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Pulsatillae Radix, the root of Pulsatilla chinensis (Bge.) Regel, is recorded in the Pharmacopoeia of the People's Republic of China and has been widely used for its pharmacological activities, such as anti-inflammatory, antioxidant, antibacterial, antitumor, and cardiovascular benefits. However, there are several look-alike species that can be marketed as Pulsatillae Radix. To distinguish P. chinensis (Bge.) Regel from its look-alikes, viz. Pulsatilla cernua (Thunb.) Bercht et Opiz., Pulsatilla dahurica (Fisch.) Spreng., Anemone tomeutosa (Maxim.) Pei., and Rhaponticum uniflorum (L.) DC, we used ultra high performance liquid chromatography with time-of-flight mass spectrometry combined with principal component analysis to compare their chemical compositions. Four ions, a (RT 8.98 min, m/z 1381.6671), b (RT 10.64 min, m/z 1219.6143), c (RT 11.52 min, m/z 1217.5978), and d (RT 13.6 min, m/z 749.4463), from P. chinensis (Bge.) Regel were identified as potential chemical markers to distinguish it from look-alike species using an unsupervised statistical model combined with orthogonal partial least-squares discriminant analysis. The results of this study provide an effective method for identifying and distinguishing P. chinensis (Bge.) Regel from similar plants.

A high-temperature environment was simulated to investigate the effects of heat stress (HS) on duck myofibrillar proteins (MPs). Compared to the control (25 °C), antemortem HS (32 °C) accelerated MP oxidation, as the contents of carbonyl and total/active sulfhydryl significantly increased. HS-induced oxidation changed MP secondary structures, and enhanced MP aggregation and surface hydrophobicity. MP digestibility was lowered for both gastric and intestinal digestions, and depletion of an essential amino acid (His) was observed, indicating nutritional loss. HS induced a sharp loss of the MP storage modulus (G') during gelation, accompanied by gel with weaker elasticity, hardness, strength, and water retention, which implicated the low quality of relevant meat products. Potential specific correlations of amino acids and structural changes with MP and MP-gel properties were also explored. The results reveal that antemortem HS causes adverse effects on duck meat quality and nutrition, and may contribute to its recognition and prevention.

In this study, probe/primers of high specificity and sensitivity were selected to analyze donkey-hide gelatin for donkey DNA and to look for horse, ox, and pig DNA as possible adulterants. The mitochondrial CO I genes in donkey, horse, and ox were selected as target sequences for design and synthesis of three pairs of specific probes and primers. In addition, eight pairs of probe/primers were obtained via literature search. Out of these eleven groups of probe/primers, those with the highest specificity and sensitivity were selected, which was fulfilled by the screening firstly with animal hide samples then the hide-glue samples. Other parameters that might affect detection specificity and efficiency-such as the amount of sampling and final concentration of primers-were also optimized. Replication tests were also conducted. The results showed that the selected probe/primers could accurately detect donkey DNA and horse, ox, and pig DNA in gelatin samples with good reproducibility. Analysis of four samples of on-market gelatin using this assay showed that two of the four samples indeed contained only donkey DNA, whereas the other two samples contained both donkey and horse DNA, indicating adulteration of these samples with horse hide. These results indicate that the TaqMan probe real-time PCR method can be used for identifying the purity of donkey DNA in gelatin samples, and can provide technical support for identifying adulterations in the gelatin market.

Licorice, one of the oldest traditional Chinese medications, is widely used in the treatment of various diseases. With the development of science and technology, an increasing amount of analytical ...

Many species of velvet antler have been used as traditional medicine for thousands of years; however, as medicinal materials, velvet antler derived from different animals have different clinical effects. To distinguish the differences and homologies, ultra-performance liquid chromatography-quadruple-time of flight mass spectrometry (UPLC-QTOF-MS) coupled with principal component analysis (PCA) was developed and applied to identify these antler samples derived from Cervus nippon Temminck, Cervus elaphus Linnaeus and Rangifer tarandus Linnaeus, which were first tested and compared at the molecular level of protein. The UPLC-MS data of the trypsin digested samples were subjected to PCA, and the potential markers based on peptide were depicted to illustrate their differences. With the integrated strategy combining UPLC-QTOF-MS with PCA, the results from this study indicated that the proposed methods could be successfully applied to distinguish reindeer antler from sika deer antler and red deer antler, which were prescribed in the Chinese Pharmacopoeia (2015 edition).

Licorice, a medicinal herb and food flavor ingredient, has been widely used in traditional Chinese medicine (TCM) for the past 4,000 years. In this study, we propose a new quality evaluation approach for licorice quality control based on the key quality attributes commonly used in TCM. The high quality of TCM formulations is ensured by verifying the genuine origin and implementing good agricultural and collection practices for each medicinal herb. In our study, the genuine production area, the harvest season, and the number of growth years were considered the key quality attributes of TCM. To ensure the representativeness of our analysis, we obtained a total of 158 licorice sample batches that differed in the number of growth years, the location of the production areas, and the season for harvesting. Initially, the 158 sample batches were subjected to ultra-high-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UHPLC-QTOF-MS/MS). A preliminary screen identified 11 licorice compounds related to the three key quality attributes of TCM formulations. Ananalysis by ultra-high-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry (UHPLC-TQ-MS/MS) verified the presence of 34 compounds in all licorice samples. These 34 compounds included the 11 compounds related to the three key quality attributes of the samples, along with other bioactive components identified in previous studies. After using UHPLC-TQ-MS/MS to assess the signal peak intensities of the 34 compounds, we selected 17 licorice compounds to establish sample content evaluation indices, which were determined by high-performance liquid chromatography at four different wavelengths in all 158 licorice sample batches. Finally, the screen identified nine compounds that were closely associated with the quality attributes of licorice based on principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA). Our results suggested that liquiritin and eight other compounds could be used as quality control indicators of licorice, which provided a foundation to establish the TCM quality composite evaluation index (TCM QCEI). In summary, this research concept can serve as a reference for research on quality markers and the evaluation of TCM formulations.

