靶向线粒体检测HNO和半胱氨酸代谢的固定性荧光探针的设计与成像

With the rapid development of fluorescent imaging technology，the fluorescent imaging and detecting of living cells are developing towards a more microscopic structures. As a result，organelle-targetable fluorescent probes emerged and have developed rapidly in recent years. Many functional fluorescent probes based on small organic molecules, which can be located on the mitochondria to detect specific reactive small molecules, have been successfully reported in achieving visual imaging in mitochondria. However, most of mitochondria-targetable fluorescent probes do not stably localize in mitochondria and have short absorption or emission wavelengths. For further detection and imaging of the reactive small molecules in mitochondria, the synthesis of near-infrared fluorescent probes and two-photon fluorescent probes bearing good optical properties, which can be stably located in mitochondria by introducing immobilization group, become important significance. Based on the specific reaction of HNO and probe, a highly selective ratiometric near-infrared fluorescent probe for detecting and imaging of HNO in mitochondria are to be synthesized. The two-photon fluorescent probe for imaging Cys and SO2 in mitochondria through distinct two channels with turn-on fluorescent emission, based on specific reaction toward Cys and SO2, are to be synthesized. Furthermore, with ratiometric fluorescent responses, the probe could visualize the enzymatic conversion of Cys to SO2 in mitochondria.

随着荧光显微成像技术的迅速发展，活细胞荧光成像和检测向着更微观结构发展，因此，亚细胞器靶向型荧光探针应运而生。基于有机小分子的功能型荧光探针既能定位于线粒体，又能实现线粒体内活性分子的检测，已成功应用于线粒体内多种活性分子的可视化成像。然而大多数荧光探针易受线粒体内膜电位的影响，对线粒体靶向标记不稳定，且发射波长较短，易受细胞自发荧光干扰。因此，本项目以引入可固定性反应活性基团增强探针线粒体靶向标记的稳定性为核心，利用长波长激发的近红外和双光子荧光探针降低生物背景荧光的干扰。基于HNO与探针分子的特异性反应，实现对线粒体内HNO比率型近红外荧光成像分析；基于双识别位点分别与半胱氨酸和SO2的特异性反应，通过两个荧光发射通道的快速响应，分别实现线粒体内半胱氨酸和SO2荧光成像分析；通过考察双通道比率荧光响应信号，将实现线粒体内半胱氨酸代谢生成SO2过程的荧光成像研究。

过渡金属催化的Sonogashira型氧化惰性C(sp3) -H键与末端炔烃的偶联反应是合成手性炔烃最直接有效的方法之一。目前最主要的困难来自于对未活化的C(sp3) -H键区域选择性控制活化和末端炔烃易发生的Glaser同质偶联的抑制。为此，我们报道了一种铜/手性金鸡纳生物碱为基础的N,N, p配体催化剂，以高度区域选择性、化学选择性和对映选择性的方式，使惰性的C(sp3) - H键与末端炔烃不对称氧化交叉偶联。使用N -氟酰胺作为温和氧化剂，在有效避免Glaser同质偶联的前提下，有选择地生成烷基自由基。一系列(杂)芳基和炔丙基C(sp3)−H键都具有较好的兼容性。而且，它还为手性C(sp3) -C (sp)、C(sp3) -C (sp2)和C(sp3) -C (sp3)键的构造提供了一个通用的工具。.本项目以引入可固定性反应活性基团增强探针线粒体靶向标记的稳定性为核心，利用长波长激发的近红外和双光子荧光探针降低生物背景荧光的干扰。基于HNO与探针分子的特异性反应，实现对线粒体内HNO比率型近红外荧光成像分析；基于双识别位点分别与半胱氨酸和SO2的特异性反应，通过两个荧光发射通道的快速响应，分别实现线粒体内半胱氨酸和SO2荧光成像分析；通过考察双通道比率荧光响应信号，将实现线粒体内半胱氨酸代谢生成SO2过程的荧光成像研究。