A caprylate esterase-activated fluorescent probe for sensitive and selective detection of Salmonella enteritidis.

Salmonella enteritidis is one of the most common foodborne pathogens. Many methods have been developed to detect Salmonella, but most of them are expensive, time-consuming, and complex in experimental procedures. Developing a rapid, specific, cost-effective, and sensitive detection method is still demanded.

Chemical constituents, clinical efficacy and molecular mechanisms of the ethanol extract of Abelmoschus manihot flowers in treatment of kidney diseases.

Abelmoschus manihot, also called as "Huangkui" in Chinese, is an annual flowering herb plant in the family of Malvaceae. As a traditional Chinese medicine, the ethanol extract of the flower in Abelmoschus manihot is made as Huangkui capsule and has been used for medication of the patients with kidney diseases. Its efficacy in clinical symptoms is mainly improving renal function and reducing proteinuria among the patients with chronic kidney disease, diabetic kidney disease or IgA nephropathy.

Colorless Silk/Copper Sulfide Hybrid Fiber and Fabric with Spontaneous Heating Property under Sunlight.

With the increasing demand for comfort, thinness, and warmth of fabrics, various functional fibers have emerged. However, natural silkworm silk, as one of the most widely used natural fibers in textile, faces the issue that it cannot be modified during the spinning process like synthetic fibers. Herein, copper sulfide nanoparticles (CuS NPs) with a near-infrared (NIR) absorption property were first prepared by using regenerated silk fibroin (RSF) as the biological template.

Carbon dots as fluorescent nanoprobe for the determination of N-acetyl-β-d-glucosaminidase activity.

Carbon dots (CDs) were synthesized from p-aminophenol and ethylenediamine via one-step under mild condition and used as a sensitive fluorescent nanoprobe for the activity determination of N-acetyl-β-d-glucosaminidase (NAG). In this assay, p-nitrophenol was in situ produced from p-nitrophenyl-β-D-N-acetyl-glucosaminide, which was exclusively hydrolyzed by NAG. The UV absorption peak of p-nitrophenol (maximum at 400 nm) overlapped the excitation peak of CDs with maximum wavelength at 415 nm, which caused the fluorescence decline of CDs based on inner filter effect.

Qualitative and quantitative analysis of saponins in the flower bud of Panax ginseng (Ginseng Flos) by UFLC-Triple TOF-MS/MS and UFLC-QTRAP-MS/MS.

Introduction: Ginseng Flos (GF), the flower bud of Panax ginseng, is a worthy functional food with medicinal potential. A few studies have focused on the comprehensive and systematic analysis of its major bioactive constituents.

Objective: The aims are to develop the methods of ultra-fast liquid chromatography coupled with triple quadrupole-time of flight tandem mass spectrometry (UFLC-Triple TOF-MS/MS) and ultra-fast liquid chromatography coupled with triple quadrupole-linear ion trap tandem mass spectrometry (UFLC-QTRAP-MS/MS) for the qualitative and quantitative analysis of the saponins in GF.

Organic polymer dot-based fluorometric determination of the activity of horseradish peroxidase and of the concentrations of glucose and the insecticidal protein toxin Cry1Ab/Ac.

Fluorescent polymer dots (PDs) with maximum excitation/emission wavelengths of 410/515 nm were prepared in water solution from 1,4-benzoquinone and ethylenediamine. The green fluorescence of these PDs is screened off by the red-colored oxidation product (PPDox, maximum absorption at 510 nm) formed by horseradish peroxidase (HRP)-catalyzed oxidation of p-phenylenediamine (PPD). It causes the reduction of the fluorescence intensity of the PDs due to spectral overlap and an inner filter effect (IFE).

Alternating Sequence Control for Poly(ester amide)s by Organocatalyzed Ring-Opening Polymerization.

Sequence-controlled polymerization is the forefront of polymer chemistry. Herein, the feasibility of sequence regulation by using organocatalyzed ring-opening polymerization (ROP) is demonstrated. In particular, ring expansion strategy is employed to synthesize pre-organized monomers 1 and 2.

The determination of α-glucosidase activity through a nano fluorescent sensor of F-PDA-CoOOH.

