Zinc Dithiocarbamate Research Articles

Contents of sensitising rubber accelerators in disposable rubber gloves: A Copenhagen market survey.

Rubber gloves contain rubber accelerators that may cause contact allergy. The content of sensitising rubber accelerators in contemporary rubber gloves is not well known. Identify and quantify the content of rubber accelerators in disposable rubber gloves. Fifty-one gloves of 49 different brands were collected. Forty-eight of the gloves were disposable and three re-usable. The gloves were analysed for their content of sensitising rubber accelerators, that is, zinc dithiocarbamates, thiurams, thiazoles/benzothiazoles, diphenylguanidine, and thioureas by high-performance liquid chromatography. Rubber accelerators were identified in 43/48 (90%) of the disposable gloves. In total, 39 gloves contained zinc dibutyldithiocarbamate (ZDBC) (0.18-1.96 mg/g), 34 zinc diethyldithiocarbamate (ZDEC) (0.032-2.78 mg/g), three zinc dibenzyldithiocarbamate (0.65-1.4 mg/g), one zinc dimethyldithiocarbamate (0.23 mg/g), and one 1,3-diphenylguanidine (0.21 mg/g). 2-cyanoethyl dimethyldithiocarbamate (CEDMC) was identified in three gloves (<0.052 mg/g). The one glove labelled as accelerator free contained ZDBC (1.07 mg/g). Only few glove packages had the specific content of rubber accelerators labelled. The most frequent rubber accelerators in rubber gloves are ZDEC and ZDBC. Accelerator-free gloves may contain rubber accelerators. Full labelling of rubber gloves is needed and producers should be sure not to falsely claim that the rubber gloves are free of rubber accelerators.

Synthesis of derivative of zinc dithiocarbamate of piperazine (ZDPC) and its application as a safe accelerator for the vulcanization of natural rubber latex

Derivative of zinc dithiocarbamate of piperazine (ZDPC) prepared in the laboratory acts as an accelerator for the vulcanization of natural rubber latex based formulations. The ZDPC synthesized in our laboratory was characterized by FTIR spectroscopy, UV-Visible spectroscopy and CHNS analysis. Results of the MTT assay show that the ZDPC is a safe (non-carcinogenic) rubber chemical. For comparable dosages of the accelerator, the ZDPC based natural rubber latex vulcanizates show improved mechanical properties as compared to zinc diethyl dithiocarbamate (ZDEC) based vulcanizates. ZDPC may be considered as a safe replacement for the nitrosamine generating ZDEC in natural rubber latex based formulations.

Effect of Deposition Temperature on the Properties of Copper-Zinc Sulphide Thin Films using Mixed Copper and Zinc Dithiocarbamate Precursors

The influence of deposition temperatures on the structural, elemental, optical and electrical properties was investigated. The Rutherford backscattering (RBS) and scanning electron microscopy (SEM) were used to measure the elemental and morphological properties of the films. The RBS confirms that the stoichiometry was controlled by the deposition temperatures with a thickness that ranged between 51.00 to 63.00 nm. SEM data of the deposited films show different morphologies with several grains that increased with deposition temperature. Optical characterization shows that the films exhibited a direct transition with an energy gap that varies from 1.79 to 2.10 eV. For copper-zinc sulphides (CZS) film deposited at 470 ᴼC, the maximum electrical conductivity was 7.38 × 10-2 (Ω.cm)-1and minimum electrical resistivity was 1.35 × 101 (Ω.cm). The results confirm the possibility of using copper and zinc dithiocarbamate precursors in depositing high-quality CZS thin films with comparable properties.

