Fragmentation methods have been widely studied for computing quantum mechanical (QM) energy of medium-sized water clusters, but less attention has been paid to large-sized ion–water clusters, in which many-body QM interaction is more significant, because of the charge-transfer effect between ions and water molecules. In this study, we utilized electrostatically embedded generalized molecular fractionation (EE-GMF) method for full QM calculation of the large-sized ion–water clusters (up to 15 Na+ and 15 Cl– ions solvated with 119 water molecules). Through systematic validation using different fragment sizes, we show that, by using distance thresholds of 6 Å for both the two-body and three-body QM interactions, the EE-GMF method is capable of providing accurate ground-state energies of large-sized ion–water clusters at different ab initio levels (including HF, B3LYP, M06-2X, and MP2) with significantly reduced computational cost. The deviations of EE-GMF from full system calculations are within a few kcal/mol. The result clearly shows that the calculated energies of the ion–water clusters using EE-GMF are close to converge after the distance thresholds are larger than 6 Å for both the two-body and three-body QM interactions. This study underscores the importance of the three-body interactions in ion–water clusters. The EE-GMF method can also accurately reproduce the relative energy profiles of the ion–water clusters.

•Development of an UPLC-Q–TOF–MS for chemical profile of Jitong Ning Tablet.•A total of 162 compounds were identified in Jitong Ning Tablet.•The fragmentation pathways of major types of compounds were characterized.Jitong Ning Tablet (JTNT), a traditional Chinese herbal formula, consists of Eucommia ulmodies oliv, Angelicae pubescentis radix, Aconiti radix cocta, Corydalis yanhusuo w.t. wang, Glycyrrhizae radix et rhizoma, Paeoniae radix rubra and Radix puerariae. It has been demonstrated to show protective effects on ankylosing spondylitis and anti-inflammatory effects. The chemical compositions of JTNT, playing a key role in quality control, remain unknown. In this study, an ultra-performance liquid chromatography combined with quadrupole time of flight mass spectrometry (UPLC-Q–TOF–MS) method in both positive and negative ion mode was established to investigate the chemical constituents of JTNT formula. In total, 162 compounds including flavonoids, triterpenoids, coumarins, alkaloids, phenylpropionic acids, lignans, terpenoids, and organic acids were detected, 152 of which were unambiguously or tentatively identified by comparing their retention times and accurate mass measurement with reference compounds and data in literatures. Our results would benefit quality control and chemical basis for JTNT.Download high-res image (101KB)Download full-size image

A copper-catalyzed aminooxygenation of unactivated alkenes with various O-nucleophiles is described. This novel methodology uses commercially available N-fluorobenzenesulfonimide as an amination reagent and provides a simple and efficient approach to a wide range of aminated saturated oxygen heterocycles in moderate to good yields. The reaction features mild reaction conditions, operational simplicity, and a broad substrate scope.

•A low-cost microdroplet chip was fabricated using paper cover and electrochemiluminescent array.•Vertically aligned silica nanochannel was modified as a signal amplification strategy.•Simultaneous analysis of six samples can be accomplished in 1 min.This paper describes a simple and miniaturized microdroplet chip (μchip) that is constructed with a silica nanochannel (SNC)-assisted electrode array and a hydrophobic paper cover (SNC&P-μchip). Vertically aligned SNCs with uniform pore size of 2–3 nm in diameter and negatively charged surface can significantly accelerate the mass transport of the positively charged tris(2,2'-bipyridyl) ruthenium (II), resulting in a remarkably enhanced electrochemiluminescence (ECL) signal. The SNC-assisted electrode array was coupled to a low cost paper cover to achieve simultaneous detection of six samples in 1 min. The feasibility and universality of the SNC&P-μchip was evaluated by detecting a series of alkaloidal drugs both in buffers and in human serum. The performance of the SNC&P-μchip was fully validated with respect to linearity (0.9999 > R > 0.9939), sensitivity (limits of detection from 1.799 nM to 11.43 nM), and accuracy (recovery rate between 94.38% and 109.12%). The facile and economic SNC&P-μchip shows promising potential for rapid drug detection in complex biofluids.Download high-res image (240KB)Download full-size image

