WITHDRAWN: Chloroplast genome evolution of Berberis (Berberidaceae): Implications for phylogeny and metabarcoding.

After consultation with external experts, the authors acknowledged discrepancies in the classification of certain Berberis samples discussed in the article. Berberis is one of the most complex plant genera, and identifications are very hard, limited to only a handful of experts due to rampant hybridizations and other issues of reticulate evolution. This article has therefore been withdrawn at the request of the authors and with the consent of the editor until the species identification issue has been resolved. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/policies/article-withdrawal.

Online preconcentration and determination of five alkaloids in Yangxinshi tablet by large-volume sample stacking and micelle to solvent stacking in cyclodextrin-modified electrokinetic chromatography.

The two-step preconcentration technique consisting of large-volume sample stacking (LVSS) and micelle to solvent stacking (MSS) in cyclodextrin-modified electrokinetic chromatography (CDEKC) was developed for the analysis of five cationic alkaloids in complex Chinese herbal prescriptions. Relevant parameters affecting separation and stacking performance were optimized separately. Under the optimal LVSS-MSS-CDEKC conditions, less analysis time and organic solvent were required, and the enhancement factors of analytes ranged from 12 to 15 compared with the normal CDEKC separation mode. Further, all validation results demonstrated good applicability and multiple alkaloids (epiberberine, dehydrocorydaline, jatrorrhizine, coptisine and berberine) in Yangxinshi tablet (YXST) have been simultaneously determined. This approach presents powerful potential for the determination of multiple components in complex preparations of Chinese medicine.

Spectrum-effect relationship study between ultra-high-performance liquid chromatography fingerprints and anti-hepatoma effect in vitro of Cnidii Fructus.

Cnidii Fructus, derived from the dried ripe fruit of Cnidium monnieri (L.) Cuss, has the effect of warming kidneys and invigorating Yang. This study established the spectrum-effect relationships between ultra-high-performance liquid chromatography (UHPLC) fingerprints and the antitumor activities of Cnidii Fructus on human hepatocellular carcinoma (HepG2) cells. In UHPLC fingerprints, 19 common peaks were obtained, and 17 batches of herbs had similarity >0.948. In Cell Counting Kit-8 (CCK-8) test, 17 batches of Cnidii Fructus extract significantly inhibited the proliferation of HepG2 cells to different degrees, showing different half-maximal inhibitory concentration (IC50) values. Furthermore, gray correlation analysis, Pearson's analysis, and orthogonal partial least squares discriminant analysis were performed to screen out eight components. The analysis of mass spectrum data and a comparison with standards revealed that the eight components were methoxsalen, isopimpinellin, osthenol, imperatorin, osthole, ricinoleic acid, linoleic acid, and oleic acid. The verification experiments by testing single compounds indicated that these eight compounds were the major anti-hepatoma compounds in Cnidii Fructus. This work provides a model combining UHPLC fingerprints and antitumor activities to study the spectrum-effect relationships of Cnidii Fructus, which can be used to determine the principal components responsible for the bioactivity.

Combination of large-volume sample stacking with polarity switching and micelle electrokinetic chromatography for the analysis of anion compounds in Yangxinshi tablets.

