Antimicrobial activity of new bicyclic lactones with three or four methyl groups obtained both synthetically and biosynthetically

Ten new derivatives of isophorone were obtained through a five-step synthesis. Among the products were several unsaturated, bicyclic lactones with three or four methyl groups. These lactones were used as the substrates for biotransformation mediated by selected fungal strains (Fusarium species, Syncephalastrum racemosum, Cunninghamella japonica, Penicillium species, Absidia species, and Pleurotus ostreatus). Four new hydroxylactones were obtained as a result of biotransformation. Because the unsaturated lactone with four methyl groups was a diastereoisomeric mixture, a structural analysis was conducted. The hydroxylactones were also included in this analysis. Both the unsaturated lactones and hydroxylactones were examined for their antimicrobial activity. It was found that some of these compounds exhibited growth inhibition against pathogenic strains of bacteria (Staphylococcus aureus, Pseudomonas fluorescens), yeasts (Candida albicans) and filamentous fungi (Alternaria sp., Penicillium sp.). All obtained compounds were also subjected to scent analysis.     

Spectrum-effect relationships between ultra performance liquid chromatography fingerprints and anti-bacterial activities of Rhizoma coptidis

The fingerprints of Rhizoma coptidis from various sources were established by ultra performance liquid chromatography (UPLC) and the anti-bacterial activities of R. coptidis on Escherichia coli (E. coli) growth was studied by microcalarimetry. The UPLC fingerprints were evaluated using similarity analysis (SA) and hierarchical clustering analysis (HCA). Some quantitative parameters obtained from the thermo-genic curves of E. coli growth affected by R. coptidis were analyzed using principal component analysis (PCA). The spectrum-effect relationships between UPLC fingerprints and anti-bacterial activities were investigated using canonical correlation analysis (CCA). The results showed that close correlation existed between the spectrum-effect relationships. Berberine, jateorrhizine and palmatine in the UPLC fingerprints might be the main anti-bacterial components. The anti-bacterial activities of R. coptidis were related with the main active constituents, along with the production place and the harvesting time of this herb, the latitude and longitude of the place. This work provides a general model of the combination of UPLC and microcalorimetry to study the spectrum-effect relationships of R. coptidis, which can be used to discover principle components of it on bioactivity.     

Fruits of ribes, rubus, vaccinium and prunus genus. Metal contents and genome

The production of fruits of genus Ribes, Rubus, Vaccinium and Prunus is particularly important in mountain communities. The contents of macro- and microelements in fruits from different cultivars of blueberry (Vaccinium corimbosus L.), red currant (Ribes rubrum L.), raspberry (Rubus idaeus L.) and cherry (Prunus avium L.) were determined. The anthocyanin and total polyphenol contents of the fruits were also determined. The results were analyzed with statistical methods. By using the one-way analysis of variance (ANOVA) the various genera of the fruits were found to be differentiable on the basis of their metal contents. Multivariate statistical analysis, performed using principal component analysis (PCA), confirms that the different fruits can also be well discriminated by their contents of metals, total anthocyanins, and polyphenols.     

Genome-Wide Analysis of the UGT Gene Family and Identification of Flavonoids in Broussonetia papyrifera

Broussonetia papyrifera is a multifunctional deciduous tree that is both a food and a source of traditional Chinese medicine for both humans and animals. Further analysis of the UGT gene family is of great significance to the utilization of B. papyrifera. The substrates of plant UGT genes include highly diverse and complex chemicals, such as flavonoids and terpenes. In order to deepen our understanding of this family, a comprehensive analysis was performed. Phylogenetic analysis showed that 155 BpUGTs were divided into 15 subgroups. A conserved motif analysis showed that BpUGT proteins in the same subgroups possessed similar motif structures. Tandem duplication was the primary driving force for the expansion of the BpUGT gene family. The global promoter analysis indicated that they were associated with complex hormone regulatory networks and the stress response, as well as the synthesis of secondary metabolites. The expression pattern analysis showed that the expression level of BpUGTs in leaves and roots was higher than that in fruits and stems. Next, we determined the composition and content of flavonoids, the main products of the BpUGT reaction. A total of 19 compounds were isolated and analyzed by UPLC-ESI-MS/MS in 3 species of Broussonetia including B. kazinoki, B. papyrifera, and B. kazinoki × B. papyrifera, and the number of compounds was different in these 3 species. The total flavonoid content and antioxidant capacities of the three species were analyzed respectively. All assays exhibited the same trend: the hybrid paper mulberry showed a higher total flavonoid content, a higher total phenol content and higher antioxidant activity than the other two species. Overall, our study provides valuable information for understanding the function of BpUGTs in the biosynthesis of flavonoids.     

