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1.
The bakers’ yeast reduction of 3-oxo-3-phenylpropanenitrile (1) has been difficult to achieve due to a dominant alkylating mechanism. A library of 20 bakers’ yeast reductases, that are overexpressed in Escherichia coli, were screened against (1). Four enzymes were found to reduce this substrate and by varying the enzyme both enantiomers of 3-hydroxy-3-phenylpropanitrile (2) could be prepared with a high enantiomeric excess. In addition, the Escherichia coli whole-cell system can be optimized to nearly eliminate the competing alkylating mechanism. By using this system, a formal biocatalytic synthesis of both antipodes of fluoxetine, atomoxetine and nisoxetine has been demonstrated. 相似文献
2.
Metas Ngernjan Atcharaporn Ontawong Narissara Lailerd Kriangsak Mengamphan Sureeporn Sarapirom Doungporn Amornlerdpison 《Molecules (Basel, Switzerland)》2022,27(12)
Crocodile oil (CO) is generated from the fatty tissues of crocodiles as a by-product of commercial aquaculture. CO is extensively applied in the treatment of illnesses including asthma, emphysema, skin ulcers, and cancer, as well as wound healing. Whether CO has anti-inflammatory properties and encourages an immune response remains uncertain. The impact of CO on inflammatory conditions in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and the mechanisms behind it were examined in this work. Cells were treated with 0.125–2% CO dissolved in 0.5% propylene glycol with or without LPS. The production and expression of inflammatory cytokines and mediators were also examined in this research. CO reduced the synthesis and gene expression of interleukin-6 (IL-6). Consistently, CO inhibited the expression and synthesis of inflammatory markers including cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2), nitric oxide (NO), and nuclear factor kappa B (NF-κB). Furthermore, CO reduced the effects of DNA damage. CO also increased the cell-cycle regulators, cyclins D2 and E2, which improved the immunological response. CO might thus be produced as a nutraceutical supplement to help avoid inflammatory diseases. 相似文献
3.
Eliza Matuszewska Joanna Matysiak Grzegorz Rosiski Elbieta Kdzia Weronika Zbek Jarosaw Zawadziski Jan Matysiak 《Molecules (Basel, Switzerland)》2021,26(9)
Royal jelly (RJ) is a complex, creamy secretion produced by the glands of worker bees. Due to its health-promoting properties, it is used by humans as a dietary supplement. However, RJ compounds are not fully characterized yet. Hence, in this research, we aimed to broaden the knowledge of the proteomic composition of fresh RJ. Water extracts of the samples were pre-treated using combinatorial hexapeptide ligand libraries (ProteoMinerTM kit), trypsin-digested, and analyzed by a nanoLC-MALDI-TOF/TOF MS system. To check the ProteoMinerTM performance in the MS-based protein identification, we also examined RJ extracts that were not prepared with the ProteoMinerTM kit. We identified a total of 86 proteins taxonomically classified to Apis spp. (bees). Among them, 74 proteins were detected in RJ extracts pre-treated with ProteoMinerTM kit, and only 50 proteins were found in extracts non-enriched with this technique. Ten of the identified features were hypothetical proteins whose existence has been predicted, but any experimental evidence proves their in vivo expression. Additionally, we detected four uncharacterized proteins of unknown functions. The results of this research indicate that the ProteoMinerTM strategy improves proteomic identification in complex biological samples. Broadening the knowledge of RJ composition may contribute to the development of standards and regulations, enhancing the quality of RJ, and consequently, the safety of its supplementation. 相似文献
4.
