Journal of Molecular Structure最新文献_第4页

Corrosion inhibition of L-(+)-Rhamnose on iron in an acid media 1.0M H2SO4: Theoretical, electrochemical and morphological studies L-(+)-鼠李糖在酸性介质1.0M H2SO4中对铁的缓蚀作用：理论、电化学和形态研究

IF 4.7 2区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Molecular Structure

Pub Date : 2026-02-05 DOI: 10.1016/j.molstruc.2026.145587

Kamelia Blyid , Jaouad Bensalah , Zaki Safi , Nuha Wazzan , Adil Errahimi , Saad Benmekki , Fouad Benhiba , Rida Allah Belakhmima , Mohamed Ebn Touhami

Corrosion of iron in acidic media causes severe damage in industrial applications, making the search for eco-friendly inhibitors essential. L-(+)-Rhamnose, a biodegradable carbohydrate, was investigated as a corrosion inhibitor for iron in 1 M H₂SO₄. The Electrochemical behavior was studied using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) at 303 K, while temperature effects, surface morphology, and theoretical calculations, including Density Functional Theory (DFT) and molecular dynamics (MD) simulations, were also examined. PDP results showed that the corrosion current density icorr decreased from 1358 µA·cm⁻² for the uninhibited solution to 44.8 µA·cm⁻² at 10⁻² M L-Rhamnose, achieving an inhibition efficiency of 96.7 %. EIS confirmed this trend, with charge transfer resistance Rct increasing from 23.6 Ω·cm² to 271.8 Ω·cm² and maximum inhibition efficiency of 91.3 %. The double-layer capacitance Cdl decreased from 218 to 32 µF·cm⁻², indicating the formation of a protective adsorbed layer. Activation energy Ea increased from 29.1 kJ/mol to 93.4 kJ/mol in the presence of the inhibitor, demonstrating enhanced thermal stability. Scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM/EDS) analysis revealed improved surface morphology, while theoretical calculations identified oxygen atoms as primary adsorption sites, supporting the inhibition mechanism.

These findings demonstrate that L- (+)-Rhamnose is an effective eco-friendly corrosion inhibitor for iron in acidic environments, providing both experimental and theoretical insight into its adsorption behavior and protective mechanism, and representing a novel contribution to green corrosion inhibition solutions.

铁在酸性介质中的腐蚀在工业应用中会造成严重的损害，因此寻找环保抑制剂至关重要。研究了L-(+)-鼠李糖作为1 M H₂SO₄中铁的缓蚀剂。利用动电位极化（PDP）和电化学阻抗谱（EIS）研究了303 K下的电化学行为，同时研究了温度效应、表面形貌以及密度泛函理论（DFT）和分子动力学（MD）模拟等理论计算。PDP结果表明，未抑制溶液的腐蚀电流密度从1358 μ A·cm - 2下降到10⁻²M l -鼠李糖时的44.8 μ A·cm - 2，达到96.7%的缓蚀效率。EIS证实了这一趋势，电荷转移电阻Rct从23.6 Ω·cm²增加到271.8 Ω·cm²，最大抑制效率为91.3%。双层电容Cdl从218µF·cm - 2下降到32µF·cm - 2，说明形成了一个保护吸附层。活化能Ea由29.1 kJ/mol增加到93.4 kJ/mol，热稳定性增强。扫描电子显微镜和能量色散x射线能谱（SEM/EDS）分析表明，表面形貌得到改善，而理论计算确定氧原子是主要的吸附位点，支持抑制机制。这些研究结果表明，L-(+)-鼠李糖是酸性环境中有效的生态友好型铁缓蚀剂，为其吸附行为和保护机制提供了实验和理论见解，并代表了绿色缓蚀溶液的新贡献。

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引用次数: 0

Unraveling the impact of bromine substitution on the molecular structure, electronic properties, and thermal stability of a cobalt schiff base 揭示溴取代对钴希夫碱的分子结构、电子性质和热稳定性的影响

IF 4.7 2区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Molecular Structure

Pub Date : 2026-02-05 DOI: 10.1016/j.molstruc.2026.145593

Jiaxuan Li , Xueyuan Hu , Yanwu Li

Enhancing the thermal stability of molecular materials to ensure their structural and functional integrity at elevated temperatures is a critical challenge in materials design. To assess the influence of halogens on thermal stability in the absence of a classic halogen bond network, a brominated Co Schiff-base complex, [Co(

