[Bioactive consistency evaluation of cardiotonic pill using marker genes].

The study is aimed to develop a method in evaluation of the bioactive consistency of cardiotonic pill (CP). HepG2 cell line was employed as a biological detector. After treated with CP for 24 h, gene chip and qRT-PCR were used to select m RNAs that can represent the bioactivity of CP. Then similarity between different batches of CP were calculated based on expression levels of marker genes to evaluate the bioactive consistency of CP. Marker genes were selected according to the criteria as follows: 1 fold change < 0.67 or > 1.5; 2 potential relevance to curative effects; 3 extensive involvement in the cellular functions and clustering analysis categories; 4 dose-dependent effect. A total of 10 genes were selected as bioactive markers of CP. Angular cosine was calculated to evaluate the similarity between two samples. The method was validated using intra-day precision and inter-day precision. Using angular cosine similarity, the intra-day and inter-day precision were 0.4% and 0.6%, respectively. The similarities of 6 batches of CDPs ranged from 0.992 to 0.999, and 1 batch of Compound Danshen Tablet was 0.534. The established method is specific and accurate, and provides comprehensive and objective evaluation of bioactive quality of CDPs. It can also benefit the bioactive consistency evaluation of other compounds in traditional Chinese medicines.

[Identification of chemical constituents in Yangxue Qingnao granule by UPLC-Q-TOF/MS~E].

In order to clarify the chemical constituents in Yangxue Qingnao granule, we established a rapid ultra-performance liquid chromatography/orthogonal acceleration time-of-flight mass spectrometry (UPLC-Q-TOF/MS(E)) method. According to the high resolution MS spectra data, fragmentation ion information and retention time,142 peaks were identified or tentatively presumed by comparison with reference standards data and literature reports. The herbal sources of these peaks were assigned. The results implied that phenolic acids, alkaloids, anthraquinones, phthalides, monoterpene glycosides were included in the main components of Yangxue Qingnao granule. The method is rapid for systematically elucidation of the constituents of Yangxue Qingnao granule and the results would facilitate the quality control of Yangxue Qingnao granule for safe and efficacious use.

Plasmonic-coupling-based sensing by the assembly and disassembly of dipycolylamine-tagged gold nanoparticles induced by complexing with cations and anions.

A surface-plasmon-coupling-mediated sensor system is developed based on Au nanoparticles tagged with a coordinative dipycolylamine and lipoyl-anchored naphthalimide derivative (AuNP@DPA). The AuNPs with tailored ligands exhibit distinct sensing activity via sequential assembly into nanoparticle aggregates induced by metal ion complexing, and disassembly in the presence of pyrophosphate (PPi) anions, which is accompanied by a swift, reversible color change due to a surface plasmon resonance coupling effect. It is found that divalent metal ions are more effective than mono- or tri-valent ions in the aggregate formation process, Mn(2+)-induced aggregates are more sensitive to the capture of PPi anions than other AuNP aggregates, and the disassembly upon anion complexation exhibits a highly selective response. The AuNP@DPA-based molecular recognition system also demonstrates a viable performance for the detection of total selective metal ions present in different types of water analytes.

Theoretical studies on the electronic structures and optical properties of (Cu, C)-codoped rutile TiO2 from GGA+U calculations.

The electronic structures, formation energy and optical properties of Cu-doped, C-doped, and (Cu, C)-codoped TiO2 were investigated by the projector augmented wave (PAW) method within GGA + U approximation. The results show that the lattice distortion of the Cu@i1&C@i2 system is the largest in all doping systems. The optical absorption edges of the C@i system and the Cu@i1&C@i2 system appear a blue-shift, which is attributed to the band gap expansion and some deep states generation. The Cu@i system exhibits a reduction in band gap and a generation of the hole state, such as it emerges the highest optical absorption in all doping systems.

Simultaneous determination of hydrophilic and lipophilic constituents in herbal medicines using directly-coupled reversed-phase and hydrophilic interaction liquid chromatography-tandem mass spectrometry.