Processing of crude drug is a key character of traditional Chinese medicine (TCM), which could enhance the efficacy and/or reduce the toxicity of crude drugs to fulfill different requirements of TCM clinical practice. Epimedii folium (EF) is a widely used TCM. As a traditional method of TCM, EF is processed with refined mutton fat before being used in clinical practice. It has been reported that processing EF with mutton fat could improve the bioavailability and intestinal absorption of epimedium flavonoids and thus enhances the pharmacological effects. For economic benefits, it is possible to adulterate processed EF with unprocessed drug or process EF with cheaper plant oils. In the present study, 17 batches of crude and processed EF samples were collected from the Chinese market and 10 batches of replica processed drugs were prepared with different edible plant oils and animal fats in our laboratory. Elemental analyzer coupled with isotopic ratio mass spectrometry (EA-IRMS) was applied to determine the δ13C values of the cyclohexane extracts of those samples. Significant differences could be observed in the results. EA-IRMS could be used to discriminate raw EF, processed EF, and EF processed with C3 plant oils.

Aristolochic acids have been demonstrated to have renal toxicity, cause carcinogenesis, and may cause gene mutations. A series of risk control measurements have been adopted worldwide since 1990s. Some varieties of traditional Chinese medicine with high content of aristolochic acids have been banned in China. However, some species containing aristolochic acids in microscale are still in use. In recent years, with the continuous awareness of drug safety, the aristolochic acid analogues were generally considered to be of potential safety risks. Among these constituents, aristolochic acid I is still the one with most studies. Therefore, in addition to aristolochic acid I, it is necessary to establish an accurate and rapid method to determine other aristolochic acid analogues. LC-MS/MS methods based on multireaction monitoring mode was established to simultaneously determine 9 aristolochic acid analogues including 5 aristolochic acids and 4 aristolactams for the first time. Furthermore, the method was applied for Long dan Xie gan Pill, a traditional complex compound preparation with a long history for treatment of diseases including hepatochlic hygropyrexia, dizziness, tinnitus, and deafness. It has attracted widespread attention because of the aristolochic acid nephropathy. The crude drug Caulis Aristolochiae manshuriensis (Guanmutong) collected in the prescription was replaced by Akebiae Caulis (Mutong), and the established method helps to understand the product safety on market. As a result, aristolochic acid I, aristolochic acid Iva, and aristolactam I were detected and determined in one batch of Long dan Xie gan Pill among 25 batches of samples. It provided practical approach to demonstrate trace aristolochic acids and aristolactams. It was beneficial to control the safety of related traditional Chinese medicine products.

Two new iridoid glycosides, callicoside E (1) and callicoside F (2), were isolated from the leaves of Callicarpa nudiflora. Their structures were established by one- and two-dimensional NMR spectroscopy and mass spectrometry. In an in vitro bioassay, compounds 1 and 2 showed an pronounced hepatoprotective activity against d-galactosamine-induced toxicity in WB-F344 rat hepatic epithelial stem-like cells.

Ultra-high-performance liquid chromatography coupled with quadrupole/time-of-flight mass spectrometry (UHPLC-Q/TOF-MS) in positive ion mode was used to profile and identify the major constituents in Euphorbia fischeriana Steud. (E. fischeriana). An Agilent ZORBAX SB-C18 column was used to separate the crude extract of E. fischeriana, and the mobile phases were acetonitrile and 0.1% aqueous formic acid (v/v). A total of 40 peaks were detected, and 37 components, including phloroglucinol derivatives, diterpenoids and nitrogenous compounds, were identified based on their accurate masses and fragmentation characteristics. The chemical structures of 7 of the detected compounds were determined by comparing standard compounds to the compounds that were isolated from E. fischeriana. Reasonable fragmentation mechanisms and key fragment ions of the four jolkinolide components were determined to aid in the identification of the other diterpenoids in E. fischeriana. In addition, the compound corresponding to peak 18, namely, jolkinomethylide, was determined to be new, and its chemical structure was determined and elucidated based on MS and NMR spectroscopic data. The present study provided valuable information on the new components in E. fischeriana and established a practical method for evaluating the quality of E. fischeriana.

Quality control is always the critical issue for Chinese medicines (CMs) with their worldwide increasing use. Different from western medicine, CMs are usually considered that multiple constituents are responsible for the therapeutic effects. Therefore, quality control of CMs is a challenge. In 2011, the strategies for quantification, related to the markers, reference compounds and approaches, in quality control of CMs were reviewed (Li, et al., J. Pharm. Biomed. Anal., 2011, 55, 802-809). Since then, some new strategies have been proposed in these fields. Therefore, the review on the strategies for quality control of CMs should be updated to improve the safety and efficacy of CMs. Herein, novel strategies related to quality marker discovery, reference compound development and advanced approaches (focused on glyco-analysis) for quality control, during 2011-2016, were summarized and discussed.

To evaluate the effect of 60Co-γ irradiation sterilization technology on the chemical composition of saffron, we collected 10 batches of saffron samples and treated them with different irradiation doses. UPLC characteristic chromatogram showed that there was no significant effect of irradiation on 13 common peak areas. The results of cluster analysis and principal component analysis showed that there were no differences in the chemical composition in nonirradiated and irradiated samples. UPLC/Q-TOF-MS identified 40 characteristic components of saffron, and the results showed that all of these were detected in the saffron samples both with and without irradiation. Irradiation doses at or below 10 kGy had no significant effect on the chemical components of saffron. This provides a sound basis for the use of 60Co-γ ray irradiation sterilization technology during the preparation of original powder saffron as a medicinal herb, for the effective destruction of mycotoxin contamination.

Two new iridoid glycosides, callicoside C (1) and callicoside D (2), together with three known compounds (3–5), were isolated from the leaves of Callicarpa nudiflora. Their structures were established by 1D and 2D NMR spectroscopy and mass spectrometry. In an in vitro bioassay, compound 1 showed pronounced hepatoprotective activity against d-galactosamine-induced toxicity in WB-F344 rat hepatic epithelial stem-like cells.