L_{3 - Br}^{1}

)(

L_{3 - Br}^{2}

)], was selected as the study subject. A non-halogenated derivative, [Co(

L^{1}

)(

L^{2}

)], was introduced for systematic comparison. Thermogravimetric analysis (TGA) reveals a fundamental enhancement in thermal robustness upon bromination. After accounting for the initial loss of methyl substituents of the non-halogenated analogue, a comparative analysis demonstrates that bromination raises the main skeletal decomposition temperature by approximately 80°C (from ∼200°C to 280°C). Crucially, the degradation pattern transitions from a non-cooperative, multi-stage fragmentation to a highly synchronous, single-step collapse. Computational analysis indicates two contributions to this enhanced thermal robustness: (i) a denser supramolecular packing driven by bromine-induced polarizability; and (ii) the promotion of a pervasive network of weak intra- and intermolecular contacts (e.g., C–H...Br, dispersion forces). This study demonstrates that modulating the overall electronic structure and packing density via halogen atoms is a promising strategy for engineering molecular materials with exceptional thermal stability.

提高分子材料的热稳定性以确保其在高温下的结构和功能完整性是材料设计中的一个关键挑战。为了评估卤素在缺乏经典卤素键网络的情况下对热稳定性的影响，选择溴化Co席夫碱配合物[Co(L3−Br1)(L3−Br2)]作为研究对象。引入了一种非卤化衍生物[Co(L1)(L2)]进行系统比较。热重分析（TGA）揭示了溴化后热稳健性的基本增强。在计算了非卤化类似物的甲基取代基的初始损失后，比较分析表明，溴化使主要骨架分解温度提高了约80℃（从~ 200℃提高到280℃）。关键是，退化模式从非合作的多阶段破碎转变为高度同步的单步崩溃。计算分析表明，这种增强的热鲁棒性有两个贡献：(i)由溴诱导的极化性驱动的更密集的超分子填料；（ii）促进普遍存在的弱分子内和分子间接触网络(例如，C-H…Br，色散力)。这项研究表明，通过卤素原子调节整体电子结构和堆积密度是一种很有前途的策略，可以用于具有优异热稳定性的工程分子材料。

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引用次数: 0

High-performance optical thermometry based on fluorescence intensity ratio in a novel Bi9V2O18Cl:Yb3+/Er3+ up-conversion material 基于荧光强度比的新型Bi9V2O18Cl:Yb3+/Er3+上转换材料的高性能光学测温

IF 4.7 2区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Molecular Structure

Pub Date : 2026-02-04 DOI: 10.1016/j.molstruc.2026.145572

Weiguang Ran , Jiayi Geng , Ziyou Zhou , Shuo Zhang , Xiang Li , Jinglin Shen , Mingjun Song , Tingjiang Yan

Luminescence thermometry requires materials with high luminescent efficiency and reliable thermal response for high-precision non-contact temperature sensing. In this work, a series of novel Er³⁺/Yb³⁺ doped Bi₉V₂O₁₈Cl phosphors were successfully synthesized via a high-temperature solid-state reaction method. Under 980 nm excitation, the up-conversion luminescence behavior and energy transfer mechanisms of the Er³⁺/Yb³⁺ co-doped system were investigated, with a focus on its optical thermometric performance in broad temperature range (80-500K). The Er³⁺-doped phosphor achieved a high relative thermal sensitivity (S_r) of 17.04 % K^-1 at 80 K, while the Er³⁺/Yb³⁺ co-doped sample exhibited a maximum S_r of 12.7 % K^-1 at 80 K along with excellent thermal cycling stability. These results demonstrate that the Bi₉V₂O₁₈Cl host effectively enhances luminescence efficiency and thermal response, making the doped phosphors promising for high-precision non-contact thermometry. The enhanced performance originates from the unique crystal and electronic structure of the host, and further improvements can be pursued through optimized co-doping strategies and host composition engineering.

