LIFTETIME MEASUREMENTS OF CRYPTOPHANE-XENON COMPLEXES

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 我们整个项目的目标是开发用于癌症早期检测和可能的治疗干预的129-Xe磁共振生物传感器。我们目前正在合成对氙气有更大亲和力、更长的129Xe超极化自旋-晶格弛豫时间和独特的化学位移的隐丹和其他载体。隐形化合物是一种有机笼状化合物，在其内腔中与氙气(Xe)结合的亲和力是已知分子中最高的，其最大荧光强度约为314 nm。水溶液中过量Xe的存在使观测到的荧光猝灭，由稳态实验测得的效率约为50%。这种猝灭被认为在本质上基本上是静态的，这是由于束缚的Xe原子非常接近于隐形原子的Veratole发色团。荧光寿命测量将允许确定生物分子猝灭常数或确认静态猝灭过程。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The goal of our overall project is to develop 129-Xe MRI biosensors for early cancer detection and possible therapeutic intervention. We are currently synthesizing cryptophanes and other carriers that will have greater affinity for xenon, longer 129Xe hyperpolarized spin-lattice relaxation times, and unique chemical shifts. Cryptophane-A, an organic cage compound, binds xenon (Xe) in its internal cavity with the highest affinity of any known molecule and fluoresces with a maximum intensity around 314nm. The presence of excess Xe in aqueous solution with the cryptophane quenches the observed fluorescence with an efficiency of about 50% as measured by steady-state experiments. This quenching is believed to be largely static in nature, a result of the bound Xe atom residing very close to the veratole chromophores of the cryptophane. Fluorescence lifetime measurements would allow for the determination of the biomolecular quenching constant or a confirmation of the static quenching process.