INTRODUCTION: Yangxinshi tablet (YXST) is a traditional Chinese medicine preparation characterized by its high efficacy and safety for the treatment of cardiovascular diseases. Anionic compounds have been revealed as potential active components. However, there is currently limited research regarding its quality control. OBJECTIVE: We aimed to establish a strategy for the simultaneous separation and determination of five key anionic compounds in YXST. METHOD: A sensitive and efficient analytical method was developed and applied for the simultaneous separation and determination of five key compounds in YXST using large-volume sample stacking with polarity switching and micelle electrokinetic chromatography (LVSS-PS-MEKC) coupled with diode array detection. Crucial parameters, including sample volume, applied voltage, composition and pH of the running buffer, concentration of organic modifier, and switching time of the polarity, were systematically evaluated and optimized using a single variable method to enhance separation performance. Furthermore, the impact of cyclodextrin and sodium dodecyl sulfate as electrolyte modifiers was also investigated. RESULTS: Under the optimal conditions, baseline separation of the five compounds (daidzein, puerarin, glycyrrhiztinic acid, chlorogenic acid, and salvianolic acid B) was achieved within 20 min. In comparison to the conventional MEKC mode, the constructed LVSS-PS-MEKC method exhibited a more than sixfold increase in the enrichment factor. The method was validated in terms of linearity, precision, accuracy, 24 h stability, and recovery and successfully applied to analyze YXST samples. CONCLUSION: A sensitive strategy was developed for the simultaneous separation and determination of five key anionic components in YXST, offering a robust and efficient strategy for pharmaceutical analysis.

Quantification and discovery of quality markers from Toddalia asiatica by UHPLC-MS/MS coupled with chemometrics.

INTRODUCTION: Toddalia asiatica (TA) is a classical traditional Chinese medicine used to treat rheumatoid arthritis and contusions. However, research regarding TA quality control is currently limited. OBJECTIVE: We aimed to establish a strategy for identifying quality markers that can be used for the evaluation of the quality of TA. METHOD: A rapid and efficient ultra-high-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry (UHPLC-MS/MS) method was developed for the quantitative determination of 19 compounds in TA from different regions. Then, the extraction process of TA was successively optimized by single-factor optimization and response surface methodology. Moreover, chemometrics was employed to confirm the correlation between quality and target compounds. RESULTS: Utilizing the UHPLC-MS/MS method, separation of the 19 bioactive compounds was achieved within 14 min. The method was validated in terms of linearity (r2 > 0.9982), precision (0.08%-3.70%), repeatability (0.50%-2.54%), stability (2.26%-5.46%), and recovery (95.8%-113%). The optimal extraction process (extraction solvent, 65% ethanol aqueous solution; solid-liquid ratio, 1:20; extraction time, 25 min) was determined with the total content of 19 bioactive compounds as indicator. Significant disparities were observed in the contents of target compounds across different batches of TA. Besides, all samples could be categorized into two distinct groups, and magnoflorine, (-)-lyoniresinol, nitidine chloride, norbraylin, skimmianine, and decarine were identified as quality markers. CONCLUSION: In the present study, we developed a strategy to improve the quality control of TA. In consideration of the pharmacodynamic activity and statistical differences, six compounds are proposed as quality markers for TA.

In-capillary screening and quantifying the antioxidants of Yangxinshi Tablet using field-enhanced sample injection-micellar electrokinetic chromatography.

An in-capillary 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate) as oxyradicals combining field-enhanced sample injection with micellar electrokinetic chromatography was developed for screening and determination of the major antioxidants in Yangxinshi Tablet. To obtain simultaneous separation and detection of radicals and analytes, relevant factors were optimized separately. Under the optimum conditions, four compounds including salvianolic acid B, hyperoside, puerarin, and caffeic acid were identified as the major antioxidants. All validation results covering recovery, precision, and stability demonstrated good applicability of the method. On this basis, the total antioxidant activity was successfully evaluated in terms of the decreased peak area of radicals. There was a correlation coefficient of 0.8974 between the total contents of major antioxidants and the total antioxidative activity of the sample. Therefore, these four compounds were selected as combinatorial markers for the quality evaluation of Yangxinshi Tablet. It was concluded that the established method presented a powerful potential to screen and quantify active ingredients in the complex preparation of Chinese medicine.

A novel reverse migration micellar electrokinetic chromatography method for in-capillary screening and quantifying of antioxidant components in Sanyetangzhiqing using 2,2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) as oxidation-free radical.

