Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore-, 560012, India.
Dalton Trans. 2010 Feb 28;39(8):2147-58. doi: 10.1039/b917265c. Epub 2010 Jan 21.
Oxovanadium(iv) complexes [VOCl(B)(2)]Cl (1-3) of phenanthroline bases (B), viz. 1,10-phenanthroline (phen in ), dipyrido[3,2-d:2',3'-f]quinoxaline (dpq in ) and dipyrido[3,2-a:2',3'-c]phenazine (dppz in ), have been prepared, characterized and their DNA and protein binding, photo-induced DNA and protein cleavage activity and photocytotoxicity have been studied. Complex , structurally characterized by X-ray crystallography, shows the presence of a vanadyl group in VOClN(4) coordination geometry. The dpq ligand displays a chelating mode of binding with a N-donor site trans to the oxo-group. The chloride ligand is cis to the oxo-group. The one-electron paramagnetic complexes show a d-d band near 715 nm in 15% DMF-Tris-HCl buffer. The complexes are redox active exhibiting a V(iv)/V(iii) redox couple within -0.5 to -0.7 V vs. SCE in 20% DMF-Tris-HCl/0.1 M KCl. The complexes bind to calf thymus (CT) DNA in the order: (dppz) > (dpq) > (phen). The binding data reveal the groove and/or partial intercalative DNA binding nature of the complexes. The complexes show "chemical nuclease" activity in the dark in the presence of 3-mercaptopropionic acid or hydrogen peroxide via a hydroxyl radical pathway. The dpq and dppz complexes are efficient photocleavers of DNA in UV-A light of 365 nm forming reactive singlet oxygen ((1)O(2)) and hydroxyl radical ( OH) species. Complexes and also show DNA cleavage activity in red light (>750 nm) by an exclusive OH pathway. The complexes display a binding propensity to bovine serum albumin (BSA) protein giving K(BSA) values in the range of 7.1 x 10(4)-1.8 x 10(5) M(-1). The dppz complex shows BSA and lysozyme protein cleavage activity in UV-A light of 365 nm via OH pathway. The dppz complex exhibits significant PDT effect in human cervical cancer HeLa cells giving IC(50) values of 1.0 microM and 12.0 microM in UV-A and visible light, respectively (IC(50) = >100 microM in the dark).
制备了苯并菲啶碱基（B）的氧钒（IV）配合物[VOCl（B）（2）]Cl（1-3），即 1,10-苯并菲啶（phen 在），二吡啶并[3,2-d：2',3'-f]喹喔啉（dpq 在）和二吡啶并[3,2-a：2',3'-c]吩嗪（dppz 在）。研究了它们与 DNA 和蛋白质的结合、光诱导的 DNA 和蛋白质断裂活性以及光细胞毒性。通过 X 射线晶体学结构表征的复合物显示 VOClN（4）配位几何结构中存在钒酰基团。dpq 配体显示出与肟基团反式配位的螯合模式。氯离子配体位于肟基团的顺式位置。单电子顺磁共振复合物在 15% DMF-Tris-HCl 缓冲液中在 715nm 附近显示 d-d 带。这些配合物是氧化还原活性的，在 20% DMF-Tris-HCl/0.1M KCl 中，V（iv）/V（iii）氧化还原偶对在-0.5 到-0.7V 范围内。这些配合物与小牛胸腺（CT）DNA 的结合顺序为：（dppz）>（dpq）>（phen）。结合数据表明，这些配合物具有沟或部分嵌入的 DNA 结合性质。在 3-巯基丙酸或过氧化氢存在下，这些配合物在黑暗中具有“化学核酸酶”活性，通过羟基自由基途径。dpq 和 dppz 配合物在 365nm 的 UV-A 光下有效切割 DNA，形成反应性单线态氧（（1）O（2））和羟基自由基（OH）物质。复合物也在红光（>750nm）中通过专有的 OH 途径显示 DNA 切割活性。复合物显示出与牛血清白蛋白（BSA）蛋白的结合倾向，给出 K（BSA）值在 7.1x10（4）-1.8x10（5）M（-1）范围内。dppz 配合物在 365nm 的 UV-A 光下通过 OH 途径显示 BSA 和溶菌酶蛋白切割活性。dppz 配合物在人宫颈癌 HeLa 细胞中具有显著的 PDT 效应，在 UV-A 和可见光下的 IC（50）值分别为 1.0μM 和 12.0μM（在黑暗中>100μM）。
