英语翻译The DNA photocleavage abilities of the dpb-based complexeswere examined by agarose gel electrophoresis of thesupercoiled pBR322DNAupon red light irradiation (g600 nm;Figure 2).[Ru(bpy)(dpb)2]2þ and [Ru(dpb)3]2þ show muchhigher
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英语翻译The DNA photocleavage abilities of the dpb-based complexeswere examined by agarose gel electrophoresis of thesupercoiled pBR322DNAupon red light irradiation (g600 nm;Figure 2).[Ru(bpy)(dpb)2]2þ and [Ru(dpb)3]2þ show muchhigher
英语翻译
The DNA photocleavage abilities of the dpb-based complexes
were examined by agarose gel electrophoresis of the
supercoiled pBR322DNAupon red light irradiation (g600 nm;
Figure 2).[Ru(bpy)(dpb)2]2þ and [Ru(dpb)3]2þ show much
higher DNA photocleavage activities than [Ru(bpy)2(dpb)]2þ.
Control experiments (Supporting Information) indicated that
theDNAphotocleavage was an 1O2 mechanism.1O2 quantum
yields of these complexes were determined to be 0.22 for
[Ru(bpy)2(dpb)]2þ,0.45 for [Ru(bpy)(dpb)2]2þ,and 0.52 for
[Ru(dpb)3]2þ in CH3CN,using [Ru(bpy)3]2þ as the standard
(0.57 in CH3CN)11 and 1,3-diphenyl-isobenzofuran as the
trapping agent of 1O2.Obviously,thehigh1O2 quantum yield,
the strong DNA binding affinity,and the long wavelength
absorption of [Ru(bpy)(dpb)2]2þ and [Ru(dpb)3]2þ are the
main reasons for their efficientDNA photocleavage activities
under red light irradiation.[Ru(bpy)2(dppz)]2þ,a well-known
DNA photocleaver that shows the activity within the visible
region (
英语翻译The DNA photocleavage abilities of the dpb-based complexeswere examined by agarose gel electrophoresis of thesupercoiled pBR322DNAupon red light irradiation (g600 nm;Figure 2).[Ru(bpy)(dpb)2]2þ and [Ru(dpb)3]2þ show muchhigher
基于dpb络合物的DNA光断裂能力用红光(≥600nm;图2)辐照下超螺旋的pBR322DNA的琼脂糖凝胶电泳进行了研究.[Ru(bpy)(dpb)2]2+和[Ru(dpb)3]2+比[Ru(bpy)2(dpb)]2+显示了高得多的光断裂活性.对比实验表明(支持信息),DNA光断裂是一种1O2机理.这些络合物的1O2量子效率确定为:[Ru(bpy)2(dpb)]2+是0.22,[Ru(bpy)(dpb)2]2+是0.45,而[Ru(dpb)3]2+是0.52,这是在CH3CN中,用[Ru(bpy)3]2+作为标准(在CH3CN中为0.57)以及用1,3-二苯基-异苯并呋喃酮作为1O2的捕获剂.显然,高的1O2量子效率、强的DNA结合亲和力、以及[Ru(bpy)(dpb)2]2+和[Ru(dpb)3]2+的长波长吸收,都是它们在红光辐照下高效DNA光断裂活性的主要原因.[Ru(bpy)2(dppz)]2+,这种众所周知的、在可见光范围(<550nm)显示活性的DNA光断裂剂在红外辐照下几乎不引起DNA光断裂,因为它有短波长吸收(支持信息).
为了更好的了解这些络合物的1O2发生性状,测量了时间分辨的吸收谱(支持信息).[Ru(bpy)2(dpb)]2+显示出中心在550nm处的基态漂白带,以及两个正的吸收带,一个低于515nm一个高于580nm,类似于Ru(II)多吡啶基络合物的3MLCT T-T吸收谱,这些络合物不发射,或者说有低的发射量子效率3e,15.[Ru(bpy)(dpb)2]2+的漂白带强度比[Ru(bpy)2(dpb)]2+的低得多.在[Ru(dpb)3]2+的情况下,观察不到漂白带.这三种络合物的瞬态吸收谱在寿命分别为66、330和530ns时的所有波长下都显示单指数的衰落.[Ru(dpb)3]2+的激发态寿命是在超出550nm有MLCT吸收最大值的Ru(II)络合物中最长的5,9.考虑到dpb配体的三重激发态是长寿命的(4μs),而且在300-570nm区域呈现出强的正带,从[Ru(bpy)2(dpb)]2+到[Ru(dpb)3]2+的瞬态吸收谱的变化似乎是dpb配体与3MLCT增进混合的结果.这一不寻常的发现毫无疑问值得进一步研究,而理论计算可能为这些令人感兴趣的性状提供线索.[Ru(bpy)(dpb)2]2+到[Ru(dpb)3]2+的长激发态寿命有利于它们的1O2的光敏化发生.