A novel method of reverse migration micellar electrokinetic chromatography (RM-MEKC) using 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate) as oxidation-free radical was developed to screen the major antioxidants from Sanyetangzhiqing (SYTZQ), which is a new patent drug for diabetes. For simultaneous detection and separation of 2,2'-bis (3-ethylbenzothiazoline-6-sulfonic acid) ammonium salt (ABTS+ ) and chemical components of SYTZQ, the key factors were optimized and the method was validated under the optimal conditions. All the relative standard deviations of recovery, precision, and stability were below 6.6%. Based on these, the RM-MEKC method has been successfully used to screen the main antioxidants from SYTZQ tablets. Five compounds, including rosmarinic acid, salvianolic acid B, lithospermic acid, hyperoside, and isoquercetin, were separated and identified as the major antioxidants. There was a linear relationship with correlation coefficient of 0.923 between the total amount of major antioxidants and total antioxidative activity of SYTZQ. Consequently, these five ingredients could be selected as combinatorial markers for quality control of SYTZQ, and the established method was concluded to be a simple, reliable, and powerful tool to screen and quantify active compounds for quality evaluation of SYTZQ.

Study on the Chemical Profile of Chrysanthemum (Chrysanthemum morifolium) and the Evaluation of the Similarities and Differences between Different Cultivars.

Chrysanthemum originates in China and has been cultivated for tea and food utilizations over two thousand years. According to differences in origin and processing methods, Chrysanthemum morifolium Ramat. can be categorized into many cultivars. This study aims to investigate the chemical components in chrysanthemum and clarify similarities and differences between different chrysanthemum varieties. A total of 55 non-volatile components and 66 volatile components in chrysanthemum were identified by ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS) and gas chromatography-mass spectrometry (GC/MS) methods, respectively. A rapid UPLC-MS/MS method was developed and validated for the simultaneous determination of 13 active components in 30 batches chrysanthemum samples of ten different cultivars. Multivariate statistical techniques were applied to analyze the samples. The result indicated that Boju, Huaiju and Chuju were more similar in terms of the ingredient content and Qiju, Jinsihuangju, Huangju, Hangju, Gongju, Fubaiju, Baiju have a high degree of similarity. Furthermore, isochlorogenic acid C, luteolin, apigenin-7-glucoside, chlorogenic acid, apigenin and cryptochlorogenic acid plays an important role in distinguishing different varieties of chrysanthemum. The established strategy explains the similarities and differences between different varieties of chrysanthemums to some extent, and provides certain reference value for the choice of chrysanthemums for eating or medicinal purposes in daily life.

Comparative Investigation of the Differences in Chemical Compounds between Raw and Processed Mume Fructus Using Plant Metabolomics Combined with Chemometrics Methods.

Mume Fructus is a well-known herbal medicine and food with a long history of processing and application. Different processing methods impact the intrinsic quality of Mume Fructus. Thus, it is of great significance to investigate the changes in chemical components during processing (i.e., raw compared to the pulp and charcoal forms). In this study, plant metabolomics methods based on mass spectrometry detection were established to analyze the chemical ingredients of Mume Fructus comprehensively. Chemometric strategies were combined to analyze the profile differences of Mume Fructus after different processing methods. The established strategy identified 98 volatile and 89 non-volatile compounds of Mume Fructus by gas chromatography-mass spectrometry (GC-MS) and ultra-high performance liquid chromatography coupled with quadrupole time of flight mass spectrometry (UHPLC-Q-TOF-MS/MS), respectively. Moreover, the orthogonal partial least squares discriminant analysis (OPLS-DA) indicated that raw Mume Fructus and the Mume Fructus pulp and charcoal were distributed in three regions. Subsequently, 19 volatile and 16 non-volatile components were selected as potential chemical component markers with variable importance in the projection using (VIP) >1 as the criterion, and the accuracy was verified by a Back Propagation Neural Network (BP-NN). To further understand the difference in the content of Mume Fructus before and after processing, 16 non-volatile chemical component markers were quantitatively determined by ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS/MS). The results revealed that, compared with raw Mume Fructus, the total content of 16 components in the pulp of Mume Fructus increased while it decreased in the charcoal. Therefore, this study used GC-MS, UHPLC-Q-TOF-MS/MS and UHPLC-MS/MS modern technology to analyze the differences in chemical components before and after the processing of Mume Fructus and provided a material basis for further research on the quality evaluation and efficacy of Mume Fructus.