Assessment of physiological and electrochemical effects of a repurposed zinc dithiocarbamate complex on Acinetobacter baumannii biofilms

Acinetobacter baumannii is an infectious agent of global proportion and concern, partly due to its proficiency in development of antibiotic resistance phenotypes and biofilm formation. Dithiocarbamates (DTC) have been identified as possible alternatives to the current antimicrobials. We report here the evaluation of several DTC-metal complexes against A. baumannii planktonic cells and biofilms. Among the DTC-metal complexes and DTCs tested, ZnL1 (N-methyl-1-phenyldithiocarbamato-S,S′ Zn(II)), originally designed as an antitumor agent, is effective against biofilm forming A. baumannii. A MIC value of 12.5 µM, comparable to that of Gentamicin (5 µM) was measured for planktonic cells in tryptic soy broth. Spectroscopy, microscopy and biochemical analyses reveal cell membrane degradation and leakage after treatment with ZnL1. Bioelectrochemical analyses show that ZnL1 reduces biofilm formation and decreases extracellular respiration of pre-formed biofilms, as corroborated by microscopic analyses. Due to the affinity of Zn to cells and the metal chelating nature of L1 ligand, we hypothesize ZnL1 could alter metalloprotein functions in the membranes of A. baumannii cells, leading to altered redox balance. Results indicate that the DTC-Zn metal complex is an effective antimicrobial agent against early A. baumannii biofilms under laboratory conditions.

Morphological studies and photocatalytic degradation of methylene blue by zinc sulfide nanoparticles

"We report the preparation, morphological and photocatalytic studies of zinc sulfide nanoparticles from zinc(II) dithiocarbamate precursors. Powder X-ray diffraction patterns were index to the wurtzite crystalline phase of zinc sulfide while transmission electron microscopy micrographs revealed spherically shaped particles with sizes in the range 2.8 to 5.2 nm. The ZnS nanoparticles were used as photocatalysts for the degradation of methylene blue with degradation efficiency of 71.41% for ZnS1 and 85.95% for ZnS2 nanoparticles at pH 9.43. The effect of catalyst concentration, pH, radical scavengers, and hole (h+ ) scavengers on the photodegradation of methylene blue dye were evaluated."

Dithiocarbamate transfer reaction from methylene-bis(dithiocarbamates) to molybdenum dithiocarbamates in engine lubricants investigated using laboratory experiments

The presence of zinc complexes or of oxidative conditions induces dithiocarbamate transfer from methylene-bis(dithiocarbamates) to molybdenum dithiocarbamates via zinc dithiocarbamate species.

New Bioconjugated Technetium and Rhenium Folates Synthesized by Transmetallation Reaction with Zinc Derivatives.

The zinc dithiocarbamates functionalized with folic acid 2Zn and 3Zn were synthesized with a simple straightforward method, using an appropriated folic acid derivative and a functionalized zinc dithiocarbamate (1Zn). Zinc complexes 2Zn and 3Zn show very low solubilities in water, making them useful for preparing Tc-99m radiopharmaceuticals with a potentially high molar activity. Thus, the transmetallation reaction in water medium between the zinc complexes 2Zn or 3Zn and the cation fac-[99mTc(H2O)3(CO)3]+, in the presence of the monodentate ligand TPPTS, leads to the formation of the 2 + 1 complexes fac-[99mTc(CO)3(SS)(P)] bioconjugated to folic acid (2Tc and 3Tc). In spite of the low solubility of 2Zn and 3Zn in water, the reaction yield is higher than 95%, and the excess zinc reagent is easily removed by centrifugation. The Tc-99m complexes were characterized by comparing their HPLC with those of the homologous rhenium complexes (2Re and 3Re) previously synthesized and characterized by standard methods. Preliminary in vivo studies with 2Tc and 3Tc indicate low specific binding to folate receptors. In summary, Tc-99m folates 2Tc and 3Tc were prepared in high yields, using a one-pot transmetallation reaction with low soluble zinc dithiocarbamates (>1 ppm), at moderate temperature, without needing a subsequent purification step.

