Development and Evaluation of a PCR Kit for Authentication of Panax quinquefolius L.with PCR-Restriction Fragment Length Polymorphism

Panax quinquefolius L.(American ginseng)and Panax ginseng C.A.Meyer are famous herbal medicines.Accurate authentication of the species has grown to be a significant impact.This study aims to develop a PCR kit for the authentication of Panax quinquefolius L.and Panax ginseng based on the nuclear internal transcribed spacer 2(ITS2)gene with the improved PCR-restriction fragment length polymorphism(PCR-RFLP)method.The reagent components in the development work were prepared and determined by the kit consisting of the DNA extraction,PCR amplification,and restriction enzyme digestion systems.A total of 21 batches of Panax quinquefolius L.and Panax ginseng samples collected from different areas were validated.Their specificity,stability,and repeatability were evaluated.The purity of genomic DNA extracted was 1.73±0.13 according to the ratio of A_(260)/A_(280),and the mass concentration was 3.15±0.22μg/g(using the kit).PCR amplicons of Panax quinquefolius L.and Panax ginseng were 122 bp in length.After the PCR products were digested by restriction enzyme Hinf I,a distinct pattern exhibited in the species of Panax quinquefolius L.with two fragments of 40 bp and 80 bp respectively,whereas those from Panax ginseng in addition to adulterated samples could not.Evaluation confirmed that the DNA kit results were stable and repeatable after 10,15,and 20 freeze-thaw cycles:the evaluation was 100%specific.The DNA kit proposed in the study can be used for the identification of Panax quinquefolius L.

Evaluation and prediction of ecological suitability of medicinal plant American ginseng (panax quinquefolius)

Objective： American ginseng is a medicinal plant with large market demands,however,its producing areas are shrinking because of the continuous cropping obstacles in China.Therefore,it is urgent to establish a suitable model to determine the new producing areas.Here we evaluated and predicted the suitable areas of American ginseng using the maximum entropy model（Max Ent）.Methods： Based on the 37 environmental variables over thirty years from 1970 to 20 0 0 and 226 global distribution points of American ginseng,Max Ent was used to determine the global ecological suitable areas for American ginseng.The Receiver Operating Curve（ROC）was used to evaluate the model prediction accuracy.Meanwhile,an innovative ecological variable,the precipitation–temperature ratio,was established to indicate the climate characteristic in the American ginseng suitable areas based on the monthly precipitation and temperature.Results： The potential ecological suitable areas of American ginseng were primarily in Appalachian Mountain in America and Changbai Mountain in China,about in the range of 35 °N–50 °N,60 °W–120 °W and 35 °N–50 °N,110 °E–145 °E,respectively,including the United States,Canada,China,North Korea,South Korea,Russia and Japan.South Korea and Japan were the potential producing regions.The precipitation–temperature ratios were stable at（0.22,0.56）of the vigorous growth period（April–October）in the best suitable areas of American ginseng,serving as characteristic parameters to optimize the prediction model.The model showed that the common soil parameters were pH 4.5–7.2,Base Saturation（BS）above 80%,Cation Exchange Capacity（CEC）10–20 cmol/kg,organic carbon（OC）〈 1.4%,and the soil types were sandy loam or loam.Conclusion： An optimized Max Ent model was established to predict the producing area for American ginseng that needed to be validated by a field test.

Chemical constituents from acid hydrolyzates of Panax quinquefolius total saponins and their inhibition activity to α-glycosidase and protein tyrosine phosphatase 1B

Objective:To investigate the hypoglycemic components from the acid hydrolyzates of Panax quinquefolius total saponins,and screen the active compounds by in vitro inhibitory activities toα-glycosidase enzymes and protein tyrosine phosphatase-1 B(PTP1 B).Methods:The hydrolyzates were chromatographed repeatedly over silica gel column,and the structures of the compounds were determined by means of NMR.The in vitro bioassay was performed through the inhibitory effects onα-glucosidase or/and PTP1 B.Results:Eight compounds were isolated,which identified as 20(S)-panaxadiol(1),(20 S,24 R)-dammarane-20,24-epoxy-3β,6α,12β,25-tetraol(2),20(R)-dammarane-3β,12β,20,25-tetraol(3),20(S)-dammarane-3β,6α,12β,20,25-pentol(4),20(R)-dammarane-3β,12β,20,25-tetrahydroxy-3β-O-β-D-glucopyranoside(5),β-sitosterol(6),oleanolic acid(7)and 20(S)-protopanaxadiol(8).Compound 5 was ginseng triterpenoid isolated from the acid hydrolysates of total saponins from P.quinquefolius for the first time.In this paper,the possible in vitro inhibitory activities were investigated.Compound 5 exhibited significantly inhibitory activity againstα-glucosidase,and the IC50 value[(0.22±0.21)μmol/L]was about 43-fold lower than positive control.For the PTP1 B inhibition assay,compound 5 indicated the strongest inhibitory effect with IC50 of(5.91±0.38)μmol/L,followed by compound 4 with IC50 of(6.21±0.21)μmol/L,which were all showed competitive inhibitory pattern by using a Lineweaver-Burk plot.Conclusion:These results supported the potential application of dammaranes from acid hydrolyzates of P.quinquefolius total saponins can be used as ingredients of ancillary anti-diabetic agent or functional factor.

基于多元素含量测定与统计学方法的西洋参产地鉴别

探讨了多元素分析对西洋参(Panax quinquefolius L.)产地鉴别的可行性,筛选鉴别西洋参产地的有效指标。试验收集产地为加拿大、美国、中国东北三省的西洋参样品共20批,用ICP-MS法测定其中Sc、Y、La、Ce、Pr、Nd、Sm、Eu、Gd、Tb、Dy、Ho、Er、Tm、Yb、Lu、Cr、Mn、Fe、Ni、Cu、Zn、As、Se、Cd、Sn、Hg、Pb共28种元素的含量,对其进行方差分析、聚类分析及判别分析。结果表明,不同地域西洋参样品中元素含量有其各自的特征。聚类分析将西洋参样品分成不同类别,与来源地基本一致。逐步判别分析筛选出Y、Fe和Ni可作为判别西洋参产地来源的指标,判别正确率均达100.0%,说明利用多元素分析技术对西洋参产地来源的判别是可行的。

基于代谢组学分析根腐病西洋参根际土壤特异代谢物

以4年生健康西洋参根际土壤(healthy ginseng soil,HS)和患根腐病西洋参根际土壤(root rot ginseng soil,RS)为研究对象,采用基于气相色谱-飞行时间质谱联用技术(GC-TOF-MS)的代谢组学方法分析根际土壤差异代谢产物。RS vs HS组共筛选到13个具有显著性差异(P<0.05)的代谢产物,其中包括9种有机酸、3种糖类和1种萜类。与HS组相比,RS组中二十四烷酸、棕榈酸、巴豆酸、苯甲酸、油酸、十七烷酸、壬二酸、水杨酸和儿茶酸的水平显著升高(P<0.05),而D-塔罗糖、甘露糖、N-乙酰-D-半乳糖胺和植醇的水平显著降低(P<0.05)。KEGG通路富集分析发现这些差异代谢产物主要富集在不饱和脂肪的生物合成、次生代谢物的生物合成、微生物在不同环境中的代谢及芳香族化合物的降解等10条代谢通路中。根腐病西洋参和健康西洋参根际土壤存在一些显著差异的代谢产物,这些差异代谢产物可能通过化感作用导致西洋参根腐病的发生,本研究为进一步研究西洋参的化感作用提供了理论依据。