F. Zhang M. Bartels A. Clark T. Erskine T. Auernhammer B. Bhhatarai 《SAR and QSAR in environmental research》2013,24(11):875-893
ABSTRACTThe accurate prediction of toxicokinetic parameters arising from oral, dermal and inhalation routes of chemical exposure is a key element in chemical safety assessments. In this research, the physiologically based pharmacokinetic (PBPK) GastroPlusTM software was evaluated against a series of chemicals for the prediction of toxicokinetic parameters. Overall, 67% of predicted intrinsic clearance (Clint) values were within 1- to 10-fold of empirical data for 463 compounds, and 87% of the predicted fraction unbounded in plasma (Fup) values were 1- to 3-fold of empirical data for 441 compounds. The r2 (coefficient of determination) of predicted Cmax (maximum plasma concentration) and AUC (Area Under Curve) values versus the corresponding empirical values from oral, inhalation and dermal exposures ranged from 0.04 to 0.92. Among the three exposures, the highest r2 values, ranging from 0.80 to 0.92, were observed for oral exposure predictions, where 88% of the compounds had 1- to 10-fold differences between predicted and empirical values for Cmax and AUC. The predicted plasma Css (steady-state plasma concentration) values were consistent with those Css values calculated by in vitro-to-in vivo extrapolation (IVIVE) approaches using experimental parameters. Based on the evaluation results, GastroPlus? can be used as a QSAR/PBPK tool for toxicokinetic parameter predictions. 相似文献
5.
This paper describes the preparation, characterization, mechanical properties and thermal stability of layered silicate nanocomposites based on poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHB-co-PHH, known as NodaxTM). The dispersed phases were organically modified montmorillonites (clay 20A and clay 25A), mica, and talc, and they were introduced by solution mixing. Wide-angle X-ray scattering results and transmission electron microscopy (TEM) images confirmed that these two clays were intercalated and finely distributed in the NodaxTM matrix. This type of layered filler led to remarkable improvements in mechanical properties even at very low loadings. Minimizing aggregation was more of a problem in the case of the mica and the talc, at least in this particular matrix. In some cases, these layered fillers slightly decreased the thermal stability of the NodaxTM. 相似文献
6.
Mohammad Reza Poor Heravi 《中国化学快报》2010,21(12):1399-1402
<正>The fluorination reaction involving aβ-ketosulfones by Selectfluor~(TM) was efficiently promoted by the ionic liquid,[Hbim]BF_4 (EL) as a reaction medium with methanol as co-solvent at room temperature under ultrasonic irradiation to afford the corresponding mono and difluoro-β-ketosulfones in excellent yields.The advantages of this method include among others the use of a recyclable, non-volatile ionic liquid,which promotes this protocol under room temperature without the requirement of any added catalyst under ultrasonic irradiation. 相似文献
7.
8.
Jakub Dobroch Klaudia Bojczuk Adrian Koakowski Marta Baczewska Pawe Knapp 《Molecules (Basel, Switzerland)》2022,27(7)
Endometrial cancer (EC) is one of the most frequent female malignancies. Because of a characteristic symptom, vaginal bleeding, EC is often diagnosed in an early stage. Despite that, some EC cases present an atypical course with rapid progression and poor prognosis. There have been multiple studies conducted on molecular profiling of EC in order to improve diagnostics and introduce personalized treatment. Chemokines—a protein family that contributes to inflammatory processes that may promote carcinogenesis—constitute an area of interest. Some chemokines and their receptors present alterations in expression in tumor microenvironment. CXCL12, which binds the receptors CXCR4 and CXCR7, is known for its impact on neoplastic cell proliferation, neovascularization and promotion of epidermal–mesenchymal transition. The CCL2–CCR2 axis additionally plays a pivotal role in EC with mutations in the LKB1 gene and activates tumor-associated macrophages. CCL20 and CCR6 are influenced by the RANK/RANKL pathway and alter the function of lymphocytes and dendritic cells. Another axis, CXCL10–CXCR3, affects the function of NK-cells and, interestingly, presents different roles in various types of tumors. This review article consists of analysis of studies that included the roles of the aforementioned chemokines in EC pathogenesis. Alterations in chemokine expression are described, and possible applications of drugs targeting chemokines are reviewed. 相似文献
9.
