Rational development of a selection model for solvent gradients in single-step separation of ginsenosides from Panax ginseng using high-speed counter-current chromatography

A new model of solvent gradients selection was rationally developed for the preparative separation of target compounds. The solvent gradients were selected based on a three-stage screening process where stationary phase retention was ensured by introducing a new parameter termed as the phase ratio. The phase ratio was calculated after mixing the upper phase of a solvent system with the lower phase of a different solvent system (1:1, v/v). The developed model was applied to the one-step separation of eight ginsenosides from Panax ginseng. Three gradients were selected on the basis of new model and eight ginsenosides, Rb(1), Rb(2), Rc, Rd, Re, Rg(1), Rf, and Rh(1), were efficiently separated by high-speed counter-current chromatography coupled with evaporative light scattering detector. The structures of all compounds were characterized by electrospray-ionization mass spectrometry and nuclear magnetic resonance spectroscopy.     

Purification and Characterization of a Novel Tetradecapeptide from Ginseng Polypeptides with Enhancing Memory Activity for Mice

Aiming at isolating and investigating the active ingredients of the aqueous extract from Panax ginseng which showed enhancing memory activity, the authors characterized one ingredient. To separate the oligosaccharides and polypeptides, a DEAE-Sephadex A-50 colum was used. The enhanced memory activity in mice was studied by Mirros water maze tesk in mice. The dose of oligosacchrides, polypeptides or Piracetam was 30 mg/kg per day with intraperitoneal administration. The oligosaccharides did not show enhancing memory effect, but polypeptides did show. This result demonstrates that the active ingredients of the aqueous extract from Panax ginseng which showed enhancing memory effect was polypeptides. The purification of the polypeptides was performed on a Sephadex G-25 column. A novel tetradecapeptide was purified from the polypeptides and its structure was determined by liquid chromatography-electrospray ionization-quadrupole-time of flight-mass spectrometry(LC-ESI-Q-TOF-MS) with the amino acid sequence of Lys-Ser-Leu-Thr-Leu-Thr-Ser-Ser-Leu-Ser-Tyr-Thr-Asp-Ser.     

动态泡沫浮选法分离富集人参提取液中的二醇型人参皂苷

采用动态泡沫浮选法分离富集人参提取液中的二醇型人参皂苷, 用高效液相色谱法测定6种人参皂苷Rg₁, Re, Rb₁, Rc, Rb₂和Rd的含量. 考察了浮选液pH值、电解质NaCl浓度、载气流量、料液浓度及料液流速对人参皂苷浮选率的影响, 确定了动态泡沫浮选的最佳条件, 并与溶剂提取法、溶剂浮选法以及静态泡沫浮选法进行了比较. 结果表明, 动态泡沫浮选法对二醇型人参皂苷Rb₁, Rc, Rb₂和Rd具有高富集效率, 回收率分别为93.3%, 98.6%, 96.9%和98.3%, 而对三醇型人参皂苷Rg1和Re的富集效率却很低, 回收率分别为4.8%和4.2%. 该法是分离纯化二醇型人参皂苷的一种简便有效的方法.     

人参中有机磷农残的基质固相分散-HPLC同时快速分析

建立了基质固相分散-高效液相色谱法(MSPD-HPLC)对中药材人参中的三种有机磷农药甲胺磷、甲基对硫磷和乙基对硫磷残留量进行快速分析:. 将HPLC法应用于有机磷农药残留量的检测, 分别采用中性Al2O3和体积比为8%的乙酸乙酯-正己烷作为MSPD的分散剂和洗脱剂, 对分析方法的质量控制问题进行了详细讨论, 并对不同种类的人参中药材进行了准确的定性定量分析. 该方法的线性范围为0.20～10.00 mg•L－1, 相关系数(R)大于0.99815, 相对标准偏差(RSD)均小于11.54%, 检测限(LOD)低于0.017 mg•L－1, 样品的加标回收率为87.29%～92.43%. 其线性范围、相关系数、准确度、精密度和LOD等指标均满足有机磷农残分析的要求.     

177 Saponins,Including 11 New Compounds in Wild Ginseng Tentatively Identified via HPLC-IT-TOF-MSn,and Differences among Wild Ginseng,Ginseng under Forest,and Cultivated Ginseng

