Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, PR China.
J Inorg Biochem. 2011 Jul;105(7):978-84. doi: 10.1016/j.jinorgbio.2011.03.021. Epub 2011 Apr 5.
Hypocrellin B (HB), a naturally occurring photosensitizer, has been extensively and intensively studied as a promising photodynamic therapy (PDT) agent. In this work, a new Co(III) complex Co(2)(HB)(tmp)(4) (tmp=3,4,7,8-tetramethyl-1,10-phenanthroline) was designed and synthesized with HB as bridging ligand and tmp as terminal ligand. Co(2)HB(tmp)(4) exhibits improved water solubility, enhanced absorptivity in the phototherapeutic window, increased binding affinity and DNA photocleavage capability toward dsDNA with respect to HB. The photodynamic activity of Co(2)(HB)(tmp)(4) stems from its (1)O(2) photosensitization ability, in sharp contrast to Cu(2)(HB)(tmp)(2) which relies on superoxide anion radical (O(2)(-)) and hydroxyl radical (·OH) to photocleave DNA, though the both complexes possess similar electrochemical properties. The remarkable difference between the photodynamic mechanisms of Co(2)(HB)(tmp)(4) and Cu(2)(HB)(tmp)(2) was discussed in detail.
竹红菌素 B（HB）是一种天然存在的光敏剂，已被广泛深入地研究为一种很有前途的光动力疗法（PDT）药物。在这项工作中，设计并合成了一种新的 Co（III）配合物[Co（2）（HB）（tmp）（4）]（4+）（tmp=3,4,7,8-四甲基-1,10-菲啰啉），其中 HB 作为桥联配体，tmp 作为端基配体。与 HB 相比，[Co（2）HB（tmp）（4）]（4+）具有更好的水溶性、在光疗窗口内更强的吸收性、更高的结合亲和力和对 dsDNA 的光解能力。[Co（2）（HB）（tmp）（4）]（4+）的光动力活性源于其 1O2 敏化能力，这与依赖超氧阴离子自由基（O2（-））和羟基自由基（·OH）来光解 DNA 的[Cu（2）（HB）（tmp）（2）]（2+）形成鲜明对比，尽管这两种配合物具有相似的电化学性质。详细讨论了[Co（2）（HB）（tmp）（4）]（4+）和[Cu（2）（HB）（tmp）（2）]（2+）光动力机制之间的显著差异。
