Study On The Separation And Purification Of Ginkgo Biloba Acids From Ginkgo Biloba Exocarp And Its Antibacterial Effec

Ginkgo biloba L.is a deciduous tree of the genus Ginkgo in the Ginkgo family,and the outer seed coat of the fruit of Ginkgo biloba L.is also called ginkgo seed coat.Ginkgolic acids is a unique protectin of ginkgo biloba,which has pharmacological effects such as insecticidal,antibacterial and anti-tumor.Therefore,the study of an industrial purification technology of ginkgolic acids from the ginkgo seed coats is conducive to the development and utilization of ginkgolic acids from the ginkgo seed coats.In the past,the content of ginkgolic acids in the dried mature ginkgo seed coats were about 8-10%.Therefore,the method for the determination of ginkgolic acids was optimized by using a chromatographic column(Supersil-U C18)with acetonitrile-0.1% trifluoroacetic acid water as the mobile phase.Through single factor experiment combined with 4 factors and 3 level orthogonal test table,the optimal extraction process of ginkgolic acids in ginkgo seed coats was determined as follows: extraction solvent was methanol,extraction temperature was 40 °C,extraction solid-liquid ratio was 1: 12(g/m L),the extraction time was 90 min.After two extraction operations,the content of ginkgo phenolic acid extract was 15.64%,and the extraction rate was more than 98%.In order to further obtain high purity of ginkgolic acids,extraction,column chromatography and preparation-type high performance liquid chromatography were used to separate and purify ginkgolic acids from the ginkgo seed coats.Firstly,ethyl acetate was used as extractant,the ratio of material to liquid was 1:2 and extracted twice.The content of ginkgolic acids in the extract were 55.62% and the recovery were 70.61%.Secondly,the static adsorption-desorption and dynamic adsorption-desorption experiments of five types of resins were carried out,and the process parameters for the separation and purification of ginkgolic acids from ginkgo seed coats were obtained as follows: HPD-5000 resin was used as column,the safe loading amount was about 19.236 mg/g,the sample flow rate was 1 BV/h,the elution agent ethanol concentration was 70%,90% ethanol solution was eluted,the volume of 90%,and the volume of eluent was 4 BV,the resin diameter to height ratio was 1∶6.The content of ginkgolic acids in column eluting extract reached79.06%,and the recovery were 50.41%.Finally,five monomers of ginkgolic acids C13:0,C15:1,C17:2,C15:0,C17:1 were obtained by preparative HPLC,and the purity was more than 98%.Three batches of pilot-scale debugging of the purification process of ginkgolic acids from ginkgo seed coats were completed and the production process CAD diagram of the workshop was determined.The average yield of ginkgolic acids product 2.43 kg per batch was 11.98%,the content of ginkgolic acids were 68.38%,and the recovery rate were 75.76%.Secondly,the stability factor test of ginkgolic acids products was carried out,and it is suggested that the packaging condition is protected from light and sealed preservation.Study on the bacteriostatic activity of ginkgolic acids against plant pathogens and human pathogenic bacteria.The effects of ginkgolic acids on Diaporthe sp.,Sclerotinia sclerotiorum,Alternaria alternata,Botrytis cinerea,Colletotrichum boninense,Alternaria sp.and Colletotrichum tropicale,were studied by mycelium growth rate method.The inhibitory rates of ginkgo acids against Diaporthe sp.And Sclerotinia sclerotiorum were 69.16% and 64.77%,respectively.Bacteriostatic MIC values of ginkgolic acids on Staphylococcus Aureus,S.aureus,Pseudomonas aeruginosa,Micrococcus luteus and Candida albicans were studied by half dilution method.The results showed that ginkgolic acids had good inhibitory effect on Staphylococcus aureus and Pseudomonas aeruginosa,and MIC values were 31.25μg/m L and 62.5 μg/m L,respectively.The research results show that the extraction and purification process of ginkgolic acids in ginkgo seed coats determined in this paper is stable,easy to operate,and suitable for industrial production.The research on its activity will provide a broader idea for the medicinal use of ginkgolic acids in ginkgo seed coats,and achieve the effect of "turning waste into treasure".