Use of electrophoretic techniques and MALDI–TOF MS for rapid and reliable characterization of bacteria: analysis of intact cells, cell lysates, and “washed pellets”

In this study electrophoretic and mass spectrometric analysis of three types of bacterial sample (intact cells, cell lysates, and “washed pellets”) were used to develop an effective procedure for the characterization of bacteria. The samples were prepared from specific bacterial strains. Five strains representing different species of the family Rhizobiaceae were selected as model microorganisms: Rhizobium leguminosarum bv. trifolii, R. leguminosarum bv. viciae, R. galegae, R. loti, and Sinorhizobium meliloti. Samples of bacteria were subjected to analysis by four techniques: capillary zone electrophoresis (CZE), capillary isoelectric focusing (CIEF), gel IEF, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI–TOF MS). These methods are potential alternatives to DNA-based methods for rapid and reliable characterization of bacteria. Capillary electrophoretic (CZE and CIEF) analysis of intact cells was suitable for characterization of different bacterial species. CIEF fingerprints of “washed pellets” and gel IEF of cell lysates helped to distinguish between closely related bacterial species that were not sufficiently differentiated by capillary electrophoretic analysis of intact cells. MALDI–TOF MS of “washed pellets” enabled more reliable characterization of bacteria than analysis of intact cells or cell lysates. Electrophoretic techniques and MALDI–TOF MS can both be successfully used to complement standard methods for rapid characterization of bacteria.     

Application of UHPLC Fingerprints Combined with Chemical Pattern Recognition Analysis in the Differentiation of Six Rhodiola Species

Rhodiola, especially Rhodiola crenulate and Rhodiola rosea, is an increasingly widely used traditional medicine or dietary supplement in Asian and western countries. Because of the phytochemical diversity and difference of therapeutic efficacy among Rhodiola species, it is crucial to accurately identify them. In this study, a simple and efficient method of the classification of Rhodiola crenulate, Rhodiola rosea, and their confusable species (Rhodiola serrata, Rhodiola yunnanensis, Rhodiola kirilowii and Rhodiola fastigiate) was established by UHPLC fingerprints combined with chemical pattern recognition analysis. The results showed that similarity analysis and principal component analysis (PCA) could not achieve accurate classification among the six Rhodiola species. Linear discriminant analysis (LDA) combined with stepwise feature selection exhibited effective discrimination. Seven characteristic peaks that are responsible for accurate classification were selected, and their distinguishing ability was successfully verified by partial least-squares discriminant analysis (PLS-DA) and orthogonal partial least-squares discriminant analysis (OPLS-DA), respectively. Finally, the components of these seven characteristic peaks were identified as 1-(2-Hydroxy-2-methylbutanoate) β-D-glucopyranose, 4-O-glucosyl-p-coumaric acid, salidroside, epigallocatechin, 1,2,3,4,6-pentagalloyglucose, epigallocatechin gallate, and (+)-isolarisiresinol-4′-O-β-D-glucopyranoside or (+)-isolarisiresinol-4-O-β-D-glucopyranoside, respectively. The results obtained in our study provided useful information for authenticity identification and classification of Rhodiola species.     

Analysis and Confirmation of Rodenticide Pindone in Human Plasma by IC–ESI–IT–MS

Pindone is a highly effective anticoagulant rodenticide. In this paper, an improved assay for the analysis and confirmation of pindone in human plasma has been proposed. After the samples protein precipitation with 10% (v/v) methanol in acetonitrile and cleaning with solid-phase extraction, the separation was carried out on an IonPac AS11-HC analytical column (250 mm × 2 mm) using 20 mmol L^?1 KOH containing 10% (v/v) methanol as organic modifier by eluent generator reagent free ion chromatography. Quantification was performed by a negative electrospray ionization ion trap mass spectrometry using diphacinone as an internal standard. The transition for quantitative analysis was m/z 229 → 172, and for qualitative analysis were m/z 229 → 145 and m/z 229 → 214 for pindone. The transition for quantitative analysis was m/z 339 → 167 for IS. The limit of detection, the limit of quantification, recovery, linearity, precision, and stability were well validated. The cracking approach of characteristic fragments for pindone and IS were proposed. It was confirmed that this method could be used in clinical diagnosis and forensic toxicology analysis.     

