Novel strategy of constructing fluorescent probe for MAO-B via cascade reaction and its application in imaging MAO-B in human astrocyte

To detect monoamine oxidase B (MAO-B), the level of which is one of the most important indicators of neurodegenerative diseases such as Parkinson's disease, a new type of cascade reaction based on the formation of coumarin was applied in this research. After the reaction with MAO-B, the protecting group of hydroxyl group in probes (DEAN-MA and DEAB-MA) was removed, and the fluorescence intensity significantly increased (λ_em = 456 nm) as the structure of coumarin was formed subsequently. The probes showed excellent sensitivity and selectivity to MAO-B. The detection limit of DEAN-MA and DEAB-MA were 0.6 ng/mL and 0.2 ng/mL, respectively. We succeeded in detecting MAO-B in vitro and imaging it in human astrocyte (U87).