A sensitive nanocomplex probe prepared from fluorescent polydopamine nanoparticles (F-PDA) and cobalt oxyhydroxide (CoOOH) nanosheets was established for the determination of α-glucosidase activity. In this detection system, the fluorescence of F-PDA was firstly quenched by CoOOH nanosheets based on fluorescence resonance energy transfer (FRET). Subsequently, ascorbic acid was produced from 2-O-α-d-glucopyranosyl-l-ascorbic acid which was selectively hydrolyzed by α-glucosidase.

Quality Evaluation of Wild and Cultivated Fructus Based on Simultaneous Determination of Multiple Bioactive Constituents Combined with Multivariate Statistical Analysis.

Fructus, also called wuweizi in China, was a widely used folk medicine in China, Korea, and Russia. Due to the limited natural resources and huge demand of wuweizi, people tend to cultivate wuweizi to protect this species. However, the quality of wild and cultivated herbs of the same species may change.

Synthesis of nitrogen-doped graphene quantum dots (N-GQDs) from marigold for detection of Fe ion and bioimaging.

Graphene quantum dots (GQDs) are synthesized by the method of high-temperature pyrolysis from marigold granules and subsequently nitrogen-doped graphene quantum dots (N-GQDs) are synthesized from ethylenediamine by hydrothermal treatment, which shows a strong blue emission with 7.84% quantum yield (QY). This will be used in detection of Fe in water environments and the field of bioimaging.

[Comparative analysis of multiple index constituents in Ophiopogonis Radix and Liriopes Radix].

An analytical method based on UFLC-QTRAP-MS/MS was established for simultaneous determination of thirty-three components including steroidal saponins, homoisoflavonoids, amino acids and nucleosides in Ophiopogonis Radix. Thirty-three target components of commercial medicinal materials of Maidong were comparative analysis. Synergi™ Hydro-RP 100 column (2.

[Simultaneous determination of lignans and organic acids in Schisandrae Chinensis Fructus by UFLC-Q-TRAP-MS/MS].

An analytical method based on UFLC-QTRAP-MS/MS was developed for simultaneous determination of fifteen components including eleven lignans (schizantherin B, schisandrol B, schizandrin C, γ-schisandrin, deoxyschizandrin, schisantherin, schisandrin, schisanhenol, gomisin D, gomisin J, and angeloylgomisin H) and organic acids (S)-malic acid, D(-)-tartaric acid, protocatechuic acid, and quinic acid) in Schisandrae Chinensis Fructus. Samples from different product specifications were evaluated and analyzed. The chromatographic separation was performed on a Synergi™ Hydro-RP 100Å column (2.

Recent progress of C-glycosylation methods in the total synthesis of natural products and pharmaceuticals.

Chemical C-glycosylation has been well developed to improve stereoselectivity in recent years. Due to its high efficiency to build C-glycosides or O-cyclic compounds, C-glycosylation has found widespread use in the synthesis of biologically active molecules. This review highlights the C-glycosylation methods that have been practised in the total synthesis of natural products and pharmaceuticals in the past decade.

SWOT analysis and revelation in traditional Chinese medicine internationalization.

Traditional Chinese medicine (TCM) is currently the best-preserved and most influential traditional medical system with the largest number of users worldwide. In recent years, the trend of TCM adoption has increased greatly, but the process of TCM internationalization has suffered from a series of setbacks for both internal and external reasons. Thus, the process of TCM internationalization faces formidable challenges, although it also has favourable opportunities.

Hyperbranched Aliphatic Polyester via Cross-Metathesis Polymerization: Synthesis and Postpolymerization Modification.

A novel postpolymerization modification methodology is demonstrated to achieve selective functionalization of hyperbranched polymer (HBP). Terminal and internal acrylates of HBP derived from cross-metathesis polymerization (CMP) are functionalized in a chemoselective fashion using the thiol-Michael chemistries. Model reactions between different thiols (benzyl mercaptan and methyl thioglycolate) and acrylates (n-hexyl acrylate and ethyl trans-2-decenoate) by using dimethylphenylphosphine or amylamine as the catalyst are investigated to optimize the modification protocol for HBP.

Precision Aliphatic Polyesters with Alternating Microstructures via Cross-Metathesis Polymerization: An Event of Sequence Control.

Sequence-regulated polymerization is realized upon sequential cross-metathesis polymerization (CMP) and exhaustive hydrogenation to afford precision aliphatic polyesters with alternating sequences. This strategy is particularly suitable for the arrangement of well-known monomer units including glycolic acid, lactic acid, and caprolactic acid on polymer chain in a predetermined sequence. First of all, structurally asymmetric monomers bearing acrylate and α-olefin terminuses are generated in an efficient and straightforward fashion.

