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 study the chemical constituents of saponins in the stems and leaves of Panax ginseng. Methods: The chemical constituents were isolated and purified by various chromatographic methods, and their structures were identified by NMR and MS data analysis. Results: Nine compounds were isolated and identified as 3β,6α,12β,25-tetrahydroxy-dammar-E-20(22)-ene-6-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside (1), sanchinoside B1 (2), 3β,6α,12β-dammar-E-20(22)-ene-3,6,12,25-tetraol (3), ginsenoside Rk3 (4), ginsenoside Rh4 (5), notoginsenoside T2 (6), 3β,6α,12β-dammar-20(21),24-diene-3,6,12-triol (7), ginsenoside Rk1 (8), and ginsenoside Rg5 (9). Conclusion: Compound 1 is a new natural product and the other eight compounds are all isolated from the stems and leaves of P. ginseng for the first time.