Notes

Improved manufacture of β-glucan by a T-DNA-based mutant regarding Aureobasidium pullulans.
Since chiral recognition mechanism based on molecularly imprinted polymers immerged, it has assisted countless chemical and electrochemical analytical sample preparation techniques. It has done this by enhancing the enatioseparation abilities of these techniques. The preparation and optimization of chiral molecularly imprinted polymers (CMIPs) are two favored methods in the separation and sensor fields. This review aims to present an overview of advances in the preparation and application of CMIPs in analytical approaches in different available formats (eg. column, monolithic column, cartridge, membrane, nanomaterials, pipette tip and stir bar sorptive) over the last decade. In addition, progress in the preparation and development of CMIPs-based sensor fields have been also discussed. Finally, the main application challenges of CMIPs are also summarily explained, as well as upcoming prospects in the field.Sterol analysis of complex matrices can be very laborious. To minimize the existing drawbacks, a new micro-method of sterols and squalene determination in cyanobacteria was developed and applied to monitor their production of Phormidium autumnale cultured heterotrophically. Sample extraction/saponification and GC analysis of the target compounds were optimized separately using Plackett-Burman design (PB) followed by a central composite rotational design (CCRD). The most influential variables were identified to maximize compound recovery. Chloroform presented the highest capability to extract all target compounds with a horizontal shaker table (HST) for homogenization in the saponification step. For the pretreatment, a small amount of chloroform was used for 90 min at 50 °C and 6 min for the saponification time. The sample introduction in the GC injector was studied by evaluating pressure and injector temperature. High response for sterols and squalene were obtained between 19 and 23 psi and at 310 °C of injection temperature. The new method was able to determine different sterol concentrations 0.2-0.6 mg kg-1 of squalene, 5-18 mg kg-1 of stigmasterol, 6 mg kg-1 of cholesterol, and 3 mg kg-1 of β-sitosterol, showing high analytical performance and fulfilling all steps, thus proving to be a promising technique.The capability of a solvent-mediated liquid-liquid extraction (LLE) method to improve the detection of ochratoxin A (OTA) in food matrixes using surface-enhanced Raman spectroscopy (SERS) is described. SERS detection of mycotoxins with nanoparticle aggregation is a simple method but with low reproducibility due to the heterogeneous distribution of the nanoparticle aggregates. We evaluated three different LLE protocols to analyze their performance in combination with SERS. A facile extraction method based on sample acidification and addition of chloroform as a separation solvent showed to not only extract OTA from wine and wheat but also facilitate the uniform distribution of the nanoparticles leading to an improvement of the detection signals and the reproducibility. This method enables rapid and simple analysis of mycotoxin Ochratoxin A in food systems.Aromatic carboxylic acids (ACAs), play important roles in preventive and therapeutic effects for some diseases. However, complex matrix effect and poor detection sensitivity make it difficult and even rare to detect ACAs in complex bio-samples. Herein, a stable isotope labeling derivatization (SILD) method based on one-pot synthesis of carboxylic amides by aniline (AN) and aniline-d5 (AN-d5) was firstly designed for quantitatively monitoring ACAs under mild conditions. The detection sensitivity was improved up to 500 folds. Importantly, when taking the trace tenuifoliside A (TA) containing p-hydroxyl-benzoyl- (HB) and 3, 4, 5-trimethoxylcinnamoyl- (TC) unit as a special example via intestinal bacteria incubation, the metabolites ACAs and whole metabolic profiles of TA were firstly accurately and systematically monitored by applying the SILD method combined with multiple-mass spectrometry (MMS) technologies. It provides a convenient, universal, high-sensitivity and high-recovery methodological tool for the systematically metabolic study of trace drugs in vitro and in vivo.Bioactive polyamines play important roles in many biological processes such as gene expression, cell growth, protein synthesis, and signal transduction. Accurate determination of polyamines is helpful for studying their biological functions. Herein, a C60-based chemical labeling strategy was proposed for the determination of polyamines (putrescine, cadaverine, spermidine, and spermine) in biological samples using matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS). An N-hydroxysuccinimide ester functionalized C60 (NHS-C60) was used as a labeling reagent and the m/z of the labeled polyamines reached up to more than 900 Da, which avoided matrix interferences in the low m/z region. In addition, as NHS-C60 derivatives, mono- and bis-substituted polyamines were produced simultaneously, which benefited the qualitative analysis of polyamines. The analytical method was validated using NHS-C60 labeled polyamines in cells and mice feces samples. Good linearities were obtained with correlation coefficients ranging from 0.9786 to 0.9982. AZD1390 concentration The limits of quantification were in the range of 0.68-1.48 pmol. Good reproducibility and reliability of our proposed method were confirmed by intra- and inter-day precisions ranged from 2.8 to 16.6%, and the recoveries ranged between 81.8 and 119.9%. Finally, the proposed method was applied to determine polyamines in cells and