To understand the residual dynamics of pesticides in Lonicera japonica Thunb. and to propose some specific suggestions for the control of pesticide residues, a method for determining hundreds of pesticide residues simultaneously by single quadrupole gas chromatography–mass spectrometry was established and 60 samples from six major distribution channels in 14 different provinces of China were collected and detected. The risk of pesticides was discussed by calculating the levels of contamination as a percentage of acceptable daily intake (ADI). The method established was suitable for detection of pesticide residues in L. japonica. All of the samples had detectable residues and 38 pesticides were found in total. The %ADI values of detectable pesticides ranged from 6.66 × 10−6 to 3.27% and the risk of major kinds detected was quite low (%ADI value less than 1%) other than omethoate and triadimenol. To control and reduce pollution and to minimize health risks, routine monitoring of pesticides in L. japonica is required especially for those that may contribute to risk the most.

α-V2O5 nanowires with a layered structure have been fabricated through a two-step procedure. When measured as a pseudo-capacitive electrode with a three-electrode configuration in 1 M Na2SO4 aqueous solutions, α-V2O5 exhibits ideal capacitive characteristics with a specific capacitance of ∼238 F g-1 at a high current of 2 A g-1, but poor cycling stability with a continuous drop in the first 2000 cycles before it is maintained. To find possible solutions towards this problem, the energy storage behavior of the α-V2O5 electrode has been carefully investigated. In situ Raman analysis suggests that it is electrolytic hydrated cations [Na(H2O)n]+ rather than anions (SO42-) that are involved in the energy storage process through reversible adsorption/desorption on the surface or intercalation/deintercalation at the interlayer of the (001) planes accompanied by interlayer spacing expansion/contraction. Moreover, the electrochemical quartz crystal microbalance results indicate that, besides a reversible mass change, there is a continuous mass loss that may originate from slow dissolution of V2O5, which should bear the main responsibility for the poor stability (initial dramatic drop). Hence, how to inhibit dissolution, such as by coating or adding additives in the electrolyte, is found to be the key approach to improve the stability of V2O5 based electrodes.

A highly sensitive and selective optical fiber-based enzymatic biosensor has been proposed in the present study for detection of uric acid (UA) in human serum. The working mechanism of sensor depends on surface plasma property and localized surface plasmon resonance technique. For this purpose, a micro-ball fiber sensor probe of $350~\mu \text{m}$ diameter was fabricated using advanced fusion-splicer and coated with gold nanoparticles (AuNPs) and graphene oxide (GO) in order to enhance its sensitivity. UV-Visible spectrophotometer and high-resolution transmission electron microscope (HR-TEM) were used to characterize the AuNPs solution and GO aqueous dispersion. The absorbance spectrum of AuNPs and GO are recorded at 519 nm and 230 nm, respectively. The coating of AuNPs and GO over fiber surface were verified by using a scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDX). Thereafter, sensor probe was functionalized with the specific enzyme i.e. uricase for the UA detection. The linearity response of uricase/GO/AuNPs-coated micro-ball optical fiber sensor is reported in the range of $10~\mu \text{M}$ –1 mM UA concentrations. The reflectance of sensor linearly decreases with the increasing UA concentrations. Sensitivity of the sensor is 2.1 %/mM with a good slope of linearity with detection limit of $65.60~\mu \text{M}$ . To test the accuracy of proposed sensor, UA concentration in serum samples have also tested by using proposed sensor and A5800 Automatic Biochemical Analyzer. The results of the developed sensor are consistent with the results of A5800 Automatic Biochemical Analyzer. Thus, proposed sensor can be successfully utilized for UA detection in human serum samples.

The quantitative analysis of multicomponents by the single-marker (QAMS) method was established and the relationship between F value (the ratio of the sum of the contents of emodin-8-O-β-D-glucopyranoside and physcion-8-O-β-D-glucopyranoside to the sum of the contents of emodin and physcion) and the steaming time was found to identify and differentiate Polygonum multiflorum Radix and its processed product. Emodin was considered as the control substance, and the correction factors of physcion, emodin-8-O-β-D-glucopyranoside, and physcion-8-O-β-D-glucopyranoside were computed. In addition, the contents of the four components were determined. When the F value is greater than or equal to 1.0, the sample was identified as Polygonum multiflorum Radix, and if the F value was between 0.6 and 1.0, the sample of Polygoni multiflori Radix Preaparata was processed incompletely. The F value of the qualified Radix Polygonum multiflorum should be no more than 0.6. However, the influence of different sample injection volumes and the chromatographic columns and instruments used on the durability of the correction factors and RSD ≤3% hindered accurate identification; therefore, a QAMS method using an external standard value with methodological verification was developed. We redefined the “Polygonum multiflorum rules.” The method using “Polygonum multiflorum rules” revised after optimization of the determination results was used, as it was accurate and led to convenient operation and low inspection costs, and moreover, the method could differentiate Polygoni multiflori Radix Preaparata and Polygonum multiflorum Radix medicinal samples and precisely identify samples that were different from the completely processed product Polygoni multiflori Radix Preaparata.

Phytochemical investigation of the aerial parts of Pteris cretica led to the isolation and elucidation of nine pterosins, including four new pterosins, creticolacton A (1), 13-hydroxy-2(R),3(R)-pterosin L (2), creticoside A (3), and spelosin 3-O-&beta, d-glucopyranoside (4), together with five known pterosins 5&ndash, 9. Their structures were identified mainly on the basis of 1D and 2D NMR spectral data, ESI-MS and literature comparisons. Compounds 1 and 3 were new type of petrosins with a six membered ring between C-14 and C-15. The new compounds were tested in vitro for their cytotoxic activities against four human tumor cell lines (SH-SY5Y, SGC-7901, HCT-116, Lovo). Results showed that compounds 1 and 2 exhibited cytotoxic activity against HCT-116 cells with IC50 value of 22.4 &mu, M and 15.8 &mu, M, respectively.

