Halogens

卤素
  • 文章类型: Journal Article
    最近开发和使用的分子建模方法通过XSAR集搜索卤素键(XB热点)的特权氨基酸已应用于5-HT7R。在这里,在所有确定的5-HT7RXB热点中,在虚拟筛查方案中采用S5x42作为约束条件.通过设计的虚拟筛选协议,从超过8百万的市售化合物中选择63个XSAR组(156个化合物),并使用针对5-HT7R的体外测定进行检查。在预测对5-HT7R的亲和力高于其未取代类似物的卤化衍生物时,发现准确率为68%。此外,观察到S5x42与芳基哌嗪片段3位的氯原子之间形成的卤素键引起了最显著的,与非卤化类似物相比,对5-HT7R的结合亲和力增加35.4倍。有趣的是,分子动力学模拟显示与S5x42形成分叉卤键。
    The recently developed and used molecular modeling approach to search for privileged amino acids for halogen bonding (XB hot spots) through XSAR sets has been applied to 5-HT7R. Herein, among all identified 5-HT7R XB hot spots, the S5x42 was employed in a virtual screening protocol as a constraint. Through a designed virtual screening protocol, 63 XSAR sets (156 compounds) were selected from more than 8 million commercially available compounds and examined using in vitro assay toward 5-HT7R. A 68% accuracy was found in predicting halogenated derivatives with higher affinity for 5-HT7R than their unsubstituted analogs. Moreover, it was observed that a halogen bond formed between S5x42 and a chlorine atom at the 3-position of the arylpiperazine fragment caused the most remarkable, 35.4-fold increase in binding affinity for 5-HT7R when compared to the nonhalogenated analog. Interestingly, molecular dynamics simulations showed the formation of a bifurcated halogen bond with S5x42.
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  • 文章类型: Journal Article
    表皮生长因子受体(EGFR)由于其在酪氨酸激酶家族中的重要性而成为癌症治疗中的关键靶标。EGFR抑制剂,如AG-1478和PD153035,具有4-苯胺基喹唑啉部分,因其有效的治疗活动而受到全球关注。虽然临床前研究强调了C3'-苯胺基位的卤素取代对药物效力的显著影响,潜在机制尚不清楚.本研究调查了卤素取代的影响(X=H,F,Cl,Br,I)在结构上,属性,和使用具有B3LYP功能的时间依赖性密度功能方法(TD-DFT)的卤素取代的4-苯胺喹唑啉酪氨酸激酶抑制剂(TKIs)的光谱学。我们的计算表明,卤素取代不会引起TKI三维构象的显着变化,但会导致电子性质的显着变化,如偶极矩和空间范围,影响EGFR结合位点的相互作用。紫外可见光谱表明,更有效的TKI-X化合物通常具有更短的波长,溴的峰值波长为326.71nm,氢,具有最低的IC50nM,将其λmax移至333.17nm,表明效力和光谱特征之间的相关性。进一步分析每个TKI-X的四个最低位构象,以及它们来自EGFR数据库的晶体结构,证实了最有效的构象通常不是全局最小结构,而是低洼的构象之一。与其他TKI-X(RMSD<0.15bias)相比,更有效的TKI-Cl和TKI-Br与其全球最小结构的偏差更大(RMSD>0.65bias),表明效力与更大的灵活性有关。TKI-X的偶极矩与药物效力(ln(IC50nM))相关,TKI-Cl和TKI-Br在其整体最小值和晶体结构中均显示出显着更高的偶极矩(>8.0德拜)。此外,光谱偏移与效力相关,由于TKI-Cl和TKI-Br从其全球最小结构表现出蓝色变化,与其他TKI-X相比。这表明光学报告可以有效地探测药物效力和构象变化。
    The epidermal growth factor receptor (EGFR) is a pivotal target in cancer therapy due to its significance within the tyrosine kinase family. EGFR inhibitors like AG-1478 and PD153035, featuring a 4-anilinoquinazoline moiety, have garnered global attention for their potent therapeutic activities. While pre-clinical studies have highlighted the significant impact of halogen substitution at the C3\'-anilino position on drug potency, the underlying mechanism remains unclear. This study investigates the influence of halogen substitution (X = H, F, Cl, Br, I) on the structure, properties, and spectroscopy of halogen-substituted 4-anilinoquinazoline tyrosine kinase inhibitors (TKIs) using time-dependent density functional methods (TD-DFT) with the B3LYP functional. Our calculations revealed that halogen substitution did not induce significant changes in the three-dimensional conformation of the TKIs but led to noticeable alterations in electronic properties, such as dipole moment and spatial extent, impacting interactions at the EGFR binding site. The UV-visible spectra show that more potent TKI-X compounds typically have shorter wavelengths, with bromine\'s peak wavelength at 326.71 nm and hydrogen, with the lowest IC50 nM, shifting its lambda max to 333.17 nm, indicating a correlation between potency and spectral characteristics. Further analysis of the four lowest-lying conformers of each TKI-X, along with their crystal structures from the EGFR database, confirms that the most potent conformer is often not the global minimum structure but one of the low-lying conformers. The more potent TKI-Cl and TKI-Br exhibit larger deviations (RMSD > 0.65 Å) from their global minimum structures compared to other TKI-X (RMSD < 0.15 Å), indicating that potency is associated with greater flexibility. Dipole moments of TKI-X correlate with drug potency (ln(IC50 nM)), with TKI-Cl and TKI-Br showing significantly higher dipole moments (>8.0 Debye) in both their global minimum and crystal structures. Additionally, optical spectral shifts correlate with potency, as TKI-Cl and TKI-Br exhibit blue shifts from their global minimum structures, in contrast to other TKI-X. This suggests that optical reporting can effectively probe drug potency and conformation changes.