发光测温需要具有高发光效率和可靠热响应的材料来实现高精度的非接触式测温。本文采用高温固相反应法制备了一系列新型Er3+/Yb3+掺杂Bi9V2O18Cl荧光粉。在980 nm激发下，研究了Er3+/Yb3+共掺杂体系的上转换发光行为和能量传递机理，重点研究了其在80-500K宽温度范围内的光学测温性能。Er3+掺杂的荧光粉在80 K时的相对热敏度（Sr）为17.04% K-1，而Er3+/Yb3+共掺杂的荧光粉在80 K时的最高Sr为12.7% K-1，并且具有良好的热循环稳定性。这些结果表明，Bi9V2O18Cl基质有效地提高了发光效率和热响应，使掺杂的荧光粉有望用于高精度非接触式测温。这种性能的增强源于寄主独特的晶体和电子结构，可以通过优化共掺杂策略和寄主成分工程来进一步提高。

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引用次数: 0

Facile synthesis, luminescent property and potential applications of trivalent europium complex nanocrystals 三价铕复合纳米晶体的简单合成、发光性能及潜在应用

IF 4.7 2区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Molecular Structure

Pub Date : 2026-02-04 DOI: 10.1016/j.molstruc.2026.145581

Ruiyan Dai , Xiaxia Zhang , Dongnan Tu, Jie Li, Yu Wang, Chuanlang Zhan

Although lanthanide complexes have a special luminous characteristic, they are quenched by environmental oscillators. Here, we describe a simple synthesis of Eu(III) complex nanocrystals (NCs) using the reverse-micelle approach. In comparison to the corresponding complex solutions in dichloromethane (DCM), a suitable solvent for the complexes, all five Eu(III) complexes exhibit noticeably higher photoluminescence quantum yields (14.0%–16.6% vs. 2.0%–4.0%) when their NC solutions are prepared in nonpolar solvents. The enhanced emission originates from a substantial reduction in the non-radiative rate constant (k_nr) which consequently increases the ratio of the radiative rate constant (k_r) to k_nr e.g. k_r/k_nr. Upon transitioning from the DCM solution to the aggregated NCs, additional inter-complex relaxation pathways are introduced, leading to a decrease in the exciton binding energy (E_b). Our results verify the simplicity of the synthesis and highlight the characteristic features of the Eu(III) complex NCs. Leveraging their enhanced emission, we further demonstrate their potential in fingerprint visualization on smooth substrates.

虽然镧系化合物具有特殊的发光特性，但它们会被环境振荡器猝灭。在这里，我们描述了一个简单的合成Eu（III）复合纳米晶体（NCs）使用反胶束方法。与合适的溶剂二氯甲烷（DCM）中相应的配合物溶液相比，这五种Eu（III）配合物在非极性溶剂中制备的NC溶液具有明显更高的光致发光量子产率（14.0% ~ 16.6% vs 2.0% ~ 4.0%）。增强的发射源于非辐射速率常数（knr）的大幅降低，从而增加了辐射速率常数（kr）与knr的比值，例如kr/knr。当从DCM溶液过渡到聚集的nc时，引入了额外的复合物间弛豫途径，导致激子结合能（Eb）降低。我们的结果验证了合成的简单性，并突出了Eu（III）配合物NCs的特征。利用其增强的发射，我们进一步证明了它们在光滑基底上的指纹可视化方面的潜力。

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引用次数: 0

Novel bromo benzoyl-substituted diazenyl benzofurans: Synthesis, structural characterization, antibacterial evaluation, and molecular docking studies 新型溴苯甲酰取代二氮基苯并呋喃：合成、结构表征、抗菌评价和分子对接研究

IF 4.7 2区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Molecular Structure

Pub Date : 2026-02-04 DOI: 10.1016/j.molstruc.2026.145588

Rezan Huseen Hama salih , Farouq Emam Hawaiz

In this study, a new set of bromobenzoyl-substituted azo-benzofurans was prepared and fully characterized by mass spectrometry, FT-IR, and ¹H/ ¹³C NMR. The molecular structures were validated on the basis of spectroscopic characteristics of azo and benzofuran moieties. In vitro antibacterial activity of the compounds obtained was tested against Escherichia coli(Gram -negative) and Staphylococcus aureus (Gram -positive). It was found that some compounds displayed moderate to strong antibacterial activity with compound 2e being the most potent compound and displaying an inhibition zone of 19 mm against both bacterial strains, which was higher than the reference drug amoxicillin (5 mm).