Tacamine-type alkaloids from Tabernaemontana bovina together with their configuration determination

Eleven undescribed tacamine type alkaloids, named tabercamines A–K were isolated from leaves of Tabernaemontana bovina, together with six known alkaloids. The planar structure of the undescribed alkaloids were determined by comprehensive spectroscopic data analysis. Their absolute configuration were established based on the combination of the electronic circular dichroism and single X-ray crystal diffraction analysis. The NMR rules (in acetone-d₆) of identifying of the stereo-configuration at C-20/16 was established.     

Widely Targeted Metabolomics Analysis of Different Parts of Salsola collina Pall

Salsola collina Pall has a long history of being used as a traditional medicine to treat hypertension, headache, insomnia, constipation and vertigo. However, only a few biologically active substances have been identified from S. collina. Here, the shoots and roots of S. collina, namely L-Sc and R-Sc, were studied. The primary and secondary metabolites were investigated using ultrahigh-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS). A total of 637 putative metabolites were identified and these metabolites were mainly classified into ten different categories. Correlation analysis, hierarchical clustering analysis, principal component analysis and orthogonal partial least squares discriminant analysis of metabolites showed that the L-Sc samples could be clearly separated from the R-Sc samples. Differential accumulated metabolite analysis revealed that most of differential primary metabolites were significantly lower in the L-Sc than in the R-Sc. Conversely, the major differential secondary metabolites had higher levels in the L-Sc than in the R-Sc. Further analysis indicated that the flavonoids were the major putative antioxidant components and most of putative antioxidant components exhibited higher relative concentrations in the L-Sc than the R-Sc. These results improve our understanding of metabolite accumulation and provide a reference for the study of medicinal value in S. collina.     

Facile synthesis of various substituted taurines,especially syn- and anti-1,2-disubstituted taurines,from nitroolefins

Taurine and substituted taurines present a group of important structural elements in many natural products. Various substituted taurines, including 1- and 2-substituted, 1,1-, syn-1,2-, and anti-1,2-disubstituted taurines, were synthesized from the corresponding nitroolefins via Michael addition with thioacetic acid, oxidation with peroxyformic acid, and the catalytic hydrogenation under the catalysis of palladium on carbon or platinum dioxide. It is a general, versatile, and salt-free method for the preparation of substituted taurines, especially for syn- and anti-1,2-disubstituted taurines and some taurines with more bulky substituents. The stereostructures of both syn- and anti-1,2-disubstituted taurines were deduced from the nitroalkyl thioacetates in the Michael addition, which were identified via the Karplus equation analysis and computational analysis, and finally confirmed by the XRD single crystal analysis. The diastereoselectivity in the Michael addition was rationalized with the Cram rule.     