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  • 文章类型: Journal Article
    骨质疏松症是一种常见的骨骼疾病,促使人们探索潜在的治疗方法,包括膳食锶离子补充剂。这项研究评估了补充三种锶形式-柠檬酸锶(SrC)的功效,雷奈酸锶(SrR),和氯化锶(SrCl)-增强50只雌性SWISS小鼠的骨骼结构,7周龄总的来说,40只小鼠接受了卵巢切除术,10人接受了假卵巢切除术。卵巢切除(OVX)小鼠被随机分配到以下组:OVX(无补充),OVX+SrR,OVX+SrC,和OVX+SrCl,浓度相当于锶的摩尔量。16周后,显微CT检查小梁和皮质骨,并测定了全骨锶含量。结果证实锶给药增加骨组织矿物质密度(TMD)和Sr含量,SrC表现出最弱的效果。股骨形态测量显示Sr影响有限,特别是在OVX+SrC组中。这项研究强调了锶在骨骼健康方面的潜力,强调其形式之间功效的差异。
    Osteoporosis stands out as a prevalent skeletal ailment, prompting exploration into potential treatments, including dietary strontium ion supplements. This study assessed the efficacy of supplementation of three strontium forms-strontium citrate (SrC), strontium ranelate (SrR), and strontium chloride (SrCl)-for enhancing bone structure in 50 female SWISS mice, aged seven weeks. In total, 40 mice underwent ovariectomy, while 10 underwent sham ovariectomy. Ovariectomized (OVX) mice were randomly assigned to the following groups: OVX (no supplementation), OVX + SrR, OVX + SrC, and OVX + SrCl, at concentrations equivalent to the molar amount of strontium. After 16 weeks, micro-CT examined trabeculae and cortical bones, and whole-bone strontium content was determined. Results confirm strontium administration increased bone tissue mineral density (TMD) and Sr content, with SrC exhibiting the weakest effect. Femur morphometry showed limited Sr impact, especially in the OVX + SrC group. This research highlights strontium\'s potential in bone health, emphasizing variations in efficacy among its forms.
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  • 文章类型: Journal Article
    通过采用量子力学方法,对存在于正杂硼烷中的卤素原子上的σ孔进行了详细研究。溴化物和羟基基团被结合在正硼烷的外取代基中。将溴化物σ-孔的电势与羟基对应物的静电势进行比较。碳原子顶点的存在,在系统的不同位置,影响σ孔,从而影响其结合能力。与它们的closo对应物相比,溴化物取代的nido-碳硼烷的潜力较小,因此结合能力较弱。与芳香族系统相比,发现与脂肪族的结合亲和力更高。溶剂的存在抑制了静电相互作用。除了中立系统,还研究了带电nido-异硼烷的结合能力。这项研究的结果将对几种应用进一步有用,即。,晶体工程,药物设计(制药),医学,材料科学,储能设备,等。
    A detailed investigation of the σ-hole on the halogen atom present in the nido-heteroboranes is made by employing quantum mechanical methods. The bromide and the hydroxyl groups are incorporated in the exo-substituents of the nido-boranes. The potential of the bromide σ-hole was compared to that of electrostatic potential of hydroxyl group counterpart. The presence of a carbon atom vertex, in a different position of a system, influences the σ-hole and hence its binding abilities. Bromide substituted nido-carboranes have less potential and hence weaker binding ability compared to their closo-counterparts. Binding affinity with aliphatic is found to be more compared to that of aromatic system. The presence of solvent dampened the electrostatic interactions. Apart from the neutral system, the binding capabilities of charged nido-heteroboranes were also studied. The results of this study will be further useful for several applications viz., crystal engineering, drug designing (Pharmaceuticals), medicine, material science, energy storage devices, etc.
