Design And Synthesis Of A Novel Thiols' Analytical Reagent And The Preliminary Establishiment Of The Detecting Thiols Method

Thiols, which play a crucial role in biology and medicine,and play an important role in metabolic pathways.Low molecular weight thiol-containing compounds such as cysteine (Cys), glutathione (GSH), homocysteine (Hcys), plasma levels of which have been linked to various human diseases such as AIDS, and Parkinson's diseases, as well as cardiovascular diseases. Therefore, it is of importance to detect thiols using appropriate reagents. In this dissertation, it was described the synthesis of novel hemicyanine dyes compounds, benzenesulfolactones and coumarins and their application in detecting thiols.Part1 Synthesis of benzenesulfolactonesMulti-substituted benzenesulfolactones was synthesized starting from cheap saccharin sodium via methylation, Grignard reaction, cyclization, and further transformed into nitro derivative by nitrification and then amino derivative by reduction. Benzenesulfolactone was sythesized starting from 2-formylbenzenesulfonate via cyclization and then reduction. It was show that by preliminary research, the speed of the obtained benzenesulfolactones reacting with thiols in normal condition is so slow that there are some difficuties to be as detecting thiols'reagents.Part 2 Synthesis of coumarinsMethyl acrylate of coumarins was synthesized starting from resorcinol via formylation, etherification, iodination, cyclization, Heck cross-coupling reaction. It doesn't react with thiols in normal condition, so this compound cann't be a reagent for detecting thiols.The adol coupound of coumarins was synthesized starting from resorcinol visa cyclization, formylation, etherification,adol reaction.Although it reacts with thiols,the difference value of UV absorbance before and after reaction is small. Hence, the compound also cann't be reagent for detecting thiols by UV analysis. Other analycial mothods to detect thiols with this compound will be established in future.Part 3 Synthesis of hemicyanine dyescompounds and their application in detecting thiolsSix hemicyanine dyes compounds were designed and prepared concisely via three steps.They can react with ethanethiol quickly, and the difference value of UV absorbance is significant before and after reaction.Hence, the analycal mothod of detecting thiols by UV-visible pectrophotometer was preliminarily established. A linear calibration curve can be observed in the range of 10-5～10-4mol/L.