Studies Of Bacteriostasis Activity And Mechanism Of Semen Cassiae Against Botrytis Cinerea Pers

A plant, Cassia obtusifolia L.. widely distributed in south of the Yangtze river of China, was investigated for its disinfectanted activity against Botrytis cinerea Pers, crude extract extracted by respective immersion, was separated by extraction and purified through column chromatograghy, and its active constitute,L3,was separated. Its activities to active methods and inhibitory mechanism were studied. The results indicated:1. The Semen Cassiae extracted by alcohol, chloroform, petroleum ether,alcohol had highest extraction rate, and lowest was petroleum ether. The result of bioassay revealed that there were the effect of inhibitory effect in varying degrees, the inhibitory effect of chloroform extract was80.55%,when the pharmacy concentration was2mg.ml-1.The inhibition rate of chloroform extract was100%, when the pharmacy concentration was1mg.ml-1in the tests of inhabiting effect of the different menstruum of Semen Cassiae siebotdii extract against conidiao production of Botrytis cinerea.The MIC was0.60mg.ml and0.24mg.ml-1,the result was more obvious than other extractions.2. The antifungal activities of the extract from Semen Cassiae against Botrytis cinerea was tested.The result indicated that the chloroform ether extract of Semen Cassiae against mycelium growth and spores germination were83.33%and100%respectively. The MIC was0.40mg.ml-1and0.19mg.ml-1.The water extract of Semen Cassiae against spores germination and mycelium growth were the lowest. So extraction of chloroform ether was studiey further more.3. The silicagel column was used to separate and purify active constitutes of the extraction of various fractions form the cacetic ether. A total of7fractions were seen by TLC analysis. The bioassay showed that the3th fraction have strong antifungal activities, after72h of which to Botrytis cinerea was100%, the MIC was0.24mg.ml-1after96h.4. L3deal with B. cinerea and found that the growth of its mycelium sparse, prostrate on the medium; in the electron microscope, tumor-like hyphae on the health and abnormal enlargement of an analysis, L3may affect the cell membrane and cell wall formation.5. Through L3after treatment B. cinerea. is found in the determination of membrane permeability, L3mycelium increased membrane permeability, leading to electrolyte leakage. At the same time in the cell wall of chitinase, protein determination, we found L3in the1mg·mL-1,3h later, on the highest chitinase activity,3h when the N-acetyl glucosamine content reached the maximum, and then began to decline, indicating that N-acetyl-glucosamine may be involved in cell wall formation is blocked. The protease activity in the treatment of3,6,12h, the activity was no difference with the control.lt significantly inhibited the synthesis of ergosterol,so indicate the existence of role of cell membrane sites.Based on the results, we discussed perspectives of using Semen Cassiae for the Botrytis cinerea Pers control.