•A simple and efficient bipolar electrode array was developed for the multiplexed detection of glucose, lactate and choline.•The biorecognition event could be directly reported by the ECL emitted on the same pole from luminol and in situ generated H2O2.A simple, efficient and versatile biosensing platform capable of the multiplexed detection for glucose, lactate and choline was developed by the integration of bipolar electrochemistry and electrochemiluminescence (ECL) imaging. The sensing bipolar electrodes (BPEs) were simply modified via a one-step method adaptable to different enzymes. The biorecognition event happening between the substrate and the corresponding enzyme could be directly reported by the ECL emitted on the same pole from luminol and in situ generated H2O2. Under optimized conditions, the BPEs array was successfully applied for the determination of glucose, lactate and choline in the ranges of 0.01–1 mM, 0.01–1 mM and 0.02–5 mM, with the LOD of 7.57 μM, 8.25 μM and 43.19 μM, respectively. Owing to the improved stability of in situ generated H2O2, a whole series of analytes testing could be completed in the same BPE biochip. Subsequently, an array chip consisting of nine BPEs enabled the concomitant detection of glucose, lactate and choline, demonstrating the capability for multifunctional detection of biomolecules. This versatile analytical system could be easily extended to sensitive screening in a miniaturized device and point of care testing.An electrochemiluminescent bipolar array for multiplexed detection was developed by correlating in situ generated H2O2 with luminol at the anodic pole.

•Intra-and extracellular succinate accumulated in cardiomyocytes upon lipid insult.•Intracellular succinate impaired PDH through HIF-1α induction.•Extracellular succinate impaired PDH through GPR91/PKCδ signaling.•Ginsenoside Rb1 alleviated cardiac I/R injury by preserving PDH activity.Altered mitochondrial oxidation increases vulnerability to cardiac ischemia/reperfusion (I/R) injury in metabolic disorders. However, the metabolic signaling responsible for the dysfunction remains partly unknown. We sought to test whether or not hypoxic succinate accumulation could inhibit pyruvate dehydrogenase (PDH) activity and subsequently aggravate I/R injury. Results showed that saturated fatty acid palmitate stimulation increased fatty acid oxidation and induced hypoxia in cardiomyocytes, leading to succinate accumulation. Intracellular succinate induced hypoxia inducible factor-1α (HIF-1α) expression and impaired PDH activity via upregulation of pyruvate dehydrogenase kinase 4 (PDK4) expression. Luciferase reporter assay showed that succinate increased PDK4 expression through gene promoter induction in a HIF-1α-dependent manner. Palmitate also induced the release of succinate into extracellular space. By activating GRP91, extracellular succinate induced the translocation of PKCδ to mitochondria and further exacerbated PDH impairment. These results demonstrated that succinate impaired PDH activity via GPR91-dependent and independent pathways. Ginsenoside Rb1 (a major compound isolated from ginseng) and trimetazidine (fatty acid β-oxidation inhibitor) prevented hypoxic succinate accumulation in cardiomyocytes and improved PDH activity by blocking succinate-associated HIF-1α activation and GPR91 signaling. Through improving PDH activity, Rb1 and trimetazidine prevented cardiac acidification, ameliorated mitochondrial dysfunction and thereby reduced apoptosis during hypoxia/reoxygenation insult. In isolated working rat hearts perfused with palmitate and in high-fat diet-fed mice, early intervention of Rb1 and trimetazidine reduced succinate production and resultantly increased heart resistance to ischemia/reperfusion injury. Taken together, our findings demonstrated that early intervention by targeting inhibition of succinate accumulation-induced PDH impairment is an effective strategy to alleviate I/R injury.

A novel and regioselective approach to carbonyl-containing alkyl chlorides via silver-catalyzed ring-opening chlorination of cycloalkanols is reported. Concurrent C(sp3)–C(sp3) bond cleavage and C(sp3)–Cl bond formation efficiently occur with good yields under mild conditions, and the chlorinated products are readily transformed into other useful synthetic intermediates and drugs. The reaction features complete regioselectivity, high efficiency, and excellent practicality.

A novel method for the oxidative trifluoromethylthiolation of cycloalkanols by AgSCF3/K2S2O8 is described. The methodology provides an efficient and regioselective approach to distally trifluoromethylthiolated ketones in moderate to good yields. The reaction that is easily handled has a good functional-group tolerance and broad scope. Initial mechanistic studies indicate that the reaction may proceed via a radical pathway involving a tandem C(sp3)–C(sp3) bond cleavage and C(sp3)–SCF3 bond formation process.

