ECD

ECD
  • 文章类型: Journal Article
    从科迪亚的果实中,11个新的酚类化合物,二分法A-K,被隔离,连同19种已知化合物。通过详细的NMR数据和HRESIMS数据的分析,证实了所有化合物的平面结构。使用NMR计算,通过比较观察到的和计算的电子圆二色性(ECD)光谱,阐明了二分法A-K的绝对构型。将双光菌素H(8)和双光菌素I(9)确定为两对对映异构体。化合物8和9的对映体采用手性相高效液相色谱(HPLC)分离,并且通过类似地计算ECD来确定每个对映异构体的立体结构。化合物3、5、7、17、18、23-25和27-30在30μg/mL的浓度下使葡萄糖摄取增加1.04-至2.85倍。进一步的研究表明,化合物3和5对L6细胞中的葡萄糖转运蛋白4(GLUT4)易位活性具有中等作用。在30μg/mL时,化合物3显著增强AMPK磷酸化和GLUT4表达。作为一个整体,化合物3有可能成为治疗2型糖尿病(T2DM)的候选药物。
    From the fruits of Cordia dichotoma, 11 new phenolic compounds, dichotomins A-K, were isolated, together with 19 known compounds. Through the analysis of detailed NMR data and HRESIMS data, the planar structures of all compounds were confirmed. Using NMR calculations, the absolute configuration of dichotomins A-K was elucidated by comparing their observed and computed electronic circular dichroism (ECD) spectra. Dichotomin H (8) and dichotomin I (9) were determined as two pairs of enantiomers. The enantiomers of compounds 8 and 9 were separated using chiral-phase high-performance liquid chromatography (HPLC), and the stereostructure of each enantiomer was determined by similarly calculating the ECD. Compounds 3, 5, 7, 17, 18, 23-25, and 27-30 increased glucose uptake by 1.04- to 2.85-folds at concentrations of 30 μg/mL. Further studies revealed that compounds 3 and 5 had a moderate effect on glucose transporter 4 (GLUT4) translocation activity in L6 cells. At 30 μg/mL, compound 3 significantly enhanced AMPK phosphorylation and GLUT4 expression. As a whole, compound 3 has the potential to be a drug candidate for the treatment of type 2 diabetes mellitus (T2DM).
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  • 文章类型: Journal Article
    (R)-(-)-Mellein,(3R,4R)-4-羟基mellein和(3R,4S)-4-羟基mellein从真菌中获得,也就是来自双创,被研究为一类呈现ESIPT(激发态分子内质子转移)现象的天然产物,通过荧光和CPL(圆偏振发光)。在研究之前,除了NMR光谱外,还通过ECD和VCD(电子和振动圆二色性)光谱法评估了绝对构型。发现ESIPT在这些系统中发生得非常快,并且没有观察到双重荧光。实验研究得到了ECD和CPL光谱的TD-DFT计算的支持,加上MD动力学,以跟踪激发态下的质子转移,并仔细分析内酯环的起皱动力学。还通过相同的手性实验和理论方法研究了三种化合物的去质子化形式,显示了如何在天然化合物中不仅可以找到生物活性,还可以找到生物相容性传感探针。
    (R)-(-)-Mellein, (3R,4R)-4-hydroxymellein and (3R,4S)-4-hydroxymellein obtained from fungi, i.e. from Diplodia globulosa, were investigated as a class of natural products presenting ESIPT (excited state intramolecular proton transfer) phenomenon, through fluorescence and CPL (circularly polarized luminescence). The study was preceded by the assessment of the absolute configuration through ECD and VCD (electronic and vibrational circular dichroism) spectroscopies in addition to NMR spectra. It is found that ESIPT takes place in these systems very rapidly, and no dual fluorescence has been observed. The experimental study is backed up by TD-DFT calculations of ECD and CPL spectra, plus MD dynamics to follow proton transfer in the excited state and careful analysis of the puckering dynamics of the lactone ring. Deprotonated forms of the three compounds were also investigated by the same chiroptical experimental and theoretical methods, showing how one can find in natural compounds not only biological activity but also biologically compatible sensing probes.
