Synthesis And Acaricidal Activity Of Heterocylic Chalcones

Chalcones are a large class of flavonoids which are widely distributed in nature.Lots of research show that they have excellent bioactivities such as anti-bacterial,anti-inflammatory,antitumor and antioxidant activities.However,there is no study about the acaricidal activity against Psoroptes cuniculi.Chalcones has a simple structure and there have been many developed synthetic methods of chalcones,but few studies about the bioactivities of heterocylic chalcones are established.Here in,a series of heterocylic chalcones were designed and synthesized.In addition,acarcidal activity against Psoroptidae cuniculi of these compounds was assayed and the preliminary structure activity relationship was discussed.The details and results of this thesis are listed as below:1.27 kinds of heterocylic chalcones were synthesized.Aldol condensation and wittig reaction were used as the main method to synthesis 18 kinds of(E)-heterocylic chalcones,2 compounds which had never been reported in literature involved.Besides,9 kinds of reduction products were synthesized by using sodium borohydride and some catalysts.All the compounds were characterized by 1H NMR,13 C NMR,ESI-MS.2.Acaricidal activity in vitro against Psoroptes cuniculi of all the compounds was assayed by dip method.According the results of the assay,the compounds showed different activity.The median lethal concentration(LC50)of compound CH(chalcone),13 and 16 were 211.25?228.99 and 241.98 ?g/mL,and the median lethal time(LT50)were 4.80?1.90 and 2.23 h respectively,the results showed the acaricidal activity of the compounds above was better than the controlled drug-ivermectin(LC50 = 247.40 ?g/m L,LT50 = 8.90 h).3.The preliminary structure-activity relationship of heterocylic chalcones and its reduction products on their acaricidal activity was discussed.The presence of electron-rich heterocylic rings,such as furan,thiophene and pyrrole,led to the great decrease in acaricidal activity.In contrast,the two compounds containing 2-pyridyl showed high acaricidal activity,however,the existence of 3-pyridyl and 4-pyridyl weakened the activity.Total or selective reduction of the carbonyl group and the carbon-carbon double bond decreased the acaricidal activity,and the result showed that the ?,?-unsaturated carbonyl may be the important pharmacophore.In conclusion,the chalcones studied in this research could be used as leading compounds to develop new acaricidal drugs,and further research on the structure optimization,animal toxicity and clinic therapeutic efficacy should be carried out.