Simultaneous determination of tanshinol,protocatechuic aldehyde,protocatechuic acid,notoginsenoside R1, ginsenoside Rg1 and Rb1 in rat plasma by LC–MS/MS and its application

Dantonic pill, consisting of Salviae miltiorrhize , Panax notoginseng and Borneol , is a widely used compound Chinese medicine for preventing and treating ischemic cardiovascular diseases in China. In the present study, an original and sensitive method for simultaneous determination of tanshinol (i.e. danshensu), protocatechuic aldehyde, protocatechuic acid, notoginsenoside R1, ginsenoside Rg1 and Rb1 in rat plasma by liquid chromatography–tandem mass spectrometry operated in positive/negative ion switching mode was established and validated. The lower limits of quantification for tanshinol, protocatechuic aldehyde, protocatechuic acid, notoginsenoside R1, ginsenoside Rg1 and Rb1 were 5, 0.5, 1, 0.5, 0.5 and 2 ng/mL, respectively. All of the calibration curves showed good linearity over the investigated concentration range (r > 0.99). Validation results demonstrated that the above compounds were accurately, precisely and robustly quantified in rat plasma. The method was successfully applied to characterize the pharmacokinetic profiles of all six compounds in rats following a single oral administration of Dantonic pill.     

Simultaneous determination of notoginsenoside R1 and ginsenoside Re in rat plasma by ultra high performance liquid chromatography with tandem mass spectrometry and its application to a pharmacokinetic study

A rapid and high sensitive ultra high performance liquid chromatography with tandem mass spectrometry method for the simultaneous determination of notoginsenoside R1 and ginsenoside Re in rat plasma was developed. The analytes and internal standard, digoxin, were extracted from rat plasma via protein precipitation with methanol and separated on an Phenomenex Gemini C₁₈ column within 2 min. Quantitation was performed on a triple quadrupole mass spectrometer employing electrospray ionization technique, operating in multiple reaction monitoring and positive ion mode. The precursor to product ion transitions monitored for notoginsenoside R1, ginsenoside Re, and internal standard were m/z 955.5→775.5, 969.6→789.1, and 803.6→283.1, respectively. The assay was validated with linear range of 1.9–380 ng/mL for notoginsenoside R1 and 0.5–100 ng/mL for ginsenoside Re. The intra‐ and interday precisions (RSD%) were within 8.96% for each analyte. The absolute recoveries were greater than 93% for R1 and 96% for Re. Each analyte was stable during all sample storage, preparation, and analytic procedures. The method was successfully applied to a pharmacokinetic study of Xuesaitong dispersible tablets in eight rats.     

高效液相色谱-飞行时间质谱联用法分析人参及人参皂苷与山楂配伍过程中的水解行为

利用高效液相色谱-飞行时间质谱联用的方法,分别对人参配伍山楂前后人参皂苷的变化进行分析,同时对人参皂苷Re、Rg1、Rb1、Rd与山楂配伍的水解规律进行系统研究,并与单独煎煮液、仿山楂配伍pH值煎煮液的水解产物进行比较,结果发现人参与山楂配伍后人参皂苷Rg1、Rb1含量明显减少,而人参皂苷Re、Rd、Rg2、Rg3、F2、Rh1含量明显增加,其中人参皂苷Re与山楂配伍后水解产物为人参皂苷20(R)-Rg2、20(S)-Rg2,仿山楂配伍pH值水解产物为人参皂苷20(R)-Rg2、20(S)-Rg2、Rg4、Rg6;人参皂苷Rg1与山楂配伍后水解产物为20(S)-Rh1、20(R)-Rh1,仿山楂pH值水解产物为20(S)-Rh1、20(R)-Rh1、Rh4、Rk3;人参皂苷Rb1与山楂配伍后水解产物为Rd、20(S)-Rg3,仿山楂pH值水解产物为F2、20(S)-Rg3;人参皂苷Rd与山楂配伍后水解产物为F2、20(S)-Rg3、20(R)-Rg3,仿山楂pH值水解产物为20(S)-Rg3、20(R)-Rg3。研究表明,不同人参皂苷和山楂配伍后与仿山楂pH值的水解产物并不相同,人参与山楂配伍改变了人参皂苷成分的种类及含量。本研究为临床方剂中人参与山楂配伍后成分的变化提供物质基础数据。     

Development of a sensitive LC‐MS/MS method for simultaneous quantification of eleven constituents in rat serum and its application to a pharmacokinetic study of a Chinese medicine Shengmai injection

