Synthesis of Water-Soluble Copolymers of N-vinylpyrrolidone with N-vinyldithiocarbamate as Multidentate Polymeric Chelation Systems and Their Complexes with Indium and Gallium.

Dithiocarbamate (DTC) derivatives of N-vinylpyrrolidone-N-vinylamine (VP-VA) copolymers were synthesized via reaction between the copolymers and carbon disulfide in alkaline medium; molecular masses of the products were 12 and 29 kDa; the VP:VDTC ratios were 94:6 and 83:17 mol.%. Complexation between the obtained DTC derivatives and metal ions (indium and gallium) was investigated. It was demonstrated that metal-DTC ligand complexes with 1:3 ratio between components were formed. Gallium metal-polymer complexes (MPC) were unstable in solution. Individual indium MPC were isolated and characterized by spectral and chromatographic methods. Unlike similar gallium MPC, they appeared to be stable in histidine challenge reaction.

Toxicity of the biocide polycarbamate, used for aquaculture nets, to some marine fish species.

We investigated toxic effects of the antifouling biocide polycarbamate (PC) on marine fish by conducting acute, early-life stage toxicity (ELS), and embryo toxicity tests. Mummichog (Fundulus heteroclitus) 96-h LC50 values for hatched larvae (body weight about 2.0 mg) and juveniles (660 ±â€¯36 mg) were about 12 and 630 µg/L, respectively. The ELS test using mummichog embryos yielded a lowest-observed-effect concentration of 3.9 µg/L and a no-observed-effect concentration of 2.1 µg/L with growth as the most sensitive endpoint. The embryo toxicity test for spotted halibut (Verasper variegatus) revealed a 10-d EC50 of 8.1 µg/L with abnormality as an endpoint. During the ELS and embryo toxicity tests, morphological abnormalities (notochord undulation) were induced in the embryos. Biochemical and gene-expression analysis suggest that PC-induced morphological abnormalities involve disruption of lysyl oxidase-mediated collagen fiber organization, essential for notochord formation, and inhibition of gene expression related to notochord formation.

Adsorption performances and mechanisms of the newly synthesized N,N'-di (carboxymethyl) dithiocarbamate chelating resin toward divalent heavy metal ions from aqueous media.

N,N'-di (carboxymethyl) dithiocarbamate chelating resin (PSDC) was synthesized by anchoring the chelating agent of N,N'-di (carboxymethyl) dithiocarbamate to the chloromethylated PS-DVB (Cl-PS-DVB) matrix, as a new adsorbent for removing divalent heavy metal ions from waste-stream. The physicochemical structures of Cl-PS-DVB and PSDC were elaborately characterized using Fourier transform infrared spectroscopy (FT-IR), elemental analysis (EA), and were further morphologically characterized using BET and BJH methods. The adsorption performances of PSDC towards heavy metals such as Cu(II), Pb(II) and Ni(II) were systematically investigated, based upon which the adsorption mechanisms were deeply exploited. For the above target, the classic batch adsorption experiments were conducted to explore the kinetics and isotherms of the removal processes with pH-value, initial concentration, temperature, and contact time as the controlling parameters. The kinetic and isotherm data could be well elucidated with Lagergren-second-order equation and Langmuir model respectively. The strong affinity of PSDC toward these target soft acids could be well demonstrated with the electrostatic attraction and chelating interaction caused by IDA moiety and sulphur which were namely soft bases on the concept of hard and soft acids and bases (HASB). Thermodynamic parameters, involving DeltaH(o), DeltaS(o) and DeltaG(o) were also calculated from graphical interpretation of the experimental data. The standard heats of adsorption (DeltaH(o)) were found to be endothermic and the entropy change values (DeltaS(o)) were calculated to be positive for the adsorption of Cu(II), Pb(II) and Ni(II) ions onto the tested adsorbents. Negative values of DeltaG(o) indicated that adsorption processes for all tested metal ions onto PSDC were spontaneous.

The effects of the wood preservative copper dimethyldithiocarbamate in the hippocampus of maternal and newborn Long-Evans rats.

The potential toxic effects on human health and deleterious effects to the environment by copper dimethyldithiocarbamate (CDDC), an alternative wood preservative to chromated copper arsenate (CCA) have not been investigated. This study describes the neurotoxicity and accumulation of copper in the hippocampus of maternal and newborn Long-Evans rats following a subacute exposure to CDDC. Pregnant rats (220-270g) were treated daily with 0mg/kg, 25mg/kg, 50mg/kg, or 75mg/kg CDDC by oral gavage starting from day 6 of gestation and continuing to parturition. Following parturition, maternal and newborn rats were euthanized and brain tissues were removed, processed, and stored for analysis. Electron microscopy revealed demyelination and by-products of peroxidative damage in treated maternal hippocampi. Treated newborn hippocampi exhibited numerous degenerating mitochondria, membrane bound inclusion bodies, and vacuoles containing degraded structures. Graphite furnace atomic absorption spectrophotometry (GFAAS) demonstrated a significant increase in copper concentration in the tissues of treated animals as compared to controls. Western blot analysis revealed an induction of stress proteins HO-1 and Hsp70 and the formation of 4-hydroxy-2-nonenal (4HNE) adducts. CDDC was shown to be toxic to the brains, at all doses used and this toxicity is attributable to copper-induced lipid peroxidation.

Experimental and theoretical vibrational study of bis(N,N-dimethylthiocarbamoylthio)acetic acid.