Exploration of Habitat-Related Chemical Markers for Stephania tetrandra Applying Multiple Chromatographic and Chemometric Analysis.

Geo-authentic herbs refer to medicinal materials produced in a specific region with superior quality. Stephania tetrandra S. Moore (S. tetrandra) is cultivated in many provinces of China, including Anhui, Zhejiang, Fujian, Jiangxi, Hunan, Guangxi, Guangdong, Hainan, and Taiwan, among which Jiangxi is the geo-authentic origin. To explore habitat-related chemical markers of herbal medicine, an integrated chromatographic technique including gas chromatography-mass spectrometry (GC-MS), ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS/MS) and ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MS/MS) combined with chemometric analysis was established. The established methods manifested that they were clearly divided into two groups according to non-authentic origins and geo-authentic origins, suggesting that the metabolites were closely related to their producing areas. A total of 70 volatile compounds and 50 non-volatile compounds were identified in S. tetrandra. Meanwhile, tetrandrine, fangchinoline, isocorydine, magnocurarine, magnoflorine, boldine, and higenamine as chemical markers were accurately quantified and suggested importance in grouping non-authentic origins and geo-authentic origins samples. The discriminatory analysis also indicated well prediction performance with an accuracy of 80%. The results showed that the multiple chromatographic and chemometric analysis technique could be used as an effective approach for discovering the chemical markers of herbal medicine to fulfill the evaluation of overall chemical consistency among samples from different producing areas.

Effect of DLT-SML on Chronic Stable Angina Through Ameliorating Inflammation, Correcting Dyslipidemia, and Regulating Gut Microbiota.

ABSTRACT: Chronic stable angina (CSA) is caused by coronary atherosclerosis. The gut microbiota (GM) and their metabolite trimethylamine-N-oxide (TMAO) levels are associated with atherosclerosis. Danlou tablet (DLT) combined with Salvia miltiorrhiza ligustrazine (SML) injection has been used to treat CSA. This study aims to investigate how DLT combined with SML (DLT-SML) regulates serum lipids, inflammatory cytokines, GM community, and microbial metabolite in patients with CSA. In this study, 30 patients with CSA were enrolled in the DLT-SML group, and 10 healthy volunteers were included in the healthy control group. The patients in the DLT-SML group were subdivided as the normal total cholesterol (TC) group and high-TC group according to their serum TC level before treatment. Blood samples were collected to investigate the (1) lipid content, including triglyceride (TG), TC, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol, (2) fasting blood glucose (Glu), (3) inflammatory cytokines, including interleukin-1 beta (IL-1ß), interleukin-6 (IL-6), interleukin-10 (IL-10), and tumor necrosis factor-α (TNF-α), and (4) gut-derived metabolite, including lipopolysaccharides and TMAO level. GM composition was analyzed by sequencing 16S rRNA of fecal samples. Results showed that DLT-SML significantly decreased serum TG, TC, low-density lipoprotein cholesterol, IL-1ß, TNF-α, and TMAO levels of patients with CSA. DLT-SML increased the abundance of Firmicutes and decreased Proteobacteria, which were significantly lower or higher in patients with CSA, respectively, compared with the healthy control group. In particular, DLT-SML increased the microbial diversity and decreased Firmicutes/Bacteroidetes ratio of patients with high-TC. The abundance of Sarcina, Anaerostipes, Streptococcus, Weissella, and Erysipelatoclostridium was decreased, whereas Romboutsia, Faecalibacterium, and Subdoligranulum were increased by DLT-SML treatment in patients with CSA. These findings indicated that DLT-SML improved patients with CSA by ameliorating dyslipidemia profile, decreasing the circulating inflammatory cytokines, and regulating the GM composition and their metabolites.

