[Analysis and evaluation on Paeoniae Radix Alba from different cultivars by UPLC-Q-TOF-MS and HPLC].

In this study, an established ultra-high performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry(UPLC-Q-TOF-MS) method was combined with multivariate statistical analysis to investigate the commonality and difference of main chemical components in the medicinal parts of Paeonia lactiflora from different cultivars; in addition, a high performance liquid chromatography(HPLC) method was established to simultaneously determine the content of eight active components in Paeoniae Radix Alba. Non-targeted analysis was carried out by UPLC-Q-TOF-MS on a Waters ACQUITY UPLC BEH C_(18)(2.1 mm×100 mm, 1.7 µm) column with a gradient elution of 0.1% aqueous formic acid(A)-acetonitrile(B) as the mobile phase at a flow rate of 0.2 mL·min~(-1). The column temperature was 30 ℃, and an electrospray ionization source was used to acquire mass spectrometry data in positive and negative ion modes. According to the accurate molecular weight and fragment ion information provided by multi-stage mass spectrometry and by comparison with reference substances and literature reports, thirty-six identical components were identified in Paeoniae Radix Alba from different cultivars with positive and negative ion modes. In the negative ion mode, two groups of samples were well separated; specifically, seventeen components with significant differences in content were screened and identified, and one component unique in "Bobaishao" was obtained. Quantitative analysis was conducted by high-performance liquid chromatography(HPLC) on an Agilent HC-C_(18)(4.6 mm×250 mm, 5 µm) column with a gradient elution of 0.1% aqueous phosphoric acid(A)-acetonitrile(B) as the mobile phase at a flow rate of 1.0 mL·min~(-1). The column temperature was 30 ℃ and the detection wavelength was at 230 nm. An HPLC method was developed for the simultaneous determination of eight active components(gallic acid, oxypaeoniflorin, catechin, albiflorin, paeoniflorin, galloylpaeoniflorin, 1,2,3,4,6-O-pentagalloylglucose, benzoyl-paeoniflorin) in Paeoniae Radix Albaa from different cultivars. Satisfactory linearity was achieved within the investigated linear ranges and with fine coefficients(r>0.999 0), and the methodological investigation showed that the method had good precision, repeatability and stability. The mean recoveries were 90.61% to 101.7% with RSD of 0.12% to 3.6%(n=6). UPLC-Q-OF-MS provided a rapid and efficient qualitative analytical method for the identification of the chemical components in Paeoniae Radix Alba, and the developed HPLC method was simple, rapid and accurate, which could provide a scientific basis for the evaluation of the germplasm resources and herbal quality of Paeoniae Radix Alba from different cultivars.

[Multiplex PCR method for simultaneous identification of Xanthii Fructus and its adulterants].

The purpose of this study is to establish a molecular method to identify Xanthii Fructus and two adulterants, the fruits of Xanthium mongolicum and X. italicum. Xanthii Fructus is the fruit of X. sibiricum, which is a Chinese herbal medicine used clinically to treat allergic rhinitis. The fruits of X. mongolicum and X. italicum have strong morphological similarities with Xanthii Fructus, while their safety of medication cannot be guaranteed. The genomes of X. sibiricum, X. mongolicum, and X. italicum were sequenced, which generated sequences of 2.21, 2.24, and 2.54 Gb, respectively. Based on the 76 specific contigs screened out by BLASTN and Bowtie 2, the corresponding primers were designed by Primer 5.0. Three pairs of primers with stable amplification efficiency and good reproducibility were screened out to establish a multiplex PCR method based on the PCR amplification results. Further, the annealing temperature, the amount of DNA template, the number of cycles, different DNA polymerases, and different PCR thermal cyclers were optimized. Fragments of 262 bp and 458 bp from X. sibiricum, 260, 454, and 927 bp from X. mongolicum, and 260 bp and 926 bp from X. italicum were amplified under the following conditions: the annealing temperature of 52 ℃, 35 cycles, 30 ng template DNA. Then, the established method was used to detect 18 samples of X. sibiricum, 17 samples of X. mongolicum, and 12 samples of X. italicum. The results showed that all the samples had positive results, which were consistent with the morphological identification results, thus proving the stability and reliability of the established method. Combining genome sequencing technology and multiplex PCR method to identify Xanthii Fructus and its adulterants can not only obtain the difference in genetic background but also facilitate the design of reliable primers. The multiplex PCR have high specificity and repeatability, providing a new method for the molecular identification of Xanthii Fructus.

Cloning and Functional Characterization of Two Germacrene A Oxidases Isolated from Xanthium sibiricum.

