Bioautographic Detection of Antimicrobial Compounds in the Edible Shiitake Mushroom (Lentinus edodes)

JPC – Journal of Planar Chromatography – Modern TLC - The shiitake mushroom is well known for its health-beneficial effects. In this study we examined its antimicrobial activity by use...     

用固体高分辨NMR研究聚(L-丙氨酸)-聚乙二醇单甲醚双嵌段共聚物的微相结构与链段运动

利用固体高分辨¹³CCP/MAS及二维WISE核磁共振技术研究了聚(L-丙氨酸)-聚乙二醇单甲醚双嵌段共聚物(MPEG-b-PLA)在固态下的微相结构和链段运动行为.结果表明,聚乙二醇链段在形成嵌段共聚物后结晶度明显下降,同时存在晶区和非晶区,从而表现出两种不同的运动状态.而聚乙二醇链段的引入对聚L-丙氨酸链段影响不大,嵌段共聚物中聚L-丙氨酸链段高度结晶,同时含有大量的α螺旋结构,分子链运动严重受限,估计聚L-丙氨酸链段的相区尺寸很小.     

同时测定食用植物油中抗氧剂叔丁基对羟基茴香醚和2，6－二叔丁基对甲酚的方法

报道了用高效液用色谱法同时测定食用植物油中的抗氧剂叔丁基对羟基茴香醚（ＢＨＡ）和２，６－二叔丁基对甲酚（ＢＨＴ）的实验方法。采用ＺｏｒｂａｘＯＤＳＣ_（１８）色谱住，甲醇：水（９０：１０，Ｖ／Ｖ）作流动相，检测波长为２４５ｎｍ，流速为１ｍＬ／ｍｉｎ。检测下限分别为１５ｎｇ（ＢＨＡ），９０ｎｇ（ＢＨＴ），回收率分别是９６．８％±９．８％（ＢＨＡ），９９．０％±３．２％（ＢＨＴ）。方法快速、准确，灵敏度高。     

A Practical Synthesis of (R) and (S) 3-Hydroxyglutaric Acid Monoesters by Enzymatic Hydrolysis with a Bacterial Esterase

The hemihydrolysis of diethyl 3-hydroxy-glutarate with an industrial enzyme, “Esterase 30 000”, in a biphasic system allows an efficient enantio-selective synthesis of (R) and (S) 3-hydroxyglutaric acid ethyl and t-butyl monoesters in large scale and with excellent yield.     

Optimisation of Vitamin B12 Extraction from Green Edible Seaweed (Ulva lactuca) by Applying the Central Composite Design

Vitamin B12, only found naturally in animal-based foods, is essential for brain functions and various chemical reactions in the human body. Insufficient vitamin B12 leads to vitamin B12 deficiency, common among strict vegetarians due to their limited intake of animal-based foods. Nevertheless, extensive studies have demonstrated that macroalgae, specifically the Ulva lactuca species, are rich in vitamin B12 and could be further exploited in future dietary applications. In the current study, the ideal extraction method of vitamin B12 from dried U. lactuca was developed and optimised to achieve the maximum vitamin B12 yield. The effects of several extraction parameters, including the solvent-to-solvent, methanol:water (MeOH:H₂O), and solute-to-solvent ratios, and pH on the total vitamin B12 content were analysed through a two-level factorial and central composite design. The highest vitamin B12 content, particularly cyanocobalamin (CN-Cbl), was recovered through the ultrasonic-assisted extraction (UAE) of oven-dried U. lactuca at 3 g:60 mL of solute-to-solvent and 25:75% of MeOH to H₂O ratios at pH 4. The extraction of CN-Cbl from oven-dried U. lactuca that employed the UAE method has elevated CN-Cbl content recovery compared to other extraction methods.     

Optimization Extraction and Antioxidant Activity of Crude Polysaccharide from Chestnut Mushroom (Agrocybe aegerita) by Accelerated Solvent Extraction Combined with Response Surface Methodology (ASE-RSM)

The present work is conducted to investigate the optimal extraction technology of polysaccharide from chestnut mushroom (Agrocybe aegerita) using a new method based on accelerated solvent extraction combined with response surface methodology (ASE-RSM). The conventional reflux extraction (CRE) method and ultrasonic-assisted extraction (UAE) method were also carried out. Additionally, the in vitro antioxidant activities, including ABTS and DPPH assay, were evaluated. The RSM method, based on a three level and three variable Box–Behnken design (BBD), was developed to obtain the optimal combination of extraction conditions. In brief, the polysaccharide was optimally extracted with water as extraction solvent, extraction temperature of 71 °C, extraction time of 6.5 min, number of cycles of 3, and extraction pressure of 10 MPa. The 3D response surface plot and the contour plot derived from the mathematical models were applied to determine the optimal conditions. Under the above conditions, the experimental value of polysaccharide yield was 19.77 ± 0.12%, which is in close agreement with the value (19.81%) predicted by the model. These findings demonstrate that ASE-RSM produce much higher polysaccharide and consumed environmentally friendly extraction and solvent systems, have less extraction discrimination and shorter time and provide scientific basis for industrialization of polysaccharide extraction. Moreover, it was proved that the polysaccharide had the potential ability to scavenge ABTS and DPPH.     

High resolution spectroscopy for the A (2)A(1) state of CH(3)I(+) by mass-analyzed threshold ionization/photodissociation

Photodissociation of CH(3)I(+) in the ground vibronic state generated by mass-analyzed threshold ionization resulted in a superb spectrum for the first excited electronic state (A (2)A(1)) with hardly any spurious peak. Rotational structure in the spectrum could be resolved by using a single mode laser. This structure for one vibronic band, 2(1)3(1)6(1), was analyzed with the assumption of Hund's case (a) scheme both in the ground and excited electronic states.     