Comparison of the chemical profile differences of Aster tataricus between raw and processed products by metabolomics coupled with chemometrics methods.

Aster tataricus, a traditional Chinese herb, has been used to treat cough and asthma for many years. Its raw and processed products have different pharmacological effects in clinical applications. To explore the chemical profile differences of components in A. tataricus processed with different methods, metabolomics methods based on ultra-high-performance liquid chromatography coupled with quadrupole time of flight mass spectrometry and gas chromatography-mass spectrometry were developed. Chemometrics strategy was applied to filter and screen the candidate compounds. The accuracy of differential markers was validated by back propagation neural network. The established methods showed that raw A. tataricus, honey-processed A. tataricus, vinegar-processed A. tataricus, and steamed A. tataricus were clearly divided into four groups, suggesting that the components were closely related to the processing methods. A total of 64 nonvolatile and 43 volatile compounds were identified in A. tataricus, and 22 nonvolatile and 12 volatile differential constituents were selected to distinguish the raw and processed A. tataricus. This study demonstrated that the metabolomics methods coupled with chemometrics were a comprehensive strategy to analyze the chemical profile differences and provided a reliable reference for quality evaluation of A. tataricus.

Recent advances of green pretreatment techniques for quality control of natural products.

A few advancing technologies for natural product analysis have been widely proposed, which focus on decreasing energy consumption and developing an environmentally sustainable manner. These green sample pretreatment and analysis methods following the green Analytical Chemistry (GAC) criteria have the advantage of improving the strategy of chemical analyses, promoting sustainable development to analytical laboratories, and reducing the negative effects of analysis experiments on the environment. A few minimized extraction methodologies have been proposed for replacing the traditional methods in the quality evaluation of natural products, mainly including solid-phase microextraction (SPME) and liquid phase microextraction (LPME). These procedures not only have no need for large numbers of samples and toxic reagent, but also spend a small amount of extraction and analytical time. This overview aims to list out the main green strategies on the application of quality evaluation and control for natural products in the past 3 years.

Comparison of the active components of Aster tataricus from different regions and related processed products by ultra-high performance liquid chromatography with tandem mass spectrometry.

We investigated crude Aster tataricus, vinegar-processed Aster tataricus, honey-processed Aster tataricus, and steamed Aster tataricus as a case study and developed a comprehensive strategy integrating quantitative analysis and chemical pattern recognition methods for the evaluation and differentiation of Aster tataricus from different regions, as well as related processed products. In the study, 15 batches of raw Aster tataricus collected from seven provinces were analyzed. A sensitive and rapid ultra-high performance liquid chromatography with tandem mass spectrometry method for simultaneous determination of 15 compounds was established to evaluate the quality of raw and processed Aster tataricus. Furthermore, multivariate statistical techniques were applied to compare the differences among Aster tataricus samples. As a result, the herbs collected from seven provinces were divided into two categories, and chlorogenic acid was the most important component distinguishing between the regions. Moreover, all of the raw and processed samples were classified by partial least squares discriminant analysis based on the 15 analyzed compounds. Results showed that raw Aster tataricus, vinegar-processed Aster tataricus, honey-processed Aster tataricus, and steamed Aster tataricus were clustered in four different areas. Shionone, chlorogenic acid and kaempferol were the significant constituents differentiating the raw and differently processed Aster tataricus samples.

An environmentally friendly sodium dodecyl sulfate-synergistic microwave-assisted extraction followed by ultra-high-performance liquid chromatography with photodiode array method for the simultaneous extraction and determination of iridoids, phenylpropanoids, and lignans from Eucommiae Cortex.

