Separation And Structural Elucidation Of Antibacterial Components From Paenibacillus YS-1 Against Postharvest Blue Mold Of Citrus

Paenibacillus have no pathogenicity on people or animals and plants, some strains can produce multiple biologically active substances. These active substances have attractive prospect in the prevention and treatment of plant diseases. According to the results of previous studies, Paenibacillus YS-1 has the very good antibacterial effect for Penicillum italicum and Penicillium digitatum, and the produce antimicrobial substances is the main mechanism of antibacterial. In order to isolation and identification their antibacterial substance produced, do the research of systematic research for ermentation antibacterial components.The main conclusions are as follow:1. In this paper, the lab isolation and identification Paenibacillus YS-1 as antagonistic bacteria for fermentation, studying its antagonistic separation and purification of active substances. Through the fermentation broth was centrifuged to remove thallus, and then extracted with n-butanol to give a crude extract. Silica gel column chromatography of the crude extracts were separated segments, get there Active fraction. After further separated by silica gel chromatography column segment with Sephodex LH-20 gel column chromatography obtain twelve component cross section(Fraction 1-12), its bacteriostasis experiment found that Fra.6 have good antibacterial activity, therefore Fra.6further separated by silica gel column chromatography to give a pure Fra.6A and Fra.6B.Fra.6B quality due to too small, can’t to further purification, therefore still Fra.6A by silica gel column chromatography for purification. After purification with three mixed system chloroform-methanol, ethyl acetate-methanol, acetone-methanol to Fra.6A was expanded and found only one point, so to get the final Fra.6A which is pure monomer compounds.2. Identification of the structure is an important step to give compound isolated after only accurate identification of the structure, it seems meaningful separation and purification. This study combines the Modern Spectra Process Analytical Technology of ESI-MS, 1H-NMR 、 13C-NMR and 2D-NMR for compound such as the structure identification of Fr.6A, determine its molecular formula for C4H5N3 O, Its concrete structure is cytosine.3. Then pure cytosine、 structural similarity compound cytidine and 5-fluorocytosine were done in vitro bacteriostasis experiment and in vivo Damage of vaccination experiment, and done its inhibitory effect exploration, discovery cytosine and cytidine there are certain inhibitory effect, but inhibitory effect of 5-fluorocytosine are the best.