Comparative analysis of plant lycopene cyclases

Carotenoids are essential isoprenoid pigments produced by plants, algae, fungi and bacteria. Lycopene cyclase (LYC) commonly cyclize carotenoids, which is an important branching step in the carotenogenesis, at one or both end of the backbone. Plants have two types of LYC (β-LCY and ϵ-LCY). In this study, plant LYCs were analyzed. Based on domain analysis, all LYCs accommodate lycopene cyclase domain (Pf05834). Furthermore, motif analysis indicated that motifs were conserved among the plants. On the basis of phylogenetic analysis, β-LCYs and ϵ-LCYs were classified in β and ϵ groups. Monocot and dicot plants separated from each other in the phylogenetic tree. Subsequently, Oryza sativa Japonica Group and Zea mays of LYCs as monocot plants and Vitis vinifera and Solanum lycopersicum of LYCs as dicot plants were analyzed. According to nucleotide diversity analysis of β-LCY and ϵ-LCY genes, nucleotide diversities were found to be π: 0.30 and π: 0.25, respectively. The result highlighted β-LCY genes showed higher nucleotide diversity than ϵ-LCY genes. LYCs interacting genes and their co-expression partners were also predicted using String server. The obtained data suggested the importance of LYCs in carotenoid metabolism. 3D modeling revealed that depicted structures were similar in O. sativa, Z mays, S. lycopersicum, and V. vinifera β-LCYs and ϵ-LCYs. Likewise, the predicted binding sites were highly similar between O. sativa, Z mays, S. lycopersicum, and V. vinifera LCYs. Most importantly, analysis elucidated the V/IXGXGXXGXXXA motif for both type of LYC (β-LCY and ϵ-LCY). This motif related to Rossmann fold domain and probably provides a flat platform for binding of FAD in O. sativa, Z mays, S. lycopersicum, and V. vinifera β-LCYs and ϵ-LCYs with conserved structure. In addition to lycopene cyclase domain, the V/IXGXGXXGXXXA motif can be used for exploring LYCs proteins and to annotate the function of unknown proteins containing lycopene cyclase domain. Overall results indicated that a high degree of conserved signature were observed in plant LYCs.     

Identification and Determination of <em>Aconitum</em> Alkaloids in <em>Aconitum</em> Herbs and <em>Xiaohuoluo Pill</em> Using UPLC-ESI-MS

A rapid, specific, and sensitive ultra-performance liquid chromatography-electrospray ionization-mass spectrometry (UPLC-ESI-MS) method to examine the chemical differences between Aconitum herbs and processed products has been developed and validated. Combined with chemometrics analysis of principal component analysis (PCA) and orthogonal projection to latent structural discriminate analysis, diester-diterpenoid and monoester-type alkaloids, especially the five alkaloids which contributed to the chemical distinction between Aconitum herbs and processed products, namely mesaconitine (MA), aconitine (AC), hypaconitine (HA), benzoylmesaconitine (BMA), and benzoylhypaconitine (BHA), were picked out. Further, the five alkaloids and benzoylaconitine (BAC) have been simultaneously determined in the Xiaohuoluo pill. Chromatographic separations were achieved on a C₁₈ column and peaks were detected by mass spectrometry in positive ion mode and selected ion recording (SIR) mode. In quantitative analysis, the six alkaloids showed good regression, (r) > 0.9984, within the test ranges. The lower limit quantifications (LLOQs) for MA, AC, HA, BMA, BAC, and BHA were 1.41, 1.20, 1.92, 4.28, 1.99 and 2.02 ng·mL^-1, respectively. Recoveries ranged from 99.7% to 101.7%. The validated method was applied successfully in the analysis of the six alkaloids from different samples, in which significant variations were revealed. Results indicated that the developed assay can be used as an appropriate quality control assay for Xiaohuoluo pill and other herbal preparations containing Aconitum roots.     

Fingerprint–efficacy study of Radix Aconiti Lateralis Preparata (Fuzi) in quality control of Chinese herbal medicine

For quality control of Chinese herbal medicine (CHM), an attempt on fingerprint–efficacy study of Radix Aconiti Lateralis Preparata (Fuzi) was developed in this paper. The fingerprints of Fuzi from various sources were determined by UPLC and hierarchical clustering analysis. Some quantitative thermo-kinetic parameters such as the heat-flow maximum power (P _max) and its time corresponding to t _max, which obtained from the thermogenic curves of mitochondria metabolic activity affected by Fuzi were analyzed using principal component analysis. The fingerprint–efficacy relationship of chemical fingerprint and promoting effect of Fuzi were established using canonical correlation analysis. Our results showed that the sources and places of production of Fuzi had some significant influence on the chemical fingerprints and promoting metabolic effects of this CHM. Fingerprint–efficacy study provided a powerful way and some references for the quality control of Fuzi and other CHMs.     

Preparation and thermal behaviour of rare earth citrate hydrates

Nine rare earth citrate hydrates (RE(C₆H₅O₇)·nH₂O,RE=La, Nd, Sm) were prepared and characterized by chemical analysis, elementary analysis, thermal analysis and IR spectra. The thermal decomposition processes were studied by using TG-DTG and IR spectra techniques. Dehydration enthalpies and dehydration entropies of 3 neodymium and 3 samarium citrate hydrates were also determined by means of DSC.     