A simple and green sodium dodecyl sulfate-synergistic microwave-assisted extraction method was developed to extract and determine the iridoids, phenylpropanoids, and lignans in Eucommiae Cortex followed by ultra-high-performance liquid chromatography with photodiode array detection. The biodegradable solution (sodium dodecyl sulfate) was used as a promising alternative to organic solvents. The response surface methodology provided the optimum extraction conditions (2 mg/mL sodium dodecyl sulfate, 1100 W microwave power, and 6 min extraction time). The recoveries of three types of components ranged from 95.0 to 105% (RSDs < 5%). The intra- and inter-day precision and accuracy were less than 3.40% and within the range of 97.1-105%, respectively. Compared with other extraction methods, this newly established method was more efficient and environmental friendly. The results demonstrated that sodium dodecyl sulfate-synergistic microwave-assisted extraction followed by ultra-high-performance liquid chromatography with photodiode array method was applicable for the simultaneous extraction and determination of these three types of compounds for quality evaluation of Eucommiae Cortex.

Biosurfactant trehalose lipid-enhanced ultrasound-assisted micellar extraction and determination of the main antioxidant compounds from functional plant tea.

Hydrosoluble trehalose lipid (a biosurfactant) was employed for the first time as a green extraction solution to extract the main antioxidant compounds (geniposidic acid, chlorogenic acid, caffeic acid, and rutin) from functional plant tea (Eucommia ulmoides leaves). Single-factor tests and response surface methodology were employed to optimize the extraction conditions for ultrasound-assisted micellar extraction combined with ultra-high-performance liquid chromatography in succession. A Box-Behnken design (three-level, three-factorial) was used to determine the effects of extraction solvent concentration (1-5 mg/mL), extraction solvent volume (5-15 mL), and extraction time (20-40 min) at a uniform ultrasonic power and temperature. In consequence, the best analyte extraction yields could be attained when the trehalose lipid solution concentration was prepared at 3 mg/mL, the trehalose lipid solution volume was 10 mL and the extraction time was set to 35 min. In addition, the recoveries of the antioxidants from Eucommia ulmoides leaves analyzed by this analytical method ranged from 98.2 to 102%. These results indicated that biosurfactant-enhanced ultrasound-assisted micellar extraction coupled with a simple ultra-high-performance liquid chromatography method could be effectively applied in the extraction and analysis of antioxidants from Eucommia ulmoides leaf samples.

Study on Structure Activity Relationship of Natural Flavonoids against Thrombin by Molecular Docking Virtual Screening Combined with Activity Evaluation In Vitro.

Thrombin, a key enzyme of the serine protease superfamily, plays an integral role in the blood coagulation cascade and thrombotic diseases. In view of this, it is worthwhile to establish a method to screen thrombin inhibitors (such as natural flavonoid-type inhibitors) as well as investigate their structure activity relationships. Virtual screening using molecular docking technique was used to screen 103 flavonoids. Out of this number, 42 target compounds were selected, and their inhibitory effects on thrombin assayed by chromogenic substrate method. The results indicated that the carbon-carbon double bond group at the C2, C3 sites and the carbonyl group at the C4 sites of flavones were essential for thrombin inhibition, whereas the methoxy and O-glycosyl groups reduced thrombin inhibition. Noteworthy, introduction of OH groups at different positions on flavonoids either decreased or increased anti-thrombin potential. Myricetin exhibited the highest inhibitory potential against thrombin with an IC50 value of 56 µM. Purposively, the established molecular docking virtual screening method is not limited to exploring flavonoid structure activity relationships to anti-thrombin activity but also usefully discovering other natural active constituents.

Ionic liquid vortex-simplified matrix solid-phase dispersion for the simultaneous determination of terpenoids, crocins, quinic acid derivatives and flavonoids in Gardeniae fructus by UHPLC.

