Study On Extraction Of Effective Components And Removal Of Heavy Metals In Se-enriched Danshen Leaf By Spectrum Detection

Danshen(Salvia miltiorrhiza)is one of the sage plants of labiatae,a Chinese herbal medicine.The antioxidant chemical constituents of Danshen include lipophilic diterpenoid quinines and some water-soluble phenolic acids,so it has been widely used for the treatment of cardiovascular and cerebrovascular diseases and with huge market demand.The root weight of Danshen is about 33% of whole grass,the aerial part about 67%.The stem and leaf of selenium-rich Danshen possess abundant water-soluble phenolic acids and selenium compound,which are the main components of antioxidant activity.If stems and leaves can be used to expand the medicine pharmaceutical,the medicinal value of Danshen can be made full use.However,some studies show Danshen possessed relatively high concentrations of heavy metals in stems and leaves,especially Pb,Cd,Cu,Hg.It hinders the comprehensive utilization of Danshen.This works study the method of the extraction of flavonoids,phenolic acids,tanshinone and selenium compounds of Danshen leaves,and removal of heavy metals in the extraction solution.Selenium-enriched cultivation is an effective method of improving the selenium content of Danshen.The content and distribution of secondary metabolities are investigated through foliar spraying selenium for Danshen.The results show that the content of total phenolic acid,total flavonoids and total tanshinone follow the order of root > leaf > stem under the same applied selenium level,the content of Se follow leaf > stem > root.Through selenium-enriched cultivation,the content of three effective components increased.The leaves and stems of selenium-enriched Danshen as medicinal part except for the root has the potential value of comprehensive development and utilization because they are as important part of Danshen plant and convenient acquisition.The effective components in selenium-enriched Danshen leaves are extracted by ultrasonic assisted with ethanol solution as extracting agent.Firstly,effects of ethanol concentration,solid-liquid ratio,ultrasonic time,extraction times,infiltration time and ultrasound power on the total phenolic acid,total flavonoids and total tanshinone yield is studied in the leaves of Salvia miltiorrhizathrough the single factor experiment.Then,the key factors influencing the extraction rate are screened by using Plackett-Burman design method.Thirdly,the key factors are optimized by response surface analysis of Box-Behnken experimental design.Finally,the optimum conditions of ultrasonic extraction of 3 kinds of effective components are determined through the test to prove the feasibility of extracting conditions.The optimum condition of extraction total phenolic acid is 32% ethanol,21mL/g ratio of liquid to solid,extraction 40 min with 80% of ultrasonic power,repeatly extracting 3 times.Actual yield is 1.83%.The optimum condition of extraction total flavonoids is 42%ethanol,25mL/g ratio of liquid to solid,extraction 45 min with 80% of ultrasonic power,repeatly extracting 3 times.Actual yield is 9.05%.The optimum condition of extraction total tanshinone: 90% ethanol,22mL/g ratio of liquid to solid,extraction26 min with 60% of ultrasonic power,repeatly extracting 3 times.Actual yield is1.28%.The total Se in selenium-enriched Danshen leaves is extracted by ultrasonic assisted with NaOH solution as extracting agent using the same method.The optimum condition of extraction total selenium is 0.078mol/L NaOH solution,32mL/g ratio of liquid to solid,with 80% of ultrasonic power extracion 60 min,repeatly extracting 3 times,Actual yield is 6.25mg/Kg.The extraction process of selenium-enriched Danshen leaves is further optimized through sequential extraction and amplified scale of experiment on the base of extraction optimum conditions of the total phenolic acid,total flavonoids,total tanshinone and total Se in selenium-enriched Danshen leaves.The optimization condition of sequential extraction is three times extraction as optimizing condition of total tanshinone,two times extraction as optimizing condition of total flavonoids,one time extraction as optimizing condition of total phenolic acid and two times extraction as optimizing condition of total Se.The method is more close to the industrialized production.The extraction only need 8 times comparing the original 12 times extraction by using sequential extraction method,meanwhile recovery rate of four components are all over 90%.The sequential extraction method saves cost,time and labor.The method of removal heavy metals of Pb,Cd,Cu,Hg in extracting solution of selenium-enriched Danshen leaves by strong acidic ion exchange resin is studied.The appropriate condition is pH of 6,55% ethanol solution as eluant.The removal rate of four heavy metals in the extraction solution in selenium-enriched Danshen leaves are all above 80%.The rate of recovery of the total lavonoids,phenolic acids andtanshinone is beyond 90%.The total selenium`s is 85.1%.Results show that strong acidic ion exchange resin can effectively remove the heavy metals of Pb,Cd,Cu,Hg in the leaves of selenium-enriched Danshen.Meanwhile the content of effective components has no obvious change.The basis for reference is provided for the comprehensive utilization of Danshen and control of the heavy metal content of products.In this paper,the total phenolic acid,total flavonoids,total tanshinone and total Se are used as detection index.Firstly,the content and distribution of secondary metabolities are investigated through foliar spraying selenium for Danshen.The study show that Aerial parts of Danshen,especially leaf has higher value of comprehensive development and utilization.Then,the extraction method of effective components in selenium-enriched Danshen leaves is optimized.The removal method of heavy metals in extraction solution is studied.I hope these studies can provide basic reference for industrial production.