A sensitive LC‐MS/MS method was developed and validated for simultaneous quantification of 11 constituents, ginsenoside Rg1, Re, Rf, Rg2, Rb1, Rd, Rc, ophiopogonin D, schisandrin, schisandrol B and schizandrin B, in rat serum using digoxin as the internal standard (IS). The serum samples were pretreated and extracted with a two‐step liquid–liquid extraction. Chromatographic separation was achieved on a C₁₈ analytical column with a proper gradient elution using 0.02% acetic acid aqueous solution and 0.02% acetic acid–acetonitrile as mobile phase at a flow rate of 0.5 mL/min. MS detection was performed using multiple reaction monitoring via an electrospray ionization source. Good linearity was observed in the validated concentration range for every analyte (r² ≥0.9929), and the lower limits of quantitation of the analytes were in the range of 0.044–1.190 ng/mL in rat serum. Intra‐ and inter‐day precisions were <14.2%. The accuracy expressed as recovery was within the range of 85.1–112.8%. The extraction recoveries were >75.8%.The validated method was successfully applied to a pharmacokinetic study of all analytes in rats after single intravenous administration of Shengmai injection. Copyright © 2014 John Wiley & Sons, Ltd.     

Chemical characteristics of three medicinal plants of the Panax genus determined by HPLC-ELSD

The morphological appearance and main ingredients of three Chinese medicines (CMs), P. ginseng, P. quinquefolius, and P. notoginseng of the Panax genus, are similar. However, their pharmacological activities are obviously different. To ensure their safety and efficacy, chemical characteristics of the three CMs were determined using pressurized liquid extraction and HPLC-evaporative light scattering detection. Twelve major saponins, namely notoginsenoside R1, pseudo-ginsenoside F11, ginsenosides Rg1, Re, Rf, Rb1, Rg2, Rc, Rb2, Rb3, Rd, and Rg3 were also quantitatively compared among the three CMs. The contents of total investigated saponins varied considerably, by up to 4-14-fold, between the highest (P. notoginseng, 82.8-136.5 mg/g) and the lowest values (P. ginseng, 10.0-21.1 mg/g). Hierarchical clustering analysis based on the characteristics of 11 investigated saponins (except ginsenoside Rb3) and notoginsenoside R1, pseudo-ginsenoside F11, and the ratio of ginsenoside Rg1/Rb1 and Rg1/Re showed that 56 tested samples were divided into three main clusters in accordance with the three Panax species. Similarity evaluation of chromatograms was also performed using "Similarity Evaluation System for Chromatographic Fingerprint of Traditional Chinese Medicine (Version 2004A)". The results showed that a high degree of similarity existed within individual clusters, but a low degree between the clusters, which could be used for quality control of the three CMs.     

Simultaneous determination of 11 saponins in Panax notoginseng using HPLC-ELSD and pressurized liquid extraction

A new HPLC coupled with evaporative light scattering detection (ELSD) method was developed for simultaneous determination of 11 major triterpene saponins, namely notoginsenoside R1 (1), ginsenosides Rg1 (2), Re (3), Rf(4), Rb1 (5), Rg2 (6), Rc (7), Rb2 (8), Rb3 (9), Rd (10), and Rg3 (11) in Panax notoginseng, a commonly used traditional Chinese medicine (TCM). Pressurized liquid extraction (PLE) was employed for sample preparation, and the analysis was achieved using a Zorbax ODS C18 column eluted with gradient water-ACN in 60 min. The drift tube temperature of ELSD was set at 60 degrees C, and nitrogen flowrate was at 1.4 L/min. The method provided good repeatability and sensitivity for quantification of 11 saponins with overall precision (including intra- and interday) and LOD of less than 2.9% (RSD) and 98 ng, respectively. The validated method was successfully applied to quantify 11 saponins in 28 samples of P. notoginseng collected in different places, which is helpful to control the quality of P. notoginseng and its related products.     

