Synthesis Of New Derivatives Of Praziquantel And Study Of The Process For Preparation Of Ethephon

Part Ⅰ:Schistosomiusis is a kind of tropical disease which seriously influences on our humanbeing. The World Health Organization estimates that200million people are infected and it is about600million people who are at risk of infection. Schistosomiasis is caused by infection with parasitic trematodes (flukes). Five kind of blood fluke species could infect humans--Schistosoma mansoni, S. haematobium, S. japonicum, S. intercalatum, and S. Mekongi; of which the first three of these are the most widely distributed and cause the highest disease burden. In spite of efforts to reduce the incidence of human schistosomiasis in the world, the disease continues to spread to new geographic areas. Schistosomiasis in our country had been effectively controlled after the liberation, however, it has a rising trend in Hubei, Hunan and other regions now.Thankfully, a highly effective drug exists to treat this disease. Praziquantel (PZQ) is the current drug of choice in the treatment of all five schistosome species that infect humans. Over the past20years, several million people have been effectively treated with praziquantel, and the drug has become the mainstay for morbidity control of schistosomiasis.Possible resistance (or innate tolerance) of schistosomes to praziquantel has been reported for at least10years. Tolerance was seen after only a few iterations of a simple laboratory-based artificial selection. There are no back-up drugs for the treatment of schistosomiasis if praziquantel become less effective. With a wider deployment of PZQ, the pressure for the development of resistance is much higher. We take the view that replacements for PZQ need to be developed in advance, rather than after they are needed. We expected an investigation of PZQ analogs with potential broad-spectrum antischistosomal activity against both juvenile and adult forms.Part Ⅱ:Plant growth regulator is a kind of biological or chemical agent which is synthetized for the regulate growth and development of plants, and it is widely used in agricultural production. As a frequently used types of pesticides, plant growth regulator is an integrated organic product of many kinds of science and technology. such as Trace Analysis, Plant Physiology as well as Modern Agriculture Cultivation.Ethephon is the only kind of vinyl release agentone which is widely used. Products applied in agricultural is40%aqueous solution which is a strong acid and safe to people. As a kind of excellent and efficient plant growth regulator, ethephon can release one molecular ethylene each molecular. The physiological effect of ethylene on plants is very extensive, and it is almost involved in every physiological process of plant. The most important effects contain promoting the development of female flower, accelerating fruit ripening, removing plant organs, awaking dormant seeds and changing geotropism.Through optimizing the reaction conditions, we developed a method with low cost, low waste emissions. The raw materials used in this method was domestic materials diester; the equipments used were simple and easy to obtain; the reaction condition was easy to control and the conversion rate could reach100%. Most of all, the products were of good quality and could meet international export standards (ethephon content is above90%).