Harmonic vibrational analysis at HF/3-21G level is performed on the ab initio optimized molecular structure of bis(N,N-dimethylthiocarbamoylthio)acetic acid, and the outcome used in assigning the infrared spectrum of the acid. The calculated spectrum compares well with the experimental solid-state FT IR spectrum recorded at 298 and at 77 K.

[Radiolabeling and biodistribution of 62Cu-dithiocarbamate--an application for the new 62Zn/62Cu generator].

The newly developed 62Zn/62Cu generator system has made available the production of the short-lived 62Cu (T1/2 = 9.8 min) positron radionuclide, eluted as 62Cu-glycine. In the search for 62Cu labeled radiopharmaceuticals for positron CT (PET) brain diagnostic studies, two ligands N,N-diethyl- and N,N-dimethyl-dithiocarbamic acid (DDC and DmDC) were selected, based on their Cu chelating abilities and the neutral lipophilic character of their copper chelates. In the present work, an in vitro study with non-radioactive Cu-glycine showed that both ligands easily formed the stable, neutral Cu-DDC and Cu-DmDC chelates (1:2 metal-ligand complexes) based on the ligand exchange reaction. Then the 62Zn/62Cu generator eluate, the 62Cu-glycine was used for the radiolabeling of DDC and DmDC. The following HPLC analysis revealed that the ligand exchange reaction proceeded rapidly; the radiochemical purities of 62Cu-DDC and 62Cu-DmDC were extremely high (non-detectable 62Cu-glycine) and both chelates were more lipophilic than 62Cu-glycine. The mouse biodistribution of both radiolabeled compounds, 62Cu-DDC and 62Cu-DmDC indicated a brain accumulation of 2.8 and 5.3 times higher than 62Cu-glycine, 15 min post injection, respectively. The brain accumulation observed with both 62Cu-DDC and 62Cu-DmDC might be due to their stable, neutral and lipophylic character; the latter enhanced by the presence of the methylated side chains. The gathered results indicated the applicability of dithiocarbamic acid derivatives in the production of new 62Cu-labeled compounds using the 62Zn/62Cu generator system based on the ligand exchange reaction with 62Cu-glycine eluate. Further studies with Cu-dithiocarbamic acid derivatives for development of new generator-produced 62Cu positron radiopharmaceuticals can be recalled.

Enhancement of cytotoxicity of bleomycin by dithiocarbamates: formation of bis(dithiocarbamato) cu(II).

Properties of the reactions of dithiocarbamates and their Cu(II) or Fe(III) complexes with Ehrlich cells were determined and related to their effects on the inhibition of cell proliferation caused by bleomycin and Cu bleomycin. In complete culture medium containing Eagle's minimal essential medium plus Earles salts and 2.5% fetal calf serum, dimethyl- and diethyldithiocarbamates and their copper complexes inhibit cell proliferation and cause cell death. The copper complexes are more effective agents. Ferric tris-diethyldithiocarbamate is also a cytotoxic species. In contrast, when cells are exposed to dimethyldithiocarbamate or its copper complex in Ringer's buffer under metal-restricted condition, washed, and then placed in complete medium, the copper complex is much more active in inhibiting cell growth. The difference is magnified when dihydroxyethyldithiocarbamate and N-methylglucamine dithiocarbamate and their copper complexes are compared in complete media. Incubation of bleomycin or copper bleomycin with Ehrlich cells in Ringer's buffer with or without dimethyldithiocarbamate or bis-dimethyldithiocarbamato Cu(II) leads to no enhancement of cytotoxicity from combinations of agents, except when the two copper complexes are present. Diethyl- or dimethyldithiocarbamate readily extracts copper from Cu(II)bleomycin and iron from Fe(III)bleomycin when ethylacetate is present to remove the tris-dithiocarbamato Fe(III) complex from aqueous solution. When bis-dimethyldithiocarbamato Cu(II) is incubated with Ehrlich cells, copper is released from the complex and bound to high molecular weight and metallothionein fractions. A reductive mode of dissociation of the copper complexes in cells is supported by ESR experiments. Reactions of diethyl- and dimethyldithiocarbamato Cu(II) with thiol compounds demonstrates one possible mechanism of reduction of these complexes.

Mechanism of diethyldithiocarbamate, dihydroxyethyldithiocarbamate, and dicarboxymethyldithiocarbamate action of distribution and excretion of cadmium.

Diethyldithiocarbamate (DEDC), dihydroxyethyldithiocarbamate (DHDC), and dicarboxymethyldithiocarbamate (DCDC) were assessed for their relative efficacies in mobilizing metallothionein-bound cadmium (Cd) from selected organs and tissues of mice and in promoting Cd excretion. The DHDC was effective but less so than DEDC in mobilizing Cd from liver, kidney and spleen. However, while DEDC effected a redistribution of Cd which resulted in higher levels in lungs, testes, heart, and brain, DHDC after 13 injections reduced the levels of Cd in all four of these organs. The DCDC analog did not alter the Cd load of any organ. Bone Cd content was most effectively reduced by DEDC; DCDC was somewhat less active, and DCDC was without effect. Skin Cd burden was enhanced markedly after treatment with DEDC but was reduced by treatment with DHDC or DCDC. Treatment with DEDC increased the muscle Cd content about 250 percent over control values; treatment with DHDC reduced it significantly, while DCDC was without effect. Both DEDC and DHDC reduced the whole body Cd burden, but DCDC was ineffective. The initial rate of fecal excretion of Cd was much greater following DHDC treatment than after DEDC treatment, while DCDC did not promote excretion to any detectable extent. The pattern of mobilization, redistribution, and excretion of Cd following treatment with each chelator was related to the organic/aqueous partition coefficient of each dithiocarbamate-Cd complex.