Forsythia Fruit Volatile Oil Separation Of Antibacterial Research And Preparation Of Solid Lipid Nanoparticles

According to the complex components of the volatile oil of Forsythia suspense(Thunb.)Vahl(VOFS), it could be separated by column chromatography and molecular distillation, in order to obtain the different fractions from which the fractions with high biological activity were screened. The compounds of VOFS, fractions and distillates were dertemined by GC-MS. The antibacterial activity and minimal inhibitory concentration (MIC) was determined by disc agar diffusion method and test tube doubling dilution method respectively. Nanoparticles drug delivery system is an advanced drug carrier, and has many advantages. VOFS made of solid lipid nanoparticles(LQ-SLN) is able to be administrated via oral,transdermal delivery, intravenous injection, et al., and improve bioavailability. LQ-SLN was prepared based on the microemulsion technique. The stability of LQ-LSN was also observed via high temperature test, high humitity test,accelerated test and long-term test.The results are as follows.1.Six different poloar fractions were extracted by the column chromatography,and were numbered LQ1～LQ6respectively.The sixth fraction is dark brown viscous fluid with strongly stimulate taste, lack of practical value, so it is not for further study. Seven distillates were separated by molecular distillation at temperature from60-110℃,whose color are deepened from colorless to light brown as the rise of the distillation temperature.2.Totally48chemical components were identified in the volatile oil from forsythia fruits, the main ingredients are β-pinene (50.01%), a-pinene (15.78%), trans-β-ocimene (13.79%), linalool (5.93%).The main ingredients of five fractions are respectively:a-pinene (33.27%),β-pinene (25.35%); β-pinene (17.59%), eucalyptus oil hormone (6.27%); linalyl alcohol (57.46%), a-sandalwood terpenes (7.14%), orangeade (3.39%); terpineol (45.58%), linalool (25.44%); trans-β-terpineol (53.29%). The common main ingredients of these distillitates were a-pinene,β-pinene,camphene,isometh4-terpineol,a4-terpineol,which were identical to that of the poar fractions,but linalool,(±)-limonene, y-terpinene or eucalyptus oil hormone were not found.3.LQ1～LQ5showed middle or strong antibacterial activity against Staphyloccocus aureus Rosenbach, and showed middle antibacterial activity against Bacillus subtilis, but showed low anti-microbial activity against Monilia albican;LQ1～LQ3showed middle antibacterial activity against Escherichia coli, while LQ4and LQ5showed poor activity. LQ2had higher antibacterial activity than the other four fractions, which was eluted by petroleum ether and ethyl acetate whose ratio is7:1, and its main ingredients are β-pinene and cineole. And its MIC to E. coli, Staphyloccocus aureus Rosenbach, Bacillus subtilis and Monilia albican wer:12.5μ1-ml-1,3.125μ1-ml-1.50.0μ·ml-1,25.0pl-ml-1,respectively. LQ11～LQ13showed middle or strong antibacterial activity against Staphyloccocus aureus Rosenbach, and showed middle antibacterial activity against Bacillus subtilis, but showed low anti-microbial activity against Monilia albican; LQ7～LQ10showed middle antibacterial activity against Escherichia coli, while LQ11～LQ13showed poor activity.In summary,LQ9had maximum antibacterial activity, especially to Staphyloccocus aureus Rosenbach,and its MIC to E. coli, Staphyloccocus aureus Rosenbach, Bacillus subtilis and Monilia albican wer:12.50μ1·ml-1,3.125μ1·nl-1,25.0μ1·ml-1,12.50μl·ml-1,respectively.4. The types and proportions of lipid materials and surfactants had a major impact on SLN’s characteristic. The size distribution of LQ-SLN was58.77～316.10nm, and the average of size was105.21nm, the polydispersity index was0.075, which indicated the particle size distribution was narrow; Zeta potential was-(51.9±6.63)mV; the particle surface with enough negative charge was able to form a sufficient repulsive force to maintain system stable. The result of stability test:the SLN maintain uniform without mustiness, sedimentation or creaming, and its particle size is almost unchanged.The results revealed the LQ-SLN had good physicochemical stability and biostability.