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  • 文章类型: Journal Article
    本研究利用密度泛函理论(DFT)和波函数分析探讨了量子尺寸对[n]芳烃(n=5、6、7、8)光学性质的影响。研究了单光子吸收(OPA)和双光子吸收(TPA)光谱中的电子跃迁机理,以及这些系统的电子圆二色性(ECD)的计算。过渡密度矩阵(TDM)和电子-空穴对密度图用于研究电子激发特性,揭示了一个值得注意的大小依赖关系。对跃迁电偶极矩(TEDM)和跃迁磁偶极矩(TMDM)的分析揭示了柱[n]芳烃内部的电磁相互作用机制。拉曼光谱计算进一步阐明振动模式,在使用静电势(ESP)分析研究与外部环境的相互作用时,在外部磁场下评估电子离域,提供对这些超分子结构中磁感应电流现象的见解。通过从头算分子动力学(AIMD)研究了柱[n]芳烃的热稳定性。
    This study explores the quantum size effects on the optical properties of pillar[n]arene (n = 5, 6, 7, 8) utilizing density functional theory (DFT) and wave function analysis. The mechanisms of electron transitions in one-photon absorption (OPA) and two-photon absorption (TPA) spectra are investigated, alongside the calculation of electron circular dichroism (ECD) for these systems. Transition Density Matrix (TDM) and electron-hole pair density maps are employed to study the electron excitation characteristics, unveiling a notable size dependency. Analysis of the transition electric dipole moment (TEDM) and the transition magnetic dipole moment (TMDM) reveals the electromagnetic interaction mechanism within pillar[n]arene. Raman spectra computations further elucidate vibrational modes, while interactions with external environments are studied using electrostatic potential (ESP) analysis, and electron delocalization is assessed under an external magnetic field, providing insights into the magnetically induced current phenomena within these supramolecular structures. The thermal stability of pillar[n]arene was investigated by ab initio molecular dynamics (AIMD).
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  • 文章类型: Journal Article
    糖基化是生物体中常见的修饰,在理解生物系统和疾病中起着核心作用。在过去的几十年中,我们探测gylcome的能力呈指数级增长。然而,对研究人员可用的分析工具箱的进一步改进将允许增强探测生物系统的结构和功能以及改善疾病治疗的能力。本文将二维傅立叶变换离子回旋共振质谱技术应用于标准糖蛋白珊瑚树凝集素(CTL)和牛核糖核酸酶B(BRB)的糖蛋白质组学工作流程,以证明其作为糖蛋白质组学工作流程工具的可行性。CTL的2D红外多光子解离和电子捕获解离光谱揭示了与其1D对应物相当的结构信息,确认聚糖的糖基化位点和单糖组成。在BRB的2D中收集的光谱揭示了使用红外多光子解离收集的数据的碎片离子扫描和垂直前体离子扫描的相关线,以及通过电子捕获解离收集的数据的对角分裂线。在不希望色谱分离或四极杆分离不充分的情况下,使用类似的技术进行糖蛋白质组分析可能证明是有价值的。
    Glycosylation is a common modification across living organisms and plays a central role in understanding biological systems and disease. Our ability to probe the gylcome has grown exponentially in the past several decades. However, further improvements to the analytical toolbox available to researchers would allow for increased capabilities to probe structure and function of biological systems and to improve disease treatment. This article applies the developing technique of two-dimensional Fourier transform ion cyclotron resonance mass spectrometry to a glycoproteomic workflow for the standard glycoproteins coral tree lectin (CTL) and bovine ribonuclease B (BRB) to demonstrate its feasibility as a tool for glycoproteomic workflows. 2D infrared multiphoton dissociation and electron capture dissociation spectra of CTL reveal comparable structural information to their 1D counterparts, confirming the site of glycosylation and monosaccharide composition of the glycan. Spectra collected in 2D of BRB reveal correlation lines of fragment ion scans and vertical precursor ion scans for data collected using infrared multiphoton dissociation and diagonal cleavage lines for data collected by electron capture dissociation. The use of similar techniques for glycoproteomic analysis may prove valuable in instances where chromatographic separation is undesirable or quadrupole isolation is insufficient.
