Synthesis, characterization, cytotoxicity and antimicrobial studies on bis( N -furfuryl- N -(2-phenylethyl)dithiocarbamato- S , S ′)zinc(II) and its nitrogen donor adducts

Sustainable tandem acylation/Diels-Alder reaction toward versatile tricyclic epoxyisoindole-7-carboxylic acids in renewable green solvents

Tandem Diels-Alder reactions are often used for the straightforward formation of complex natural compounds and the fused polycyclic systems contained in their precursors. In the second step of this reaction, regio- and stereochemically controlled intramolecular cyclization leads to the formation of versatile nitrogen-containing tricyclic systems. However, these useful organic transformations are usually carried out in highly toxic organic solvents such as benzene, toluene, chloroform, etc. Despite recent efforts by 'green chemists', synthetic chemists still use these traditional toxic organic solvents in many of their reactions, even though safer alternatives are available. However, in addition to the harmful effects of these petrochemical solvents on the environment, the prediction that their resources will run out in the near future has led 'green chemists' to explore solvents that can be derived from renewable resources and used effectively in various organic transformations. In this context, we have shown for the first time that the 100% atom-economical tandem Diels-Alder reaction between aminofuranes and maleic anhydride can be carried out successfully in vegetable oils and waxes. The reaction was successfully carried out in sunflower seed oil, olive oil, oleic acid and lauryl myristate under mild reaction conditions. A series of epoxyisoindole-7-carboxylic acid and bisepoxyisoindole-7-carboxylic acids were obtained in good yields after a practical isolation procedure. The results obtained in this study demonstrate the potential of vegetable oils and their renewable materials to provide a reaction medium that is more sustainable than conventional organic solvents in cascade Diels-Alder reactions and can be used repeatedly without significant degradation. These materials also allow the reaction to be completed in less time, with less energy consumption and higher yields.

The structural chemistry of zinc(ii) and nickel(ii) dithiocarbamate complexes

Dithiocarbamate complexes are of immense interest due to their diverse structural properties and extensive application in various areas. They possess two sulfur atoms that often act as the binding sites for metal coordination in a monodentate, bidentate, or anisodentate fashion. These different coordination modes enhance the possibility for complex formation and make them useful in different areas especially in biomedical fields. A synergy exists in the metal ions and dithiocarbamate moieties, which tends to exert better properties than the respective individual components of the complex. These improved properties have also been attributed to the presence of the C–S bonds. Zinc and nickel ions have been majorly found to bind to the dithiocarbamate in bidentate modes, and consequently different geometries have resulted from this interaction. The aim of this review is to present some studies on the synthesis, structural chemistry, and the relevance of zinc and nickel dithiocarbamates complexes especially in biological systems.

Insights into the Antimicrobial Potential of Dithiocarbamate Anions and Metal-Based Species

Bacterial infection remains a worldwide problem that requires urgent addressing. Overuse and poor disposal of antibacterial agents abet the emergence of bacterial resistance mechanisms. There is a clear need for new approaches for the development of antibacterial therapeutics. Herein, the antibacterial potential of molecules based on dithiocarbamate anions, of general formula R(R’)NCS2(−), and metal salts of transition metals and main group elements, is summarized. Preclinical studies show a broad range of antibacterial potential, and these investigations are supported by appraisals of possible biological targets and mechanisms of action to guide chemical syntheses. This bibliographic review of the literature points to the exciting potential of dithiocarbamate-based therapeutics in the crucial battle against bacteria. Additionally, included in this overview, for the sake of completeness, is mention of the far fewer studies on the antifungal potential of dithiocarbamates and even less work conducted on antiparasitic behavior.

PbS Nanoparticles Prepared Using 1, 10-Phenanthroline Adduct of Lead(II) Bis(N-alkyl-N-phenyl dithiocarbamate) as Single Source Precursors

Dithiocarbamate complexes have remained prominent as single source precursors for the synthesis of clean metal sulfide nanoparticles. This study reports the synthesis of lead sulfide (PbS) nanoparticles using some novel complexes of 1, 10-phenanthroline lead(II) bis(N-alkyl-N-phenyl dithiocarbamate), represented as [Pb(L¹)₂phen] (1) and [Pb(L²)₂phen] (2) (where L¹ = bis(N-ethyl-N-phenyldithiocarbamate; L² = bis(N-butyl-N-phenyldithiocarbamate); phen = 1, 10 phenanthroline) as a single source precursors. The complexes (1 and 2) were synthesized and characterized using various spectroscopic techniques and elemental analysis. The nanoparticles were synthesized via a solvothermal approach in oleylamine, used as a capping agent, and were given as PbS(1) and PbS(2) from [Pb(L¹)₂phen] (1) and [Pb(L²)₂phen] (2), respectively, which were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), and absorption spectroscopy. The diffraction patterns confirmed the formation of face-centered cubic phase PbS nanoparticles with a preferential growth orientation along the (200) plane. The TEM images showed that PbS(1) were of a spherical morphology, while the morphology of PbS(2) tended to produce short rods. This was due to variation in the functional group on the precursor compounds. This variation also resulted in the different band gap energies found such as 1.148 and 1.107 eV for PbS(1) and PbS(2), respectively, indicating a blue shift from the bulk.

