Studies On The Extraction Methods Of Molluscicidal Composition From Plant And The Mechanism Of Snail Control

Controlling the snail is a key technology to control the schistosomiasis.Developing a new plant molluscicide that is efficient,durable,safe,inexpensive(WHO's standards) is the hot spots of domestic and international study to control the schistosomiasis and Oncomelania hupensis.There is no plant molluscicides which can reach WHO's standards,due to the lack of synchronization of environmental security and economic study in the molecular level.This research is aboat the extracting and isolating of sponins, which is from molluscicidal plant and to inhibit snail of climbing upward with Nic,and the kinetic characteristics and antibiotic sensitivity of transaminase.These results were provides a foundation and material basic study of new molluscicidals.1.Study on the method of extracting and isolating molluscicidal saponin from RCThe RC powder was extracted and separated by soxhlet extraction,TLC and CCL. Then,we got a molluscicidal saponin RCI.The purity of RCI is 83.53%.Molluscicidal test method according to the WHO'S standards,molluscicidal rates was 80.0%at 5.0mg·L^-1 of RCI for immersion in 72h.2.Study on the optimization method of extracting alkaloids from SXThe optimum procedure was selected with the content of SXâ…¡and SXâ…¢extracting rates by L₁6(4⁴).Result provided a method for studying production and application of alkaloids from SX.Results:The optimum procedure of SXâ…¡were 10 times of water, extracting for 15 h,pH 3.0,40°C.The optimum procedure of SXâ…¢were 10 times of water,extracting for 15 h,pH 3.0,10°C.3.Study on synergistic function on snails of combined use of the Nic and alkaloid from SXMolluscicidal test method according to the WHO'S standards,immersed snails 24h, the inhibiting rate all were 100%when the snails under the concentration of SXâ… ,â…¡andâ…¢were 100,8 and 200 mg·L^-1 for 24h.When Nic combined with SXâ… (50 mg·L^-1), SXâ…¡(2.7 mg·L^-1) and SXâ…¢(100 mg·L^-1),the inhibiting rate of Nic increased 100,60 and 100%.Respectively,SXâ…¡was an efficient molluscicide and increased inhibiting rate on snail when combined with Nic.4.In vitro test for toxity of pesticides on GPT and GOT activityIt was a study on the optimal reaction conditions of the maximum activity of GPT and GOT from snails by L_255⁶ orthogonal matrix method,as well as the effect on it by molluscicides.The crude enzyme was prepared by 60-90%salt precipitation.When the reaction conditions were 0.1 mg •L^-1GPT,5μmol •L^-1 substrate,pH 6.5,35°C,30 minutes,the efficiency of transamination was the maximum.When the reaction conditions were 0.2mg •L^-1GOT,2.5μmol •L^-1 substrate,pH 6.0,40°C,30 minutes, the efficiency of transamination was the maximum.When the concentration of Nic,SXâ…¡and CuSO₄ rose to 4 mg •L^-1,the inhibition rates of GPT were 81.2,-32.2 and 16.2%,the inhibition rates of GOT were 89.7,-18.8 and -11.4%.The results indicated that GPT and GOT were sensitive about CuSO₄,but insensitive about Nic and SXâ…¡.