Limitations in the separation ability of conventional liquid chromatography system remains a challenge in developing a versatile method for simultaneously determining both hydrophilic and lipophilic constituents in herbal medicines (HMs). To measure compounds covering a broad polarity span in HMs, we developed a directly-coupled reversed-phase and hydrophilic interaction liquid chromatography-tandem mass spectrometry system. Samples were firstly separated according to lipophilicity by using a C18 column. Utilizing a T-piece as connector, the eluent was then pumped into an amide column to get further separation that mainly based on the hydrogen bonding effects. Dan-Qi pair, an extensively used herb-combined prescription in China, was selected to test the practicability and performance of the established system. A total of 27 components, containing 9 hydrophilic and 18 lipophilic constituents, were simultaneously determined using a schedule multiple reaction monitoring method in 15 min. Up to 69.9% content could be monitored in one injection in Dan-Qi pair extract, showing a significant advantage over previous methods. The proposed method was expected to benefit the controllability of herbal medicines.

A multi-residue method for simultaneous determination of 74 pesticides in Chinese material medica using modified QuEChERS sample preparation procedure and gas chromatography tandem mass spectrometry.

The present study is focused on the development of an analytical method for the simultaneous analysis of seventy-four pesticides belonging to different chemical classes (organochlorines, organophosphates, pyrethroids, dinitroanilines, dicarboximides, triazoles, etc.) in Chinese material medica. The samples were extracted according to the acetate QuEChERS protocol. To reduce the amount of co-extracted compounds, n-hexane instead of acetonitrile was employed as the extraction solvent. To improve the overall recoveries of problematic basic and base-sensitive compounds, sodium acetate was used to adjust the pH to a neutral condition, and florisil combined with octadecyl-modified silica (C18) were utilized in the cleanup step. The samples were analysed by GC-MS/MS, and quantified by matrix-matched calibration. The validation study was carried out on two representative herbs, Chuanxiong Rhizoma and Angelica Sinensis Radix. In two matrices, the linearity of the calibration was good between 5 and 250 ng/mL concentration ranges, and the limits of quantification (LOQs) less than 0.01 mg/kg for most pesticides. At the LOQs and ten times the LOQs, the mean recoveries of almost all pesticides were within 70-120%, with relative standard deviations (RSDs) lower than 10%. The method was applied on twenty real samples. Seven batches of Chuanxiong and five batches of Danggui were found to contain the residues. The combination of modified QuEChERS and GC-MS/MS offers low cost of analysis as well as excellent accuracy and sensitivity. This method could be especially useful for trace analysis of pesticide residues in complex matrices.

Selection of reference standard during method development using the analytical hierarchy process.

Reference standard is critical for ensuring reliable and accurate method performance. One important issue is how to select the ideal one from the alternatives. Unlike the optimization of parameters, the criteria of the reference standard are always immeasurable. The aim of this paper is to recommend a quantitative approach for the selection of reference standard during method development based on the analytical hierarchy process (AHP) as a decision-making tool. Six alternative single reference standards were assessed in quantitative analysis of six phenolic acids from Salvia Miltiorrhiza and its preparations by using ultra-performance liquid chromatography. The AHP model simultaneously considered six criteria related to reference standard characteristics and method performance, containing feasibility to obtain, abundance in samples, chemical stability, accuracy, precision and robustness. The priority of each alternative was calculated using standard AHP analysis method. The results showed that protocatechuic aldehyde is the ideal reference standard, and rosmarinic acid is about 79.8% ability as the second choice. The determination results successfully verified the evaluation ability of this model. The AHP allowed us comprehensive considering the benefits and risks of the alternatives. It was an effective and practical tool for optimization of reference standards during method development.

Identification of metabolites of Radix Paeoniae Alba extract in rat bile, plasma and urine by ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry.

Ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF/MS) was developed to identify the absorbed parent components and metabolites in rat bile, plasma and urine after oral administration of Radix Paeoniae Alba extract (RPAE). A total of 65 compounds were detected in rat bile, plasma and urine samples, including 11 parent compounds and 54 metabolites. The results indicated that glucuronidation, hydroxylation and methylation were the major metabolic pathways of the components of RPAE. Furthermore, the results of this work demonstrated that UPLC-Q-TOF/MS combined with MetaboLynx™ software and mass defect filtering (MDF) could provide unique high throughput capabilities for drug metabolism study, with excellent MS mass accuracy and enhanced MSE data acquisition. With the MSE technique, both precursor and fragment mass spectra can be simultaneously acquired by alternating between high and low collision energy during a single chromatographic run.