A novel ionic-liquid-based vortex-simplified matrix solid-phase dispersion method using 2,6-dimethyl-ß-cyclodextrin was established by ultra high performance liquid chromatography coupled with a photodiode array detector. 2,6-Dimethyl-ß-cyclodextrin was first used as a promising adsorbent in this proposed method for simultaneous determination of eight compounds in Gardeniae fructus. These compounds are terpenoids (geniposidic acid, genipin-1-ß-D-gentiobioside, geniposide, 8-o-acetyl shanzhiside methyl ester), crocins (crocin-I, crocin-II), quinic acid derivatives (chlorogenic acid), and flavonoids (isoquercitrin), respectively. Several parameters were investigated in the adsorption and desorption processes to obtain the optimal conditions, including 2,6-dimethyl-ß-cyclodextrin as sorbent, 0.5 mL 100 mM 1-dodecyl-3-methylimidazolium hydrogen sulfate as the extraction solvent, 2:1 of sample/sorbent ratio, grinding for 2 min and vortexing for 60 s. The recoveries of the eight compounds ranged from 96.6 to 100% (<3.50%). The limits of detection and quantification were in the range of 0.02-0.30 and 0.06-1.25  µg/mL, respectively. Meanwhile, a good linearity was attained with r values (>0.9997). The established method showed higher extraction efficiency and less reagent consumption than traditional matrix solid phase dispersion and ultrasonic-assisted extraction. Hence, it could be applied for sample preparation and analysis of natural products.

A rapid and efficient extraction method based on industrial MCM-41-miniaturized matrix solid-phase dispersion extraction with response surface methodology for simultaneous quantification of six flavonoids in Pollen typhae by ultra-high-performance liquid chromatography.

An industrial MCM-41-miniaturized matrix solid-phase dispersion extraction coupled with response surface methodology was explored to determine L-epicatechin, typhaneoside, isorhamnetin-3-O-neohespeidoside, naringenin, kaempferol, and isorhamnetin in Pollen typhae by ultra-high performance liquid chromatography connected to a photodiode array detection. Several variables were optimized in detail, including mesh number of sieve, type of adsorbent, mass ratio of sample to adsorbent, grinding time, methanol concentration, and elution volume. Central composite design was applied to optimize the best conditions for the maximum yields of the total flavonoids. The results displayed a good linear relationship (R > 0.9992) and the recoveries ranged from 92.9 to 103% (RSD < 4.53%) of the six flavonoids. The optimal method with high efficiency and low consumption was obviously better than heating reflux and ultrasonic extraction. It was proven that the developed industrial MCM-41-miniaturized matrix solid-phase dispersion extraction coupled with simple ultra-high performance liquid chromatography method could be a rapid and efficient tool for extraction and determination of flavonoids in natural products.

Pharmacokinetics and tissue distribution study of bisabolangelone from Angelicae Pubescentis Radix in rat using LC-MS/MS.

A sensitive and accurate LC-MS/MS method was established for quantifying bisabolangelone in rat plasma and tissues. Bisabolangelone was isolated and purified from Angelicae Pubescentis Radix. The pharmacokinetic and tissue distribution of bisabolangelone after administration to rat was performed by LC-MS/MS. Separation was carried out on a C8 (4.6 × 100 mm, 1.8 µm) column. The MS/MS transitions of bisabolangelone and tussilagone (internal standard) were set at m/z 249.1 → 109.1 and m/z 391.4 → 217.4, respectively. The lower limit of quantification in plasma and other tissues ranged from 1 to 4 ng/mL. The biosamples were prepared using protein precipitation method with acetonitrile. The recovery was >92%. The results showed that values of maximum concentrations and area under the curve depended linearly on the studied doses (2.5, 5 and 7.5 mg/kg body weight). The other ingredients in Angelicae Pubescentis Radix extract possibly reduce the absorption of bisabolangelone in rat. Tissue distribution revealed that bisabolangelone was widely distributed in vivo. The highest and lowest concentrations of bisabolangelone were found in the stomach and in the brain, respectively. It was concluded that the newly established HPLC-MS/MS method was suitable to describe the pharmacokinetic characteristics of bisabolangelone in rat after administration.