银杏酸5种同系物单体的制备及其杀灭钉螺的作用

Preparation of Five Ginkgolic Acid Monomers and Their Molluscicidal Effects Against Oncomelania hupensis

目的探索分离纯化的银杏酸同系物单体对钉螺的影响。方法用石油醚从银杏外种皮提取银杏酸,经半制备高效液相色谱(HPLC)分离,通过液相-质谱联机系统鉴定。按WHO"杀螺剂实验室终筛方法"检测银杏酸分离纯化的5个同系物单体杀灭湖北钉螺的作用。结果纯化的银杏酸5个同系物单体为GA13:0、GA15:1、GA15:0、GA17:1和GA17:2,其母核苯环上分别有1个13、15及17烷基或烯基的侧链。各单体占总银杏酸的比例分别为17.6%、52.3%、3.2%、23.3%和3.6%。杀螺活性顺序为:GA13:0>GA15:1>GA15:0>GA17:1>GA17:2。24h对钉螺的半数致死浓度(LC50)依次为20.79、22.28、33.76、51.89和59.10mg/L。GA13:0和GA15:1对钉螺上爬的抑制作用明显。结论银杏酸单体杀灭钉螺的作用受其侧链碳原子数量以及所含双键数目的影响,单体GA13:0及GA15:1杀钉螺作用明显,并能显著抑制钉螺上爬。单体GA15:0也有一定的杀螺活性。

Objective To investigate the molluscicidal activities of the ginkgolic acid（GA） monomers isolated and purified from GAs. Methods Five monomers of GAs from the sarcotesta of Ginkgo biloba. were extracted by petrol ether,separated by silica gel column chromatography,purified by semi-prepared reversed-phased HPLC,and identified by LC-MS analysis. The molluscicidal activities of GAs and their monomers against Oncomelania hupensis were determined as referring to the WHO guidelines for laboratory molluscicidal test. Results The five purified ginkgolic acid monomers were GA13：0.,GA15：0.,GA15：1 ,GA17：1 and GA17：2 ,with a side chain of 13,15,17 alkyl or ethylenic radicals respectively on their benzene loop. The five monomer proportions to the total GAs were 17.6%,3.2%,52.3%,23.3% and 3.6% respectively. The order of molluscicidal activities for the five monomers was as follows： GA13：0〉GA15：1〉GA15：0〉GA17：1〉GA17：2 ,and their LC50 for snails was 20.79 mg/L,22.28 mg/L,33.76 mg/L,51.89 mg/L,and 59.10 mg/L respectively after immersion for 24 hours. Two monomers,GA13：0 and GA15：1 inhibited the snails＇ climbing up significantly. Conclusion The molluscicidal activities of GAs may be dependent on the monomer＇s structure with different number of carbon molecules and double-bonds on the side carbon-chain. The two monomers,GA13：0 and GA15：1 ,are mainly responsible for the molluscicidal activities of GAs and both effectively inhibit snails＇ climbing up as well. GA15：0 also shows certain molluscicidal activity.