Simultaneous determination of ginsenoside Rg1, Re and notoginsenoside R1 in human plasma by LC‐MS/MS and its application in a pharmacokinetic study in Chinese volunteers

A rapid and sensitive liquid chromatography–tandem mass spectrometry (LC‐MS/MS) method has been developed and validated for simultaneous quantification of ginsenosides Rg₁, Re and notoginsenoside R₁ in human plasma. Chromatography was performed on Capcell Pak C₁₈ MG II column using a binary gradient using mobile phase A (5 mm ammonium formate solution) and B (methanol, containing 5 mm ammonium formate) at a flow rate of 0.3 mL/min. The entire chromatographic run time was 3.2 min. Quantification was achieved using multiple reaction monitoring in positive mode using API 3000. This method was validated in terms of specificity, linearity, precision, accuracy, matrix effect and stability. The calibration curves were linear in the concentration range of 0.020–5.00 ng/mL for ginsenosides Rg₁, Re and notoginsenoside R₁. The lower limit of quantification (LLOQ) of this method was 0.020 ng/mL. The intra‐run and inter‐run precision values were within 12.31% for ginsenoside Rg₁, 14.13% for ginsenoside Re and 11.46% for notoginsenoside R₁ at their LLOQ levels. The samples were stable under all tested conditions. This method was successfully applied to study the pharmacokinetics of ginsenoside Rg₁ and notoginsenoside R₁ in 24 healthy volunteers following oral administration of 200 mg Sanqi Tongshu Enteric‐Pellets Capsule.     

Analysis of Low-polar Ginsenosides in Steamed Panax Ginseng at High-temperature by HPLC-ESI-MS/MS

A high performance liquid chromatography coupled with electrospray ionization-tandem mass spectrometry( HPLC-ESI-MS/MS) method was developed for the analysis and identification of ginsenosides in the extracts of raw Panax ginseng(RPG) and steamed Panax ginseng at high temperatures(SPGHT). A total of 25 ginsenosides were extracted include of which 10 low-polar ginsenosides, such as ginsenosides F4, Rk3, Rh4, 20S-Rg3, 20R-Rg3 and so on, were identified according to their HPLC retention time and MS/MS data. The results indicated that the low polar ginsenosides were seldom found in RPG. For the exploration of the transformation pattern of the ginsenosides in steam processing, the standards of ginsenosides Re, Rg1, Rb1, Rc, Rb2, Rb3 and Rd were selected and hydrolyzed at a temperature of 120 ℃. The results show that these polar ginsenosides can be converted to low-polar ginsenosides such as Rg2, Rg6, F4, Rk3 and Rg5 by hydrolyzing the sugar chains.     

Determination of marker constituents in radix Glycyrrhizae and radix Notoginseng by near infrared spectroscopy

High-performance liquid chromatographic (HPLC) methods were developed for the determination of glycyrrhizin in radix Glycyrrhizae and ginsenosides Rb1, Rb2, Rc, Rd, Re, Rf and Rg, in radix Notoginseng. These methods were used as reference methods for near-infrared (NIR) spectroscopy. Spectroscopic calibrations were developed for the determination of glycyrrhizin, the total content of ginsenosides and the individual major ginsenosides Rb1, Rd, Re and Rg1. Standard errors of cross validation (SECV) were 1.22 mg g(-1) for glycyrrhizin (concentration range 21.3-34.1 mg g(-1)) and 0.99 mg g(-1) for the sum of ginsenosides (concentration range 55.3-71.1 mg g(-1)). The corresponding coefficients of determination (R2) were 0.94 and 0.98, respectively. The SECVs were generally less than a factor of 2.5 of the repeatability standard deviation of the HPLC methods.     

Comparative analysis on microbial and rat metabolism of ginsenoside Rb1 by high-performance liquid chromatography coupled with tandem mass spectrometry

Ginsenoside Rb1 is an active protopanaxadiol saponin from Panax species. In order to compare the similarities and differences of microbial and mammalian metabolisms of ginsenoside Rb1, the microbial transformation by Acremonium strictum and metabolism in rats were comparatively studied. Microbial transformation of ginsenoside Rb1 by Acremonium strictum AS 3.2058 resulted in the formation of eight metabolites. Ten metabolites (M1-M10) were detected from the in vivo study in rats and eight of them were identified as the same compounds as those obtained from microbial metabolism by liquid chromatography-tandem mass spectrometry analysis and comparison with reference standards obtained from microbial metabolism. Their structures were identified as ginsenoside Rd, gypenoside XVII, 20(S)-ginsenoside Rg3, 20(R)-ginsenoside Rg3, ginsenoside F2, compound K, 12beta-hydroxydammar-3-one-20(S)-O-beta-d-glucopyranoside, and 25-hydroxyl-(E)-20(22)-ene-ginsenoside Rg3, respectively. The structures of the additional two metabolites were tentatively characterized as 20(22),24-diene-ginsenoside Rg3 and 25-hydroxyginsenoside Rd by HPLC-MS/MS analysis. M7-M10 are the first four reported metabolites in vivo. The time course of rat metabolism of ginsenoside Rb1 was also investigated.     

