The Study Of Antibacterial Activity Of Sapium Sebiferum (L.)Roxb And Eucalyptus Robusta Smith

In order to determine antibacterial activity of leaves extracts from II species of common trees and essential oils from 4 species of trees leaves, we carried out halo tests using filter paper disks against Staphylococcus aureus G~+ and Escherichia coli. G . Among 15 species of samples, 95% ethanol extract of Sapium sebiferum (L.)Roxb showed better antibacterial activity against S. aureus and essential oil of E. robusta Smith did show some antibacterial activity against E. coli. at the concentrations conducted in this experiment.1 On the base of Sebiferum's antibacterial activity previously affirmed, we screened antibacterial compounds of Sebiferum on the principle of separation conducted by activities. The main study is below:Use separately petroleum aether, chloroform, ethyl acetate, acetone, 95% ethanol to extract the dry power of sebiferum leaves. They were conducted to test their antibacterial activities against Staphylococcus aureus. after the extracts were condensed. Result showed: 95% ethanol extract showed better antibacterial activities compared with the other extracts, and its average antibacterial diameter reached 19.5. mmDifferent concentrations of ethanol were used to extract the dry power of Sapium sebiferum leaves. The extracts were conducted to test their antibacterial activity against S. aureus. Results showed: 70%, 80%, 90% and 95% ethanol extracts showed stable antibacterial activity ,and all zones of antibacteria were more than 20mm.Compare antibacterial activity of 95% ethanol extracts from S. sebiferum with Coptis chinemis Franch. Result showed: antibacterial activity of S. sebiferum and C. chinemis had no notable difference.After studying minimum inhibition concentration(MIC) and minimum bactericidal concertration(MBC) of Sapium sebiferum 95% ethanol extracts, we gained a result that MIC and MBC of Sapium sebiferum 95% ethanol extracts were both 0.008g/ml.Use "separation method of systematic solvent" to separate Sapium sebiferum ethanol extract, then study antibacterial activity of the fractions. Result showed: ethanol fraction showed best activity, and acetone fragment also showed some antibacterial activity, while other fragments showed no activities .