Bis[N-benzyl-N-(2-phenylethyl)dithiocarbamato-κ2S,S′](1,10-phenanthroline-κ2N,N′)zinc(II)

In the title compound, [Zn(C16H16NS2)2(C12H8N2)], the ZnIIatom exists within an N2S4donor set that defines a distorted octahedral geometry; weak intramolecular C—H...S hydrogen bonds are noted. In the crystal, molecules are linkedviaweak C—H...π interactions, formingC(11) chains propagating along [001].

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.

Synthesis and characterization of Ni(II) and Zn(II) complexes of (furan-2-yl)methyl(2-(thiophen-2-yl)ethyl)dithiocarbamate (ftpedtc): X-ray structures of [Zn(ftpedtc)2(py)] and [Zn(ftpedtc)Cl(1,10-phen)]

Seven complexes of a new dithiocarbamate ligand (ftpedtc = (furan-2-yl)methyl(2-(thiophen-2-yl)ethyl)dithiocarbamate) namely [Ni(ftpedtc)2] (1), [Ni(ftpedtc)(NCS)(PPh3)] (2), [Ni(ftpedtc)(PPh3)2]ClO4 (3), [Zn(ftpedtc)2] (4), [Zn(ftpedtc)2(py)] (5), [Zn(ftpedtc)2(1,10-phen)] (6) and [Zn(ftpedtc)2(2,2'-bipy] (7) have been prepared. The complexes were characterized by IR, UV-Vis and NMR ((1)H and (13)C) spectroscopy. Single crystal X-ray structural analysis was carried out for complexes 5 and [Zn(ftpedtc)Cl(1,10-phen)] (8). Electronic spectral studies suggest square planar geometry for nickel complexes. The (13)C NMR peaks of the group N(13)CS2 are found in all the cases, at around 205.0 ppm, which indicates the bidentate character of the dithiocarbamate ligand. X-ray structures of 5 and 8 show bidentate coordination by dithiocarbamate ligands and a distorted trigonal bipyramidal geometry for zinc, defined by NS4 and ClN2S2 donor sets, respectively. The packing in 8 involves π-π stacking interactions involving the 1,10-phenanthroline ring systems with the distance between ring centroids being 3.587 Å.

Synthesis, spectral (IR, UV-Vis and variable temperature NMR) characterization and crystal structure of (N-benzyl-N-furfuryldithicarbamato-S,S')(thiocyanato-N)(triphenylphosphine)nickel(II)

Planar (N-benzyl-N-furfuryldithiocarbamato-S,S')(thiocyanato-N)(triphenylphospine)nickel(II), [Ni(bfdtc)(NCS)(PPh3)], (1) was prepared from bis(N-benzyl-N-furfuryldithiocarbamato-S,S')nickel(II), [Ni(bfdtc)2], (2) and characterized by elemental analysis, cyclic voltammetry, electronic, IR and variable temperature (1)H and (13)C NMR spectra. For complex 1, the thioureide vCN value is shifted to higher wavenumber compared to 2 and N(13)CS2 carbon signal observed for 1 is additionally shielded compared to the parent complex 2, suggesting increased strength of the thioureide bond due to the presence of the π-accepting phosphine. In the room temperature (13)C NMR spectrum of 1, two pseudo doublets are observed in the aliphatic region. Variable temperature (13)C NMR spectral studies suggest that the fast thiocyanate exchange appears to be responsible for the appearance of pseudo doublets. Single crystal X-ray structural analysis of 1 and 2 confirm the presence of four coordinated nickel in a distorted square planar arrangement with the NiS2PN and NiS4 chromophores, respectively. The NiS bonds are symmetric in 2 (2.1914(14) and 2.2073(13)Å). But significant asymmetry in NiS bond distances was observed in 1 (2.2202(8)Å and 2.1841Å). This observation clearly supports the less effective trans effect of SCN(-) over PPh3. Cyclic voltammetric studies revealed easier reduction of nickel(II) to nickel(I) in complex 1 compared to 2.

Synthesis, structure, spectroscopy of four novel supramolecular complexes and cytotoxicity study by application of multiple parallel perfused microbioreactors

Synthesis of four supramolecular complexes and study of their cytotoxicity using multiple parallel perfused microbioreactors.