Study On The Degradation And Activity Of Konjac Glucomannan

This thesis use Konjac Glucomannan(KGM)as materials,the main research contents as follows:First,the degradate methods of KGM were explored;Then,the effects of structure and physical and chemical properties by synergetic degradation;Last,the mechanism of antitumor activity of the different molecular weight of KGM was studied,the main conclusions are as follows:The methods all can be used for the degradation of KGM,enzymolysis combined with irradiation or synergic degradation by irradiation and H2O2.though this two methods can made KGM degradate,but the effect of degradation,the compositions of degradate products and the mechanism of are completely different,the effect of synergic degradation is significantly better than degradation by enzymolysis combined with irradiation,after synergic degradation,the compositions of degradate products are relatively single,and close to the single scattered system,while after degradation by enzymolysis combined with irradiation,the compositions of degradate products are complex,and the compositions may more complex with the increase of irradiate dose;During the process of degradation by irradiation combined with enzymolysis,the main factor is irradiation,radiation have very strong energy,which can made glycosidic bond breakaged,and this process is random,so the composition of degradate products are more complex,in the process of synergistic degradation,the presence of H2O2 can conducive to the formation of · OH and · OH is a kind of strong activity free radical,which can be applied to break the β-1,4-glycosidic bond of KGM,and this process is relatively orderly,so the composition of degradate products are relatively single.We used gel permeation chromatography(GPC),Fourier transform infrared spectroscopy(FT-IR),Raman spectroscopy(Raman),X-ray diffraction(XRD),scanning electron microscopy(SEM),thermogravimetric analysis(TGA),solubility and viscosity measurement method to analyze the synergic degradation affects the structure and the physical and chemical properties of KGM.Results showed that after synergistic degradation,there was no changed in the main chain of KGM,but part of functional groups was changed,the crystal structure of KGM was not changed,KGM became smooth,loose,thermal stability and solubility were increased,molecular weight and viscosity were decreased.Overall,synergic degradation can not change the structure of KGM,but significantly altered the physical and chemical properties of KGM.The antitumor activity mechanism of KGM is likely to be achieved by regulating the body’s immune function,KGM can thought increasing the body’s immune ability to achieve antitumor effect.Like immune activity,antitumor activity will increase with the decrease of the molecular weight of KGM.