Primary Identification Of Active Saponins From Schima Superba Gardn Et Champ Against Magnaporthe Oryzae

The thesis studied extraction technology of total saponins, colored methods, indoor toxicities determination against Magnaporthe oryzae, optimization of gradient elution conditions and LC-MS analysis of saponins and diosgenin M2IGR5. The purpose was obtaining efficient and high sensitive method to extract and determine total saponins, definiting toxicities of active components against Magnaporthe oryzae, establishing better gradient elution conditions of saponins M2IGR5on HPLC, completing the task to definite molecular weight of active components from saponins and diosgenin M2IGR5.Total saponins from schima superba Gardn et Champ extracted by①extraction method at room temperature,②Hot extraction method,③Ultrasonic wave extraction method, not colored and colored with vanilla-perchloric acid, the vanilla-strong sulfuric acid and Libermann-the Bruchard, selecting the best sensitivitive colored method to determe the content of total saponins from schima superba Gardn et Champ by adopting the ultraviolet-visible spectrophotometric. Results showed the content of total saponins by no coloration and the coloration:③>②>①; sensitivity in different colored methods: Vanilla-perchloric acid method>Libermann-Bruchard method≥vanilla-strong sulfuric acid method. Therefore, the ultrasonic wave extraction method was used to extract total saponins from schima superba Gardn et Champ, Vanilla-perchloric acid coloration method was adopted to determine content of total saponins.Active components from Schima superba Gardn et Champ were separated by using macroporous resin column, silica gel column, RP-18column, and the indoor toxicities against Magnaporthe oryzae were determined by using the mycelium growth rate method in the laboratory. The results showed that the different active components had different levels toxicities effect against Magnaporthe oryzae, The EC50and EC90values of M2IGR5were16.4143,76.1582(μg/mL); The EC50values of supernatant of M2IGR5R1, M2IGR5R2, M2IGR5R3, M2IGR5R4were62.8415,13.1103,18.5500,29.6187(μg/mL), The EC90values of them were210.7384,51.9870,74.4309,217.1198(μg/mL); The EC50values of precipitates of M2IGR5R2, M2IGR5R3, M2IGR5R4were9.1313,8.7662,9.6927(μg/mL), The EC90values of them were17.6899,17.5825,205.398l(μg/mL). The toxicities of precipitates of M2IGR5R2and M2IGR5R3were the strongest and had the potential of developing plant-based fungicide.Saponins M2IGR5was separated in gradient elution by Waters HPLC, the gradient elution conditions of better separation effect:preferable gradient elution procedure was in the tab.4-6; the column temperature30℃; flow rate1.0min/L; the injection volume15μLSaponins and diosgenin M2IGR5were analyzed by LC-MS.Correlative information of molecular weight of components were obtained throught quasi-molecular ion and fragment ion peak in positive and negative ion mode.