Determination of ginsenoside content in Asian and North American ginseng raw materials and finished products by high-performance liquid chromatography: single-laboratory validation

A single-laboratory validation study was conducted for the quantification of Rg1, Re, Rb1, Rc, Rb2, and Rd in Asian ginseng (Panax ginseng C.A. Meyer) and North American ginseng (Panax quinquefolius L.) raw materials and finished products by RP-HPLC. The extraction with aqueous methanol was optimized for whole root, powdered extract, and finished product (raw, tablet, and capsule matrixes) test articles. Root materials were treated with base to hydrolyze acidic malonyl ginsenosides to their neutral counterparts. Calibration curves for each ginsenoside were linear over the following ranges (microg/g): 5-394 for Rg1, 15-1188 for Re, 39-2981 for Rb1, 6-499 for Rc, 5-406 for Rb2, and 7-600 for Rd, all having a coefficient of determination (r2) of > or = 99.5%. The LOD for Rg1, Re, Rb1, Rc, Rb2, and Rd was determined to be 1.06, 1.25, 2.19, 1.24, 1.27, and 1.70 microg/mL, respectively. Quantitative determinations performed with eight test materials by two analysts over 3 days (n = 12) resulted in RSDr values that ranged from 1.11 to 7.61%.     

A UFLC‐MS/MS method with a switching ionization mode for simultaneous quantitation of polygalaxanthone III,four ginsenosides and tumulosic acid in rat plasma: application to a comparative pharmacokinetic study in normal and Alzheimer's disease rats

A fast, sensitive and reliable ultra fast liquid chromatography‐tandem mass spectrometry (UFLC‐MS/MS) method has been developed and validated for simultaneous quantitation of polygalaxanthone III (POL), ginsenoside Rb1 (GRb1), ginsenoside Rd (GRd), ginsenoside Re (GRe), ginsenoside Rg1 (GRg1) and tumulosic acid (TUM) in rat plasma after oral administration of Kai‐Xin‐San, which plays an important role for the treatment of Alzheimer's disease (AD). The plasma samples were extracted by liquid–liquid extraction using ethyl acetate–isopropanol (1:1, v/v) with salidrdoside as internal standard (IS). Good chromatographic separation was achieved using gradient elution with the mobile phase consisting of methanol and 0.01% acetic acid in water. The tandem mass spectrometric detection was performed in multiple reaction monitoring mode on 4000Q UFLC‐MS/MS system with turbo ion spray source in a negative and positive switching ionization mode. The lower limits of quantification were 0.2–1.5 ng/ml for all the analytes. Both intra‐day and inter‐day precision and accuracy of analytes were well within acceptance criteria (±15%). The mean absolute extraction recoveries of analytes and IS from rat plasma were all more than 60.0%. The validated method has been successfully applied to comparing pharmacokinetic profiles of analytes in normal and AD rat plasma. The results indicated that no significant differences in pharmacokinetic parameters of GRe, GRg1 and TUM were observed between the two groups, while the absorption of POL and GRd in AD group were significantly higher than those in normal group; moreover, the GRb1 absorbed more rapidly in model group. The different characters of pharmacokinetics might be caused by pharmacological effects of the analytes. Copyright © 2013 John Wiley & Sons, Ltd.     

流速/溶剂双梯度反相高效液相色谱法快速同时测定复方丹参片中7种有效成分

采用整体柱建立了流速/溶剂双梯度反相高效液相色谱法快速同时测定复方丹参片中三七皂苷R1,人参皂苷Rg1,Re,Rb1,Rd,Rb2及丹参酮ⅡA 7种有效成分。通过对溶剂和流速双梯度体系的逐步优化,并应用色谱模拟软件Dry Lab,得到分离7种成分的最佳色谱条件。采用色谱柱Merck Chromolith Performance RP-18e(100 mm×4.6 mm),以乙腈-水为流动相体系,流速/溶剂双梯度洗脱,柱温30℃;片剂中的7种成分在21 min内达到基线分离;Rg1在60.60~242.40 mg/L(r=0.999 0)、丹参酮ⅡA在16.52~66.08 mg/L(r=0.999 9),其余皂苷在30.70~142.66 mg/L(r≥0.999 4)范围内具有良好的线性关系;定量下限(S/N=10)为21~124μg/kg,回收率为96.7%~100.1%。该方法能在短时间内同时分离不同极性的化合物,提高被测物的柱效,减少半峰宽和拖尾,可应用于复方丹参片中7种成分的含量分析。     

