytotoxicity profile of the complexes on the brine shrimp shows that all the complex exhibit noteworthy cytotoxic activity with LC₅₀ values ranging from 7.87 to 15.94 μg/mL. The complexes have been evaluated for cell proliferation potential in human colon carcinoma cells (HCT 116) and IC₅₀ value of complexes by MTT assay (IC₅₀ = 125–1000 μg/mL).     

Synthesis, structural characterization, antiradical and antidiabetic activities of copper(II) and zinc(II) Schiff base complexes derived from salicylaldehyde and beta-alanine

A series of copper(II) and zinc(II) complexes involving a tridentate O,N,O'-donor Schiff base derived from salicylaldehyde and beta-alanine {i.e. N-salicylidene-beta-alanine(2-), (L)}, having the composition [Cu(2)(L)(2)(H(2)O)].H(2)O (1), [Cu(L)(H(2)O)](n) (2), and [Zn(L)(H(2)O)](n) (3), have been prepared and characterized by elemental analyses, UV-visible (UV-VIS), FT-IR and ESI-MS spectra, and thermal analyses. Complexes 1 and 2 have been investigated by single crystal X-ray analysis and also by temperature dependent magnetic susceptibility measurements (294-80K). All prepared complexes have been evaluated by the antiperoxynitrite activity assay and alloxan-induced diabetes model. The significant antioxidant and antidiabetic activities have been found in the case of both copper(II) complexes 1 and 2. In spite of first two complexes, the zinc(II) complex 3, as well as the potassium salt of the ligand (KHL) showed only insignificant protective effect against the tyrosine nitration in vitro.     

Synthesis and characterization of Mg(II), Mn(II), Zn(II) and Cd(II) complexes with a new heptaaza Schiff base pendant-armed macrocycle: X-ray crystal structure, NMR and computational study

New 2-aminoethyl pendant-armed Schiff base macrocyclic complexes, [ML⁷]²⁺ (M = Mn(II), Mg(II), Zn(II) and Cd(II)), have been prepared via M(II) templated [1 + 1] cyclocondensation of 2,6-diacetylpyridine with a new branched hexamine, N,N,N′,N′-tetrakis(2-aminoethyl)-2,2-dimethylpropane-1,3-diamine. The ligand is a 16-membered pentaaza macrocycle having two 2-aminoethyl pendant arms [L⁷ is 2,14-dimethyl-6,10-bis(2-aminoethyl)-3,6,10,13,19-pentaazabicyclo[13.3.1]8,8-dimethylnonadeca-1(19),2,13,15,17-pentaene]. The crystal structures of [MnL⁷]²⁺ and [MgL⁷]²⁺ were determined from X-ray diffraction data. The geometry of the coordination sphere of complexes is a slightly distorted pentagonal bipyramid with the metal ion located within a pentaaza macrocycle and two pendant amines coordinating on opposite sides. All complexes were characterized by IR, microanalysis and except of [MnL⁷]²⁺ by ¹H NMR, ¹³C NMR, DEPT135, COSY(H, H) and HMQC spectroscopy. The data indicate that the structure is pentagonal bipyramidal in each case. The structure of all complexes has also been theoretically studied by ab initio Hartree-Fock and density functional theory methods.     

DNA interaction of some polymer-copper(II) complexes containing 2,2'-bipyridyl ligand and their antimicrobial activities

The water soluble polymer-copper(II) complex samples, [Cu(bpy)(2)(BPEI)]Cl(2).4H(2)O (bpy=2,2'-bipyridine, BPEI=branched polyethyleneimine), with varying degrees of copper(II) chelates content in the polymer chain, were prepared by ligand substitution method in water-ethanol medium and characterized by Infra-red, UV-visible, EPR spectral and elemental analysis methods. The interaction of these polymer-copper(II)-bipyridyl complex samples with calf thymus DNA has been explored by using electronic absorption spectroscopy, emission spectroscopy and gel electrophoresis techniques. The observed changes in the physico-chemical features of the polymer-copper(II) complex on binding to DNA suggest that the complex binds to DNA with electrostatic interaction mode. A sample of polymer-copper(II) complex was tested for its antibacterial and antifungal activity and it was found to have good antibacterial and antifungal activities.     

Anticandidal cytotoxicity,antitumor activities,and purified cell wall modulation by novel Schiff base ligand and its metal (II) complexes against some pathogenic yeasts

The preparation of metal (II) complexes [CoCl₂·6H₂O, Ni(CH₃COO)₂·4H₂O, Cu(CH₃COO)₂·2H₂O, and Zn (CH3COO)₂ ·2H₂O] with 2[N-(cinnamlidene) amino]-5-nitro phenol as a novel ligands and their biological evaluation against candida species was studied. The inhibitory effects of the tested metal complexes were tested against six pathogenic yeasts (Candida albicans, C. fructus, C. glabrata, C. oleophila, C. parapsilosis, and C. tropicalis). The effect of the most efficient metal complex (Zn(II) complex) was more pronounced at 1.25 μg/ml, while Ni(II) complex was exhibited the least suppressive effect. Co(II) and Zn(II) complexes act as potential antitumor agents, while Zn(II) complex has shown promising cytotoxic activity with slow candidal respiration rate. Addition of Zn(II) complex leading to suppression of cell wall components in all candidal cells accompanied with leaking out of amino acids. Purification of the cell wall mannoprotein of C. glabrata treated with Zn(II) complex was established, resulting one pure fissured protein peak. Cell wall protein modulation was showed by appearance of two new protein bands with molecular weights of 72 and 39 KDa in C. glabrata cells treated with Zn(II) complex compared with one pure protein band 55.6 KDa in the non treated yeast cell.     

A new Schiff base copper (II) complex derived from estrone and d-glucosamine: Synthesis,characterization and its interaction with DNA

A novel copper (II) complex of Schiff base prepared through condensation between 2-formyl-17-deoxyestrone and d-glucosamine was synthesized and characterized. Fluorescence spectroscopy was conducted to assess their binding ability with CT-DNA. The results showed that the copper (II) complex could bind to DNA with a weak intercalative mode. The interaction between the copper (II) complex and DNA was also investigated by gel electrophoresis. Interestingly, we found that the complex could cleave plasmid DNA (pUC19) to nicked and linear forms through an oxidative mechanism without the use of exogenous agents.     

Synthesis, crystal structure, characterization of zinc(II), cadmium(II) complexes with 3-thiophene aldehyde thiosemicarbazone (3TTSCH). Biological activities of 3TTSCH and its complexes

The reaction of zinc(II) chloride, cadmium(II) chloride and bromide with 3-thiophene aldehyde thiosemicarbazone leads to the formation of a series of new complexes. They have been characterized by spectroscopic studies: infrared, ¹H NMR, and electronic spectra. The crystal structures of the compound [ZnCl₂(3TTSCH)₂] and [CdBr₂(3TTSCH)₂] have been determined by X-ray diffraction methods. For the complexes [ZnCl₂(3TTSCH)₂] and [CdBr₂(3TTSCH)₂], the central ion is coordinated through the sulfur, and for the complexes [CdCl₂(3TTSCH)], [CdBr₂(3TTSCH)] the ion is coordinated through the sulfur as well as azomethine nitrogen atom of the thiosemicarbazone. In addition, fungistatic and bacteriostatic activities of both ligand and complexes have been evaluated. Cadmium(II) complexes have shown the most significant activities.