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  • 文章类型: Journal Article
    为了更好地研究低疲劳荷载下粉煤灰或磨细高炉矿渣对混凝土中氯离子迁移的影响,本文建立了Caputo时间分数阶氯离子扩散模型。模型,以Fick第二定律为基础,具有分数阶导数,采用隐式数值方法进行离散化,产生分数阶数值格式。本文严格证明了该方案的稳定性和收敛性。模型的未知参数采用遗传算法和网格方法进行估计。为了验证模型的有效性,其数值解与氯化物侵蚀研究的实验结果并列。此外,将Caputo时间分数阶数值格式的拟合功效与经典Fick第二定律数值格式和解析解的拟合功效进行了比较。研究结果表明,分数阶数值格式可以更准确地模拟含粉煤灰或矿渣混凝土中的氯化物浓度。此外,该模型在预测粉煤灰或矿渣混凝土的使用寿命方面显示出了希望。
    To better study the chloride ion migration in concrete with fly ash or ground granulated blast furnace slag under low fatigue load, a Caputo time fractional-order chloride diffusion model is developed in this paper. The model, grounded in Fick\'s second law with a fractional-order derivative, employs an implicit numerical method for discretization, resulting in a fractional-order numerical scheme. The stability and convergence of the scheme are rigorously proven within the paper. The model\'s unknown parameters are estimated using genetic algorithm with a grid method. To validate the model\'s effectiveness, its numerical solution is juxtaposed with experimental results from chloride erosion studies. Furthermore, the fitting efficacy of the Caputo time fractional-order numerical scheme is compared with that of the classical Fick\'s second law numerical scheme and analytical solution. The research findings demonstrate that the fractional-order numerical scheme can more accurately simulate the chloride concentration in concrete containing fly ash or slag. Additionally, the model shows promise in predicting the service life of fly ash or slag concrete.
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  • 文章类型: Journal Article
    短链氯化石蜡(短链氯化石蜡)被列入《斯德哥尔摩公约》。因此,选择合适的方法对它们的准确量化至关重要。如今,不能保证用作定量标准的商业试剂的质量。作为解决方案,我们采用具有已知同源物组成比的SCCP制剂参考材料作为定量标准,以评估方法的适当性.通过混合SCCP配方和干扰,独立制备分析样品并用作模拟环境样品。短链氯化石蜡的同系物组成概况类似于定量标准和分析样品。质量分数和同系物轮廓,包括碳链长度和氯同系物,14个不同的实验室报告了短链氯化石蜡。对于质量分数,参与者报告的结果是一致的,除了使用低分辨率气相色谱法(GC)的参与者。液相色谱(LC)和GC产生的结果略有不同,尽管定量标准和分析样品之间的同源组成比相似。尽管在整个氯同系物中存在差异,从GC和LC获得的碳链长度分布相似。差异取决于所采用的方法。此外,与低分辨率数据相比,由于高分辨率仪器的质量精度降低了干扰对分析样品的影响,因此高分辨率数据的波动较小。因此,实验室间试验采用相似的同系物组成的定量标准和分析样品证明有价值的方法之间的差异,考虑到设备,分辨率规格,和电离。
    Short-chain chlorinated paraffins (SCCPs) are listed in the Stockholm Convention. Therefore, selecting suitable methods for their accurate quantification is essential. Nowadays, the quality of commercial reagents employed as quantification standards is not guaranteed. As a solution, we adopted an SCCP formulation reference material with known homolog composition ratios as the quantification standard to evaluate the appropriateness of the methods. By mixing the SCCP formulation and interferences, an analytical sample was independently prepared and used as the simulation environmental sample. The homolog compositional profiles of the SCCPs resembled those of the quantification standard and the analytical sample. The mass fractions and the homolog profiles, including the carbon chain length and chlorine homolog profiles, of the SCCPs were reported by 14 different laboratories. For the mass fraction, the results reported by participants were consistent, except for the participants that employed low-resolution gas chromatography (GC). The results generated from liquid chromatography (LC) and GC were slightly different, despite of the similar homolog composition ratios between the quantification standard and the analytical sample. Although there were discreet discrepancies in the overall chlorine homolog profiles, the carbon chain length profiles acquired from GC and LC were similar. The differences depended on the method employed. Additionally, compared with the low-resolution data, the high-resolution data displayed less fluctuation since the effect of the interferences on the analytical sample was reduced because of the mass accuracy of high-resolution instruments. Accordingly, the interlaboratory trial employing the similar homolog compositional profiles of the quantification standard and the analytical sample proved valuable in elucidating the differences among methods, considering equipment, resolution specification, and ionization.