Sesquiterpene lactones (STLs) from the cocklebur Xanthium sibiricum exhibit significant anti-tumor activity. Although germacrene A oxidase (GAO), which catalyzes the production of Germacrene A acid (GAA) from germacrene A, an important precursor of germacrene-type STLs, has been reported, the remaining GAOs corresponding to various STLs' biosynthesis pathways remain unidentified. In this study, 68,199 unigenes were studied in a de novo transcriptome assembly of X. sibiricum fruits. By comparison with previously published GAO sequences, two candidate X. sibiricum GAO gene sequences, XsGAO1 (1467 bp) and XsGAO2 (1527 bp), were identified, cloned, and predicted to encode 488 and 508 amino acids, respectively. Their protein structure, motifs, sequence similarity, and phylogenetic position were similar to those of other GAO proteins. They were most strongly expressed in fruits, according to a quantitative real-time polymerase chain reaction (qRT-PCR), and both XsGAO proteins were localized in the mitochondria of tobacco leaf epidermal cells. The two XsGAO genes were cloned into the expression vector for eukaryotic expression in Saccharomyces cerevisiae, and the enzyme reaction products were detected by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) methods. The results indicated that both XsGAO1 and XsGAO2 catalyzed the two-step conversion of germacrene A (GA) to GAA, meaning they are unlike classical GAO enzymes, which catalyze a three-step conversion of GA to GAA. This cloning and functional study of two GAO genes from X. sibiricum provides a useful basis for further elucidation of the STL biosynthesis pathway in X. sibiricum.

A rapid reduction of Au(I→0) strategy for the colorimetric detection and discrimination of proteins.

A gold nanoparticle (AuNP)-based sensing strategy based on rapid reduction of Au(I→0) is proposed. As a proof-of-concept study, the proposed sensing principle is designed for simultaneous and colorimetric detection and discrimination of multiple proteins. In the presence of H2O2, the target proteins could reduce Au(I) (i.e. HAuCl2) to AuNPs with different sizes, shapes and dispersion/aggregation states, thus resulting in rapidly colorimetric identification of different proteins. The optical response (i.e. color) of AuNPs is found to be characteristic of a given protein. The color response patterns are characteristic for each protein and can be quantitatively differentiated by statistical techniques. The sensor array is capable of discriminating proteins at concentrations as low as 0.1 µg/mL with high accuracy. A linear relationship was observed between the total Euclidean distances and protein concentration, providing the potential for protein quantification using this sensor array. The limit of detection (LOD) for catalase (Cat) is 0.08 µg/mL. The good linear range (from 0 to 8 µg/mL) has been used for the quantitative assay of Cat. To show a potentially practical application, this method was used to detect and discriminate proteins in human urine and tear samples. Graphical abstract We report a facile gold nanoparticle (AuNP)-based sensing strategy, that is, "a rapid reduction of Au(I) to Au(0) nanoparticles with different sizes and shapes by analytes that having certain reducing capabilities, resulting in different colours." The proposed sensing principle is designed for simultaneous, colorimetric detection and discrimination of multiple proteins.

Magnetic and magneto-transport studies of two-dimensional ferromagnetic compound Fe3GeTe2.

We have systematically reported the magnetic and magneto-transport properties of two-dimensional itinerant ferromagnetic compound Fe3GeTe2 at high magnetic fields of 58 T and demonstrated the correlation between its transport and magnetism. Anomalous two-steps magnetic ordering and antiferromagnetic-like transitions in zero field-cooling (ZFC) curves for H ∥ ab-plane are observed. Additionally, we find that intrinsic negative magnetoresistances in bulk Fe3GeTe2 single crystal are mainly attributed to the suppression of spin-fluctuations in low magnetic fields. Complex evolutions of temperature dependent high field magnetoresistances are detected under different magnetic field and current configurations, which can be explained as a result of the competition between spin-fluctuations, the magnon-scatterings and classical cyclotronic effects.

[Next generation sequencing and transcriptome analysis of root bark from Paeonia suffruticosa cv. Feng Dan].

Moutan Cortex is an important traditional Chinese medicine, "Fengdan Pi" was known as Dao-di herbs from the root bark of Paeonia suffruticosa cv. Feng Dan for its extracted various active components. However, the genetic basis for their activity is virtually unknown. The transcriptome of the root bark from "Fengdan" was sequenced using the Illumina HiSeq 4000 sequencing platform. The clean reads were then de novo assembled into 72 997 unigenes. Among them, the number of unigenes which could been annotated by dataset Nr and GO was 41 139 and 34 592. The 20 016 unigenes could been annotated by KEGG dataset, which were involved in 5 major categories, 34 middle categories, and 352 metabolism pathways. The number of unigenes which were mapped to the phenylpropanoid biosynthesis pathway, terpenoid backbone biosynthesis pathway, terpenoid biosynthesis pathway, alkaloid biosynthesis pathway, and flavonoid biosynthesis pathway was 214, 104, 152, 55 and 36 respectively, suggesting that they are involves in these pathways of pharmaceutically important. Furthermore, there also showed remarkable differences in groups which enrichment ratio of the different expressed gene compared. In addition, a total of 9 939 SSRs were identified from the sequence of 72 997 unigenes. This study not only provides many valuable basal data which was important gene in the synthesis pathway of secondary metabolites with gene searching, but also has important significance to find molecular marker in germplasm for breeding and improvement.