| Thirty species of Chinese herbal medicines were extracted with ethanol and the rough extracts were tested for their antimicrobial and fungitoxity activity on seven species microorganisms. The method of inhibitory area was used to test the inhibitory effects of thirty species of plant extracts on microganisms and spore germination of Aspergillus niger and Peronophythora litchi chen. Results showed that five species, Rhizoma Acori Rhizone, Eugenia caryophyllata Thumb, Alpinia officinarum Hance.,Cinnamomum Japonicum, Rheum palmatum L. have the best antimicrobial and fungitoxity effect. The five species'ethanol extracts have showed strong inhibitory effects in mycelial growth inhibition test and inhibitory area test for their inhibitory effects on spore germination of Aspergillus niger and Peronophythora litchi chen also show storng inhibitory effect. The inhibition rate of the five species were above 85%.Three species'ethanol extracts, Rhizoma Acori Rhizone, Eugenia caryophyllata Thumb, Cinnamomum Japonicum showed completely inhibition rate on mycelial growth and the zoospores release of Peronophythora litchi chen, showed equivalent strong inhibitory effects with the chemical control-0.2% sodium benzoate. Ten matching liquors were generated by the above five extractions. Inhibitory effects of extractions and matching liquors were made by means of the middle inhibitory concentration(MIC), the tests showed the ethanol extracts of clove(TW-15) and the matching liquor ,PW-6 have the strongest inhibitory effect on mycelial growth and the zoospores release of Peronophythora litchi chen. MIC of PW-15 is half of TW-15. The physical and chemical characts of TW-15 and PW-6 were tested after being treated at different temperature, illumination and pH values. And the time lengths for preservation and the activity maintenance time lengths of two liquors. The results showed that matching liquor PW-6 have better effects than TW-15 in these testing items.The inhibitory activity of TW-15 decreased sharply when temperature higher than 60℃, TW-15 and PW-6 remained most active at pH , both increasing and decreasing of pH caused the dropping down of inhibitory activity.After treated with illumination for 72h, both of extracts had no significant change in their inhibitory activities. The preservative experiment results of TW-15 and PW-6 on pear, grape and litchi showed that two preservative liquors have really significant fresh-keeping effects.Compared to the control testing, two preservative liquors could reduce loss of water and remain nutritional ingredient of the fruits. The matching liquor PW-6 have better keeping-fresh effect than ethanol extracts of clove(TW-15).The two preservative liquors have significant inhibitory effect on mycelial growth of Peronophythora litchi chen. on the surface of lichi. The paper covers a method for extracting eugenol form colve by ethyl alcohol reflux factors affecting the yield were studied. The results show that the optimum technologial conditions were reflux solvent is 80% ethyl alcohol, reflux time is 30min, Alkalinity is pH=9-10, alcohol:water=3:1, extraction solvent is ethylether, acidity is pH=5. After isolated the main active component of TW-15, chemical qualitative method, TLC chromatogragh, UV, HPLC and IR was used to identify the structure of the main component of TW-15 and PW-6, the standard sample of eugenol was used for comparison in all the experiments. Accoding to the results, eugenol was one of the main active component of TW-15 and PW-6. The absorption peak of eugenol in UV is 282nm, and its holding time in HPLC is 10.019min. The inhibition experiment of breath to brewers'yeast had been carried out. The results showed that the bacteriostasic mechanism of ethanol extracts of clove(TW-15) is inhibit TCA respiratory pathways by compared overlap rate with other three typical respiratory inhibitor, iodoacetic acid, propandioic acid and sodium phosphate. The overlap ratio of TW-15 with propandioic acid was 32.5%. |
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