ABSTRACT
Objective: To optimize the production of ginenoside Rg5 by microwave-assistant degradation method of total saponins from the stems and leaves of Panax notoginseng (PN) by orthogonal design and response surface method. Methods: Using microwave-assistant degradation technology to obtain rare ginsenosides from the stems and leaves of PN. The content of ginsenoside Rg5 was determined by HPLC. With the production of ginsenoside Rg5 as the evaluation index, the orthogonal experiment design and response surface method were performed on the basis of single factor experiments to investigate the effects of microwave temperature, microwave power, and microwave time on the degradation yield of ginsenoside Rg5. Results: The influence of each factor on the yield of ginsenoside Rg5 was the same by the two methods, the order of which was microwave temperature > microwave power > microwave time. Results: indicated that the optimum conditions were the microwave power of 500 W, the microwave temperature of 150 ℃, and the microwave time of 20 min by orthogonal design, resulting in the yield of ginsenoside Rg5 of 44.76%. The yield of ginsenoside Rg5 was 43.07% when the conditions was optimized by response surface method under microwave power 540 W, temperature 153 ℃,and time 20 min. Conclusion: Each of the two methods had its own advantages, all of which are valuable for the preparation of rare saponins from the stems and leaves of PN.
ABSTRACT
Objective: To optimize the sulfated modification conditions of Rhodiola sachalinensis polysaccharide (RSP) and improve the anti-oxidant activity of RSP. Methods: RSP were sulfated by chlorosulfonic acid-pyridine method, and the optimal conditions for the sulfated modification were determined by single factor experiments. The physical and chemical properties of RSP and sulfated RSP (S-RSP) were analyzed by infrared spectroscopy (IR) and scanning electron microscopy (SEM). The relation between substituting degree (DS) of S-RSP and anti-oxidative activity of polysaccharide was investigated by testing the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging ability of RSP and S-RSP. Results: When the volume ratio of chlorosulfonic acid to pyridine was 1∶4, the reaction time was 2 h and the reaction temperature was 60 ℃, the maximum sulfur content of S-RSP was 18.83% and the DS was the highest for 2.38. Moreover, the anti-oxidant activity of RSP was enhanced by the sulfated modification, and there was a certain positive proportional relationship between DS and DPPH free radical scavenging ability of S-RSP. Conclusion: The volume ratio of chlorosulfonic acid to pyridine affects the DS of S-RSP, and the sulfated modification can increase the anti-oxidant capacity of RSP by changing its polarity.