Study On The Main Chemical Substances Of The Antibacterial Effect Of Forsythia Suspense Leaves

Forsythia suspensa（Thunb）Vahl belongs to forshthias in OIesceae.The ripe fruit is a kind of traditional Chinese medivine which is non-toxic,bitter in taste and slight cold-natured.Modern studies show that the chemical composition of forsythia suspense leave is similar to the fruit of forsythia suspensa,and the pharmacological activity is similar.And its bacteriostatic effect is even stronger than that of Yu Qingqiao and Lao Qiao.However,forsythia suspense leaves are not taken seriously in China,At the same time,forsythia suspensa fruit is mainly used in pharmaceutical and clinical prescription,while forsythia suspense leaves were abandoned,not being used.Therefore,in order to make full use of forsythia suspense leaves resources.This article is mainly guided by antibacterial activity,the antibacterial components of forsythia suspense leaves were screened.And evaluate the antibacterial effect of a combination of the main active ingredients of Forsythia suspensa leaves of forsythoside A and cefazolin and vancomycin effect.Specific contents are as follows:1.This study selected the representative upper respiratory tract bacteria:Staphylococcus aureus,methicillin-resistant Staphylococcus aureus,Escherichia coli,Escherichia coli,Pseudomonas aeruginosa,multiple Pseudomonas aeruginosa,Streptococcus pneumoniae,using the diameter of bacteriostasis as an evaluation index.The results showed that the 40%ethanol extract of forsythia suspense leaves had no bacteriostatic activity to common Escherichia coli and Streptococcus pneumoniae,and had certain antibacterial activity against other bacteria.Therefore,this subject takes the 40%ethanol extract of forsythia suspense leaves as the research object,and carries out an experimental study on it.2.The 40%ethanol extract of forsythia suspense leaves was separated by medium and low pressure preparation,and the D101macroporous resin was used as the separation material,E₁,E₂,E₃,E₄ and E₅ are obtained.The strength of bacteriostatic activity was evaluated by the diameter of bacteriostasis circle,and E₃ was selected as the part of strong bacteriostasis.Therefore,the component E₃ is the subject of the next experiment.Then,the separation technology of medium and low pressure was used to separate the component E₃,and C18 was used as column separation material,and M₁,M₂ and M₃ were obtained.In the same way,the strength of bacteriostatic activity was evaluated by the diameter of bacteriostasis circle,and M₁ was selected as the part of strong bacteriostasis.3.The component of M₁ were knocked out by the preparation of liquid phase separation technology,the components F1,F2,F3,F4 and F5were obtained.The bacteriostatic activity was also evaluated by the diameter of the bacteriostasis,and F2 and F4 were the main antibacterial components.Component F4 is determined to be the forsythoside A according to the comparison with the standard product.There are two compoents in the F2,so F2 continues to be separated.F2 was separated by hydroxypropyl dextran gel column（Sephadex LH-20）and forsythenside F and forsythoside I were identified.Evaluation of bacteriostasis activity by Oxford cup method,and it was found that forsythenside F had no bacteriostasis activity.It was concluded that the Bacteriostasis of forsythia suspense leaves is forsythoside A and forsythoside I.4.The trace chessboard dilution method was used to assess the antibacterial activity of the combination of forsythoside A and cefazolin and vancomycin.According to the results,when forsythosideA was combined with cefazolin and vancomycin,an additive effect was shown,and the combination of forsythosideA with vancomycin produced a significant synergistic inhibitory effect and reduced significantly the amount of vancomycin.Conclusion:forsythoside A and cefazolin and vancomycin combination,has a certain synergistic effect of reduction.5.The content determination method and characteristic fingerprint of active component of forsythoside A and forsythoside I were established by HPLC method.The results showed that the content range of the active component of forsythoside A in E₃ was 0.53-0.58mg/mg,and the content range of Forsythoside I was 0.06-0.07mg/mg;there are 4 characteristic peaks in the liquid phase characteristic map of E₃.With the No.3 peak as the control peak,the relative retention time of peak 1 is 0.6667-0.7227,and the relative peak area range is 0.1544-0.1987;the relative retention time of peak 2 is 0.7341-0.7477,and the relative peak area is 0.0264-0.07937;The relative retention time range of peak 4 is 1.5485-1.6035,and the relative peak area is 0.0623-0.1058.3 of the characteristic peaks were Forsythoside I,Forsythoside Aand rutin.6.In the first part of the experiments,Forsythoside A,Forsythoside I were identified as the main antibacterial components of Forsythia suspense leaves.The later period,the spectral effect of Forsythia suspense leaves was studied,and the common index of the antioxidant and antibacterial activity of Forsythia suspense leaves was defined as Forsythoside A.