<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>

Abstract

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