Analysis of saponins in raw and steamed Panax notoginseng using high-performance liquid chromatography with diode array detection

A reversed-phase high-performance liquid chromatography-diode array detection method was developed and validated for the simultaneous determination of six saponins (notoginsenoside R1, ginsenosides Rg1, Re, Rb1, Rc, Rd) in raw and steamed Panax notoginseng. Linearity (r2 > 0.9988), intra- and inter-day precision (RSD < 4%), limit of detection (0.008-0.013 mg/ml), limit of quantification (0.027-0.042 mg/ml) of the saponins were determined. The method was successfully applied to 11 pairs of raw and steamed P. notoginseng products. Three products showed discrepancies between theirlabelled claims (raw or steamed) and the results of analysis. This new, simple and reliable method could be used in the quality control of raw and steamed P. notoginseng.     

Compatible stability study of panax notoginseng saponin injection (xueshuantong®) in combination with 47 different injectables

Panax Notoginseng Saponin (PNS) injection (Xueshuantong®, XST) plays an important role in acute and chronic treatment of cardiovascular disease in China. XST, a freeze‐dried powder injection of PNS, contains ginsenosides, Rg1, Rb1, Re, Rd. and notoginsenoside, R1. Study of the stability of herbal medicine injections is limited. The degradation products may contribute to adverse drug reactions (ADRs). The stability kinetics and degradation mechanisms of the five ingredients of PNS in XST injection were systematically explored in aqueous solution. The compatible stability of XST injection in combination with 47 injectables was evaluated using biophysical analysis. A principal components analysis model provided a good clustering result after compatibility. The degradation of the five ingredients in aqueous solution was found to be acid, temperature, oxidation and trivalent ion‐dependent. All ingredients were much more stable in XST injection than in aqueous solutions. Nine degradation products were identified by adopting LC‐Q‐TOF/MS. Standards exceeding the osmotic pressure and/or particle size were found to be the probable causes of the ADR, which were related to drug combination. To minimize the risk of ADRs, drug combinations should be avoided until the complicated chemical matrices of the Chinese medicine injections are more clearly understood. Copyright © 2016 John Wiley & Sons, Ltd.     

Simultaneous quantification of Panax and Epimedium species using Rapid Resolution Liquid Chromatography (RRLC)

Two Rapid Resolution Liquid Chromatography (RRLC) methods have been developed and validated for simultaneous quantification of eight major ginsenosides from Panax species, namely, R1, Rg1, Re, Rf, Rb1, Rb2, Rc, and Rd, and flavonoids from Epimedium species, namely, epimedins A, B, and C and icariin. The analyses were performed using an Agilent 1200 series RRLC system with Phenomenex Luna C18-HST and Zorbax Eclipse XDB columns. The separation was performed with a gradient mobile phase of A (pure water) and B (acetonitrile) at a flow rate of 1.0 mL/min and 2.5 mL/min, respectively. Both columns were kept at 40 degrees C with the detection wavelength set at 203 nm. Specific eluted compounds were identified by using reference samples of ginsenosides R1, Rg1, Re, Rf, Rb1, Rc, Rb2, and Rd, and epimedins A, B, C and icariin. Baseline separation was achieved in less than 15 minutes for the Phenomenex Luna column and 4 minutes for the Zorbax Eclipse column. Characteristic RRLC profiles were established for complex mixtures of ginsenosides from Panax species and flavonoids from Epimedium species. Both methods developed here are effective for the quality control of formulated products containing both Panax and Epimedium varieties.     

LC-MS/MS法测定大鼠血浆中人参皂苷Rb1的含量及其药代动力学研究

采用液相色谱-串联质谱法快速、灵敏地测定大鼠血浆中人参皂苷Rb1(GRb1)的含量,并将该方法应用于大鼠口服GRb1后的代谢动力学研究。血浆样品采用96孔板进行液-液萃取后,应用Agilent SB-C18色谱柱(100 mm×2.1 mm,3.5μm)进行分离,以甲醇-0.1%甲酸溶液(体积比为75∶25)为流动相进行洗脱,在正离子模式下对GRb1和内标人参皂苷Rg1(GRg1)进行检测,用于定量的离子反应分别为1131.5→365.1(GRb1),823.3→643.4(GRg1)。人参皂苷Rb1血浆样品测定方法的定量线性范围为1~500 ng/mL,线性相关系数大于0.999,定量下限为1 ng/mL,批内和批间精密度(RSD)小于9.05%,回收率为79.7%~81.0%,基质效应为96.6%~99.3%。大鼠灌胃给予Rb15 mg/kg后,大鼠体内血药浓度到达高峰时间tmax为1.53 h,半衰期t1/2为13.54 h,药时曲线面积AUC0~72为16237.76(ng·h)/mL。该方法快速、高效、灵敏,适用于人参皂苷Rb1的代谢动力学研究。     

