Structure-Acaricidal Activity Relationship Of Protopines And Their Direviatives

Protopines are a class of isoquinoline alkaloids with numerous pharmacological activities,including antibacterial,insecticidal,protection of liver injury,relaxant effects on smooth muscle,anti-tumor and anti-cerebral ischemia and so on.They are widely used in clinical medicine,but seldom found in pesticides and veterinary drugs.No study on structureactivity relationship(SAR)research of protopines is found so far.In order to research the structure-acaricidal activity relationship of protopines then get better acaricidal active pesticides,this essay forcus on structural modification of allocryptopine,protopine,and cryptopine and then acaricidal activity of the compounds were tested.The main contents and results of the research were showed below:1 Fifteen derivatives of the three alkaloids have been synthesized.Among the derivatives,seven compounds include QYY-2,QYY-3,QYY-7,QYY-10,QYYC-1,QYYC-2,QYYC-3 have not been reported yet.The structures of the compounds were well confirmed by 1H NMR,13C NMR and ESI MS.2 In vitro acaricidal activity of the 18 compounds were tested with 24-well plate culture method against P.cuniculi.The results showed that all of the compounds showed different levels of acaricidal activity at the concentration of 5 mg/ml and QYY-1 was the most active one.The death rate of QYY-1 was 71.7%,while others were all lower than 30.0%.3 In vitro acaricidal activity of the 18 compounds were tested with impregnation method against T.cinnbarinus.To varying degrees,all of the compounds have acaricidal activity at the concentration of 1 mg/ml.Compared with the model compounds,the activity of QYY-1、QYYP-1 and QYYP-4 increased significantly.Again,QYY-1 was the most active one among all the compounds which got a death rate of 60.0%and adjusted death rate of 57.1%.4 The SAR research showed that the carbon-carbon double band existed in the 10-membered ring improves the acaricidal activity significantly and the carbonyl group on the 13-position improves the acaricidal activity against T.cinnbarinus.And the benzene at 12-position is not the active part.These results enriched the content of structural modification and biological activity research of allocryptopine,protopine and cryptopine and provided a theoretical basis and reference method for SAR research of similar compounds.