Studies Of Biological Activity Of Syzygium Aromaticum (L.) Merr. EtPerry Against Phytophthora Capsici

This study selected Phytophthora capsici as tested fungi, screened biological activity of 22 kinds of plant ethanol extracts and futher studied Syzygium aromaticum (L.) Merr. EtPerry, such as the separation of active ingredients and mechanism of exploration. The results showed as follows:1. The mycelium growth rate method is used to filter antibacterial activity of the 22 species of plant ethanol extracts. The results showed that:under the concentration of 2.00mg·mL-1,12 kinds of plant extracts showed inhibitory effect on the mycelia growth, including Eugenia caryophyllata, Cinnamomum cassia, Sophora flavescens etc; the antibacterial effect of Eugenia caryophyllata extract was most obvious, antibacterial rate were 100%.2. Eugenia caryophyllata were extracted respectively by ethanol, chloroform and petroleum ether, the extraction yield of which were 34.41%,15.42% and 18.06%. Minimal inhibitory concentration(MIC) and antibacterial activity were determined by double broth dilution method. The results showed that:the MIC of three solvent extracts were all 1.00mg·mL-1, antibacterial activity of petroleum ether extract was the highest, EC50 of which was 0.12 mg·mL-1.3. The petroleum ether extracts of Eugenia caryophyllata wrere extracted with methanol, petroleum ether and chloroform, the results showed that the chloroform extraction yield was highest, petroleum ether second, methanol lowest. The antibacterial activity of chloroform part was the highest, EC50 of which was 0.14mg·mL-1; under the concentration of 1.00mg·mL-1, the antibacterial rate of petroleum ether part was only 12.96%, methanol part was 5.79%.4. The chloroform extract was purified by column chromatography and fractions were detected by thin layer chromatography method, merging the same fractions obtained 3 fractions. The bioassay showed that t flow L1 have strong antifungal activities, EC50 of which was 0.11 mg·mL-1.5. Treated by flow L1 with a concentration of 0.25 mg·mL-1, as shown by biological microscope, the mycelium of tested fungi were irregular with deformity, more branches and inclusions leaked. Treated by flow L1 with different concentrations, hyphae cell membrane permeability increased, at the same time, the content of soluble proteins,pyruvic acid and reducing sugar in mycelia were reduced in different degree.