•This short communication details a new automated multi-step preparative separation system, known as Sepbox.•Sepbox afforded a quick, reliable and easy separation of 11 ginsenosides from the crude extract of steamed PNG.•Inclusive in the 11 ginsenosides separated were rare ginsenosides Rh4, 20 (S) −Rg3, Rk1 and Rk5 from PNG.The root and rhizome of Panax notoginseng (PNG) are used as folk medicine. Recent studies have reported PNG to possess immunomodulatory, cardioprotective, hepatoprotective, anti-diabetic and anticancer activities among a host of other pharmacological effects. The main active constituents responsible for these pharmacological effects are saponins. It has also been proven that the chemical constituents of steamed PNG differs from the raw form. Traditional methods of separating individual components in crude extracts are usually tedious, almost irreproducible and time-consuming. In this study, an automated multi-step preparative separation system, known as Sepbox afforded a quick, reproducible and fast separation of saponins from PNG. With Sepbox, a total of 11 saponins of high purity were obtained in a short period of time. The separated compounds were identified as notoginsenosides R1, T5, ginsenosides Rb1, Rg1, Rg2, Rh1, Rh4, Rd, 20 (S) −Rg3 and a mixture of ginsenosides Rk1 and Rg5.

•RGSE attenuated acute myocardial infarction-induced heart injury.•RGSE inhibited oxidative stress and apoptosis during AMI in vivo and in vitro.•TXNIP-NLRP3-IL-1β signaling, for the first time, was revealed to be activated in AMI, promoting cell death in the end.•RGSE exerted cardioprotection by suppression of TXNIP/NLRP3 activation during ER stress.•Ginsenosides Rh4, Rg5, Rk3, and Rk1 were the most abundant, and notoginsenoside T5/isomer was first identified in steamed notoginseng.Panax notoginseng possesses therapeutic potential for cardiovascular disorders. Endoplasmic reticulum (ER) stress plays a critical role in cardiovascular disease. Here we show that a rare ginsenoside-standardized extract (RGSE) from notoginseng exerts cardioprotection via attenuating ER stress-associated apoptosis. A total of 18 ginsenosides with a concentration of 816.75 mg/g were characterized and quantified in RGSE. Ginsenoside Rh4, Rg5, Rk3, and Rk1 were the most abundant. RGSE at 50 and 100 mg/kg significantly attenuated myocardial infarction and improved cardiac function in acute myocardial infarction (AMI). RGSE also prevented myocardial ischemia-induced oxidative stress and apoptosis in vivo and in vitro. In addition, RGSE decreased the overexpression of GRP78, GRP94 and CHOP, and inhibited the phosphorylation of PERK and IRE1α in ER stress. Further investigation revealed that RGSE effectually inactivated TXNIP/NLRP3 signaling pathway in AMI hearts. These observations suggest a novel role for notoginseng in regulating AMI.

•A strategy was proposed to discover chemical markers for herbal quality control.•Chromatographic profile of 3 processed aconite herbs were performed.•A compound/species-based classifer was established by probabilistic neural network.•Contribution of each compound toward species classification was calculated.•Characteristic markers were obtained from 26-batch samples covering 3 aconite herbs.Most Aconitum species, also known as aconite, are extremely poisonous, so it must be identified carefully. Differentiation of Aconitum species is challenging because of their similar appearance and chemical components. In this study, a universal strategy to discover chemical markers was developed for effective authentication of three commonly used aconite roots. The major procedures include: (1) chemical profiling and structural assignment of herbs by liquid chromatography with mass spectrometry (LC-MS), (2) quantification of major components by LC-MS, (3) probabilistic neural network (PNN) model to calculate contributions of components toward species classification, (4) discovery of minimized number of chemical markers for quality control. The MS fragmentation pathways of diester-, monoester-, and alkyloyamine-diterpenoid alkaloids were compared. Using these rules, 42 aconite alkaloids were identified in aconite roots. Subsequently, 11 characteristic compounds were quantified. A component–species modeling by PNN was then established combining the 11 analytes and 26-batch samples from three aconite species. The contribution of each analyte to species classification was calculated. Selection of fuziline, benzoylhypaconine, and talatizamine, or a combination of more compounds based on a contribution order, can be used for successful categorization of the three aconite species. Collectively, the proposed strategy is beneficial to selection of rational chemical markers for the species classification and quality control of herbal medicines.