Synthesis and properties of polyimides derived from a new diamine containing bulky-flexible pendent group

Novel aromatic polyimides containing bulky-flexible pendent group were successfully synthesized by direct polycondensation of N-(4-(4-(4,5-diphenyl-1H-imidazole-2-yl)phenoxy)phenyl)-3,5-diaminobenzamide with various tetracarboxylic dianhydrides. These polymers are soluble in most of the aprotic organic solvents such as N-methyl-2-pyrrolidone, N,N-dimethylformamide, dimethylsulfoxide, N,N-dimethylacetamide, hexamethylphosphoramide, m-cresol, and pyridine. The prepared polymers were characterized by viscometry, FT-IR, ¹H NMR, and UV-Vis spectroscopy, fluorimetry, elemental analysis; the thermal properties were evaluated by differential scanning calorimetric and thermogravimetric analysis.     

Integrated LC/MS and GC/MS Metabolomics Data for the Evaluation of Protection Function of Fructus Ligustri Lucidi on Mouse Liver

A comprehensive metabolomic strategy, integrating GC/MS and LC/MS data, had been developed to study the protection function of herbal medicine, Fructus Ligustri Lucidi, on mouse liver. Mouse plasma samples were analyzed by GC/MS and LC/MS in conjunction with multiblock multivariate analysis method, multiblock partial least squares discriminant analysis (MBPLS-DA), to supply more important and distinct information of metabolomic biomarkers. Then, the biological pathway analysis was carried out to help further understanding the mechanism of liver protection of Fructus Ligustri Lucidi.     

Rapid quality assessment of Radix Aconiti Preparata using direct analysis in real time mass spectrometry

This study presents a novel and rapid method to identify chemical markers for the quality control of Radix Aconiti Preparata, a world widely used traditional herbal medicine. In the method, the samples with a fast extraction procedure were analyzed using direct analysis in real time mass spectrometry (DART MS) combined with multivariate data analysis. At present, the quality assessment approach of Radix Aconiti Preparata was based on the two processing methods recorded in Chinese Pharmacopoeia for the purpose of reducing the toxicity of Radix Aconiti and ensuring its clinical therapeutic efficacy. In order to ensure the safety and effectivity in clinical use, the processing degree of Radix Aconiti should be well controlled and assessed. In the paper, hierarchical cluster analysis and principal component analysis were performed to evaluate the DART MS data of Radix Aconiti Preparata samples in different processing times. The results showed that the well processed Radix Aconiti Preparata, unqualified processed and the raw Radix Aconiti could be clustered reasonably corresponding to their constituents. The loading plot shows that the main chemical markers having the most influence on the discrimination amongst the qualified and unqualified samples were mainly some monoester diterpenoid aconitines and diester diterpenoid aconitines, i.e. benzoylmesaconine, hypaconitine, mesaconitine, neoline, benzoylhypaconine, benzoylaconine, fuziline, aconitine and 10-OH-mesaconitine. The established DART MS approach in combination with multivariate data analysis provides a very flexible and reliable method for quality assessment of toxic herbal medicine.     

Synthesis of TiO2 nanoparticles by electrochemical method and their antibacterial application

Titanium dioxide nanoparticles were successfully prepared by electrochemical method. The tetra propyl ammonium bromide salt was used as stabilizing agent in an organic medium viz. tetra hydro furan (THF) and acetonitrile (ACN) in 4:1 ratio by optimizing current density. The parameters such as current density, solvent polarity, distance between electrodes and concentration of stabilizers were used to control the size of nanoparticles. The synthesized titanium dioxide nanoparticles were characterized by using UV–Visible spectroscopy, X-ray diffraction, scanning electron microscopy (SEM), energy dispersive spectrophotometer (EDS) and transmission electron microscopy (TEM) analysis techniques. TEM analysis proved a nearly tetragonal structure with size of 25–30 nm which was in agreement with the result calculated from the XRD analysis. EDS analysis revealed the presence of Ti and O element. The nanoparticles were screened for their in vitro antibacterial activity against human pathogens such as gram negative Escherichia coli (E. coli), and gram positive Staphylococcus aureus strains and which proved excellent results.