Polypyridyl iron(II) complexes showing remarkable photocytotoxicity in visible light
作者:ADITYA GARAI、UTTARA BASU、ILA PANT、PATURU KONDAIAH、AKHIL R CHAKRAVARTY
DOI:10.1007/s12039-015-0815-0
日期:2015.4
Iron(II) complexes of polypyridyl ligands (B), viz. [Fe(B)2]Cl2 (1 and 2) of N, N, N-donor 2-(2-pyridyl)-1,10-phenanthroline (pyphen in 1) and 3-(pyridin-2-yl)dipyrido[3,2-a:2’,3’-c]phenazine (pydppz in 2), are prepared and characterized. They are 1:2 electrolytes in aqueous DMF. The diamagnetic complexes exhibit metal to ligand charge transfer band near 570 nm in DMF. The complexes are avid binders to calf thymus DNA giving binding constant (K b) values of ∼106 M−1 suggesting significant intercalative DNA binding of the complexes due to presence of planar phenanthroline bases. Complex 2 exhibits significant photocytotoxicity in immortalized human keratinocyte cells HaCaT and breast cancer cell line MCF-7 giving IC50 values of 0.08 and 13 μM in visible light (400–700 nm). Complex 2 shows only minor dark toxicity in HaCaT cells but is non-toxic in dark in MCF-7 cancer cells. The light-induced cellular damage follows apoptotic pathway on generation of reactive oxygen species as evidenced from the dichlorofluorescein diacetate (DCFDA) assay.
通过配位体B的铁(II)配合物,即N,N,N捐赠体2-(2-吡啶基)-1,10-菲啰啉(1中的pyphen)和3-(吡啶-2-基)双吡啶[3,2-a:2',3'-c]苯嗪(2中的pydppz),制备并表征了[Fe(B)2]Cl2(1和2)。它们在水相DMF中为1:2电解质。这些顺磁性配合物在DMF中显示出近570 nm的金属-配体电荷转移带。由于平面菲啰啉基团的存在,这些配合物与小牛胸腺DNA的结合常数(Kb)约为106 M−1,表明其具有显著的插层DNA结合能力。配合物2在永生化的人角质形成细胞HaCaT和乳腺癌细胞系MCF-7中表现出显著的光细胞毒性,在可见光(400-700 nm)下的IC50值分别为0.08和13 μM。配合物2在HaCaT细胞中仅显示出轻微的暗毒性,但在MCF-7癌细胞中则无毒性。光诱导的细胞损伤通过活性氧物质的生成遵循凋亡途径,DCFDA测定表明了这一点。