To improve the quantification sensitivity of large molecular weight compounds--with ginsenosides as example

High cone voltage was used to improve the quantification sensitivity of large molecular weight compounds in high-performance liquid chromatography electrospray ionization mass spectrometry (HPLC/ESI-MS), with ginsenosides as example. Investigations on the effect of cone voltage showed that within a voltage range of 30-130 V, for all the ginsenosides tested, i.e., Rb(1), Rb(2), Rc, Rd, Re, R(f) and R(g1), an increase in the applied cone voltage can significantly increase the sensitivity of the method. The maximum sensitivity in the determination decreases with the decreasing molecular weight of the ginsenosides in the order of Rb(1) > Rb(2) > Rc > Re > Rd > R(g1) > R(f). At the high cone voltage of 130 V, both molecular weight and structural information was obtained from a single mass spectrum. It can also be used for isomer differentiation and determination of O-glycosidic linkages in ginsenosides. Linear relationships between the peak area response and concentration were observed in the range of 50-2 x 10(5) ng/mL, with the correlation coefficients >0.99. The limits of detection reached down to pg for ginsenosides. The method was successfully applied to the determination of ginsenosides in commercial ginseng samples.     

Retention behavior of ginsenosides on a poly(vinyl alcohol)-bonded stationary phase in hydrophilic interaction chromatography

The influences of the organic component of the mobile phase and the column temperature on the retention of ginsenosides on a poly(vinyl alcohol) (PVA) bonded stationary phase operated under hydrophilic interaction chromatographic mode were investigated. The retention of the ginsenosides was found to increase with increasing amount of acetonitrile (MeCN) in the mobile phase, which is typical of hydrophilic interaction chromatographic behavior. It was also found that the retention of the analytes was highly affected by the type of the organic modifier used. Aqueous MeCN (75–90%) gave the most satisfactory retention and separation of ginsenosides Rf, Rg1, Rd, Re, Rc, Rb2 and Rb1 compared with aqueous methanol, isopropyl alcohol or tetrahydrofuran at the same composition levels. The effects of the different types of organic modifiers on the retention of the analytes were attributed to their solvent strength and hydrogen-bond accepting/donating properties. The effect of temperature on the retention of ginsenoside on the PVA-bonded phase was assessed by constructing van’t Hoff plots for two temperature ranges: subambient (273–293 K) and ambient-elevated (298–333 K) temperatures. van’t Hoff plots for all analytes were linear at the two temperature intervals; however, the slopes of the lines corresponding to ginsenosides Rg1 and Re were completely different from those for the rest of the analytes especially in the subambient temperature range. Enthalpy-entropy compensation (EEC) studies were conducted to verify the difference in thermodynamics observed for ginsenosides Rg1 and Re compared with the other analytes. EEC plots showed that Rf, Rd, Rc, Rb2 and Rb1 were possibly retained by the same retention mechanism, which was completely different from that of Rg1 and Re at subambient temperatures. Retention prediction models were derived using multiple linear regression to identify solute attributes that affected the retention of the analytes on the PVA-bonded phase. The mathematical models derived revealed that the number of hydrogen-bond donors and the ovality of the molecules are important molecular properties that govern the retention of the compounds on the chromatographic system.     

改性松香键合二氧化硅高效液相色谱固定相的制备及其对三七总皂苷的分离

三七中发挥药效的主要成分为三七皂苷R1、人参皂苷Rg1、人参皂苷Re、人参皂苷Rb1和人参皂苷Rd,用于贫血、冠心病、高血压、脑卒中后遗症等疾病的治疗,但其化学成分多且难分离.将氢化松香丙烯酸羟乙酯(HRHA)通过巯基-烯点击化学反应键合到烷基化硅胶表面,制备出一种新型的改性松香键合二氧化硅高效液相色谱固定相(SiO2...