The Researches Of The Stability Of Catalitaxol And Its Freeze-thaw Concentration Separation

In the article,Endophyte FSN002 fermentation broth was used as the raw material,did the research about that how the heat,light and other factors affect the stability of the active secondary metabolites catalitaxol;using the freeze-thawing concentrated method to concentrate and purificate the catalitaxol in Endophyte FSN002 fermentation broth.First of all,HPLC was used to study the dynamic degradation of catalitaxol at different temperatures.It was found that the activation energy of the catalitaxol’s thermal degradation is only 62.8k J/mol,catalitaxo is unstable when it’s heated.The high temperature conditions likely cause the degradation of catalitaxo.The thermal degradation rate rapidly increased with temperature increasing.It was found that the thermal degradation of catalitaxol in Endophyte FSN002 fermentation broth is first-order reaction kinetic.The thermal degradation rate constant increased rapidly with the increasing temperature,fitting the Arrhenius equation.The half-life at 4 ℃is 25 days;the half-life of catalitaxol at 25 ℃ is shortened to 6 days;the half-life is only 14 hours at 55 ℃.The model predicts that the half-life of catalitaxol would be only 3.7 hours at 70 ℃.The rotary evaporation of catalitaxol from Endophyte FSN002 fermentation broth will cause substantial degradation,low yield,which is entirely consistent with the experimental data.Secondly,HPLC was used to study the dynamic degradation of catalitaxol under different illumination conditions.The photodegradation kinetic model was established to quantitatively analyze the effect of light on the stability of catalitaxol.The experimental results showed that the illumination has a huge influence on the stability of catalitaxol: with the extension of irradiation time,the content of catalitaxol has an exponentially decreasing trend.Using the establishment of the dynamic degradation model of catalitaxol in Endophyte FSN002 fermentation broth,we analyzed quantitatively the effect of the illumination conditions on the stability of catalitaxol.It was found that the photodegradation of catalitaxol in Endophyte FSN002 fermentation broth is first-order reaction kinetic.The photodegradation rate constant rapidly increased with the increasing light intensity.Under the conditions of the direct fluorescent or natural light scattering next to the window,the photodegradation is around 85% in the proportion of total degradation.And this is the main factor of the catalitaxol’s degradation in this environment.With the increase of light intensity,the photodegradation turned to be the main degradation,and the proportion of thermal degradation was getting smaller during the whole degradation process.Catalitaxol should be stored in the condition of avoiding light.Thirdly,used the progressive frozen concentration and freeze-thawing concentration methods to concentrate and separate the catalitaxol in Endophyte FSN002 fermentation broth.The research was more focused on the layered crystal during the progressive frozen concentration.Did a qualitative analysis of the concentration and the ice crystals which were obtained from the progressive frozen concentration from the senses,and showed the contrast between the two pictures;studied the relationship between the concentration ratio and the content of catalitaxol,and the relationship between the concentration ratio and the yield of catalitaxol in details.Also tried to use the inverse process of progressive frozen concentration——the freeze-thawing concentration method to concentrate and separate the catalitaxol in Endophyte FSN002 fermentation broth,preliminary inquiry its concentration and separation effect.