AbstractOxidation of hydroxamic acids (HXs) generates HNO, and it is not clear whether it is formed also in the presence of metal ions. The kinetics of the oxidation of HXs, such as acetohydroxamic acid, suberohydroxamic acid, and suberoylanilide hydroxamic acid (SAHA), by compounds I and II of horseradish peroxidase (HRP) at pH 7.0 and 25?°C have been studied using rapid-mixing stopped-flow. The kinetics of these reactions were compared to those observed in the presence of Cu(ClO4)2, NiSO4, or ZnSO4. The rates decrease upon increasing [CuII] at constant [HXs], and no oxidation of HX occurs when [HX]/[CuII] ≈ 2, implying that HX oxidation in the presence of CuII proceeds through the free ligand since the predominant complex is CuX2. In the case of NiII, the oxidation rate decreases upon increasing the ratio [NiII]/[HX] beyond 1, where the predominant complex is NiIIX+, implying that its oxidation is feasible. The effect of ZnII could be studied only on the rate of HXs oxidation by compound II demonstrating similar behavior to that of NiII. HXs were also oxidized catalytically by HRP/H2O2 at pH 7.0, demonstrating that metal ions facilitate the formation of HNO while hardly affecting its yield and the extent of HX oxidation. 相似文献
10.
A small organic molecule P was synthesized and characterized as a fluorometric and colorimetric dual-modal probe for Hg2+. The sensing characteristics of the proposed probe for Hg2+ were studied in detail. A fluorescent enhancing property at 583 nm (>30 fold) accompanied with a visible colorimetric change, from colorless to pink, was observed with the addition of Hg2+ to P in an ethanol-water solution (8:2, v/v, 20 mM HEPES, pH 7.0), which would be helpful to fabricate Hg2+-selective probes with “naked-eye” and fluorescent detection. Meanwhile, cellular experimental results demonstrated its low cytotoxicity and good biocompatibility, and the application of P for imaging of Hg2+ in living cells was satisfactory. 相似文献
11.
R. Plasil I. Korolov T. Kotrik J. Glosik 《International journal of mass spectrometry》2008,275(1-3):80-85
Recombination rate coefficients of protonated and deuterated ions KrH+, KrD+, XeH+ and XeD+ were measured using Flowing Afterglow with Langmuir Probe (FALP). Helium at 1600 Pa and at temperature 250 K was used as a buffer gas in the experiments. Kr, Xe, H2 and D2 were introduced to a flow tube to form the desired ions. Because of small differences in proton affinities of Kr, D2 and H2 mixtures of ions, KrD+/D3+ and KrH+/H3+ are formed in the afterglow plasma, influencing the plasma decay. To obtain a recombination rate coefficient for a particular ion, the dependencies on partial pressures of gases used in the ion formation were measured. The obtained rate coefficients, αKrD+(250 K) = (0.9 ± 0.3) × 10−8 cm3 s−1 and αXeD+(250 K) = (8 ± 2) × 10−8 cm3 s−1 are compared with αKrH+(250 K) = (2.0 ± 0.6) × 10−8 cm3 s−1 and αXeH+(250 K) = (8 ± 2) × 10−8 cm3 s−1. 相似文献
12.
Oxidative stress leads to protein degeneration or mitochondrial dysfunction, causing neuronal cell death. Glutamate is a neurotransmitter that nerve cells use to send signals. However, the excess accumulation of glutamate can cause excitotoxicity in the central nervous system. In this study, we deciphered the molecular mechanism of catechin-mediated neuroprotective effect on glutamate-induced oxidative stress in mouse hippocampal neuronal HT22 cells. Cellular antioxidant activity was determined using the 1,1-diphenyl-picryl hydrazyl (DPPH) assay and 2′,7′-dichlorodihydrofluorescein diacetate (DCFDA) staining. Furthermore, the levels of intracellular calcium (Ca2+) as well as nuclear condensation and protein expression related to neuronal damage were assessed. All five catechins (epigallocatechin gallate, gallocatechin gallate (GCG), gallocatechin, epicatechin gallate, and epicatechin) showed strong antioxidant effects. Among them, GCG exhibited the highest neuroprotective effect against glutamate excitotoxicity and was used for further mechanistic studies. The glutamate-induced increase in intracellular Ca2+ was reduced after GCG treatment. Moreover, GCG reduced nuclear condensation and the phosphorylation of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinases (JNK) involved in cell death. The neuroprotective effect of GCG against glutamate-induced oxidative stress in HT22 cells was attributed to the reduction in intracellular free radicals and Ca2+ influx and also the inhibition of phosphorylation of ERK and JNK. Furthermore, the antioxidant effect of GCG was found to be likely due to the inhibition of phosphorylation of ERK and JNK that led to the effective suppression of neurocytotoxicity caused by glutamate in HT22 cells. 相似文献
13.