Optical Properties of Copper-Zinc Sulphide Network from Mixed Single Solid Source Precursors of Copper and Zinc Dithiocarbamates

Thin films of copper-zinc sulphide (CxZn1-xS) have been deposited by metal-organic chemical vapour deposition (MOCVD) technique at 400 °C on soda-lime substrates. The films contained copper dithiocarbamate and zinc dithiocarbamate of various concentrations. The effect of the precursor’s concentration was investigated using Fourier transforms infrared (FTIR) spectroscopy and UV-Vis Spectrophotometer. The precursors’ FTIR spectrums have the characteristics of copper sulphide and zinc sulphide absorption bands below 800 cm-1. The optical properties for all the samples were studied by reading the absorbance and transmittance spectra in the range of 300 - 900 nm. The results indicate direct bandgap energy that ranged between 2.20 to 3.42 eV. The films were found to have a very high transmittance in the visible and near-infrared regions and an average reflectance of about 0.14 in the same regions. Optical constants like refractive index, extinction coefficient, and optical conductivity were estimated as a function of photon energy. The various properties exhibited by the films indicate that the films can find application in various optoelectronic devices.

Synthesis and study of N, N` -(ethane-1,2-diyl)bis(1-phenyl methanimine) and thier complex derivative with in-vivo and in-vitro Bacteryal biological study

In this research, the synthesis and biological activity evaluation of N, N`-(ethane-1,2-diyl)bis(1-phenyl methanimine) as Schiff base with Zinc (II) dithiocarbamate complex are successfully reported. The suggested geometry around zinc ion centre was determined using selected unique physicochemical and spectroscopic techniques. These include melting point, conductance, FTIR, UV-Vis, mass spectroscopy and 1H-NMR spectroscopy. The analytical as well as the spectroscopic characterization data proves the formation of zinc complex with general formula [Zn(L)]2 and the complex of this ion is adopting tetrahedral geometry about the metal centre. Furthermore, the present study was carried out to evaluate antibacterial activity of obtained Schiff base ligand and Zn complex against five strains of bacteria (Staphylococcus aureus, Escherichia coli, Lacto bacillus, Klebsiella Pneumonae,and Salmonella typhi). The results of antimicrobial screening suggest that Schiff bases can show a considerable activity against Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia and Salmonella typhi while Zn-complex was reported to be more active against all bacterial strains which is used in this test. The antibacterial activity of each compound has been examined practically (in vivo) by treating burns rats infected with tested bacteria (Staphylococcus aureus and Salmonella typhi), the results have shown signs of good recovery at short time if it compared with antibiotic Ofloxacin (OFX) used at the same time. And the number of bacteria was reduced significantly (P ≤ 0.001) during the treatment days. Furthermore, the results showed that Zn-complex is effective in treating various skin conditions; it is preferable to use it in the treatment of pathological injuries and against other skin infections.

Bioconjugated technetium carbonyls by transmetalation reaction with zinc derivatives

The transmetalation reaction between zinc dithiocarbamates functionalized with organic groups and the cation fac-[99mTc(H2O)3(CO)3]+ has been studied as a new strategy to bind biomolecules to this radionuclide for preparing radiopharmaceuticals with high molar activity. All complexes were obtained in high yields by heating at moderate temperatures and without subsequent purification. The chemical identity was ascertained by HPLC comparison with the homologous rhenium complexes. Stability studies in cysteine solution and serum have shown a good stability of the coordination set fac-[99mTc(CO)3(SS)(P)]. Preliminary biological studies of the radiocomplex functionalized with D-(+)-glucosamine with carcinoma cells have been performed.

Synthesis and characterization of cadmium and zinc dithiocarbamate complexes derived from α-aminoacid L-proline