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  • 文章类型: Journal Article
    合成了一系列卤素取代的aurone衍生物(2a-k),并进行了针对NCI60癌细胞系的抗增殖研究,并显示大多数化合物主要表现出对MCF-7的有希望的活性。在10μM的单剂量测定中,化合物2e表现出对MCF-7癌细胞系的有希望的抗癌活性,具有84.98%的生长抑制百分比,IC50值为8.157±0.713μM。在凋亡试验中,化合物2e对细胞周期进程的影响表明,MCF-7细胞暴露于化合物2e诱导细胞周期谱的显著破坏,包括G0/G1和G2/M期细胞群的时间依赖性减少,并将细胞周期阻滞在S期。在硅片中,还进行了分子对接ADME和所有化合物的毒性研究。对接研究表明,所有的aurone衍生物都显示出良好的对接分数,范围为-7.066至-8.573。对活性最高的化合物2e和活性最低的化合物2k的分子静电势映射(MESP)和密度泛函理论(DFT)研究的结果也有利于实验结果。
    A series of halogen-substituted aurone derivatives (2a-k) were synthesized and evaluated for an anti-proliferative study against NCI 60 cancer cell line panel and showed that most of the compounds predominantly exhibited promising activity against MCF-7. Compound 2e exhibited promising anticancer activity against the MCF-7 cancer cell line with 84.98% percentage growth inhibition in a single dose assay of 10 μM with an IC50 value of 8.157 ± 0.713 μM. In apoptotic assay, the effect of compound 2e on the cell cycle progression indicated that exposure of MCF-7 cells to compound 2e induced a significant disruption in the cell cycle profile including a time-dependent decrease in the cell population at G0/G1 and G2/M phase and arrests the cell cycle at the S phase. In silico, molecular docking ADME and toxicity studies of all compounds were also carried out. The docking study revealed that all the aurone derivatives displayed good docking scores ranging from -7.066 to -8.573. The results of Molecular Electrostatic Potential Mapping (MESP) and Density Functional Theory (DFT) studies of the most active compound 2e and least active compound 2k also favoured the experimental results.
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  • 文章类型: Journal Article
    X射线显微断层成像(micro-CT)的内部三维特征在青铜腐蚀领域具有巨大的应用潜力。这项工作提出了一种基于原位显微CT图像模拟青铜病的方法,以研究氯化铜(I)和氯化铜(II)二水合物的氧化水解反应的特征。通过在整个实验过程中的三个关键点进行显微CT,获得了一系列高分辨率的重建图像。我们发现,在micro-CT视图中,氯化铜(I)和氯化铜(II)二水合物的反应在模拟的不同阶段表现出不同的特征。这项工作中提出的方法专门模拟了一种单一类型的青铜腐蚀,并表征了模拟青铜病害的演变特征。它为研究青铜病提供了一个新的视角,并可以帮助改善后续使用Micro-CT来区分真实的青铜腐蚀。
    The internal three-dimensional characteristics of X-ray microtomography (micro-CT) has great application potential in the field of bronze corrosion. This work presents a method of simulating bronze disease based on an in situ micro-CT image to study the characteristics of the oxidative hydrolysis reactions of copper(I) chloride and copper(II) chloride dihydrate. A series of high-resolution reconstruction images were obtained by carrying out micro-CT at three key points throughout the experiment. We found that the reactions of copper(I) chloride and copper(II) chloride dihydrate showed different characteristics at different stages of the simulation in the micro-CT view. The method proposed in this work specifically simulated one single type of bronze corrosion and characterized the evolution characteristics of simulated bronze disease. It provides a new perspective to investigate bronze disease and can help improve the subsequent use of micro-CT to distinguish real bronze corrosions.