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  • 文章类型: Journal Article
    研究了卟啉-卟啉Tröger碱和卟啉-二氢卟啉螺-Tröger碱的镍(II)配合物的手性,其内消旋位置具有苯基或3-甲氧基苯基取代基。通过高效液相色谱(HPLC)在分析性ReproSil手性-NR柱上研究了外消旋混合物的对映体分离。最佳条件用于半制备色谱柱的多毫克规模分离。通过HPLC和UV-Vis光谱法测定分离的对映体的纯度。通过评估电子圆二色性光谱中的Cotton效应来确定分离的对映体的绝对构型。该确定得到了TDDFT计算的支持,其中实验和模拟光谱之间达到了很好的一致性。最大摩尔椭圆率值,[θ]λmax,单位为deg•cm2•dmol-1,苯基螺TB为[θ]435=1.73•107,3-甲氧基苯基TB为[θ]436=1.24•107和[θ]436=2.15•107,分别。
    The chiral properties of nickel(II) complexes of porphyrin-porphyrin Tröger\'s base and porphyrin-chlorin spiro-Tröger\'s base with phenyl or 3-methoxyphenyl substitutions in their meso-positions were studied. Enantioseparation of racemic mixtures was investigated via high-performance liquid chromatography (HPLC) on an analytical ReproSil Chiral-NR column. The optimal conditions were utilized for a multimilligram scale isolation with a semipreparative column. The purity of the isolated enantiomers was determined by HPLC and UV-Vis spectroscopy. The absolute configurations of the isolated enantiomers were determined by evaluating the Cotton effect in electronic circular dichroism spectra. The determination was supported by TDDFT calculations, in which good agreement was achieved between the experimental and simulated spectra. The maximum molar ellipticity values, [θ]λmax given in deg ∙ cm2 ∙ dmol-1, were [θ]435 = 1.73 ∙ 107 for phenyl spiroTB and [θ]436 = 1.24 ∙ 107 and [θ]436 = 2.15 ∙ 107 for 3-methoxyphenyl TB and spiroTB, respectively.
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  • 文章类型: Journal Article
    真菌在不同的培养条件下具有不同的遗传表达能力和生物合成途径,可以产生各种次生代谢产物。“一株多化合物”策略用于激活真菌的沉默生物合成基因以产生各种化合物,这是一种有效的方法。为了在食用菌Pholiotanameko中发现各种新化合物,已经采用了涉及前体进料和酶抑制剂添加的发酵策略。一种新的伊卢丹倍半萜(1),连同一种已知的吲哚二萜生物碱,从P.nameko的液体培养物的提取物中分离出克多孢菌素A(2)。通过1D和2DNMR的组合鉴定了新化合物,MS,旋光,和ECD计算。我们对所有分离的化合物对三种癌细胞系的细胞毒性进行了实验,但我们没有观察到任何显著的细胞毒性(IC50>40μM)。
    Fungi have different genetic expression abilities and biosynthetic pathways under different cultivation conditions, which can produce various secondary metabolites. The \"one strain many compounds\" strategy is used to activate silent biosynthetic genes of fungi to produce various compounds, which is an effective method. In order to discover various new compounds in the edible fungus Pholiota nameko, a fermentation strategy involving precursor feeding and enzyme inhibitor addition has been employed. A new illudane sesquiterpene (1), along with one known indole diterpenoid alkaloid, cladosporine A (2) were isolated from the extracts of liquid culture of P. nameko. The new compound was identified by combination of 1D and 2D NMR, MS, optical rotation, and ECD calculations. We conducted experiments on the cytotoxicity of all isolated compounds on three cancer cell lines, but we did not observe any significant cytotoxicity (IC50 > 40 μM).
