Optimization of production of ginenoside Rg5 by microwave-assistant degradation method of total saponins from stems and leaves of Panax notoginseng / 中草药

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.

Identification of natural compounds targeting Annexin A2 with an anti-cancer effect

Annexin A2, a multifunctional tumor associated protein, promotes nuclear factor-kappa B (NF-κB) activation by interacting with NF-κB p50 subunit and facilitating its nuclear translocation. Here we demonstrated that two ginsenosides Rg5 (G-Rg5) and Rk1 (G-Rk1), with similar structure, directly bound to Annexin A2 by molecular docking and cellular thermal shift assay. Both Rg5 and Rk1 inhibited the interaction between Annexin A2 and NF-κB p50 subunit, their translocation to nuclear and NF-κB activation. Inhibition of NF-κB by these two ginsenosides decreased the expression of inhibitor of apoptosis proteins (IAPs), leading to caspase activation and apoptosis. Over expression of K302A Annexin A2, a mutant version of Annexin A2, which fails to interact with G-Rg5 and G-Rk1, effectively reduced the NF-κB inhibitory effect and apoptosis induced by G-Rg5 and G-Rk1. In addition, the knockdown of Annexin A2 largely enhanced NF-κB activation and apoptosis induced by the two molecules, indicating that the effects of G-Rg5 and G-Rk1 on NF-κB were mainly mediated by Annexin A2. Taken together, this study for the first time demonstrated that G-Rg5 and G-Rk1 inhibit tumor cell growth by targeting Annexin A2 and NF-κB pathway, and G-Rg5 and G-Rk1 might be promising natural compounds for targeted cancer therapy.

Identification of saponins from Panax notoginseng in metabolites of rats / 中国中药杂志

UPLC-QTOF-MS/MS was used to identify metabolites in rat blood, urine and feces after the administration of n-butanol extract derived from steamed notoginseng. The metabolic process of saponins came from steamed notoginseng was analyzed. The metabolites were processed by PeakView software, and identified according to the structural characteristics of prototype compounds and the accurate qualitative and quantitative changes of common metabolic pathways. Four saponins metabolites were identified based on MS/MS information of metabolites, namely ginsenoside Rh₄, Rk₃, Rk₁, Rg₅,and their 15 metabolites were verified. The metabolic pathways of the four ginsenosides in n-butanol extract included glucuronidation, desugar, sulfation, dehydromethylation, and branch loss. The metabolites of main active saponin components derived from steamed Panax notoginseng were analyzed from the perspective of qualitative analysis. And the material basis for the efficacy of steamed notoginseng was further clarified.

Simultaneous Determination of Four Kinds of Rare Saponins in Black Ginseng by HPLC / 中国药学杂志

OBJECTIVE: To establish an HPLC method for determining four kinds of rare saponins, ie, 20(S)-Rg3, 20(R)-Rg3, Rk1, and Rg5 in black ginseng. METHODS: COSMOSIL C18-PAQ (4.6 mm×250 mm, 5 μm) column was used and temperature was maintained at 30℃. Gradient elution was conducted using mobile phase consisting of acetonitrile and water at a flow rate of 1.0 mL·min-1. The detection wavelength was set at 203 nm. The injected sample volume was 10 μL. RESULTS: Good resolution was achieved for the four rare saponins in the ranges of 0.051-0.256 (r=0.999 9), 0.009-0.280(r=0.999 7), 0.051-0.303(r=0.999 9) and 0.093-0.279 mg·mL-1(r=0.999 9) for 20(S)-Rg3, 20(R)-Rg3, Rk1, and Rg5, respectively. The corresponding average recovery rates were 103.9%, 99.2%, 97.0%, and 100.6%, and the standard deviations were 0.71%, 0.73%, 1.97%, and 0.57%, respectively. CONCLUSION: The method is accurate, simple, reliable and reproducible for the determination of saponins in black ginseng. The determination result can be used as a reference for the rational medication, quality control, and further study of black ginseng.

The Change of Ginsenoside Composition in the Ginseng (Panax ginseng) Flower Buds by the Ultrasonication and Vinegar Process

The purpose of this study was to develop a new ginseng (Panax ginseng) flower buds extract with the high concentration of ginsenoside Rg3, Rg5, Rk1, Rh1 and F4, the Red ginseng special component. Chemical transformation from the ginseng saponin glycosides to the prosapogenin was analyzed by the HPLC. The ginseng flower buds were processed at the several treatment conditions of the ultrasonication (Oscillator 600W, Vibrator 600W) and vinegar (about 14% acidity). The result of UVGFB-480 was the butanol fraction of ginseng flower buds that had been processed with ultrasonication and vinegar for 480 minutes gained the highest amount of ginsenoside Rg5 (3.548%), Rh1 (2.037%), Rk1 (1.821%), Rg3 (1.580%) and F4 (1.535%). The ginsenoside Rg5 of UVGFB-480 was found to contain 14.3 times as high as ginseng flower buds extracts (GFB, 0.249%).

A new triterpene natural product from stems and leaves of Panax ginseng / 中草药

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.