Traditional Chinese medicinal materials derived from animal bile are widely applied in clinical therapy for thousands of years in several Southeast Asian countries. Although the constituents are similar, these crude drugs exhibit different pharmacological activities; bile acids are the main bioactive constituent. Depending on the source, the price of these crude drugs differs significantly. Therefore, a reliable fingerprint method is needed to analyze and distinguish these crude drugs with a similar composition. In this milieu, we aimed to establish a fingerprint chromatography method that can separate and detect several bile acids simultaneously. A high-performance liquid chromatography separation method was established with evaporative light scattering detection to detect the analytes. The main bioactive constituents of pig bile, cattle bile, sheep bile, bear bile, and three types of cow bezoar were analyzed using the proposed method. The fingerprint chromatography profile of 35 samples were obtained and analyzed using chemometric methods. Considering the differences among samples, a reference scaleplate method was used in the peak alignment procedure. Unsupervised methods (hierarchical cluster analysis and principle component analysis) and supervised methods (K-nearest neighbor, partial least squares discriminant analysis, support vector machine discriminant analysis, and soft independent modeling of class analogy) were used in the chemometric analysis. The results indicated that the fingerprint chromatograms of the seven crude drugs had fingerprint specificity and that they can be well distinguished. In addition, the reference scaleplate method using the chromatogram of a mixed standard solution is practically applicable for peak alignment in the analysis of samples with a large difference in chromatographic peaks. Overall, 17 bile acids can be separated and detected simultaneously using this method and some frequently used TCMMs derived from animal bile can be distinguished accurately.

To investigate the effects of various duck sources on the lipid oxidation and aroma flavor of sauced-ducks, Mallard (ML), Sheldrake (SD), Muscovy (MC), and Cherry-Valley (CV) ducks were used in sauced-duck processing. The results showed significantly different thiobarbituric acid reactive substances (TBARS) values of the four samples (SD CV ML MC, p 0.05), while the contents of unsaturated fatty acids (UFAs) were ML SD/CV MC (p 0.05). Altogether, 105 volatile flavor compounds were detected in sauced-ducks, including acids, alcohols, aldehydes, ketones, esters, hydrocarbons, furans, nitrogen compounds, and others. The volatile compounds were observed differentially composed in the four products, and nineteen potential characteristic biomarkers were explored. The correlation analysis indicated that the characteristic aroma flavor of sauced-ducks were significantly associated with specific free fatty acids. These information are useful for learning aroma formation and meat selection and identification in duck products.

Sunlight-clean water production from industrial wastewater, domestic sewage, and seawater is a sustainable water purification technology with the potential to solve environmental and energy problems. Semiconductor has good application prospects for photothermal conversion due to its advantages of earth-abundance, nontoxicity, and stability. While, most of its energy is released in the form of radiative relaxation, which leads to a low light-to-heat conversion efficiency. Enhancing its non-radiative relaxation is an effective way to improve light-to-heat conversion efficiency. In this work, heterostructured copper oxide/carbon nitride (CuO/CN) was designed to enhance non-radiative relaxation and thus improve the solar energy-to-thermal energy performance by constructing heterogeneous electric field. Electron paramagnetic resonance spectroscopy, X-ray photoelectron spectroscopy and differential charge density analyses proved the formation of heterogeneous electric fields between CuO and CN. Under the enhanced non-radiative relaxation, CuO/CN has an excellent light absorption range and carrier separation efficiency. The water evaporation rate under sunlight increased from 0.31 to 1.14 kg·m−2·h−1 and photothermal conversion efficiency increased from 19% to 72%. Simultaneously, CuO/CN can remove nearly 100% of the ions in seawater and Chemical Oxygen Demand (COD), Ammonia Nitrogen (NH3-N), Nitrate Nitrogen (NO3-N), and Total Phosphorus (TP) in industrial wastewater to produce clean water. Combined with photo-Fenton-like technology, it can effectively remove organic pollutants and volatile organic compounds (VOCs) from water. This work provides an efficient solar-clean water production technology with excellent pollution decontamination ability, which will be extremely attractive for future life.

Maleimide groups are used extensively in bioconjugation reactions, but limited mechanistic studies are available regarding their hydrolysis reactions. In this paper, five single-crystal structures related with the reaction of four-step hydrolytic degradation of N,N′-ethylenedimaleimide have been investigated. On the basis of experimental results, the reaction mechanisms without or with water catalysis are proposed, which could provide some enlightenment into the study of similar hydrolytic degradations.

Manganese oxides of different structures, especially α-MnO2, have been extensively studied as electrodes for pseudocapacitors. However, the poor stability associated with intercalation of proton has been the main obstacle to their commercial applications. To effectively mitigate this problem, it is necessary to fully understand the energy storage mechanism of the MnO2 phases. In this study, δ phase MnO2 has been synthesized through controllable electroplating on architectural Ga-doped ZnO (GZO) bones, demonstrating a high specific capacitance of 1068 F g−1 and high stability (slight performance drop focus on the first 2000 cycles and then remained relatively constant in the subsequent 13,000 cycles). The charge storage mechanism of the δ-MnO2 coated GZO has been carefully investigated under this extreme reaction condition. Results suggest that the amount of charge stored in the electrode material correlates well with the amount of Na+ inserted into the electrode material from the electrolyte. It is also noted that no spectral features corresponding to H+ insertion were detected during cycling when the sample was probed using in operando Raman spectroscopy. Therefore, for layered δ-MnO2, a charge storage mechanism of Na+ intercalation/deintercalation dominated, accompanied by interlayer spacing expansion/contraction, was proposed. Moreover, theoretical calculations also confirmed that the insertion of Na+ is more energetically favorable than H+ at all sites of the interlayer in δ-MnO2, offering a rational explanation of the proposed mechanism and the observed excellent stability.