Dithocarbamate metal complexes have been used to prepare nanoparticles and nanowires of a variety of semiconducting metals including CdS, ZnS, PbS, and EuS. The two new cadmium (II) L-Proline Dithiocarbamate and zinc (II) L-proline dithiocarbamate complexes have been synthesized. Both of the metal complexes are able to produce semiconductor sulphides, nanoparticles which are applicable in the electronic industries. The amino acid L-proline has the unique property, it is the only DNA determined amino acid which has a secondary five membered cyclic amino group alpha to the carbonyl group in the biosystem. Metal dithiocarbamate which is derived from L-proline is able to produce the corresponding metal sulphides as nanoparticles and nanowire. This is very much applicable in Thin Film Technology. Besides, the Zinc complex is used as a drug in increasing the immune system of the body against bacteria and viruses. Zinc dithiocarbamate derived from alpha aminoacid is biocompatible so that it can be used as pharmaceutical products. The two complexes exhibit the important NCS2 peak from 202.73-215 in 13C NMR, attributing to the presence of the dithiocarbamate ligand. A resonance signal around δ 4.92 is due to COOH-proton in 1H NMR. The complexes also shows the important IR frequencies, ν(CN), ν(CS) and ν(CO) in the ranges 1443-1430 cm-1, 954-945 cm-1 , and 1720-1712 cm-1 , respectively. LMCT transitions have been observed at λ 214 nm for the Cd complex. Based on the thermo gram the complexes are stable up to 200°C, and fast decomposed to produce M(SCN)2 at 400C and finally MS(M= Cd), as residue at 600°C by slow steps. From FTIR, 1H, 13C NMR, only dithiocarbamate sulphurs are coordinated to metal and not the carboxylate oxygen in the two complexes.

Evaluation of DNA/BSA interactions and DFT calculations of gold(III), zinc(II) and palladium(II) complexes with triammonium N-dithiocarboxyiminodiacetate

Dithiocarbamates, with their high lipophilic character and good chelating properties, could provide stabile transition metal complexes and enable these metal-based drugs to reach their biological targets. Palladium(II) and gold(III) complexes, due to its structural similarity with platinum(II)compounds, could be competitive candidates for implementing and developing new pharmacological agents. Herein, novel gold(III) complex with triammonium N-carboxyiminodiacetate as ligand has been synthesized and characterized by elemental analysis, molar conductivity measurements, FT-IR and 1H and 13C NMR spectroscopy. The proposed structure was examined and compared with analogue palladium(II) and zinc(II) complexes by density functional theory (B3LYP/def2tzvp). Additionally, DNA-binding studies by UV/Vis-spectrometer as well as ethidium-bromide (EB) and bovine serum albumin (BSA) quenching studies by spectrofluorometer were performed for gold(III), palladium(II) and zinc(II) dithiocarbamate complexes. The investigated complexes showed a good affinity to calf thymus DNA (CT-DNA) and BSA, with a higher affinity to BSA. Palladium(II) complex exhibited 5-fold a stronger affinity to DNA binding in comparison to zinc(II), but no significantly higher than gold(III) complex. Furthermore, palladium(II) and gold(III) complexes demonstrated a similar affinity toward BSA and these interactions are stronger than showed by zinc(II) complex.

Comparative study of the effects of ziram and disulfiram on human monocyte-derived macrophage functions and polarization: involvement of zinc.

Ziram, a zinc dithiocarbamate is widely used worldwide as a fungicide in agriculture. In order to investigate ziram-induced changes in macrophage functions and polarization, human monocytes-derived macrophages in culture were treated with ziram at 0.01-10μmol.L-1 for 4-24h. To characterize zinc involvement in these changes, we also determined the effects of disulfiram alone (dithiocarbamate without zinc) or in co-incubation with ZnSO4. We have shown that ziram and disulfiram at 0.01μmol.L-1 increased zymosan phagocytosis. In contrast, ziram at 10μmol.L-1 completely inhibited this phagocytic process, the oxidative burst triggered by zymosan and the production of TNF-α, IL-1β, IL-6, and CCL2 triggered by LPS. Disulfiram had the same effects on these macrophages functions only when combined with zinc (10μmol.L-1). In contrast, at 10μmol.L-1 ziram and zinc associated-disulfiram induced expression of several antioxidants genes HMOX1, SOD2, and catalase, which could suggest the induction of oxidative stress. This oxidative stress could be involved in the increase in late apoptosis induced by ziram (10μmol.L-1) and zinc associated-disulfiram. Concerning gene expression profiles of membrane markers of macrophage polarization, ziram at 10μmol.L-1 had two opposite effects. It inhibited the gene expression of M2 markers (CD36, CD163) in the same way as the disulfiram-zinc co-treatment. Conversely, ziram induced gene expression of other M2 markers CD209, CD11b, and CD16 in the same way as treatment with zinc alone. Disulfiram-zinc association had no significant effects on these markers. These results taken together show that ziram via zinc modulates macrophages to M2-like anti-inflammatory phenotype which is often associated with various diseases.

