Department of Chemistry, University of Tsukuba, Tsukuba 305-8571, Japan.
Tsukuba Research Center for Energy Materials Science (TREMS), University of Tsukuba, Tsukuba 305-8571, Japan.
J Phys Chem B. 2023 May 25;127(20):4514-4522. doi: 10.1021/acs.jpcb.2c09016. Epub 2023 May 10.
Pyropheophorbide (Pyro-), a chlorophyll metabolite, is a potential photosensitizer for photodynamic therapy (PDT), but little is known about its interaction with the target molecules for PDT, e.g., nucleic acids. Elucidation of the interaction between photosensitizers and nucleic acids will help us understand the initial process of PDT at the molecular level and hence to develop photosensitizing agents. We found that pyro- forms a 1:1 complex with an all parallel-stranded G-quadruplex DNA and that pyro- in the complex exhibits a quantum yield for singlet oxygen generation, with excitation at 664 nm, higher by a factor of ∼10 than that of pyro- in an aqueous solution. These findings provided novel insights into molecular design of pyro--based photosensitizers to enhance their PDT efficacy.
原卟啉（Pyro-）是一种叶绿素代谢物，是光动力疗法（PDT）的潜在光敏剂，但人们对其与 PDT 的靶分子（如核酸）的相互作用知之甚少。阐明光敏剂与核酸之间的相互作用将有助于我们在分子水平上理解 PDT 的初始过程，从而开发出光敏剂。我们发现，Pyro-与全平行链 G-四链体 DNA 形成 1:1 复合物，并且在复合物中，Pyro-的单线态氧生成量子产率在 664nm 激发下比在水溶液中高约 10 倍。这些发现为基于 Pyro-的光敏剂的分子设计提供了新的见解，以增强其 PDT 疗效。