mice feces. Three polyamines were detected in the cells, and the contents of cadaverine and spermidine in the feces of high-fat diet mice were found to be significantly lower than those in the normal diet mice. The results show that the proposed NHS-C60 labeling coupled with MALDI MS strategy is suitable for the determination of polyamines in biological samples.In this study, a novel functional nanocomposite was synthesized, characterized and selectively used in pH-controlled separation, pre-concentration and speciation analysis of Cu(I) and Cu(II) from sample matrices where extraction is assisted, facilitated and greatly enhanced by ultrasound energy. The hydrophilic composite material functionalized with tris(2-hydroxymethyl)aminomethane (Tris) and Fe3O4 NPs was characterized in detail by ATR-FT-IR, 1H NMR, XRD, EDX peaks and SEM images. After optimization of the main variables influencing extraction efficiency such as pH, volumes of buffer, modified copolymer in acetone, CTAB and Triton X-114 at fixed concentrations including sonication conditions, the Cu(I) and Cu(II) were monitored against a blank at 347 nm by micro-volume UV-vis spectrophotometer. A good linearity was obtained in the range of 2-140 and 5-150 μg L-1 for Cu(II) and Cu(I) with r2 ≥ 0.993. The limits of detection (LODs) of 0.66 and 1.60 μg L-1 for each analyte, were obtained from a pre-concentration of 70-fold. After validation, the method was applied to speciation of Cu(I), Cu(II), and total Cu in the pre-treated and diluted beverage samples before and after pre-oxidation of Cu(I) to Cu(II) due to be more sensitive of extraction process to Cu(II) at pH 6.0. The results were also compared with those obtained by FAAS analysis to ensure the reliability of the results. It was observed that there was a statistically good agreement between the results of both methods.Urinary sarcosine was considered to be a potential biomarker for prostate cancer (Pca). In this work, an integrated strategy of multiplex tags chemical isotope labeling (MTCIL) combined with magnetic dispersive solid phase extraction (MDSPE), was proposed for specific extraction and high-throughput determination of sarcosine by ultra high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). In the past three months, we have developed 8-plex MTCIL reagents with excellent qualitative and quantitative performance. In this work, the multiplexing capacity of MTCIL reagents (MTCIL360/361/362/363/364/365/366/375/376/378/379/381) was increased 1.5-fold from 8-plex to 12-plex. MTCIL359 was prepared and used to label sarcosine standard as internal standard (IS). The structural analogue derivative (MTCIL373-sarcosine) of all targeted MTCIL-sarcosine derivatives was synthesized and used as a novel dummy template to prepare dummy magnetic molecularly imprinted polymers (DMMIPs). The integration of MTCalysis throughput and large-scale experiments about the potential biomarker research.A highly sensitive and selective label-free electrochemical immunosensor was successfully fabricated for measuring prostate-specific antigen (PSA). A composite of chitosan, graphene, ionic liquid and ferrocene (CS-GR-IL-Fc) was drop casted onto a screen-printed carbon electrode (SPCE) and frozen to create a layer of 3D porous cryogel (CS-GR-IL-Fc cry) which was decorated with gold nanoparticles (AuNPs). The biocompatibility and porosity of the cryogel increased the surface area available for AuNPs loading via amino groups and the population of anti-PSA, immobilized on the AuNPs via chemisorption, could be increased. The CS-GR-IL-Fc cry displayed excellent conductivity, enhancing electron transfer and amplifying the current signal. Differential pulse voltammetry was employed to determine PSA by measuring the reduction in the Fc oxidation peak current in response to the formation of PSA/anti-PSA immunocomplex. Under the optimized incubation time and electrolyte pH, the developed immunosensor displayed excellent analytical performances, including a wide linear range at concentrations from 1.0 × 10-7 to 1.0 × 10-1 ng mL-1, with a very low limit of detection of 4.8 × 10-8 ng mL-1 and good reproducibility (relative standard deviation of 0.05), and indicated the promising potential of the proposed immunosensor in clinical diagnosis.The metal ion fluorescence probes based on chemical reactions triggered by specific metal ions is characterized by high selectivity. However, they are also subject to inherent limitations, such as easy aggregation under water solution, poor optical stability, and long response time. In order to solve these problems, a simple and effective method was studied. The specific design is as follows. Fluorescence probe RACD is assembled onto a single layer graphene oxide (GO) via π-π interaction and hydrogen bonding to prepare RACD functionlized graphene oxide RACD/GO. The experimental results show that the resulting RACD/GO possesses very well monodispersion, hydrophilicity and photostability, particularly reduce the aggregation degree of RACD owing to π-π effect. Simultaneously, it was found that due to the strong synergy between GO and RACD, the response time, selectivity, anti-interference ability, detection sensitivity, detection limit and bioimaging ability of RACD/GO were significantly improved compared with RACD. The resulting RACD/GO not only possesses very well photostability, multiple repeated cycles, but also have been triumphantly put into the monitoring Cu2+ of environmental water, sewage, cells and zebrafish specimens in practice. The detection limit is as low as 1.76 nM, and the correlation coefficient is 0.9998.
Homepage: https://www.selleckchem.com/products/azd1390.html