•Malonyl-ginsenosides in ginseng products were characterized by LC–Q-TOF/MS.•Twelve malonyl ginsenosides were rapidly screened by the characterized ions.•Contents of 17 amino acids and polysaccharides in ginseng products were determined.•Arginine, glutamic acid, and aspartic acid were abundant in ginseng products.•Optimal time for the accumulation of ingredients was suggested to be 5–6 years.Many analytical methods have been developed to characterize ginsenosides in ginseng. Relatively less attention has been paid to the malonyl ginsenosides, amino acids and polysaccharides in various processing ginsengs. In this study, malonyl ginsenosides were characterized by LC–Q-TOF/MS. In positive mode, the most abundant ions at m/z 425.38 were observed corresponding to the protopanoxadiol-type ginsenosides. A rich diagnostic ion at 835.48 was shown representing the malonyl ginsenosides with at least two glucosides. Twelve malonyl ginsenosides were rapidly screened using 835.48–835.49 to restructure ion chromatograms. In negative mode, besides the high deprotonated ion, a neutral loss of 44 Da (CO2) was found. High-energy collision-induced dissociation at 50 V produced the most abundant product ion [M−H-malonyl]− by a neutral loss of 86 Da. Determination of 17 common amino acids was performed on an automatic amino acid analyzer. Arginine, glutamic acid, and aspartic acid were abundant. The contents of amino acids were 9.1% in fresh ginseng and 3.1% in black ginseng. Phenol-sulfuric acid method was applied to analysis of polysaccharides. The contents of polysaccharides were 29.1% in fresh ginseng and 11.1% in black ginseng. The optimal growth age for the accumulation of constituents was supposed to be 5–6 years. In conclusion, the contents of malonyl ginsenosides, amino acids, and polysaccharides, based on decreasing order, ranked as follows: fresh ginseng > frozen ginseng > white ginseng > stoved ginseng > red ginseng > black ginseng. Processing should be paid more attention for the quality control of ginseng products.

•The effect of UV wavelength and standard solution concentrations on RRF was studied.•A peak area ratio-wavelength curve was given to help choose UV wavelength.•Line regression equation and one single point methods to calculate RRF were compared.•Suggestions on concentrations were given when using one single point method.Single standard to determine multi-components (SSDMC) is a practical pattern for quality evaluation of herbal medicines (HMs). However, it remains challenging because of potential inconsistency of relative response factors (RRF) on different instruments. In this work, the effects of two key roles, i.e., ultraviolet (UV) wavelength and standard solution concentrations, on reproducibility of RRF were investigated. The effect of UV wavelength on reproducibility of RRF was studied by plotting the relationship of the peak area ratios (internal standard vs analyte) to wavelengths. The preferable wavelength should be set at the flat parts of the curve. Optimized 300 nm produced a 0.38% RSD for emodin/emodin-8-O-β-D-glucopyranoside on five instruments, much lower than 2.80% obtained from the maximum wavelength at 290 nm. Next, the effects of standard solution concentrations of emodin on its response factor (RF) were investigated. For one single point method, low concentration less than 49b/k resulted in significant variations in RF. For emodin, when the concentration is higher than 7.00 μg mL−1, a low standard deviation (SD) value at 0.13 was obtained, while lower than 7.00 μg mL−1, a high SD at 3.71 was obtained. The developed SSDMC method was then applied to determination of target components in 10 Polygonum cuspidatum samples and showed comparable accuracy to conventional calibration methods with deviation less than 1%.

•Three chemical constituents from Salvia miltiorrhiza were extracted by new designed TSURE.•Optimized TSURE offered good extraction efficiency that was comparable or even better than conventional methods.•TSURE method was extended to the quality control of Salvia miltiorrhiza.•Application of TSURE to other herbal medicines was also explored and similar results were discovered.•Mechanisms of TSURE were discussed in detail.Sample extraction is the first challenge in analysis of herbal medicines (HMs). Numerous methods have been developed to improve extraction efficiency, use less solvent and short time. In this work, a tissue-smashing based ultra-rapid extraction (TSURE) method has been proposed through the designed particle crushing, drastic stir, and dynamic molecular permeation at normal temperature. Factors in TSURE like extraction time, volts, and solvents were optimized for extraction efficiency of salvianolic acid B, cryptotanshinone, and tanshinone IIA from Salvia miltiorrhiza. The TSURE method was validated in terms of repeatability (RSD < 2.2%) and extraction recoveries (93–106% with RSD < 5.0%). TSURE showed a comparable extraction efficiency to conventional heat reflux extraction (HRE) and better than ultrasonic assisted extraction (UAE). The extraction time was about 2.0–3.0 min for TSURE, 60 times faster than the performance of HRE and 20 times faster than UAE. Microscopic analysis showed that the Krummbein diameter of plant particles after extraction were about 600–1200 μm for HRE and UAE, and decreased to 50–80 μm for TSURE. Subsequently, the developed TSURE was applied to high-throughput extraction of 19 S. miltiorrhiza samples collected in different regions of China. Besides, application of TSURE to other herbal medicines was also investigated, including Panax quinquefolius and Lonicera japonica. TSURE method provided an ultra-rapid and promising alternation for extraction of ingredients in herbal medicines, and can be extended to pharmaceutics, foods and cosmetics.