Bacterial transglycosylation is an interesting target in antibiotic drug development. An in vitro transglycosylation assay was developed and used to search for possible inhibitors of Staphylococcus aureus Penicillin Binding Protein 2-mediated transglycosylation. Since the substrate, Lipid II, has no UV-chromophore, the assay relies on LC coupled to MS for analysis of the incubation mixtures. Extracts from Thymus sipyleus, Salvia verticillata, Salvia virgata and Oolong tea were tested, as well as epigallocatechin gallate and ursolic acid, which are chemical compounds derived from plants. Matrix effects hampered Lipid II quantification in samples treated with very high concentrations of extracts. None of these extracts or isolated compounds appeared to have inhibitory activities towards the transglycosylation function of Penicillin Binding Protein 2. publisher: Elsevier articletitle: Bioanalytical LC/MS study of potential bacterial transglycosylation inhibitors journaltitle: Journal of Pharmaceutical and Biomedical Analysis articlelink: http://dx.doi.org/10.1016/j.jpba.2015.12.050 content_type: article copyright: © 2016 Elsevier B.V. All rights reserved. ispartof: Journal of Pharmaceutical and Biomedical Analysis vol:127 pages:123-128 ispartof: location:England status: published

Four unsaturated norcantharimide (UNCI) dimers were synthesized and characterized by elemental analysis, ESI-QTOF-MS, FT/IR, UV–Vis, 1H and 13C NMR as well as single crystal X-ray diffraction. In addition, theoretical studies have been investigated to compare with the experimental findings. Introduction of various lengths of single bond link chains provides high conformational flexibility and thus unusual molecular and crystal structures for dimers. Two of the four dimers twist into helicate, but crystallize into centrosymmetric lattice; one adopts approximately centrosymmetric conformer, but packs into non-centrosymmetric polar space group (P21). Moreover, in vitro cytotoxic activities of four UNCI dimers and their corresponding saturated NCI dimers were evaluated. All four UNCI dimers are inactive and one NCI dimer shows modest cytotoxicity. These findings were compared with the relevant results in literature. It is found that the antitumor properties of UNCI/NCI dimers depend mainly on the length of link chains (the longer chain, the higher therapeutic efficacy) and have relationship with the double bond, which requires more experimental support.

The method of ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC-Q/TOF-MS) was established and combined with principal component analysis (PCA) to identify natural Calculus Bovis, in vitro cultured Calculus Bovis and artificial Calculus Bovis. PCA, which was particularly powerful in dealing with multicollinearity and variables that outnumber the samples, was used to analyze the UHPLC-MS data of the processed samples, and potential markers were analyzed and described based on orthogonal partial least-squares discriminant analysis. According to the results in this study, the approach of combining UHPLC-QTOF-MS with PCA was proven to be credible and could be used to identify Calculus Bovis from in vitro cultured Calculus Bovis and artificial Calculus Bovis and to determine if there is Calculus Bovis in patented Chinese medicines that should contained Calculus Bovis medicinal materials.

Long dan Xie gan pill is a traditional complex compound preparation with a long history for treatment of diseases, including hepatocolic hygropyrexia, dizziness, tinnitus, and deafness. Quality of products from different manufacturers may be varied. Since the current standard could not control the quality of products in a comprehensive and effective way, this study aimed at establishing a practical and convenient approach for holistic quality control of the preparation. This study included both qualitative and quantitative works to get information on the overall composition and main components, respectively. As a result, HPLC fingerprint (UV 240 nm) similarities of all fifty samples were in the range of 0.65∼0.99. Results indicated that there was a difference among products from different manufacturers. Additionally, ten characteristic peaks of the fingerprint were tentatively identified by LC-MS. Further chemometrics analysis was utilized to evaluate the products from different manufacturers. At the same time, the HPLC (UV 285 nm) multicomponent quantification result showed that contents of gentiopicrin, baicalin, baicalein, and wogonin were in the range of 0.61–5.40, 1.96–5.33, 0.10–3.40, and 0.046–1.16 mg·g−1, respectively. Data analysis verified the main different component of baicalein from the fingerprint statistical analysis. It is worth mentioning that the qualitative fingerprint and quantitative multicomponent determination were simultaneously accomplished by HPLC-DAD with dual channels. The study provided sound basis for improving quality control standards. This study also provided practical strategy for overall quality control of traditional Chinese medicines.

Background: Snake bile originates from nearly 20 species from three families (Elapidae, Colubridae, and Viperidae). However, the components of various snake bile were not compared with one another. Objecive: The aim of the study was to develop a TLC-MS method for differentiation of various snake bile derived from a different genus. Method: As a type of traditional identification method for Chinese herbs, TLC has considerable advantages as a multicomponent separation system. Results: In this paper, TLC was used to separate the components in snake bile. It was found that the snake bile from Colubridae family and Cobra species is different from the others using TLC. The molecular formulas of the bands were elucidated with TLC coupled with quadrupole–time-of-flight–MS by the TLC-MS interface. Two bands on the plate were identified with the reference substance, and the other three bands were analyzed by the TLC-MS method without the reference substance. The corresponding molecular formulas of these bands were given according to accurate molecular weights. Conclusions: The results from this study indicate that the proposed method is reliable, and it has been successfully applied to the identification of snake bile samples.

Dianthrone derivatives are minor constituents of Polygonum multiflorum Thunb. (PM). These derivatives are potential hepatotoxic components in PM. Fraction D6 contains many dianthrone derivatives and was successfully enriched using an efficient three-step approach. An effective and reliable high-performance liquid chromatography (HPLC) technique coupled with ultraviolet detection (UV) and a linear ion trap FT-ICR hybrid mass spectrometry (HPLC-UV/LTQ-FT-ICR-MS) method were successfully developed to separate and identify the dianthrones of the fraction D6. The characteristic diagnostic fragment ions and characteristic fragmentation pathway of the seven dianthrone standards, namely, Polygonumnolide B1 (S1), Polygonumnolide C3 (S2), Polygonumnolide C2 (S3), Polygonumnolide E (S4), Polygonumnolide A1 (S5), Polygonumnolide A2 (S6) and cis-emodin dianthrones (S7), were compared with unknown compounds in fraction D6, and 45 dianthrone derivatives were characterized or tentatively identified. Of these derivatives, 32 new dianthrone derivatives were tentatively characterized in PM. Therefore, LTQ-FT-ICR-MS combined with a selective enrichment method provided a powerful means for analyzing dianthrone derivatives. This study provides a meaningful basis for correcting some mistakes in previous studies, as well as further quality control and pharmacological and toxicological research.

