Simultaneous analysis and retention behavior of major isoflavonoids in Radix Puerariae lobatae and Radix Puerariae thomsonii by high performance liquid chromatography with cyclodextrins as a mobile phase modifier

In order to differentiate two species of Radix Puerariae (Radix Puerariae lobatae and Radix Puerariae thomsonii) and to determine major isoflavonoids (puerarin, daidzin, daidzein and genistein) in the samples, a simple high performance liquid chromatography (HPLC) method with isocratic elution employing cyclodextrins (CDs) as mobile phase additives was developed. Various factors affecting the retention of isoflavonoids in the C₁₈ reversed-phase column, such as the nature of CDs, the concentration of hydroxypropyl-β-cyclodextrin (HP-β-CD) and the methanol percentage in the mobile phase, were studied. Experimental results confirmed that HP-β-CD, as a very effective mobile phase additive, could markedly reduce the retention of isoflavonoids, especially daidzein and genistein. The elution of four isoflavonoids could be achieved on a Kromasil^® C₁₈ column within 56 min by using the methanol–water contained 5 mM HP-β-CD (25/75, v/v) mixture as the mobile phase. The formation of the inclusion complexes between isoflavonoids and HP-β-CD explained the modification of the retention of analytes. The apparent formation constants determined by HPLC confirmed that the stoichiometry of HP-β-CD-isoflavonoid complexes was 1:1, and the stability of the complexes depended on the size and property of isoflavonoids. The optimized method was successfully applied for the simultaneous determination of major isoflavonoids in P. lobatae and P. thomsonii samples. This work provides a useful method for the analysis of traditional Chinese herbs.     

Rapid quality assessment of Radix Aconiti Preparata using direct analysis in real time mass spectrometry

This study presents a novel and rapid method to identify chemical markers for the quality control of Radix Aconiti Preparata, a world widely used traditional herbal medicine. In the method, the samples with a fast extraction procedure were analyzed using direct analysis in real time mass spectrometry (DART MS) combined with multivariate data analysis. At present, the quality assessment approach of Radix Aconiti Preparata was based on the two processing methods recorded in Chinese Pharmacopoeia for the purpose of reducing the toxicity of Radix Aconiti and ensuring its clinical therapeutic efficacy. In order to ensure the safety and effectivity in clinical use, the processing degree of Radix Aconiti should be well controlled and assessed. In the paper, hierarchical cluster analysis and principal component analysis were performed to evaluate the DART MS data of Radix Aconiti Preparata samples in different processing times. The results showed that the well processed Radix Aconiti Preparata, unqualified processed and the raw Radix Aconiti could be clustered reasonably corresponding to their constituents. The loading plot shows that the main chemical markers having the most influence on the discrimination amongst the qualified and unqualified samples were mainly some monoester diterpenoid aconitines and diester diterpenoid aconitines, i.e. benzoylmesaconine, hypaconitine, mesaconitine, neoline, benzoylhypaconine, benzoylaconine, fuziline, aconitine and 10-OH-mesaconitine. The established DART MS approach in combination with multivariate data analysis provides a very flexible and reliable method for quality assessment of toxic herbal medicine.     

Screening out Potential Cardio-Toxic Components of Chinese Herb Radix Aconiti Lateralis in Rat Dosed Plasma by High Performance Liquid Chromatography/Electrospray Ionization Quadrupole Time-Of-Flight Mass Spectrometry

This study established a new, rapid, and accurate method for bioactive compound screening by the combination of serum pharmacochemistry and serum pharmacology based on a spectrum-effect relationship model. HPLC/ESI-Q-TOF-MS was used for the chemical profiling of samples of dosed plasma, control plasma, and Radix Aconiti Lateralis decoction. A comparison was made of the resulting chemical profiles, which totaled 20 compounds including 16 prototype compounds and 4 metabolites derived from SF decoction that were detected as potential bioactive components. Using MS/MS analysis and accurate molecular weight assessments of TOF, 17 components in 20 potential bioactive compounds were structurally identified. Moreover, the pretreated plasma samples were injected into venous sinus of isolated toad hearts to investigate the cardio-toxicity according to heart ratio (HR) situation and electrocardiograph (ECG) parameters, including PR interval, QRS interval, and QT interval. Finally, 4 compounds in these 20 potential bioactive components that had closest correlation with 4 cardio-toxic experimental indexes respectively were investigated by spectrum-effect relationship model for the first time. The 4 compounds were considered as the real cardio-toxic components. This study proposed a series of potential bioactive components in Radix Aconiti Lateralis and provided a general research pattern to identify the potential bioactivity compounds in Chinese herbs or natural pharmacy.     

高效液相色谱-质谱分析指导下制备黄芩中系列黄酮成分对照品

在高效液相色谱-质谱分析指导下,针对性地分离制备了黄芩药材中系列黄酮成分对照品。首先对黄芩药材乙醇提取物进行液相色谱-质谱分析,获得各色谱峰的保留时间、紫外光谱和质谱特征。经波谱数据解析结合文献对比,鉴定了黄芩药材中的19种黄酮类成分。然后根据液相色谱-质谱分析结果和文献,设计了目标成分对照品的制备流程,采用低压制备柱色谱法依次制备了黄芩苷、汉黄芩苷、黄芩素、汉黄芩素和千层纸素A共5种黄酮类成分的对照品。结果表明这5种黄酮类成分对照品的纯度均大于98%。该方法可用于针对性地快速分离制备中药中的化学成分。     