•A MSPD method for extraction and clean-up of ginkgo components.•UHPLC–QQQ-MS for simultaneous analysis of 18 ginkgo components.•Direct quantification of 10 flavonol glycosides without hydrolysis.•Analysis of the 12 Ginkgo biloba tablets available in the global market.Analysis and quality control of Ginkgo biloba have been comprehensively studied. However, little attention has been devoted to the simultaneous extraction and analysis of flavonols and terpene trilactones, especially for direct quantification of flavonol glycosides. This work described a rapid strategy for one-step extraction and quantification of the components. A matrix solid phase dispersion (MSPD) method was designed for the extraction of ginkgo ingredients and compared with the heat-reflux and ultrasonic extraction methods. An ultra-high performance liquid chromatography (UHPLC)–tandem-triple-quadrupole-mass spectrometry (QQQ-MS) method was developed for detection of the 18 components, including 10 original flavonol glycosides, 3 aglycones, and 5 lactones. Subsequently, the proposed strategy was used for the analysis of 12 G. biloba tablets. Results showed that MSPD produced comparable extraction efficiency but consumed less time and required lower solvent volumes compared with conventional methods. Without hydrolysis, the concentration detected was much closer to the original in the sample. The total flavonol glycoside contents in ginkgo tablets ranged from 3.59 to 125.21 μg mg−1, and the terpene trilactone varied from 3.45 to 57.8 μg mg−1 among different manufacturers. In conclusion, the proposed MSPD and UHPLC–QQQ-MS is rapid and sensitive in providing comprehensive profile of chemical constituents especially the genuine flavonol glycosides for improved quality control of ginkgo products.

BackgroundPathogenesis and diagnostic biomarkers for diseases can be discovered by metabolomic profiling of human fluids. If the various types of coronary artery disease (CAD) can be accurately characterized by metabolomics, effective treatment may be targeted without using unnecessary therapies and resources.ObjectivesThe authors studied disturbed metabolic pathways to assess the diagnostic value of metabolomics-based biomarkers in different types of CAD.MethodsA cohort of 2,324 patients from 4 independent centers was studied. Patients underwent coronary angiography for suspected CAD. Groups were divided as follows: normal coronary artery (NCA), nonobstructive coronary atherosclerosis (NOCA), stable angina (SA), unstable angina (UA), and acute myocardial infarction (AMI). Plasma metabolomic profiles were determined by liquid chromatography–quadrupole time-of-flight mass spectrometry and were analyzed by multivariate statistics.ResultsWe made 12 cross-comparisons to and within CAD to characterize metabolic disturbances. We focused on comparisons of NOCA versus NCA, SA versus NOCA, UA versus SA, and AMI versus UA. Other comparisons were made, including SA versus NCA, UA versus NCA, AMI versus NCA, UA versus NOCA, AMI versus NOCA, AMI versus SA, significant CAD (SA/UA/AMI) versus nonsignificant CAD (NCA/NOCA), and acute coronary syndrome (UA/AMI) versus SA. A total of 89 differential metabolites were identified. The altered metabolic pathways included reduced phospholipid catabolism, increased amino acid metabolism, increased short-chain acylcarnitines, decrease in tricarboxylic acid cycle, and less biosynthesis of primary bile acid. For differential diagnosis, 12 panels of specific metabolomics-based biomarkers provided areas under the curve of 0.938 to 0.996 in the discovery phase (n = 1,086), predictive values of 89.2% to 96.0% in the test phase (n = 933), and 85.3% to 96.4% in the 3-center external sets (n = 305).ConclusionsPlasma metabolomics are powerful for characterizing metabolic disturbances. Differences in small-molecule metabolites may reflect underlying CAD and serve as biomarkers for CAD progression.

This work aimed to establish a systematic strategy to enrich and separate quercetin-3-O-β-d-glucuronide (Q3GA) from lotus leaves with macroporous resin and semi-preparative HPLC. Six resins were tested, and LX-5 was chosen as the appropriate resin for Q3GA based on the adsorption and desorption performances. After one-step enrichment, the content of Q3GA increased from 2.15% in crude extract to 52.25% in 30% ethanol fraction with yield of 11.97%. The Q3GA was then isolated from the 30% ethanol fraction by semi-preparative HPLC, and the purity of Q3GA was above 98.00% with yield of 19.76%. These results suggested that the aforementioned strategy was a useful and economic method to enrich and separate Q3GA from lotus leaves. Additionally, the anti-inflammatory effect of Q3GA was evaluated in lipopolysaccharide-treated RAW264.7 macrophages, and the result demonstrated that Q3GA could significantly inhibit LPS-induced NO release in vitro in a dose-dependent manner compared with control group.