Since the cost of Ophiocordyceps sinensis, an important fungal drug used in Chinese medicine, has increased dramatically, and the counterfeits may have adverse health effects, a rapid and precise marker using the peptide mass spectrometry identification system could significantly enhance the regulatory capacity. In this study, we determined the marker peptides in the digested mixtures of fungal proteins in wild O. sinensis fruiting bodies and various commercially available mycelium fermented powders using ultra-performance liquid chromatography/Orbitrap Fusion mass spectrometry coupled with chemometrics. The results indicated the following marker peptides: TLLEAIDSIEPPK (m/z 713.39) was identified in the wild O. sinensis fruiting body, AVLSDAITLVR (m/z 579.34) was detected in the fermented O. sinensis mycelium powder, FAELLEK (m/z 849.47) was found in the fermented Ophiocordyceps mycelium powder, LESVVTSFTK (m/z 555.80) was discovered in the artificial Ophiocordyceps mycelium powder, and VPSSAVLR (m/z 414.75) was observed in O. mortierella mycelium powder. In order to verify the specificity and applicability of the method, the five marker peptides were synthesized and tested on all samples. All in all, to the best of our knowledge, this is the first time that mass spectrometry has been employed to detect the marker peptides of O.sinensis and its related products.

A series of mono- and di-Schiff-bases based on Benzil Dihydrazone (BDH) were designed and synthesized to be set as the model compounds to explain which one should be the advanced product and which parameters will determine the end-product. As the first step of a series of investigations, this article presents the syntheses and characterization of five new Schiff-bases plus one preliminary reported Schiff-base, all derived from BDH. The compounds were characterized by single crystal (or conventional powder) X-ray diffractometry, elemental analysis, m.p., 1H NMR, 13C NMR, IR and UV–Vis. Structural features of the five new Schiff-bases are similar. For instance, all molecules are nonsymmetrical/symmetrical double helix with the torsion angle of two “half-parts” about 72–97°. The Ph-C N–N C-Ph moiety all exists in planar and anti form, indicating significant conjugation. The crystal structures appear to be stabilized by π-stacking between the aromatic rings, as well as by intermolecular hydrogen bonds and C–H … π stacking interactions. DFT calculations have been performed to explain the trend of the experimentally measured reaction yields. In the case of the studied systems by us, the type of Schiff-bases exhibits a clear dependence on the molar ratio of reactants if the products have similar stabilities. Otherwise the importance of reaction conditions will be weakened and the most stable product will be favored.

An accurate and sensitive high-performance liquid chromatography method coupled with ultralviolet detection and precolumn derivatization was developed for the simultaneous quantification of the major bile acids in Artificial Calculus bovis, including cholic acid, hyodeoxycholic acid, chenodeoxycholic acid, and deoxycholic acid. The extraction, derivatization, chromatographic separation, and detection parameters were fully optimized. The samples were extracted with methanol by ultrasonic extraction. Then, 2-bromine-4'-nitroacetophenone and 18-crown ether-6 were used for derivatization. The chromatographic separation was performed on an Agilent SB-C18 column (250 × 4.6 mm id, 5 μm) at a column temperature of 30°C and liquid flow rate of 1.0 mL/min using water and methanol as the mobile phase with a gradient elution. The detection wavelength was 263 nm. The method was extensively validated by evaluating the linearity (r(2) ≥ 0.9980), recovery (94.24-98.91%), limits of detection (0.25-0.31 ng) and limits of quantification (0.83-1.02 ng). Seventeen samples were analyzed using the developed and validated method. Then, the amounts of bile acids were analyzed by hierarchical agglomerative clustering analysis and principal component analysis. The results of the chemometric analysis showed that the contents of these compounds reflect the intrinsic quality of artificial Calculus bovis, and two compounds (hyodeoxycholic acid and chenodeoxycholic acid) were the most important markers for quality evaluating.

A detailed understanding of the phase changes of manganese oxides in a pseudocapacitor during cycling is vital to reveal the mechanism by which they store energy and to achieve a rational design of improved electrode materials. Here we report the results of our probing the phase changes of a Mn3O4 electrode material in a pseudocapacitor during a charging/discharging process using in operando Raman spectroscopy. Along with enhancing performance, the spinel Mn3O4 was transformed to a layered birnessite-type MnO2 upon potential cycling and two types of processes were shown to contribute to the energy storage: intercalation/deintercalation of Na+ and oxidation/reduction of Mn2+. After charging and discharging for ∼10 000 cycles, the specific capacitance of manganese oxide increased almost 3-fold; and the maximum specific capacitance approached 230 F g−1 at a cycling rate of 0.5 A g−1.

Phase transition of active electrode materials for pseudocapacitors always plays a pivotal role during the energy storage/release process. Here, large-scale hybrid CoCO 3 /CoO nanostructure arrays were obtained on carbon fiber paper substrate in a mild environment and tested as pseudo-capacitor electrode. After several cycles’ activity, the as-prepared electrodes exhibited good energy storage performance with maximum specific capacitance of 0.77 F/cm 2 in area and 510 F/g in gram at a discharge current of 1 A/g, and 82% of the capacity is retained when the discharge current increased to be 10 A/g from 0.2 A/g, indicating high power capability. Most interestingly, the electrode showed excellent cycling durability with gradually increased capacitance along with cyclic voltammetry at first 5,000 cycles and then maintained at least more than other 15,000 cycles. The initial phase transition of CoCO 3 /CoO to Co(OH) 2 /CoO induced by alkaline electrolyte was demonstrated to be the critical factor for the capacitance enhancement. The phase transition before and after long cycles was discussed through ex-situ X-ray diffraction, Raman and high resolution transmission electron microscope analysis.

