Résumé
Cordyceps militaris exopolysaccharides (EPS) have many pharmacological activities such as boosting immunity and antifatigue. To obtain EPS efficiently, we added moderate Vernonia amygdalina leaf powder as inducer to the fermentation medium to promote the production of Cordyceps militaris EPS and studied the infrared absorption spectrum and antioxidant activities of the EPS after optimization. The optimum liquid fermentation conditions were as follows: addition of Vernonia amygdalina leaf powder of 8 g/L, fermentation duration of 9 d, initial pH of 6.5, inoculation quantity of 5.0 mL. Under such a condition, the yield of Cordyceps militaris EPS reached (5.24±0.28) mg/mL, increased by 205.20% compared to the control group without adding Vernonia amygdalina leaf powder. Results of infrared analysis and antioxidant activity showed that the Vernonia amygdalina leaves had little effect on the structure and activities of Cordyceps militaris EPS. The results of this research suggest that Vernonia amygdalina leaf can enhance the production of Cordyceps militaris EPS effectively, and provides a novel method for efficient production of EPS in Cordyceps militaris.
Sujets)
Antioxydants , Cordyceps , Feuilles de plante , Polyosides , VernoniaRésumé
The development of embryo has close relation with the occurrence of type 2 diabetes in adulthood and is attracting increasingly more attention recently. Pancreatic and duodenal homeobox 1 ( pdx1 )expresses in all stages of β-cell development and in mature β cells. As a transcription factor,pdx1 plays a critical role in the formation of whole pancreas,especially in the development and function of β-cell in fetal period,and it is also necessary for the maintenance of mature β-cell function. However, changes in epigenetic modification can alter the expression of pdx1, and then influence pancreatic development and β-cell function . We will make a summary about pdx1 gene structure, function, regulation ,epigenetic modification and so on.