To explain the biological activity as defined by the observed biological activity at the molecular level, a docking experiment was conducted against DNA gyrase A (PDB ID: 1KZN). The binding energies were found to be between -6.7 and -7.2 kcal/mol which are good indicators of interaction between the ligands and the protein. The compound 2e exhibited the strongest binding profile that was mainly maintained through the hydrogen bonding and hydrophobic interactions within the active site of the enzyme. The integrated spectroscopic, biological, and computational evidence indicates azo-benzofuran context to be an effective framework of structuring new antibacterial agents.

本研究制备了一组新的溴苯甲酰取代偶氮苯并呋喃，并通过质谱、FT-IR和1H/ 13C NMR对其进行了表征。根据偶氮和苯并呋喃基团的光谱特征对分子结构进行了验证。对所得化合物进行了对大肠杆菌（革兰氏阴性）和金黄色葡萄球菌（革兰氏阳性）的体外抗菌活性测试。结果表明，部分化合物具有中强抑菌活性，其中化合物2e的抑菌活性最强，对两种细菌均有19 mm的抑制带，高于对照药物阿莫西林（5 mm）。为了解释在分子水平上观察到的生物活性所定义的生物活性，我们对DNA gyrase a （PDB ID: 1KZN）进行了对接实验。结合能在-6.7 ~ -7.2 kcal/mol之间，是配体与蛋白质相互作用的良好指标。化合物2e表现出最强的结合谱，这种结合谱主要通过酶活性位点内的氢键和疏水相互作用维持。综合光谱、生物学和计算证据表明偶氮-苯并呋喃环境是构建新型抗菌剂的有效框架。

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引用次数: 0

Schiff base liquid crystals bearing terminal p-substituted phenylacetanilide and n-alkoxy Chains: Experimental and computational studies 端对取代苯乙酰苯胺和正烷氧基链的希夫碱液晶：实验和计算研究

IF 4.7 2区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Molecular Structure

Pub Date : 2026-02-04 DOI: 10.1016/j.molstruc.2026.145584

Nagwa H.S. Ahmed , Amira A. Hamed , Gamal R. Saad , Mohsen M.T. El-Tahawy

This work investigates the combined effects of hydrogen bonding through an amide linkage, terminal alkoxy chain length, and substituent electronics on the mesomorphic behavior and thermal stability of a novel series of Schiff base liquid crystalline compounds. The synthesized homologues incorporate p-substituted phenylacetamide units (X = –OCH₃, H, and Br) with varying alkoxy chains (n = 6, 8, 12, and 16). Phase transitions were analyzed using differential scanning calorimetry (DSC), and the mesophases were identified by polarized optical microscopy (POM). Longer-chain derivatives (n = 12 and 16) favored lamellar packing and exhibited a smectic A (SmA) phase, whereas shorter-chain analogues showed limited or no mesomorphism. TGA confirmed adequate thermal stability within the mesophase ranges. DFT calculations supported the experimental results, indicating that the trans hydrogen-bonded conformer is the most stable and that substituent-dependent dipole moments contribute to the enhanced mesomorphic stability, particularly for the methoxy‑substituted derivative. These results contribute to the understanding of structure–property relationships governing mesophase formation and stability in hydrogen-bonded Schiff base liquid crystalline systems

本文研究了酰胺键氢键、末端烷氧基链长度和取代基电子学对一系列新型希夫碱液晶化合物的介形行为和热稳定性的综合影响。合成的同系物包括对取代苯乙酰胺单元（X = -OCH₃，H和Br）和不同的烷氧基链（n = 6, 8, 12和16）。用差示扫描量热法（DSC）分析了相变，用偏光显微镜（POM）鉴定了中间相。长链衍生物（n = 12和16）有利于层状堆积，并表现出近晶a （SmA）相，而短链类似物则表现出有限的或没有中胚性。TGA证实在中间相范围内具有足够的热稳定性。DFT计算支持实验结果，表明反式氢键构象是最稳定的，取代基依赖的偶极矩有助于增强亚晶稳定性，特别是对甲氧基取代衍生物。这些结果有助于理解氢键席夫碱液晶体系中控制中间相形成和稳定性的结构-性能关系

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引用次数: 0

A study on rotational diffusion dynamics of non-polar laser dyes in varying viscous media: Experimental and theoretical approach 非极性激光染料在变粘性介质中的旋转扩散动力学研究：实验与理论方法