A facile and cost-efficient approach to functionalize raw carbon fiber paper (CFP) used for a self-standing capacitive electrode has been proposed here. Benefiting from the improved specific surface area and surface functional groups, the functionalized CFP (F-CFP) showed much enhanced capacitive performance, 3 orders of magnitude higher than that of the raw CFP. It delivered the areal capacitance of 1275 mF cm-2 at 5 mA cm-2 with a rather wide voltage window of 1.4 V (-0.4 to 1 V vs Ag/AgCl) in 0.5 M H2SO4. However, in a neutral 1 M Na2SO4 aqueous solution, although the areal capacitance of 1115 mF cm-2 at 3 mA cm-2 is slightly smaller, the potential window is much wider (2 V, -1 to 1 V vs Ag/AgCl), indicating a high overpotential of hydrogen evolution. The areal capacitance was still as high as 722 mF cm-2 at a very fast charge-discharge current density of 50 mA cm-2, and about 66% of the initial capacitance (at 3 mA cm-2) was remained in Na2SO4, indicating considerable rate capability.

Oxidative stress has been associated with diverse diseases, including obesity, cancer and neurodegeneration. In fact, Valeriana jatamansi Jones (valerian) and its extracts possess strong antioxidant activities that extend their application in clinical practice to the treatment of these illnesses, even though the underlying mechanisms are not well understood. Iridoid valepotriate, a characteristic iridoid ester in valerian with poor chemical stability, possesses considerable antioxidant components. The original compounds and their degradation products have been found to exhibit strong antioxidant activities. However, the relationship between their structure and antioxidant effects and the mechanism underlying their oxidation resistance remain unclear. A forced degradation study using three iridoid valepotriates (valtrate, acevaltrate and 1-β acevaltrate) was performed in this work, and the structures of their degradation products were estimated by TLC-MS and LC-MS. Comparison of the antioxidant activities of the iridoid valepotriates before and after forced degradation revealed that degradation reduced the activities of the iridoid valepotriates in free radical scavenging and cytotoxic and cell apoptosis tests. The results suggested that the oxirane nucleus is important for defining the antioxidant profile of iridoid valepotriate. We uncovered possible mechanisms that could explain the antioxidant activities, including the generation of two hydroxyl groups through intramolecular transfer of an H• from an oxirane ring and a reduction in ROS levels through interactions with GABAergic signalling pathways.

In operando Raman spectroscopy has been used to monitor the phase changes of non-stoichiometric α-MnO 2 , α-Mn 0.98 O 2 , electrode materials in a pseudo-capacitor during the charging/discharging process. Results indicate that the α-Mn 0.98 O 2 can be converted to MnO 2 and Mn 3 O 4 when placed in electrolyte exposed to laser for the Raman measurements. Both the phases contribute to the energy storage process through reversible phase transformation which involves hydrated cations M + , protons H + and Mn 2+ intercalation/deintercalation during the charging/discharging process.

A new dimeric phthalide, chaxiongnolide A (1), and a new natural product, chaxiongnolide B (2), together with a known compound Z-ligustilide (3), were isolated from the rhizome of Ligusticum sinense Oliv cv. Chaxiong. Their structures were elucidated by various spectroscopic methods and confirmed by X-ray crystallographic analysis.

In this study, The fingerprints of Cuscutae Semen and its processed products such as qing chao pin (QCP), jiu zhi pin (JZP), and yan zhi pin (YZP) were performed using high performance liquid chromatography. Ten chromatographic peaks were selected as characteristic peaks, the relative peak areas (RPA) of which were calculated for quantitative expression of the HPLC fingerprints. The RPA of 10 chromatographic peaks were subjected to principal component analysis (PCA) in order to classify raw Cuscutae Semen and its processed products. Principal component analysis (PCA) of the analytical data showed that raw Cuscutae Semen and its processed products could be clustered reasonably into four different groups corresponding to different processed procedure. The chemical markers of different samples given by the loadings plot of PCA were identified tentatively by electrospray ionization iontrap mass spectrometry and partially verified by the available reference standards. The results from this study indicate that ...

In electrospray ionization (ESI) mode, peptides and proteins can be multiply charged ions; in this situation a doubly charged selected ion (DCSI) coupled with mass spectrometry (MS/MS) fragments monitoring (DCSI-MS/MS) method is the most suitable scanning mode to detect known peptides in complex samples when an ion-trap mass spectrometer is the instrument used for the analysis. In this mode, the MS detector is programmed to only select a doubly charged ion as a precursor and to perform continuous MS/MS on one or more of the selected precursors, either during a specific time interval or along the whole chromatographic run. Gelatin is a mixture of high molecular weight polypeptides from the hydrolysis of collagen. In this study, the DCSI-MS/MS monitoring mode was applied to the detection of previously characterized species-specific peptides from different gelatins. The proposed methodology makes use of tryptic digestion for sample preparation and peptide separation and identification by rapid resolution liquid chromatography coupled to an ion trap working in the DCSI-MS/MS mode for the analysis. This methodology was applied to the differential classification of five commercial, homological species of gelatins and proved to be an excellent tool for gelatin product authentication.

As the loadings of precious metals in surface-chemical systems continue to decrease for photo-and electro-catalysts for energy and environmental applications, the study of near-surface electronic and atomic structure in functional materials becomes critically important. Extremely small quantities of active elements, whether grown as clusters or ultrathin films, exhibit changes in catalytic activity that arise from both size effects and electron-transfer effects. These size and transfer effects can be related to increased propensity for oxidation of the metallic deposit, as well as to various changes in electrochemical performance such as durability or required overpotential for a given reaction. This work establishes a minimum threshold for Pt loading beyond which bulk-type electronic behavior may be expected. By iteratively growing atomic monolayers and multilayers using self-limited electrodeposition and studying these films using core-electron spectroscopy (X-ray absorption and X-ray photoelectron spectroscopy), electrochemical methods and DFT-based computations the fundamental interactions that govern oxidation state and electron transfer near the surface of a Pt–Au bimetallic system have been explored. It has been shown that the Pt–Au system exhibits increased tendency for the Pt layer to remain cationic below a minimum threshold film thickness of two monolayers. At monodispersed levels of submonolayer coverage Pt exhibits deviated electronic structure, reactivity, and metal stability compared to films in excess of this minimum threshold thickness. At three monolayers Pt is thick enough to avoid the preference for cationicity and the resulting higher rates of metal dissolution, but thin enough to benefit from electron transfers from Au that assist in lowering the overpotentials for CO oxidation. This study shows the efficacy of a concerted method for the investigation of near-surface phenomena in multicomponent systems. By combining electrochemical and vacuum studies of solute-derived samples with advanced computational techniques, a multifaceted understanding of these architectures has been achieved.