本文通过分子生物学方法将八肋游仆虫中心蛋白N端半分子loop区的首个氨基酸,天冬氨酸Asp37和Asp73,分别突变为带相反电荷的赖氨酸。使用铽敏化荧光、TNS疏水探针研究了八肋游仆虫中心蛋白N端半分子loop区的首个氨基酸的作用。结果表明:当中心蛋白loop Ⅰ区37位的天冬氨酸突变为赖氨酸后,loop Ⅰ丧失了金属离子结合能力,进而影响了中心蛋白依赖于金属离子的构象变化;而loop Ⅱ区73位的天冬氨酸突变为赖氨酸后仍保持金属离子结合能力,依赖于金属离子的构象变化减小。中心蛋白发挥大部分生物功能都依赖于金属离子,这就表明loop Ⅰ区37位的天冬氨酸在中心蛋白发挥生物功能时起着重要作用,是不可缺少的。在10 mmol·L-1 Hepes、pH 7.4、20 mmol·L-1 KCl条件下,八肋游仆虫中心蛋白N端半分子loop Ⅱ与金属离子Tb3+和Ca2+的结合常数分别为:KⅡ(Tb3+)=(8.31±0.18)×104 L·mol-1和KⅡ(Ca2+)=(0.94±0.12)×102 L·mol-1,中心蛋白N端半分子的两个金属结合部位结合能力顺序为:Ⅰ>Ⅱ。 相似文献
14.
In this work, we synthesised and characterised three novel fluorescence macrocyclic sensors containing optically active dansyl groups. The studies for the interaction of the synthesised compounds with various mental ions (Li+, Na+, K+, Ag+, Mg2+, Ca2+, Ba2+, Pb2+, Zn2+, Co2+, Cd2+, Hg2+, Ni2+, Cu2+, Mn2+, Cr3+, Al3+, Fe3+) were performed by fluorescence titration, Job’s plot, ESI-MS and DFT calculations. The results showed that the sensors 1a–1c displayed selective recognition for Cu2+ and Fe3+ ions and formed stoichiometry 1:1 complex through PET mechanism in DMSO/H2O solution (1:1, v/v, pH 7.4 of HEPES). The binding constant (K) and detection limit were calculated. 相似文献
15.
Shuai Ye Mingming Zhang Jiaqing Guo Xiantong Yu Jun Song Pengju Zeng Junle Qu Yue Chen Hao Li 《Molecules (Basel, Switzerland)》2022,27(19)
High-quality fluorescent probes based on carbon dots (CDs) have promising applications in many fields owing to their good stability, low toxicity, high quantum yield, and low raw material price. The fluorine- and nitrogen-doped fluorescent CDs (NFCDs) with blue fluorescence was successfully synthesized using 3-aminophenol and 2,4-difluorobenzoic acid as the raw material by the hydrothermal method. The NFCDs as probe can be used to directly and indirectly detect Fe3+ (detection range: 0.1–150 μM and detection limit: 0.14 μM) and ascorbic acid (AA) (detection range: 10–80 μM and detection limit: 0.11 μM). The NFCDs-based probe shows exceptional selectivity and strong anti-interference for Fe3+ and ascorbic acid (AA). In addition, we examined the response of NFCDs to Fe3+ and AA in living cells, which showed that the timely use of AA can reduce the effects of iron poisoning. This has important biological significance. This means that using NFCDs as fluorescent probes is beneficial for Fe3+ and AA detection and observing their dynamic changes in living cells. Thus, this work may contribute to the study of Fe3+- and AA-related diseases. 相似文献
16.