Wild ginseng (W-GS), ginseng under forest (F-GS, planted in mountain forest and growing in natural environment), and cultivated ginseng (C-GS) were compared via HPLC-DAD and HPLC-IT-TOF-MSⁿ. A total of 199 saponins, including 16 potential new compounds, were tentatively identified from 100 mg W-GS (177 saponins in W-GS with 11 new compounds), F-GS (56 saponins with 1 new compound), and C-GS (60 saponins with 6 new compounds). There were 21 saponins detected from all the W-GS, F-GS, and C-GS. Fifty saponins were only detected from W-GS, including 23 saponins found in ginseng for the first time. Contents of ginsenosides Re (12.36–13.91 mg/g), Rh₁ (7.46–7.65 mg/g), Rd (12.94–12.98 mg/g), and the total contents (50.52–55.51 mg/g) of Rg₁, Re, Rf, Rb₁, Rg₂, Rh₁, and Rd in W-GS were remarkably higher than those in F-GS (Re 1.22–3.50 mg/g, Rh₁ 0.15–1.49 mg/g, Rd 0.19–1.49 mg/g, total 5.69–18.74 mg/g), and C-GS (Re 0.30–3.45 mg/g, Rh₁ 0.05–3.42 mg/g, Rd 0.17–1.68 mg/g, total 2.99–19.55 mg/g). Contents of Re and Rf were significantly higher in F-GS than those in C-GS (p < 0.05). Using the contents of Re, Rf, or Rb₁, approximately a half number of cultivated ginseng samples could be identified from ginseng under forest. Contents of Rg₁, Re, Rg₂, Rh₁, as well as the total contents of the seven ginsenosides were highest in ginseng older than 15 years, middle–high in ginseng between 10 to 15 years old, and lowest in ginseng younger than 10 years. Contents of Rg₁, Re, Rf, Rb₁, Rg₂, and the total of seven ginsenosides were significantly related to the growing ages of ginseng (p < 0.10). Similarities of chromatographic fingerprints to W-GS were significantly higher (p < 0.05) for F-GS (median: 0.824) than C-GS (median: 0.745). A characteristic peak pattern in fingerprint was also discovered for distinguishing three types of ginseng. Conclusively, wild ginseng was remarkably superior to ginseng under forest and cultivated ginseng, with ginseng under forest slightly closer to wild ginseng than cultivated ginseng. The differences among wild ginseng, ginseng under forest, and cultivated ginseng in saponin compositions and contents of ginsenosides were mainly attributed to their growing ages.     

高效液相色谱-电喷雾质谱联用法测定人参和西洋参的皂苷类成分

利用高效液相色谱（LC—ELSD）与电喷雾质谱（ESI—MS）联用技术对人参和西洋参中的人参皂苷类成分进行了比较研究。通过液相色谱与质谱联用技术获得了相应化合物的分子量信息;利用质谱的源内CID技术获得了相应化合物的结构信息。根据人参皂苷Rf和拟人参皂苷F11两种同分异构体在质谱中的源内CID裂解规律的不同,建立了人参和西洋参药材的LC-ESI-MS简便、准确的鉴别方法。     

基于壳聚糖的QuEChERS-气相色谱-串联质谱法测定人参中30种农药残留

建立了一种以壳聚糖为净化材料的QuEChERS-气相色谱-串联质谱检测人参中30种农药残留的检测方法。探究了吸附剂及其用量对样品提取和净化效果的影响,确定壳聚糖为吸附剂净化。采用选择离子监测(SRM)模式,基质匹配标准曲线外标法定量。30种农药在各自的浓度范围内,线性关系良好(r> 0.996);检出限范围为1.5~3.0μg/kg,定量限范围为5.0~10.0μg/kg。3个添加水平(10,20,100μg/kg)的回收率在84.1%~113.7%之间,相对标准偏差均小于15%。该方法适用于检测人参中农药残留。     

中药材三七提取液近红外光谱的支持向量机回归校正方法

提出近红外光谱的支持向量机回归校正建模方法.以中药材三七渗漉提取液为实际分析对象,对其近红外光谱数据进行预处理和主成分分析后,用支持向量机回归算法建立人参皂苷R_g1,R_b1和R_d以及三七总皂苷的近红外光谱校正模型.以R_g1,R_b1和R_d的HPLC测定值及三七总皂苷的比色法测定值为参照,将本文方法与偏最小二乘回归和径向基神经网络建模方法相比较,结果表明,本文所建模型的预测准确性优于后两者,可推广应用于中药提取过程的近红外光谱分析.     

变量扩维-筛选方法优化西洋参的毛细管电泳分析条件

以西洋参干品的70％乙醇溶液回流提取液为模型样品,研究获取西洋参的中药指纹图谱,应用均匀设计法安排实验,使用变量扩维-筛选方法优化其毛细管区带电泳的实验条件,得出了分离度较好的谱图。主要峰的面积与西洋参重量的线性相关系数都大于0．930。     

微波水解衍生高效液相色谱法测定西洋参中的氨基酸

用微波辅助提取酸水解西洋参中的蛋白质, 对生成的氨基酸进行微波衍生后用高效液相色谱法进行测定.对微波衍生条件和微波水解的条件进行了优化.研究结果表明, 190 ℃, 15 min微波水解得到氨基酸的产率与传统加热水解(110 ℃, 24 h)的结果基本相同.用2,4-二硝基氟苯(DNFB)对氨基酸进行微波衍生, 氨基酸在微波衍生时间大于20 s时, 衍生反应基本完全; 而传统DNFB衍生需在60 ℃水浴加热1 h, 所以微波衍生法明显缩短了氨基酸分析时间.用高效液相色谱法对西洋参根中的氨基酸进行了测定, 结果令人满意.