New parasite treatment with old alcohol drug targeting COP9 signalosome

The Ubiquitin‐Proteasomal System (UPS) is essential for cell survival because it is responsible for the large majority of protein degradation within the cell. Thus, targeting the UPS has emerged as an attractive approach for combating protozoan parasites. Yet, the regulation of UPS‐mediated protein degradation remains poorly understood in clinically important protozoans. We identified COP9 signalosome to be conserved in multiple pathogenic parasites including Leishmania, Trypanosoma, Toxoplasma and Entamoeba. Here, we show that COP9 signalosome is an essential and druggable parasite target that regulates protein degradation. Using Entamoeba histolytica as a model parasite, we found that genetic disruption of COP9 subunit 5 (CSN5) by two independent but complementary approaches, inhibited parasite cell proliferation and viability. Both CSN5 knockdown and dominant negative mutation trapped cullin1 in a neddylated state disrupting UPS activity and protein degradation. Using virtual screening by molecular docking, we identified zinc dithiocarbamate (ZnDTC), a metabolite of the FDA approved alcohol drug disulfiram, as a potential COP9 inhibitor. We found that ZnDTC acts in a COP9‐dependent manner, phenocopy CSN5 gene disruption, and is active against E. histolytica parasites at nanomolar concentrations. In addition, in‐vivo studies revealed that ZnDTC had oral efficacy in clearing E. histolytica parasites in a mouse model that mirrors human amebic colitis. Parasite clearance was assessed by live bioluminescent imaging, amebic culture and immunohistochemistry. Also, ZnDTC treatment promoted resolution of inflammation and tissue damage. Our findings provide insights into how COP9 signalosome regulates parasite protein degradation, and supports COP9 inhibition as a potential anti‐parasite therapy.

Direct Synthesis of Rhenium and Technetium-99m Metallosurfactants by a Transmetallation Reaction of Lipophilic Groups: Potential Applications in the Radiolabeling of Liposomes.

A new zinc dithiocarbamate functionalized with palmitoyl groups is described as a useful tool for the preparation of metallosurfactants through a transmetallation reaction with the transition metals rhenium and technetium. An amphiphilic rhenium complex is synthesized by a transmetallation reaction with the zinc complex in presence of the polar phosphine sodium triphenylphosphine trisulfonate, which leads to a rhenium complex with a lipophilic dithiocarbamate and a polar phosphine ligand. The study of this rhenium complex has shown that it self-aggregates, leading to the formation of aggregates that have been analyzed by dynamic light scattering and cryotransmission electron microscopy (cryo-TEM). In addition, this amphiphilic rhenium complex is incorporated into soy phosphatidylcholine liposomes, whether liposomes are prepared by mixing phospholipid and the rhenium complex or by the incorporation of the rhenium complex into preformed liposomes. The one-pot reaction of the radiocompound [99mTc(H2O)3(CO)3]+ with the above-mentioned zinc dithiocarbamate, the phosphine sodium triphenylphosphine trisulfonate and the phospholipid soy phosphatidylcholine, leads to liposomes labeled with a Tc-99m homologous complex of the rhenium complex, in accordance with the high-performance liquid chromatography (HPLC) data.

Understanding the role of zinc dithiocarbamate complexes as single source precursors to ZnS nanomaterials.

