Synthesis and evaluation of pyrazine and quinoxaline fluorophores for in vivo detection of cerebral tau tangles in Alzheimer's models.

A series of pyrazine and quinoxaline probes (QNNs) were synthesized and evaluated. The quinoxaline derivative 3b, with high affinity and selectivity for tau aggregates, favorable fluorescence turn-on capability and brain kinetics, was successfully applied to the detection of tau tangles both in vitro and in mice in vivo.