Studies On The Synthesization Of The Water-soluble Anti-Schistosomal Agents By Structure Modification

Objective: As main anti-schistosomal agents , nithiocyanmine and praziquantel are effective. These two medicines show good effects in animal experiment and clinical treatment. But these two medicines are fat-soluble: nithiocyanmine is insoluble in water, and praziquantel is soluble only 0. 04g in 100ml H20. In clinic patients always take these two medicines orally in tiny powder, and the absorption of durg is not high. Furthermore, it is very difficult for animals infected with schistosomes to take medicines orally .The aim of this study was to increase these two medicines' solubility in water by structural modification, to improve and simplify the mode of administration to infected animals.Method: Water-soluble functional radicels (e. g:-COOH, -SO3H)were intruduced into ni thiocyanmine and praziquantel, whose water-soluble derivatives are good materials of injection.Results: The nithiocyanmine's derivatives ( their sodium salts) withglycin and alanine had good solubility in water, and they were 2708mg/100ml(25#) and5800mg/100ml (25#) respectively.Praziquantel's sulfonic reaction wasn't successful, the sulfonic derivative was very difficult to be separated and purified; Some of praziquantel were decomposed, so the productivity of the derivative was very low.Conclusion: The nithiocyanmine's sodium salt canbe produced into injection, and then used to treat the animals infected with schistosomes,by intravenous or intramuscular injection after pharmacologic filtration.