Euphorbia ebracteolata Hayata (E. ebracteolata) is a Chinese herbal medicine used for the treatment of tumor diseases. An ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLCâQâTOF/MS) based chemical profiling approach was established for the rapid separation and characterization on phloroglucinol derivatives and diterpenes in E. ebracteolata. Three phloroglucinol derivatives and nine diterpenes were identified by exact mass measurement and were further confirmed by Ms2 data. In addition, the chemical profiles of six compounds were acquired by reference standards. Furthermore, the fragmentation rules of phloroglucinol derivatives and diterpenes of E. ebracteolata were analyzed, and each chromatographic peak was classified. Keywords: Phloroglucinol derivatives, Diterpenes, Euphorbia ebracteolata Hayata, UPLC-Q-TOF/MS

Little is known about human polyol metabolism, but recent studies indicate that abnormal polyol concentrations in body fluids are related to several diseases. In this study, a rapid and sensitive method for the determination of seven major polyols in urine including two groups of polyol isomers, C5-polyols (Rib+Arb+Xyl) and C6-polyols (Sor+Gal+Man), was developed using capillary zone electrophoresis coupled with amperometric detection (CZE-AD). The effects of the working electrode potential, pH, running buffer components and concentrations, separation voltage and injection times were investigated. Under the optimised conditions, seven types of polyols could be perfectly separated via the formation of anionic polyol-borate complexes in a borate buffer solution. Highly linear current responses to the polyol concentrations were obtained with good correlation (0.9984

Quantitative nuclear magnetic resonance is a powerful tool in drug analysis because of its speed, precision, and efficiency. In present study, the application of variable temperature proton quantitative nuclear magnetic resonance (VT-1H-qNMR) for the calibration of three C-glycosylflavones including orientin, isoorientin, and schaftoside as reference substances was reported. Since there was conformational equilibrium due to the restricted rotation around the C(sp3)-C(sp2) bond in C-glycosylflavones, the conformational behaviors were investigated by VT-NMR and verified by molecular mechanics (MM) calculation. The VT-1H-qNMR method was validated including the linearity, limit of quantification, precision, and stability. The results were consistent with those obtained from mass balance approach. VT-1H-qNMR can be deployed as an effective tool in analyzing C-glycosylflavones.

Dendrobium nobile is one of the fundamental herbs in traditional Chinese medicine. Sesquiterpene alkaloids are the main active components in this plant. Due to weak ultraviolet absorption and low content in D. nobile, these sesquiterpene alkaloids have not been extensively studied using chromatographic methods. Herein, tandem mass spectrometry combined with liquid chromatography separation provides a tool for the identification and characterization of the alkaloids from D. nobile. A total of nine sesquiterpene alkaloids were characterized by ultrahigh-performance liquid chromatography tandem mass spectrometry. These alkaloids can be classified into two subgroups that are represented by dendrobine and nobilonine. Tandem mass spectrometric studies revealed the fragmentation pathways of these two subgroup alkaloids that were used for the identification and characterization of other alkaloids in D. nobile. Characterization of these alkaloids using accurate mass and diagnostic fragments provided a reliable methodology for the analysis of D. nobile by ultrahigh-performance liquid chromatography tandem mass spectrometry. The limit of detection was defined as the signal-to-noise ratio equal to 3 : 1. Limits of detection of dendrobine and nobilonine were less than 30 ng/mL. The developed method was applied for the analysis of various Dendrobium species and related dietary supplements. Alkaloids were identified from D. nobile, but not detected from commercial samples including 13 other Dendrobium species and the 7 dietary supplements.

Four new dianthrone glycosides, named polygonumnolides C1-C4 (1–4), were isolated from the dried roots of Polygonum multiflorum Thunb, together with two known emodin dianthrones (5–6). Their hepatotoxicities were evaluated against L-02 cell lines. Compounds 1–4 showed weak hepatotoxicity against L-02 cell lines with IC50 values of 313.05, 205.20, 294.20, and 207.35 μM, respectively.

A quantitative determination of six neuroactive amino acids (NAAs) was performed by capillary zone electrophoresis with amperometric detection (CZE-AD). This CZE-AD method utilized two electrolytes: the borate solution flowing in a capillary has the NAAs-separation effects, and the sodium hydroxide (NaOH) solution filled in the detection reservoir for the amperometric analysis of NAAs. The following experimental parameters were optimized: the working electrode potential, the pH value, the component, and the concentration of running buffer, the separation voltage, and the injection time on CZE-AD. Then, under the optimum conditions, the six NAAs could be completely separated in 30 min and had well-shaped AD responses at 0.75 V (versus SCE) on a copper electrode. The linear calibration range of NAAs was from 5 × 10−4 to 5 × 10−6 mol L−1 with the limits of detection (LODs) ranging from 10−6 to 10−7 mol L−1 (signal-to-noise ratio = 3), and the relative standard deviations (RSDs) of the migration time and peak area were 0.45–0.55 and 3.8–6.3 %, respectively. Moreover, this method has succeeded in human serum analysis, and the determined contents of the six NAAs in human serum were in an average recovery range of 85.3–117.9 %, which confirmed the validity and practicability of this method.

A simple and sensitive method for determination of free amino acids in milk by microchip electrophoresis (MCE) coupled with laser-induced fluorescence (LIF) detection was developed. Seven kinds of standard amino acids were derivated with sulfoindocyanine succinimidyl ester (Cy5) and then perfectly measured by MCE-LIF within 150 s. The parameters of MCE separation were carefully investigated to obtain the optimal conditions: 100 mmol·L−1 sodium borate solution (pH 10.0) as running buffer solution, 0.8 kV as injection voltage, 2.2 kV as separation voltage etc. The linear range of the detection of amino acids was from 0.01 µmol·L−1 to 1.0 µmol·L−1 and the detection limit was as low as about 1.0 nmol·L−1. This MCE-LIF method was applied to the measurements of free amino acids in actual milk samples and satisfactory experimental results were achieved.