The evaluation of lysosome targetability with nitrogen-containing basicity groups based on phenoxazinium derivatives

摘要

To evaluate the lysosome targetability of different nitrogen-containing basicity groups, seven fluorescent probes based on phenoxazinium connected different nitrogen-containing basicity groups were prepared. Probe 8b containing N, N-dimethylphenyl, 8c containing N, N-diethylphenyl group and 8d containing quinolin-8-yl group exhibited obvious emission responses at 675 nm with pH ranging from 2.4 to 5.6, 3.4-7.6 and 1.8-4.2, and their calculated pk(a) were 3.99, 5.57 and 2.46 respectively. While probe 8a containing morphoyl group, probe 8e containing pyridine-4-yl, probe 8f containing pyridine-3-yl and probe 8g containing pyrimidine group showed no significant changes of emission intensity when pH changes from 2.0 to 8.0. Moreover, three probes 8b, 8c and 8d showed good selectivity for hydrogen ion. Fluorescent imaging experiments indicated that probes 8c and 8d were lysosome biomarkers for Ges-1 and HeLa cells.