Zinc sulfide is an important wide-band gap semi-conductor and dithiocarbamate complexes [Zn(S2CNR2)2] find widespread use as single-source precursors for the controlled synthesis of ZnS nanoparticulate modifications. Decomposition of [Zn(S2CNiBu2)2] in oleylamine gives high aspect ratio wurtzite nanowires, the average length of which was increased upon addition of thiuram disulfide to the decomposition mixture. To provide further insight into the decomposition process, X-ray absorption spectroscopy (XAS) of [Zn(S2CNMe2)2] was performed in the solid-state, in non-coordinating xylene and in oleylamine. In the solid-state, dimeric [Zn(S2CNMe2)2]2 was characterised in accord with the single crystal X-ray structure, while in xylene this breaks down into tetrahedral monomers. In situ XAS in oleylamine (RNH2) shows that the coordination sphere is further modified, amine binding to give five-coordinate [Zn(S2CNMe2)2(RNH2)]. This species is stable to ca. 70 °C, above which amine dissociates and at ca. 90 °C decomposition occurs to generate ZnS. The relatively low temperature onset of nanoparticle formation is associated with amine-exchange leading to the in situ formation of [Zn(S2CNMe2)(S2CNHR)] which has a low temperature decomposition pathway. Combining these observations with the previous work of others allows us to propose a detailed mechanistic scheme for the overall process.

Perplexing Coordination Behaviour of Potentially Bridging Bipyridyl-Type Ligands in the Coordination Chemistry of Zinc and Cadmium 1,1-Dithiolate Compounds

The X-ray structural chemistry of zinc and cadmium 1,1-dithiolates (for example, xanthate, dithiophosphate and dithiocarbamate) with potentially bridging bipyridyl-type ligands (for example, 4,4′-bipyridine) is reviewed. For zinc, the xanthates and dithiophosphates uniformly form one-dimensional coordination polymers, whereas the zinc dithiocarbamates are always zero-dimensional, reflecting the exceptional chelating ability of dithiocarbamate ligands compared with xanthates and dithiophosphates. For cadmium, one-dimensional coordination polymers are usually found, reflecting the larger size of cadmium compared with zinc, but zero-dimensional aggregates are sometimes found. Steric effects associated with the 1,1-dithiolate-bound R groups are shown to influence supramolecular aggregation and, when formed, polymer topology in order to reduce steric hindrance; the nature of the bipyridyl-type ligand can also be influential. For the dithiocarbamates of both zinc and cadmium, in instances where the dithiocarbamate ligand is functionalised with hydrogen bonding potential, extended supramolecular architectures are often formed via hydrogen bonding interactions. Of particular interest is the observation that the bipyridyl-type ligands do not always bridge zinc or cadmium 1,1-dithiolates, being monodentate instead, often in the presence of hydrogen bonding. Thus, hydroxyl-O–H…N(pyridyl) hydrogen bonds are sometimes formed in preference to M←N(pyridyl) coordinate-bonds, suggesting a competition between the two modes of association.

Multiple isomerization of structural units in ion-polymeric heteronuclear gold(III)–zinc(II) complex ([Au{S2CN(C4H9)2}2]2[ZnCl4])n: Chemisorption-based synthesis, supramolecular structure (self-organization of long-period cation–cationic polymer chains), and thermal behavior

Chemisorption of gold(III) from solutions in 2 M HCl with freshly precipitated binuclear zinc dithiocarbamate [Zn2{S2CN(C4H9)2}4] resulted in the formation of a polymeric heteronuclear gold(III)–zinc(II) dithiocarbamato-chlorido complex ([Au{S2CN(C4H9)2}2]2[ZnCl4]) n (I), which was characterized by MAS 13C NMR, X-ray diffraction (CIF file CCDC no. 1526616), and simultaneous thermal analysis. Compound I isolated on a preparative scale was found to have a highly intricate supramolecular structure composed of 13 centrosymmetric and non-centrosymmetric isomeric complex cations, [Au{S2CN(C4H9)2}2]+, with 24 structurally non-equivalent BuDtc ligands, and six isomeric [ZnCl4]2– anions. The isomeric gold(III) cations perform different structural functions. Four and six cations are involved in the formation of two sorts of long-period cation–cationic chains (via pair non-valence secondary Au···S bonds): (···A···B···C···D···C···B···) n and (···F···G···H···I···J···K···) n . The discrete E, L, and M cations and the [ZnCl4]2– complex anions are located alongside of the polymer chains and do not take part in the secondary interactions. According to simultaneous thermal analysis, thermolysis of I includes destruction of the dithiocarbamate moiety with reduction of gold to the metal in the cation and liberation of zinc chloride with partial conversion to ZnS in the anion.