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  • 文章类型: Case Reports
    跨越心理学等领域数十年的研究,教育,神经科学始终强调社会情绪技能在个人各个方面的关键作用,学术,和专业发展(1-3)。教科文组织认识到社会情感学习(SEL)不仅对于实现其教育目标,而且对于实现可持续发展目标至关重要,这一事实凸显了强大的社会情感发展在建立可持续社会中的关键作用。虽然各种研究强调了SEL的重要性,关于组织如何通过有意识地将SEL纳入其工作实践中来为构建此类开发做出贡献的关注有限。
    我们的案例研究介绍了在9个月内将SEL整合到组织实践中的过程。SEL的选定结构是由组织的需求和价值观决定的。测量变化的方法被用来框架和实施干预,互动讨论是关键的方法。数据是通过调查收集的,反射分享,和观察。
    记录了选定的SEL构建体的偏移,数据突出了个体差异。
    共同设计和持续反思实践的过程是在组织的子集内实现变革的关键,而不是所使用材料的具体内容。
    Research spanning decades across fields such as psychology, education, and neuroscience consistently highlights the crucial role of social-emotional skills in various aspects of personal, academic, and professional development (1-3). The fact that UNESCO recognises social-emotional learning (SEL) as essential not just for meeting its educational objectives but also for accomplishing the Sustainable Development Goals highlights the crucial role robust social-emotional development plays in establishing sustainable societies. Whilst various studies highlight the importance of SEL, there is limited attention on how organizations can contribute to building such development by consciously including SEL in their work practice.
    Our case study presents the process of integrating SEL into organizational practice over a period of 9 months. The selected constructs of SEL were determined by the organisation\'s needs and values. The Measurement for Change approach was used to frame and implement the intervention, with interactive discussions being the key methodology. Data were collected via surveys, reflective sharing, and observations.
    A shift in the selected constructs of SEL was recorded, with data highlighting individual differences.
    The process of co-design and continual reflective practice was key to achieving change within the subset of the organisation rather than the specific content of the materials used.
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  • 文章类型: Journal Article
    阿尔茨海默病(AD)是世界范围内痴呆的最常见原因,被归类为神经退行性疾病。从药物设计的角度来看,与大多数合成库相比,天然产物(NPs)更像药物,并且与生物系统高度兼容.NP为新药发现提供了更有效和更具成本效益的方法。然而,NP的复杂性使其识别成为一项具有挑战性的任务。嵌合体,具有三个手性中心的双环单萜,具有广泛的生物活性。尽管如此,到目前为止,黑猩猩的确切结构仍不清楚。在这项研究中,我们使用配备光电二极管阵列检测器的分析反相高压液相色谱法(RP-HPLC-PDA)定量了Ferulahaussknechtii中的嵌合体含量。此外,我们通过电子圆二色性(ECD)光谱和时间依赖性密度泛函理论(TDDFT)计算确定了黑猩猩的绝对构型。最后,我们通过体外和计算机模拟研究评估了其对AChE的抑制作用。提取过程的产量为2.82±0.10%,每100克植物的确切数量为0.62±0.04mg。根据ECD和TDDFT计算结果,黑猩猩的绝对构型被确定为1S,2S,4S。嵌合体对AChE表现出抑制作用,IC50为37.43µM,发现其作用机制具有竞争性。HighlightsChimgin是从Ferulahaussknechtii的根中分离出来的。通过RP-HPLC-PDA测定植物中的嵌合体的量。使用ECD确定其黑猩猩的绝对构型。评估了黑猩猩的体外乙酰胆碱酯酶活性。对黑猩猩进行了对接和分子动力学模拟。由RamaswamyH.Sarma沟通。
    Alzheimer\'s disease (AD) is the most common cause of dementia worldwide and is classified as a neurodegenerative disorder. From a drug design perspective, natural products (NPs) are more drug-like and are highly compatible with biological systems compared to most synthetic libraries. NPs provide a more efficient and cost-effective approach to new drug discovery. However, the complexity of NPs makes their identification a challenging task. Chimgin, a bicyclic monoterpene with three chiral centers, exhibits a wide range of biological activity. Despite this, the exact structure of chimgin has remained unclear until now. In this study, we quantified