The Study On Chemical Compounds And Biological Activity Of Endophytes Metabolites From Plantago Asiatica L.

As a class of microorganism groups coexisting with host plants,endophytes synthesis chemical compounds,which are similar or same with what host plants contains.Plantago asiatica L.,a well-known medicinal plant,is widely used for treatment of the diseases of kidney,liver and the circulation,against cancer and lung channels.It has effects in inducing diuresis to treat strangurla,excreting dampness to arrest diarrhea,clearing heart from the liver to improve the acuity of vision.It has been used as a diuretic,an anti-inflammatory and an anti-asthmatic drug.The endophytes is a potential resource to discover new chemical compounds and new drug.In present study,the fresh Plantago asiatica L.was used to isolate endophytes;furthermore,the different biological activities of its secondary metabolites were evaluated,all of which would offer theoretical basis for Plantago asiatica L.application.The results of the present study are as followed:Isolation and diversity analysis of entophytes:the fresh Plantago asiatica L.plants from Gansu province including roots,stems and leaves were used to isolate endophytes by tissue homogenate method in twenty different mediums in the present study.As a result,a total of 37 endophytic strains were isolated from Plantago asiatica L.as followed:21 strains were isolated from the root samples,9 strains were isolated from the stem samples and 7 strains were isolated from the leaves.The morphological biological methods were used to identify and analyze the biodiversity of 28 endophytes.The results showed that the isolates belonged to four Subphylum and eleven families.Our results demonstrated that the numbers and species of endophytes were abundant.Evaluation of antioxidant activity of endophytes from Plantago asiatica L.and its metabolites:74 samples were produced by extraction respectively from metabolites by butanol and ethyl acetate.37 samples were produced by extraction from bacteria by methanol.The antioxidant activity of 111 samples were evaluated by DPPH radical scavenging,hydroxyl radical scavenging and reducing power.Our results showed that the antioxidant activity of cqc-11 strain was the best.,whose EC₅₀ of reducing power is 0.087mg/m L,Slightly higher than the result of V_C,showing good anti-oxidant activity and potential value for the use of drug.Evaluation of antimicrobial activity of endophytes from Plantago asiatica L.and its metabolites:74 samples were produced by extraction respectively from metabolites with butanol and ethyl acetate.37 samples were produced by extraction from bacteria by methanol.The results showed that cqc-11 mycelia had a good inhibitory activity against five test strains including Escherichia coli,Pseudomonas aeruginosa,Bacillus licheniformis,Staphylococcus aureus and Diplococcus pneumonia,in particular,its MIC value against Staphylococcus aureus was 0.312mg/m L,showing good potential application value.10 chemical compounds was isolated from substance extracted form the srain cqc-23 metabolites with ethyl acetate by modern chromatographic separation technology(Macroporous resin,MIC,reversed-phase C₁₈ column chromatography,silica gel column chromatography,LH-20 gel column,high performance liquid chromatography,etc.),7 of which were identified by NMR?IR?MS.The name of these chemical compounds are as followed:Terreomycinone?1?,alboatrin?2?,orcinol?4?,2-hydroxybenzothiazole?5?,6-Demethylkigelin?6?,4-Hydroxykigelin?7?,3-methyl-6-methoxy-8-hydroxydihydroisocoumarin?3?.In conclusion,our results showed that the species of endophytes from Plantago asiatica L.is rich and varied.The result provides a certain reference for further exploring the medicinal value of Plantago asiatica L.