IF 4.7 2区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Molecular Structure

Pub Date : 2026-02-04 DOI: 10.1016/j.molstruc.2026.145542

Vikram Pujari, Manjunath N. Wari, Basavaraj G. Mulimani, Sanjeev R. Inamdar

This study explores the rotational diffusion dynamics of large non-polar laser dyes in solvent milieus of varying viscosity, including alkanes, alcohols, and binary mixtures of methanol and decanol. Using steady state and time-resolved fluorescence measurements, the rotational reorientation times of two large nonpolar laser dyes Exalite 384 and Exalite 416 were determined and examined as a function of solvent viscosity. The experimental data were compared against Stokes-Einstein-Debye (SED) hydrodynamic models based on stick and slip boundary conditions, as well as quasihydrodynamic theories based on Dote–Kivelson–Schwartz (DKS) and Geirer Wirtz (GW) models. Across all the systems, a monotonic relationship between rotational relaxation time and viscosity was observed, affirming the viscosity dependence of molecular mobility. Both probes exhibit sub-slip behaviour in alcohols as well as in the methanol–decanol binary mixture, while their rotational motion in alkanes is significantly slower compared to that in alcohols and the mixed system. These findings highlight the significant influence of solvent properties on the rotational behaviour of non-polar dyes and underscore the importance of model selection in accurately interpreting molecular dynamics in viscous media.

本研究探讨了大型非极性激光染料在不同粘度的溶剂环境中的旋转扩散动力学，包括烷烃，醇，甲醇和癸醇的二元混合物。利用稳态和时间分辨荧光测量，测定了两种大型非极性激光染料Exalite 384和Exalite 416的旋转重定向时间，并考察了其作为溶剂粘度的函数。将实验数据与基于粘滑边界条件的Stokes-Einstein-Debye （SED）水动力模型以及基于Dote-Kivelson-Schwartz （DKS）和Geirer Wirtz （GW）模型的准水动力理论进行了比较。在所有体系中，观察到旋转弛豫时间与粘度之间的单调关系，证实了分子迁移率对粘度的依赖。这两种探针在醇和甲醇-癸醇二元混合物中都表现出亚滑移行为，而它们在烷烃中的旋转运动明显慢于在醇和混合体系中的旋转运动。这些发现强调了溶剂性质对非极性染料旋转行为的重要影响，并强调了模型选择在准确解释粘性介质中的分子动力学中的重要性。

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引用次数: 0

Synthesis and evaluation of O-propargyl containing propargylamine derivatives as multipotent ligands for the treatment of Alzheimer’s disease 含丙炔胺衍生物的o -丙炔基多能配体治疗阿尔茨海默病的合成及评价

IF 4.7 2区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Molecular Structure

Pub Date : 2026-02-04 DOI: 10.1016/j.molstruc.2026.145583

Vinay Kumar , Kailash Jangid , Bharti Devi , Jayapriya Mishra , Naveen Kumar , Jasvinder Singh Bhatti , Rakesh Kumar , Vinod Kumar

Alzheimer's disease (AD) is among the most prevalent forms of dementia worldwide and poses a substantial burden to the healthcare system. Currently available medications merely decelerate the progression of the disease and provide no effective prevention. The recognition of multiple targets associated with this disease has established it as a multifactorial neurodegenerative disease, necessitating innovative multifunctional agents for its management and potentially explaining the ineffectiveness of existing single-target drugs. In the current study, we have designed and synthesized a series of O-propargylated propargylamine derivatives for the development of potent acetylcholinesterase (AChE) and monoamine oxidase-B (MAO-B) inhibitors. All the synthesised compounds were tested against cholinesterases (ChEs) and monoamine oxidase (MAO) enzymes to evaluate IC₅₀ values. In the series, VS-8 and VS-18 were identified as potent leads, displaying IC₅₀ values in the lower/submicromolar range against AChE (VS-8: 1.60 µM, VS-18: 1.87 µM) and MAO-B (VS-8: 3.31 µM, VS-18: 0.19 µM). Additionally, the lead molecules displayed good neuroprotection against SH-SY5Y cells without exhibiting cytotoxicity even at 25 µM. In amyloid-β (Aβ)-induced neurotoxicity in the SH-SY5Y cells, VS-8 and VS-18 showed remarkable neuroprotection. In reactive oxygen species (ROS) inhibition studies, VS-8 displayed moderate inhibition of the ROS levels. In AChE reversibility and kinetic studies, both the lead compounds were found to be reversible in nature and displayed non-competitive inhibition. Furthermore, in molecular modelling studies, both compounds displayed good binding interactions and orientations at the active site of enzymes, and were found to be thermodynamically stable within the active sites of proteins for a simulation duration of 100 ns.