the amount of chimgin in Ferula haussknechtii using analytical Reversed-phase high-pressure liquid chromatography equipped with photodiode array detector (RP-HPLC-PDA). Furthermore, we determined the absolute configuration of chimgin through electronic circular dichroism (ECD) spectroscopy and time-dependent density functional theory (TDDFT) calculations. Finally, we evaluated its inhibitory effect on AChE through in vitro and in silico studies. The extraction process yielded an output of 2.82 ± 0.10% with an exact amount of 0.62 ± 0.04 mg of chimgin per 100 g of plant. Based on the results of ECD and TDDFT calculation, the absolute configuration of chimgin was determined to be 1S, 2S, 4S. Chimgin exhibited an inhibitory effect on AChE with an IC50 of 37.43 µM and its mechanism of action was found to be competitive. HighlightsChimgin was isolated from the roots of Ferula haussknechtii.The amount of chimgin in the plant was determined by RP-HPLC-PDA.Its absolute configuration of chimgin was determined using ECD.In vitro acetylcholinesterase activity of the chimgin was evaluated.The docking and molecular dynamic simulation of chimgin was done.Communicated by Ramaswamy H. Sarma.
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  • 文章类型: Journal Article
    在不同的条件下,DNA双螺旋可以采取不同的几何形式。在它的大量构象中,除了“规范”B表格之外,A,C,Z形式是众所周知的,还有D,Hoogsteen,和X形式是鲜为人知的。DNA在当地取A,C,Z在细胞中形成,与蛋白质的复合物。我们比较了检测非规范DNA构象的不同方法:X射线,IR,和拉曼光谱,红外和紫外区域的线性和圆二色性,以及NMR(化学位移及其各向异性的测量,标量和残余偶极耦合以及来自NOESY(核Overhauser效应光谱)数据的质子间距离)。我们讨论了应用这些方法的困难,实验结果的理论解释问题,以及可靠鉴定非规范DNA构象的前景。
    Under different conditions, the DNA double helix can take different geometric forms. Of the large number of its conformations, in addition to the \"canonical\" B form, the A, C, and Z forms are widely known, and the D, Hoogsteen, and X forms are less known. DNA locally takes the A, C, and Z forms in the cell, in complexes with proteins. We compare different methods for detecting non-canonical DNA conformations: X-ray, IR, and Raman spectroscopy, linear and circular dichroism in both the infrared and ultraviolet regions, as well as NMR (measurement of chemical shifts and their anisotropy, scalar and residual dipolar couplings and inter-proton distances from NOESY (nuclear Overhauser effect spectroscopy) data). We discuss the difficulties in applying these methods, the problems of theoretical interpretation of the experimental results, and the prospects for reliable identification of non-canonical DNA conformations.
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  • 文章类型: Journal Article
    从淫羊藿的叶子中分离出一种先前未描述的异戊烯化类黄酮(1)和三种已知类黄酮(2-4)。通过广泛的光谱分析并与文献中的NMR数据进行比较,确定了它们的结构。化合物1显示中等细胞毒性,IC50值为18.7μM,而已知的化合物2和3对Lewis肺癌细胞(LLC细胞)的IC50值分别为29.2和32.8μM,分别。
    One previously undescribed prenylated flavonoid (1) and three known ones (2-4) were isolated from leaves of Epimedium brevicornu maxim. Their structures were determined through extensive spectroscopic analysis and comparison with the NMR data in the literature. Compound 1 showed a moderate cytotoxicity with an IC50 value of 18.7 μM, while known compounds 2 and 3 elicited weak cytotoxicities with IC50 values of 29.2 and 32.8 μM against Lewis Lung cancer cells (LLC cells), respectively.
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