High Pressure Liquid Chromatographic Separation of 6-Acetoxybenzo(A)pyrene from In Vitro Incubation of 6-Nitrobenzo(A)pyrene

Abstract

We carried out studies of the microsomal metabolism of 6-nitrobenzo(a)pyrene (NBaP) to understand why the compound is a marginal carcinogen. Microsomal incubation products were separated by reverse phase high-pressure liquid chromatography. A chromatographic peak with a retention time of 24.8 mins was isolated and examined by ultraviolet, mass and nuclear magnetic resonance spectra. The product was characterized as 6-acetoxy-benzo(a)pyrene. The source of the acetylating agent could be cytosolic.     

Extraction of Ce(III), Gd(III) and Yb(III) from Citrate Medium by High Molecular Weight Amines

Abstract

High molecular weight amines have been used for the extraction of citrate complexes of Ce(III), Gd(III) and Yb(III). The effect of different variables on extraction has been studied. The citrate species extracted in the organic phase have been proposed as [(RNH₃ ⁺)₃] [M(Cit)₂]^3-.     

C_（60），C_（70）液相色谱分离方法的研究

较系统地考察了不同柱系统及不同流动相组成下Ｃ＿（６０）,Ｃ＿（７０）的保留规律。在实验的基础上,提出了分离Ｃ＿（６０）,Ｃ＿（７０）的最佳柱系统及流动相组成。并在此分离条件下,对高分子量的富勒烯组分进行了分离。     

Effective uranium biosorption by macrofungus (<Emphasis Type="Italic">Russula sanguinea</Emphasis>) from aqueous solution: equilibrium,thermodynamic and kinetic studies

Russula sanguinea (R. sanguninea) macrofungus was employed as a novel cost-effective biosorbent for efficient removal of U(VI) ions from aqueous solution. FT-IR spectroscopy and SEM/EDS technique were used for morphological and chemical characterizations. The maximum adsorption capacity of the macrofungus was found as 174.3 mg/g at pH 5 and 20 °C. The kinetic data best fit with the pseudo-second-order kinetic model (r²?>?0.99 for the studied temperatures). The exothermic and spontaneous nature of the biosorption process was confirmed by the thermodynamic findings. The reusability test demonstrated that the macrofungus had a good sorption/desorption performance.     

一种新的分离三硝基甲苯及其代谢产物的高效液相色谱方法

An HPLC method is described for separation of TNT and its main reduction metabolites. Two columns(LC-C(18) and LC-CN)are connected in series and operated isocratically at 1.0mL/min with water-methanol-tetrahydrofuran(60+ 35+ 5 ). The baseline separation of 4-amino-2,6-dinitrotoluene(4A) and 2-amino-4,6-dinitrotoluene(2A) ,which are main metabolites of TNT,is obtained(Rs=2.1).     

High Enrichment of MMP-9 and Carboxypeptidase A by Tweezing Adsorptive Bubble Separation (TABS)

Tweezing adsorptive bubble separation (TABS) was used as a method for the enrichment of matrix metalloproteinases (92-kDa type IV, gelatinase B (MMP-9)) and carboxypeptidase A (CPA) from dilute aqueous solutions. The method is based on the chelation of metalloenzymes applying 2-(carbamoylmethyl-(carboxymethyl)amino)acetic acid (ADA) coupled with an octyl part to form a surface active unit. MMP-9 could be enriched with an enrichment ratio of 12.0 and a recovery of 87.3%, and CPA could be enriched 18.8-fold and with 95.3% recovery. Both enzymes were enriched without significant losses of enzymatic activity. To verify that the enzymes were tweezed by ADA-C8 without abstraction of the zinc ions from the active center, TABS trials were additionally conducted with zinc ions in complex with ADA-C8, which revealed only negligible enrichment ratios of the enzymes (2.2 for MMP-9 and 0.2 for CPA). The results obtained impressively demonstrate that zinc-containing proteases can be enriched selectively and efficiently by TABS.     

Metabolic Evaluation of Urine from Patients Diagnosed with High Grade (HG) Bladder Cancer by SPME-LC-MS Method

Bladder cancer (BC) is a common malignancy of the urinary system and a leading cause of death worldwide. In this work, untargeted metabolomic profiling of biological fluids is presented as a non-invasive tool for bladder cancer biomarker discovery as a first step towards developing superior methods for detection, treatment, and prevention well as to further our current understanding of this disease. In this study, urine samples from 24 healthy volunteers and 24 BC patients were subjected to metabolomic profiling using high throughput solid-phase microextraction (SPME) in thin-film format and reversed-phase high-performance liquid chromatography coupled with a Q Exactive Focus Orbitrap mass spectrometer. The chemometric analysis enabled the selection of metabolites contributing to the observed separation of BC patients from the control group. Relevant differences were demonstrated for phenylalanine metabolism compounds, i.e., benzoic acid, hippuric acid, and 4-hydroxycinnamic acid. Furthermore, compounds involved in the metabolism of histidine, beta-alanine, and glycerophospholipids were also identified. Thin-film SPME can be efficiently used as an alternative approach to other traditional urine sample preparation methods, demonstrating the SPME technique as a simple and efficient tool for urinary metabolomics research. Moreover, this study’s results may support a better understanding of bladder cancer development and progression mechanisms.