Synthesis of Oxylipin Mimics and Their Antifungal Activity against the Citrus Postharvest Pathogens.

Nine oxylipin mimics were designed and synthesized starting from d-mannose. Their antifungal activity against three citrus postharvest pathogens was evaluated by spore germination assay. The results indicated that all the compounds significantly inhibited the growth of Penicillium digitatum, Penicillium italicum and Aspergillus niger.

Amino acid-catalyzed formation of 2-vinylfuran from lipid-derived 4-oxo-2-hexenal.

The formation of 2-vinylfuran from the corresponding 4-oxo-2-hexenal (OHE, a lipid oxidation product) under the catalysis of amino acid were studied. The effects of amino acids, reaction temperature, reaction time, water content, pH, metallic ions and some food additives on the formation of 2-vinylfuran were investigated. Amino acids promoted the formation of 2-vinylfuran except aspartic acid, histidine and glutamine.

Postligation-desulfurization: a general approach for chemical protein synthesis.

Native chemical ligation, involving regioselective and chemoselective coupling of two unprotected peptide segments, enabled the synthesis of polypeptide with more than 200 amino acids. However, cysteine was indispensable in this synthetic technique in its initial format, which limited its further application. Thus, considerable effort has been put into breaking the restriction of cysteine-containing ligation.

Collective synthesis of 4-hydroxy-2-pyridone alkaloids and their antiproliferation activities.

A collective synthesis of 4-hydroxy-2-pyridone alkaloids--specifically, pretenellin B, prebassianin B, farinosone A, militarione D, pyridovericin, and torrubiellone C--has been achieved. Key steps include using a strategic convergent method to synthesize the densely substituted pyridone key intermediate by Suzuki-Miyaura cross-coupling reaction, a divergent synthesis approach of target molecules by aldol condensation of pyridone intermediate with homologous aldehydes, and an iterative synthesis of homologous aldehydes with all-trans-polyene backbones. Interestingly, among the six tumor cell lines investigated, torrubiellone C was found to induce potent and apoptotic inhibitory activities on Jurkat T cells with IC50 values of 7.

Cell-penetrating peptides mediated protein cross-membrane delivery and its use in bacterial vector vaccine.

It is an attractive strategy to develop a recombinant bacterial vector vaccine by expressing exogenous protective antigen to induce the immune response, and the main concern is how to enhance the cellular internalization of antigen produced by bacterial vector. Cell-penetrating peptides (CPPs) are short cationic/amphipathic peptides which facilitate cellular uptake of various molecular cargoes and therefore have great potentials in vector vaccine design. In this work, eleven different CPPs were fused to the C-terminus of EGFP respectively, and the resultant EGFP-CPP fusion proteins were expressed and purified to assay their cross-membrane transport in macrophage J774 A.

One-pot synthesis of β-N-glycosyl imidazole analogues via a palladium-catalysed decarboxylative allylation.

A concise and highly efficient strategy for the synthesis of N-glycosyl imidazole analogues is reported. This reaction is based on a palladium catalysed decarboxylative allylation and three steps, namely, carbamation, decarboxylation and allylation are involved. All the substrates can afford the desired products with excellent yields and selectivities.

Facile access to cis-2,6-disubstituted tetrahydropyrans by palladium-catalyzed decarboxylative allylation: total syntheses of (±)-centrolobine and (+)-decytospolides A and B.

cis-2,6-Tetrahydropyran is an important structural skeleton of bioactive natural products. A facile synthesis of cis-2,6-disubstituted-3,6-dihydropyrans as cis-2,6-tetrahydropyran precursors has been achieved in high regio- and stereoselectivity with high yields. This reaction involves a palladium-catalyzed decarboxylative allylation of various 3,4-dihydro-2H-pyran substrates.

The effects of phytic acid on the Maillard reaction and the formation of acrylamide.

Phytic acid, myo-inositol hexaphosphoric acid, exists in substantial (1-5%) amounts in edible plant seeds. In this study the effects of phytic acid on the Maillard reaction and the formation of acrylamide were investigated. Both phytic acid and phosphate enhanced browning in glucose/β-alanine system, but phytic acid was less effective than phosphate.