阿尔茨海默病（AD）是世界上最普遍的痴呆症之一，给卫生保健系统带来了沉重的负担。目前可用的药物只是减缓疾病的进展，并没有提供有效的预防。对与该疾病相关的多个靶点的认识使其成为一种多因素神经退行性疾病，需要创新的多功能药物来治疗该疾病，并可能解释现有单靶点药物的无效。在本研究中，我们设计并合成了一系列o -丙基化丙炔胺衍生物，用于开发有效的乙酰胆碱酯酶（AChE）和单胺氧化酶- b （MAO-B）抑制剂。对合成的化合物进行胆碱酯酶（ChEs）和单胺氧化酶（MAO）的IC50测定。在该系列中，VS-8和VS-18被认为是有效的先导物，对AChE （VS-8: 1.60µM, VS-18: 1.87µM）和MAO-B （VS-8: 3.31µM, VS-18: 0.19µM）的IC50值在较低/亚微摩尔范围内。此外，铅分子对SH-SY5Y细胞表现出良好的神经保护作用，即使在25µM下也没有表现出细胞毒性。在淀粉样蛋白-β (Aβ)诱导的SH-SY5Y细胞神经毒性中，VS-8和VS-18表现出显著的神经保护作用。在活性氧（ROS）抑制研究中，VS-8表现出适度的抑制ROS水平。在乙酰胆碱酯酶的可逆性和动力学研究中，发现这两种先导化合物在本质上是可逆的，并表现出非竞争性抑制作用。此外，在分子模拟研究中，这两种化合物在酶的活性位点表现出良好的结合相互作用和取向，并且在100 ns的模拟持续时间内，在蛋白质的活性位点内具有热力学稳定性。

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引用次数: 0

Dual-pathway solvate transformation: synthesis of a more stable temozolomide-ferulic acid cocrystal hydrate 双途径溶剂转化：合成更稳定的替莫唑胺-阿魏酸共晶水合物

IF 4.7 2区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Molecular Structure

Pub Date : 2026-02-04 DOI: 10.1016/j.molstruc.2026.145585

Fengxia Zou , Longlong Yan , Binghang Du , Wensu Chen , Hao Xu , Tao Shen , Pengpeng Yang , Hanjie Ying

Temozolomide (TMZ), a first-line chemotherapeutic for glioblastoma multiforme, exhibits high oral bioavailability but suffers from a short plasma half-life due to pH-dependent chemical instability, which limits its therapeutic efficacy. This study developed two novel cocrystals—cocrystal solvate TMZ-FEA·ACN (1:1:1) and cocrystal hydrate TMZ-FEA·H₂O (1:1:1)—using ferulic acid (FEA) as cocrystal coformer (CCF). Synthesized via solution method, both cocrystals were systematically characterized by SCXRD/PXRD, FT-IR, NMR, DVS, TG-DSC, and solubility testing. Molecular electrostatic potential (MESP) and Hirshfeld surface analyses revealed TMZ-FEA·ACN's intermolecular contacts dominated by H⋯H interactions, with structural flexibility enabling its subsequent transformation. The cocrystal hydrate TMZ-FEA·H₂O demonstrated significantly enhanced solubility (16.57 mg/mL at pH 6.8, 3.89-fold higher than API) and improved physical stability. Notably, TMZ-FEA·ACN underwent complete solvate transformation to the thermodynamically stable cocrystal hydrate TMZ-FEA·H₂O under elevated humidity (>30% RH) and physiological pH (1.2/6.8), maintaining structural integrity through a dual solvent-free restructuring pathway combining humidity-induced solid-state transformation (SST) and, (SMT). Molecular dynamics (MD) simulations confirmed stronger hydration affinity for TMZ-FEA compared to acetonitrile, validating the thermodynamic preference for the hydrate. This cocrystal engineering strategy provides a comprehensive solution for enhancing TMZ's pharmaceutical performance and industrial implementation.