山麦冬、麦冬对照药材电喷雾-质谱(ESI-MS)特征图谱的比较研究

报道了采用电喷雾-质谱负离子全扫描法,分析山麦冬、麦冬对照药材的甲醇提取物。经分析发现,山麦冬、麦冬对照药材负离子的全扫描质谱图差异显著,从中选择16强峰建立山麦冬、麦冬对照药材甲醇提取物的特征图谱。研究表明,该分析方法有较好的重现性,图谱特征性强,可快速、准确鉴别山麦冬、麦冬药材。     

流动注射-氢化物发生原子发射光谱法测定板蓝根中的有害元素

使用流动注射-氢化物发生-电感耦合等离子体原子发射光谱联用技术同时测定中药板蓝根中微量有害元素砷、铅、镉和汞的含量。对影响分析信号的主要工作条件进行了选择和优化。砷、铅、镉和汞的检出限分别为0．51、1．5、0．33和0．25μg／L;其回收率分别为98%、101%、103％和108％。本法用于中药板蓝根中微量有害元素的分析,结果满意。     

Species differentiation and quality assessment of Radix Paeoniae Rubra (Chi-shao) by means of high-performance liquid chromatographic fingerprint

There are two species under the monograph of Radix Paeoniae Rubrae ("Chi-shao" in Chinese) in Chinese Pharmacopoeia 2005 edition-Paeonia lactiflora Pallas and Paeonia veitchii Lynch. Due to different species and growing conditions, there are significant chemical differences between the two species, which may result in the improper clinical usage under the same name. Chemical pattern expressed by high performance liquid chromatographic (HPLC) fingerprint analysis can play an important role in species differentiation and quality control of Radix Paeoniae Rubra. In the present work, HPLC fingerprints of two kinds of Radix Paeoniae Rubra have been established and analysed with chemometric methods including similarity evaluation and principal component analysis. Both of the fingerprint common patterns of the two species comprise 13 characteristic peaks, nine of which were common peaks of the two species. However, significant differences between the roots of P. veitchii and P. lactiflora exist not only in the content of certain constituents, especially phenolic acids but also in peak-to-peak ratios expressed by the fingerprint patterns. According to the recent pharmacological studies on polyphenolic constituents, root originating from P. veitchii may possess better efficacy and quality than that from P. lactiflora. Our research reveals that further pharmacological investigation is very necessary to determine whether the two species should be embodied under the same monograph in Chinese Pharmacopoeia.     

The analysis of Radix Angelicae Sinensis (Danggui)

Radix Angelicae Sinensis, known as Danggui in China, is one of the most popular traditional Chinese medicines (TCMs), which is contained by more than 80 composite formulae. Modern researches indicate that phthalides, organic acids and their esters, polysaccharides are main chemical components related to the bioactivities and pharmacological properties of Danggui. Some of them, such as Z-ligustilide and ferulic acid, are selected as marker compounds to evaluate the quality of Danggui frequently. Because of the diversity of chemical structures and characters of these components, analytical methods of Danggui are various, including GC-MS, HPLC-DAD-MS, TLC, CE-DAD, and so on. Besides that, the development of analytical technology makes the quality control of Danggui more effective and reliable. Quality evaluation is from single or several components' analysis to fingerprinting, or in combination. Furthermore, bioactive components screening of Danggui has also attracted much attention, which will help us evaluate the selected marker components to some extent. In this paper, the literatures about the major phytoconstituents of Danggui, quality control and bioactive components screening methods have been reviewed. Main attention is given to the different methodologies developed to perform chemical analysis, including separation, detection and identification.     

Determination of Three Tanshinones from Radix Salvia Miltiorrhiza by Molecularly Imprinted Solid-phase Extraction

A selective molecularly imprinted solid‐phase extraction procedure was developed for the selective separation of tanshinone I, tanshinone IIA, and cryptotanshinone from Radix Salvia Miltiorrhiza samples. Tanshinone IIA imprinted polymers (MIP) synthesized in ethanol‐dodecanol system show high affinity to tanshinone IIA and its structure analogs in aqueous environment and the affinity can be controlled by adjusting the intensity of the eluents. By using 60% water‐40% methanol (volume ratio) and 99.5% methanol‐0.5% trifluoroacetic acid (volume ratio) as washing and eluting solvents, most interferences originating from the salvia matrix were eliminated. The extracts were sufficiently clean enough to be directly injected into HPLC for further chromatographic analysis. Good linearity was obtained from 0.4 to 500.0 mg·L^?1 (r²=0.999) with the relative standard deviations less than 4.2%. The mean recoveries of tanshinone IIA in Radix Salvia Miltiorrhiza were more than 85.6% at three different concentrations and the limits of detection were 0.06–0.09 mg·L^?1. This method is a viable alternative tool to the existing HPLC methods for analyzing the content of the three tanshinones in Radix Salvia Miltiorrhiza samples.     

溶剂浮选法分离富集大黄中的有效成分

采用溶剂浮选法对大黄提取液中的芦荟大黄素、大黄素、大黄酚以及大黄素甲醚进行了分离富集,并用高效液相色谱法分别测定了其含量。考察了料液浓度、浮选溶剂、浮选时间、浮选液pH值、氮气流速和电解质NaCl浓度对浮选效率的影响,并与泡沫浮选法和溶剂萃取法进行了比较。结果表明：溶剂萃取效果最差,泡沫浮选次之,溶剂浮选法分离富集效果最好。当料液浓度为6．4mg／mL,浮选时间为30min,浮选液pH一1～2,氮气流速为20mL／min,电解质NaCl浓度为0．4mol／L时,溶剂浮选效率最佳。