Design Of Kd-based Glutathione Reversible Probe And Synthesis

The intracellular glutathione concentration is 0-10 mM,and the maximum probe concentration that cells can tolerate is 10 ?M.Therefore,to achieve the goal of quantitative detection of intracellular glutathione,the reaction of the probewith glutathione must be reversible.Michael addition reacts to a fast-balanced reaction,especially when the donor of the Michael addition reaction is a sulfhydryl group.The key to design a reversible probe for glutathione based on the Michael addition reaction of a reactive double bond with a thiol group is to construct a reactive double bond with moderate reactivity,and the construction of the active double bond should be based on the Kd value to meet the actual detection time.The probe requirement can be applied to the actual in vivo detection of glutathione probe Kd value should be 3 mM.At present,there are only three probes capable of quantitatively detecting glutathione,but the Kd values of these three probes are not very close to 3 mM,so the structure of the probe needs to be further optimized to make Kd?3 mM.In this paper,the Kd value is fine-tuned as the target,and the target molecule is designed by using the strategy of long-distance regulation of the stability of Michael reverse reaction intermediates.The synthesis and characterization of four probe molecules were completed and the relationship between the remote control group and the Kd value was discussed.The results showed that the probe QG-d with the group of morpholine had the best performance.That is,the response time is short,the minimum detection limit is low(4.4 ?M)and Kd=3.26 mM.The Kd value of the probe QG-d is one of the closest to the best value in the current reported literature.In addition,the morpholino group also has a function of lysosomal localization.The probe QG-d can be used for quantitative detection of glutathione in lysosomes,which provides a good basis for further understanding of the physiological processes in lysosomes.