Design,Synthesis Of Novel Fluorescent Probes Based On Hemiocyanine Framework And Evaluation On Detection Of Cys/Hcy

With the development of molecular biology,fluorescent probe technology has been rapidly developed and applied since the last century.Compared with traditional detection methods which showed a series of shortcomings such as high cost and complicated operation,this technology has been widely used in biological detection with a series of advantages such as high sensitivity,low cost,easy operation and strong designability.These advantages have attracted wide attention of analytical scientists and have been widely used in bioactive molecule detection and quantitative analysis in many fields such as analytical science,especially in targeted drug delivery,efficacy detection,monitoring of homeostasis in human environment and quantitative and qualitative analysis.Biothiols are a class of amino acids containing sulfhydryl groups such as cysteine(Cys),glutathione(GSH),homocysteine(Hcy),participate in the process of protein synthesis in cells,and maintain the stable state of oxidation-reduction of life activities properly,which are important signal molecules for enzyme function and subsequent physiological activities and play a positive role in a series of physiological activities such as cardiovascular relaxation and neurotransmitter conduction.Many diseases are closely related to their abnormal contents in human body,and the lack of cysteine(Cys)easily leads to growth retardation,hair discoloration,liver damage,etc.Therefore,the detection of thiol content in these organisms plays an important role in the research,early diagnosis and treatment of some diseases.The traditional methods for the detection of thiols are limited because of the characteristics of small molecular thiols that are easy to be oxidized,similar active structures that are difficult to distinguish,the distribution in organisms is unbalanced and they are easy to be converted to each other.Based on theadvantages of high selection,high expression and high throughput of fluorescent probes and the ability to visually track a single cell,people pay attention to the application of fluorescent probes.It is of great scientific value and practical significance to focus on fluorescent probes that can detect mercaptan and intuitively show its dynamic distribution and transformation rules.Based on the reports of related literature and previous studies,this thesis focuses on the detection of active small molecules thiol cysteine(Cys)and homocysteine(Hcy),with a hemicyanine structure as the fluorescent mother nucleus combining the optical biological characteristics designed,and synthesized three series of new fluorescent probes: 1)Design and synthesize a probe P1 with o-chlorobenzoyl chloride as a response switch to achieve specificity for Cys.The probe showed orange-red(?ex = 495 nm)and Cys fluorescence(?em = 540 nm)was yellow fluorescence upon response to Cys.Experimental results show that the probe can distinguish the structure and function of similar biothiols from Cys.The fluorescence intensity has a linear relationship with the concentration of Cys.2)Design and synthesize a series of probes P2,P3,P4,P5,and P6 with thiopyrimidine as response switches,which are selective for Cys and Hcy,respectively.Spectral detection showed that after responding to Cys and Hcy respectively,they showed pink purple,P2(?em = 555 nm),P3(?em = 540 nm),P4(?em = 543 nm),P5(?em = 546 nm),P6(?em=596 nm),the response to Cys,Hcy is slightly different in response time and fluorescence intensity.The responses of these probes to Cys and Hcy have a good linear relationship.3)A probe P7 with Acetyl chloride as switch was designed and synthesized with a good linear relationship to Cys.The response mechanism was preliminarily speculated.