LIFTETIME MEASUREMENTS OF CRYPTOPHANE-XENON COMPLEXES

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 中心，不一定是研究者的机构。 我们整个项目的目标是开发用于早期癌症检测和可能的治疗干预的129-MRI生物传感器。我们目前正在合成隐辉石和其他载体，这些载体对氙有更大的亲和力，更长的129 Ω超极化自旋晶格弛豫时间，以及独特的化学位移。Cryptophane-A是一种有机笼状化合物，在其内部空腔中以任何已知分子中最高的亲和力结合氙（Xe），并以314 nm左右的最大强度发出荧光。在具有隐石烷的水溶液中存在过量的柠檬酸可以淬灭所观察到的荧光，其效率约为50%，如通过稳态实验所测量的。这种淬灭被认为在本质上是静态的，这是由于结合的碳原子非常接近隐色烷的碳原子发色团。荧光寿命测量将允许测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.