Design,Synthesis And Biological Application Of Anti-tumor Theranostic Prodrug And Dual-site Fluorescent Probe

Biothiols,including cysteine?Cys?,homocysteine?Hcy?,glutathione?GSH?and hydrogen sulfide?H₂S?,which play a vital role in human physiological and pathological processes.The abnormal levels of these biothiols have been associated with various diseases such as Parkinson's disease,cancer,Alzheimer's disease,acquired immune deficiency syndrome?AIDS?,liver damage,cardiovascular disease and neurodegenerative disease.Hypochlorous?HC1O?is produced by Myeloperoxidase?MPO?catalyzed reaction between chloride ion?Cl^-?and hydrogen peroxide?H₂O₂?.Its of very importance for human immune defense system,and the abnormal level of hypochlorous has been associated with various diseases such as cardiovascular disease,neurodegenerative disorder,lung injury,arthritis,rheumatism and even cancer.Therefore,fluorescent probes of biothiols and hypochlorous have attracted more and more attention.In this paper,a anti-tumor theranostic prodrug and two dual-site fluorescent probes were introduced.1.A anti-tumor theranostic prodrug T1-O-Drug for detection of Cys based on dicyano isophorone was designed and synthesized.The prodrug is composed of several functional parts,including T1-OH as signal reporter,camptothecin Drug as the anticancer drug and disulfide bond as cleavable linker triggered by Cys.Research on photophysical properties showed that,after Cys was added to the prodrug T1-O-Drug,significant fluorescence enhancement occurred at 435 nm?drug fluorescence?and 588 nm?T1-OH fluorescence?.2.We synthesized a novel dual-site fluorescent probe FDOCl-N-NBD through4-Hydroxybenzylaminelinkedmethyleneblueand4-Chloro-7-nitro-1,2,3-benzoxadiazole?NBD-Cl?for the separate detection of Hcy and HOCl.In addition,the reference compound FDOCl-O-NBD was synthesized by resorcinol linked methylene blue and NBD-Cl.It was found that the reference compound FDOCl-O-NBD was difficult to release methylene blue.In addition,the probe FDOCl-N-NBD has the advantages of good stability,low detection limit?Hcy:51.4 nM,HOCl:2.16?M?,fast response?Hcy:280 s,HOCl:140 s?,high selectivity and strong anti-interference,and the probe can sequentially recognize Hcy and HOCl or HOCl and Hcy,and has been applied to detect endogenous Hcy and HOCl in U87MG,MDA-MB-231 and Huh7 cells successfully.3.We synthesized two novel dual-site fluorescent probes FDOCl-N₃-1 and FDOCl-N₃-2 through ethylenediamine or 1,8-Diamino-3,6-dioxaoctane linked methylene blue and 4-Bromo-1,8-naphthalic anhydride for simultaneous detection of H₂S and HOCl.Among them,FDOCl-N₃-1 has more excellent photophysical properties than FDOCl-N₃-2,with more obvious changes in fluorescence intensity and lower detection limit.The probe FDOCl-N₃-1 has fast response,high selectivity and high sensitivity to detect H₂S and HOCl,it can sequentially recognize H₂S and HOCl or HOCl and H₂S.