Simultaneous spectrophotometric methods are described for the determination of Zn2+, Co2+ and Ni2+ by 1-(2-pyridylazo)2-naphthol (PAN) in micellar media, using absorbance correction-H-point standard addition method (HPSAM) and partial least squares (PLS) regression. The ligand and its metal complexes, i.e. Zn2+-PAN, Co2+-PAN and Ni2+-PAN, were made water-soluble by the neutral surfactant Triton X-100, and therefore extraction with organic solvents was no longer required. Formation of all of these complexes was complete within 10min at pH 9.2. The linear range was 0.1–1.5mgL–1 for Zn2+, 0.1–2.0mgL–1 for Co2+ and 0.1–2.0mgL–1 for Ni2+. The relative standard deviation (RSD) for the simultaneous determination of 0.50mgL–1 each of Zn2+, Ni2+ and Co2+ by applying the H-point standard addition method was 2.55%, 2.04% and 3.70%, respectively. The total relative standard error for applying the PLS method to 9 synthetic samples in the linear ranges of these metals was 1.8%. Interference effects of common anions and cations were studied, and both methods were applied to the simultaneous determination of Zn2+, Co2+ and Ni2+ in alloy samples. 相似文献
17.
Weitao Li Ningjia Jiang Luoman Zhang Yongqian Chen Jie Gao Jihang Zhang Baoshuo Yang Jianxin He 《Molecules (Basel, Switzerland)》2022,27(22)
Due to the rapid development of industrialization, various environmental problems such as water resource pollution are gradually emerging, among which heavy metal pollution is harmful to both human beings and the environment. As a result, there are many metal ion detection methods, among which fluorescence detection stands out because of its rapid, sensitive, low cost and non-toxic characteristics. In recent years, graphene quantum dots have been widely used and studied due to their excellent properties such as high stability, low toxicity and water solubility, and have a broad prospect in the field of metal ion detection. A novel high fluorescence Cu2+, Co2+ sensing probe produced by graphene quantum hydrothermal treatment is reported. After heat treatment with hydrazine hydrate, the small-molecule precursor nitronaphthalene synthesized by self-nitrification was transformed from blue fluorescent GQDs to green fluorescent amino-functionalized N–GQDs. Compared with other metal ions, N–GQDs are more sensitive to Cu2+ and Co2+ on the surface, and N–GQDs have much higher selectivity to Cu2+ and Co2+ than GQDs. The strategy proposed here is simple and economical in design. 相似文献
18.
Neelum Gul Qazi Arif-ullah Khan Sumra Wajid Abbasi Fawad Ali Shah Faisal Rasheed Fawad Ali Syed Shams ul Hassan Simona Bungau 《Molecules (Basel, Switzerland)》2022,27(18)
This present study aimed to delineate Rumex hastatus D. Don crude extract (Rh.Cr), n-Hexane, ethyl acetate, aqueous fractions (Rh.n-Hex, Rh.ETAC, Rh.Aq) and rutin for antidiarrheal, antisecretory effects, anti-spasmodic, gastrointestinal transient time, anti H. pylori, antiulcer effects, and toxicology. The preliminary phytochemical analysis of Rumex hastatus showed different phytoconstituents and shows different peaks in GC-MC chromatogram. Rumex hastatus crude extract (Rh.Cr), fractions, and rutin attributed dose-dependent (50–300 mg/kg) protection (0–100%) against castor oil-induced diarrhea and dose-dependently inhibited intestinal fluid secretions in mice. They decreased the distance traversed by charcoal in the gastrointestinal transit model in rats. In rabbit jejunum preparations, Rh.Cr and Rh.ETAC caused a concentration-dependent relaxation of both spontaneous and K+ (80 mM)-induced contractions at a similar concentration range, whereas Rh.n-Hex, rutin, and verapamil were relatively potent against K+-induced contractions and shifted the Ca2+ concentration–response curves (CRCs) to the right, Rh.Cr (0.3–1 mg/mL) and Rh.ETAC (0.1–0.3 mg/mL) shifted the isoprenaline-induced inhibitory CRCs to the left. Rh.n-Hex, Rh.ETAC and rutin showed anti-H. pylori effect, also shows an inhibitory effect against H+/K+-ATPase. Rumex hastatus showed gastroprotective and antioxidant effects. Histopathological evaluation showed improvement in cellular architecture and a decrease in the expression of inflammatory markers such as, cyclooxygenase (COX-2), tumor necrosis factor (TN,F-α) and phosphorylated nuclear factor kappa B (p-NFƙB), validated through immunohistochemistry and ELISA techniques. In RT-PCR it decreases H+/K+-ATPase mRNA levels. Rumex hastatus was found to be safe to consume up to a dose of 2000 mg/kg in a comprehensive toxicity profile. Docking studies revealed that rutin against H+/K+-ATPase pump and voltage-gated L-type calcium channel showed E-values of −8.7 and −9.4 Kcal/mol, respectively. MD simulations Molecular Mechanics Poisson Boltzmann surface area and molecular mechanics Generalized Born surface area (MMPBSA/GBSA) findings are consistent with the in-vitro, in-vivo and docking results. 相似文献
19.