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  • 文章类型: Journal Article
    煤炭自燃(CSC)是全球性灾害,危害生态环境。本研究旨在更好地将环境友好的可溶性微小泡沫灭火器(DTE)应用于CSC,并进一步研究其抑制机理。采用热重分析和差示扫描量热法(TG-DSC)测试了DTE处理煤样的氧化性能,NaCl,MgCl2和CaCl2抑制剂,确定了高温阶段煤氧化的反应机理和动力学参数。结果表明,在煤氧化初期,四种抑制剂的抑制作用相似,DTE将煤的裂解温度提高了37°C,达到点火温度时,质量损失最小,在低温下抑制效果优于其他抑制剂。DTE具有较高的热稳定性,在高温下起到稳定的抑制作用,而氯盐抑制剂促进了氧化放热反应。DTE煤样在吸热阶段吸收的热量比原煤多40倍,比MgCl2多十倍,释放的热量最少。在分解和燃烧阶段,煤与氧的反应机理符合三维扩散Z.-L。-T.方程,DTE处理煤样的表观活化能比原煤高约40kJ/mol。
    Coal spontaneous combustion (CSC) is a global disaster and detrimental to the ecological environment. This study aims to better apply environmentally friendly dissolvable tiny-foam extinguisher (DTE) to CSC and look further into the inhibition mechanism. Thermogravimetric analysis and differential scanning calorimetry (TG-DSC) were employed to test the oxidation properties of coal samples treated with DTE, NaCl, MgCl2, and CaCl2 inhibitors, and the reaction mechanisms and kinetic parameters in the high-temperature stage of coal oxidation were determined. The results revealed that the inhibition of the four inhibitors was similar in the initial period of the coal oxidation, DTE increased the cracking temperature of the coal by 37 °C, mass loss was a minimum when reaching the ignition temperature, and inhibition was better than the other inhibitors at the low temperature. DTE had higher thermal stability and played a stable role in suppression at the high temperature, while chlorine salt inhibitors promoted the oxidative exothermic reaction. DTE coal sample absorbed forty times more heat during the endothermic stage than raw coal, ten times more than MgCl2, and released a minimum of heat. In the decomposition and combustion stages, the reaction mechanism of coal and oxygen conformed to the three-dimensional diffusion Z.-L.-T. equation, and the apparent activation energy of the DTE-treated coal sample was about 40 kJ/mol higher than raw coal.
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  • 文章类型: Journal Article
    为了探索身体的影响,机械,氧化石墨烯(GO)在水泥基胶凝材料上的抗劣化性能,采用改进的Hummers法和超声分散法制备GO片材分散体。研究了GO含量对水泥浆抗压强度和抗弯强度的影响,并利用电加速侵蚀法探讨了氯离子在氧化石墨烯混凝土中的渗透过程。结合快速冻融试验,对氧化石墨烯混凝土的劣化进行了分析。获得的结果表明,适量的GO可以提高水泥的抗压强度和抗弯强度。在氯化物环境中,0.03%GO混凝土的氯离子扩散系数比普通混凝土小18.75%。在冻融循环的作用下,随着盐冻次数的增加,GO混凝土的劣化模式是砂浆脱落的组合,微裂纹扩展,剥蚀,块脱落;随着盐冻次数的增长,试样的应力-应变曲线趋于平坦。峰值应力逐渐减小,峰值应变逐渐增加,并且弹性模量显著降低。与普通水泥浆相比,GO能够促进水泥浆水化晶体的生长,改变晶体的大小和形状,实现了对水泥浆体微观结构的调控。掺入适量的GO可以促进水泥水化过程,并提高水泥浆中的化学水结合量。据报道,最佳GO含量为水泥质量的0.03%。
    To exploretheeffects of physical, mechanical, anti-deterioration properties of graphene oxide (GO) on cement-based cementitious materials, GO sheet dispersions areprepared by the improved Hummers method and ultrasonic dispersion method. The influence of theGO content on the compressive and flexural strengths of cement paste is investigated, and the penetration process of chloride ions in graphene oxide concrete is discussed by the electric accelerated erosion method. Combined with the rapid freeze-thaw test, the deterioration of graphene oxide concrete ismethodically analyzed. Theobtained results reveal that an appropriate amount of GO improves both the compressive and flexural strengths of cement pastev. In the chloride environment, the chloride diffusion coefficient of 0.03% GO concrete is 18.75% less than that of ordinary concrete.Under the action of freeze-thaw cycles, with the increase of salt freezing times, the deterioration mode of GO concrete is a combination of mortar shedding, micro-crack expansion, denudation, and block shedding; The stress-strain curve of the specimen tends to be flat with the growth of salt freezing times. The peak stress gradually lessens, the peak strain gradually grows, and the elastic modulus remarkably reduces. Compared with ordinary cement paste, theGO is capable of promoting the growth of cement paste hydration crystals, changing the size and shape of crystals, and realizingthe regulation of cement paste microstructure. Incorporating an appropriate amount of theGO could promote the cement hydration process and enhance the chemical water-binding amount in the cement paste. The optimal GO content is reported to be 0.03% of the cement mass.
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