替莫唑胺（TMZ）是治疗多形性胶质母细胞瘤的一线化疗药物，具有较高的口服生物利用度，但由于ph依赖性化学不稳定性，其血浆半衰期较短，限制了其治疗效果。本研究以阿魏酸（FEA）为共晶共成体（CCF），制备了两种新型共晶：溶剂化共晶TMZ-FEA·ACN（1:1:1）和水合共晶TMZ-FEA·H₂O（1:1:1）。通过溶液法合成，用SCXRD/PXRD、FT-IR、NMR、DVS、TG-DSC和溶解度测试对两种共晶进行了系统表征。分子静电势（MESP）和Hirshfeld表面分析揭示了TMZ-FEA·ACN的分子间接触以H⋯H相互作用为主，其结构灵活性使其能够进行后续转化。共晶水合物TMZ-FEA·H₂O的溶解度显著提高（pH为6.8时溶解度为16.57 mg/mL，是API的3.89倍），物理稳定性显著提高。值得注意的是，TMZ-FEA·ACN在高湿度（>30% RH）和生理pH（1.2/6.8）条件下完全溶剂化转化为热力学稳定的共晶水合物TMZ-FEA·H₂O，通过湿致固态转化（SST）和SMT相结合的双无溶剂重构途径保持结构完整性。分子动力学（MD）模拟证实，与乙腈相比，TMZ-FEA的水化亲和力更强，验证了水合物的热力学偏好。这种共晶工程策略为提高TMZ的制药性能和工业实施提供了全面的解决方案。

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引用次数: 0

Solvent-free synthesis of benzothiazole-based pyrimido[4,5-d]pyrimidine heterocycles for multitarget biological applications 苯并噻唑基嘧啶[4,5-d]嘧啶杂环的无溶剂合成及其多靶点生物应用

IF 4.7 2区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Molecular Structure

Pub Date : 2026-02-04 DOI: 10.1016/j.molstruc.2026.145532

Amrutha. M, Yadav D. Bodke

Present work describes the synthesis of new series of 9-methoxy-5-substituted-phenyl-1,5-dihydro-2H-benzo[4,5]thiazolo[3,2-a]pyrimido[4,5-d]pyrimidine-2,4(3H)-dione derivatives via Knoevenagel condensation followed by intramolecular cyclization using a solvent free, grinding protocol. The structures of all synthesized compounds were characterized using FT-IR, ¹H NMR, ¹³C NMR and mass spectroscopic techniques. The molecules were tested against two bacterial strains, Escherichia coli and Staphylococcus aureus, as well as the fungal strain Aspergillus flavus to evaluate their antimicrobial activity and further screened for their antioxidant and antidiabetic potential using DPPH, iron chelating, NO scavenging, and α-amylase enzyme inhibition assays. in silico Molecular docking studies were performed as a qualitative tool to explore plausible ligand–protein interaction patterns, while ADMET predictions were used as preliminary indicators of physicochemical properties. In addition, DFT calculations were carried out to analyze the electronic properties, frontier molecular orbitals, and molecular electrostatic potential surfaces of the synthesized compounds. Overall, this study integrates green synthetic methodology with structural, electronic, and exploratory biological evaluation of benzothiazole-based fused heterocycles.

本工作描述了一系列新的9-甲氧基-5-取代苯基-1,5-二氢- 2h -苯并[4,5]噻唑[3,2-a]嘧啶[4,5-d]嘧啶-2,4(3H)-二酮衍生物的合成，通过Knoevenagel缩合，然后使用无溶剂研磨工艺进行分子内环化。利用FT-IR、1H NMR、13C NMR和质谱等技术对合成的化合物进行了结构表征。通过DPPH、铁螯合、NO清除、α-淀粉酶抑制等实验，对两种细菌（大肠杆菌、金黄色葡萄球菌、真菌黄曲霉）的抑菌活性进行了评价，并进一步筛选了其抗氧化和抗糖尿病的潜力。分子对接研究作为一种定性工具来探索合理的配体-蛋白质相互作用模式，而ADMET预测被用作物理化学性质的初步指标。此外，通过DFT计算分析了合成化合物的电子性质、前沿分子轨道和分子静电势面。总体而言，本研究将绿色合成方法与苯并噻唑基融合杂环的结构、电子和探索性生物学评价相结合。

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