Pandeeswaran M El-Mossalamy EH Elango KP 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,82(1):375-382
Lanthanide sensitized luminescence and chemiluminescence (CL) are of great importance because of the unique spectral properties, such as long lifetime, large Stokes shifts, and narrow emission bands characteristic to lanthanide ions (Ln3+). With the fluoroquinolone (FQ) compounds including enoxacin (ENX), norfloxacin (NFLX), lomefloxacin (LMFX), fleroxacin (FLRX), ofloxacin (OFLX), rufloxacin (RFX), gatifloxacin (GFLX) and sparfloxacin (SPFX), the luminescence and CL properties of Tb3+–FQ and Eu3+–FQ complexes have been investigated in this contribution. Ce4+–SO32− in acidic conditions was taken as the CL system and sensitized CL intensities of Tb3+–FQ and Eu3+–FQ complexes were determined by flow-injection analysis. The luminescence and CL spectra of Tb3+–FQ complexes show characteristic peaks of Tb3+ at 490 nm, 545 nm, 585 nm and 620 nm. Complexes of Tb3+–ENX, Tb3+–NFLX, Tb3+–LMFX and Tb3+–FLRX display relatively strong emission intensity compared with Tb3+–OFLX, Tb3+–RFX, Tb3+–GFLX and Tb3+–SPFX. Quite weak peaks with unique characters of Eu3+ at 590 nm and 617 nm appear in the luminescence and CL spectra of Eu3+–ENX, but no notable sensitized luminescence and CL of Eu3+ could be observed when Eu3+ is added into other FQ. The distinct differences on emission intensity of Tb3+–FQ and Eu3+–FQ might originate from the different energy gap between the triplet levels of FQ and the excited levels of the Ln3+. The different sensitized luminescence and CL signals among Tb3+–FQ complexes could be attributed to different optical properties and substituents of these FQ compounds. The detailed mechanism involved in the luminescence and CL properties of Tb3+–FQ and Eu3+–FQ complexes has been investigated by analyzing the luminescence and CL spectra, quantum yields, and theoretical calculation results. 相似文献
20.
Bianca S. Shemper 《European Polymer Journal》2004,40(4):651-665
The synthesis of a fluorinated macroinitiator for copper-catalyzed atom transfer radical polymerization (ATRP) is reported, as well as its use for the controlled living polymerization of poly(propylene glycol) methacrylate (PPGM) in MEK at 80 °C. The ATRP system used was efficient for polymerization of the functionalized monomer and the molecular weight of the polymer estimated by NMR spectroscopy was in close agreement with the theoretical molecular weight, as expected for controlled processes. The statistical copolymerization of PPGM or methyl ether poly(ethylene glycol) methacrylate (MPEGMA) with a perfluoroalkyl ethyl methacrylate by copper-mediated ATRP was also investigated and led to copolymers with essentially random incorporation of monomers. The syntheses and characterization of star-like homopolymers of MPEGMA or the fluorinated monomer via ATRP are also reported, as well as an amphiphilic star-like block copolymer containing ethyleneglycol units as the core and fluorinated moieties in the shell. The micellar behavior of this copolymer was investigated as a function of the external environment. 相似文献