Synthesis and Characterization of Coordinatively Unsaturated Copper (II) Complexes of 1,3-Bis(2'-Pyridyl)-1,2-Diaza-2-Butene and Their Antityrosinase Activity

The coordinatively unsaturated copper (II) complexes of 1,3-bis(2'-pyridyl)-1,2-diaza-2- butene with different ancillary anions were synthesized which can bind to copper centers of tyrosinase enzyme. The compounds were found to exhibit inhibitory activities against mushroom tyrosinase and the nature and extent of inhibition is modulated according to the type of ancillary anions

<span style="font-size:12.0pt;font-family:"Times New Roman","serif"; mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;color:black; mso-ansi-language:EN-IN;mso-fareast-language:EN-US;mso-bidi-language:AR-SA">X-ray crystal structure of the cytotoxic planar Ni(II) complex of ⁴N-dimethy <span style="font-size:12.0pt;font-family:"Times New Roman","serif";mso-fareast-font-family: Fd694969-Identity-H;color:black;mso-ansi-language:EN-IN;mso-fareast-language: EN-US;mso-bidi-language:AR-SA">1-<span style="font-size:12.0pt; font-family:"Times New Roman","serif";mso-fareast-font-family:Calibri; mso-fareast-theme-font:minor-latin;color:black;mso-ansi-language:EN-IN; mso-fareast-language:EN-US;mso-bidi-language:AR-SA">2-acetylpyridine thiosemicarbazone</span></span></span>

981-984Transition metal complexes of thiosemicarbazone ligands are emerging as a <span style="font-size:12.0pt; font-family:" times="" new="" roman","serif";mso-fareast-font-family:calibri;="" mso-fareast-theme-font:minor-latin;color:#0f0f0f;mso-ansi-language:en-in;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">new class of non-platinum experimental anticancer chemotherapeutic compounds. 1-3<span style="font-size:12.0pt; font-family:" times="" new="" roman","serif";mso-fareast-font-family:fd687457-identity-h;="" color:#0f0f0f;mso-ansi-language:en-in;mso-fareast-language:en-us;mso-bidi-language:="" ar-sa"=""> The observed cytotoxicities of the active complexes have been thought to arise from their interaction with intracellular thiols such <span style="font-size: 12.0pt;font-family:" times="" new="" roman","serif";mso-fareast-font-family:fd687457-identity-h;="" color:#0f0f0f;mso-ansi-language:en-in;mso-fareast-language:en-us;mso-bidi-language:="" ar-sa"="">as glutathiones (GSH) generating a thiolato Complex of the type [ML]+ <span style="font-size:12.0pt; font-family:" times="" new="" roman","serif";mso-fareast-font-family:calibri;="" mso-fareast-theme-font:minor-latin;color:#0f0f0f;mso-ansi-language:en-in;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">which in turn <span style="font-size:12.0pt; font-family:" times="" new="" roman","serif";mso-fareast-font-family:calibri;="" mso-fareast-theme-font:minor-latin;color:#0f0f0f;mso-ansi-language:en-in;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">is capable of promoting redox reactions with other thiols and oxygen generating the disulphide species (GSSG) alongwith superoxide and hydroxyl radicals.<span style="font-size: 12.0pt;font-family:" times="" new="" roman","serif";mso-fareast-font-family:fd687457-identity-h;="" color:#0f0f0f;mso-ansi-language:en-in;mso-fareast-language:en-us;mso-bidi-language:="" ar-sa"=""> 4 The other possibility involves the binding of the drug to the enzyme, viz., ribonucleotide  reductase, an obligatory enzyme for DNA synthesis, thereby hindering or blocking the DNA replication.</span

<span style="font-size:12.0pt;line-height:115%; font-family:"Times New Roman","serif";mso-fareast-font-family:Calibri; mso-fareast-theme-font:minor-latin;mso-ansi-language:EN-IN;mso-fareast-language: EN-US;mso-bidi-language:AR-SA">Crystal structure of cationic complex of 2[Co^III (APOTSC)₂]⁺[Co^IICI₄]^2-</span>

977-980<span style="font-size:12.0pt;line-height:115%; font-family:" times="" new="" roman","serif";mso-fareast-font-family:calibri;="" mso-fareast-theme-font:minor-latin;mso-ansi-language:en-in;mso-fareast-language:="" en-us;mso-bidi-language:ar-sa"="">The reaction between 4N-dimethyl-2-acetylpyridine-N-oxide thiosemicarbazone (HAPOTSC) ligand and cobalt chloride leads to the formation of a cationic complex containing two thiolato N-oxide thiosemicarbazone ligands, which has been characterized by spectroscopic and X-ray crystallographic studies.</span

Synthesis, crystal structures and antimicrobial activity of palladium metal complexes of sulfonyl hydrazone ligands

Palladium complexes of sulfonyl hydrazone based ligands have been prepared by refluxing with the corresponding ligands and Pd(II) salt in 2:1 ratio. The compounds have been characterized by FT-IR and UV-Vis spectroscopic methods. The crystal structure of the prepared palladium complexes has been determined by single-crystal X-ray crystallographic technique. Crystal data for C40H50N4O6PdS2 (PMHT-Pd(II) complex): triclinic, space group P-1 (no. 2), a = 7.1561(6) Å, b = 12.1300(11) Å, c = 12.6117(17) Å, α = 63.498(11)°, β = 86.694(9)°, γ = 81.451(7)° and Z = 1. The final R1 was 0.0699 (I > 2σ(I)) and wR2 was 0.1834 (all data). Crystal data for C36H42N4O6PdS2 (PTHC-Pd(II) complex): monoclinic, space group P21/n (no. 14), a = 8.6726(2) Å, b = 20.8824(4) Å, c = 10.3351(2) Å, β = 104.429(2)° and Z = 2. The final R1 was 0.0344 (I > 2σ(I)) and wR2 was 0.0840 (all data). Crystal data for C36H42N4O6PdS2 (PTHT-Pd(II) complex): monoclinic, space group P21/n (no. 14), a = 9.7658(2) Å, b = 10.0488(3) Å, c = 18.7714(4) Å, β = 99.602(2)° and Z = 2. The final R1 was 0.0334 (I > 2σ(I)) and wR2 was 0.0832 (all data). Crystal data for C40H50N4O6PdS2 (PMHC-Pd(II) complex): triclinic, space group P-1 (no. 2), a = 10.2070(9) Å, b = 12.1841(13) Å, c = 16.8879(19) Å, α = 109.005(6)°, β = 90.061(5)°, γ = 99.032(5)° and Z = 2. The final R1 was 0.0822 (I > 2σ(I)) and wR2 was 0.2293 (all data). The single-crystal structure data showed a good agreement with the experimental results. The synthesized complexes were screened for their in vitro antibacterial activity against one Gram-negative (Escherichia coli) and two Gram-positive (Bacillus subtilis and Staphylococcus aureus) bacterial strains and for in vitro antifungal activity against Aspergillus niger, Aspergillus flavus and Aspergillus fumigatus. The PTHC-Pd(II) complex possesses the nearby significant antifungal activity analogous to the standard drug fluconazole against selected fungal strains Aspergillus niger, Aspergillus Flavus and Aspergillus fumigatus as well as the same complex showed the antibacterial activity for Staphylococcus aureus as comparable to standard ofloxacin drug