Effect of functionalization of N-bound organic moiety in zinc(II) dithiocarbamate complexes on structure, biological properties and morphology of zinc sulfide nanoparticles

Bis(N-furfuryl-N-substituted benzyldithiocarbamato-S,S′)zinc(II) (1–4) [substituted benzyl=4F–C6H4–CH2– (1), 4Cl–C6H4–CH2– (2), 4OH–C6H4–CH2– (3), 4OCH3–C6H4–CH2– (4)] complexes were prepared and characterized by elemental analysis, IR and NMR (1H and 13C) spectroscopy. Structures of complex 2 and 4 were determined by single crystal X-ray crystallography. X-ray crystal structure of 2 revealed that the complex is dimeric and the geometry of this coordination polyhedron [ZnS5] is intermediate between tetragonal pyramid and trigonal bipyramid. The structure of 4 features, in contrast to 2, mononuclear species and the coordination geometry for the zinc atom is a highly distorted tetrahedron. The energy gap between the HOMO and LUMO in dimer 2 is lower than those of monomers (2 and 4). This indicates that the monomers are more stable than dimer. In vitro cytotoxic activity of the complexes 1–4 was evaluated on KB cell line. Complex 1 showed better cytotoxic activity than other complexes. These complexes were also screened for in vitro antibacterial and antifungal activities. Complexes 2 and 4 have been used as single source precursors for the preparation of ZnS nanoparticles. As-prepared ZnS nanoparticles were characterized using PXRD, TEM, UV–Vis and photoluminescence spectroscopy. TEM images show that spherical and rod nanoparticles were obtained from complexes 2 and 4, respectively. The photocatalytic activities of the as-prepared ZnS nanoparticles were evaluated by degradation of rhodamine B in aqueous solution under UV irradiation.

Molecular mechanisms of apoptosis and cell selectivity of zinc dithiocarbamates functionalized with hydroxyethyl substituents

In the solid state each of three binuclear zinc dithiocarbamates bearing hydroxyethyl groups, {Zn[S2CN(R)CH2CH2OH]2}2 for R=iPr (1), CH2CH2OH (2), and Me (3), and an all alkyl species, [Zn(S2CNEt2)2]2 (4), features a centrosymmetric {ZnSCS}2 core with a step topology; both 1 and 3 were isolated as monohydrates. All compounds were broadly cytotoxic, specifically against human cancer cell lines compared with normal cells, with greater potency than cisplatin. Notably, some selectivity were indicated with 2 being the most potent against human ovarian carcinoma cells (cisA2780), and 4 being more cytotoxic toward multidrug resistant human breast carcinoma cells (MCF-7R), human colon adenocarcinoma cells (HT-29), and human lung adenocarcinoma epithelial cells (A549). Based on human apoptosis PCR-array analysis, caspase activities, DNA fragmentation, cell apoptotic assays, intracellular reactive oxygen species (ROS) measurements and human topoisomerase I inhibition, induction of apoptosis in HT-29 cells is demonstrated via both extrinsic and intrinsic pathways. Compounds 2–4 activate the p53 gene while 1 activates both p53 and p73. Cell cycle arrest at the S and G2/M phases correlates with inhibition of HT-29 cell growth. Cell invasion is also inhibited by 1–4 which is correlated with down-regulation of NF-κB.