Molecular Structure,Vibrational Spectra,Molecular Docking,and ADMET Study of Cellulose Triacetate II

Optics and Spectroscopy - People have started to look for alternative sources because of the health problems created by petrochemical products used in all areas of human life and environmental...     

Synthesis,Spectroscopic and Antimicrobial Studies of Lead (II) Complexes of Schiff Bases Derived From Amino Acids and Isatins

A new series of lead (II) complexes have been synthesized with Schiff bases derived from isatins and amino acids. These ligands act as bidentate species and coordinate to the metal atom through the azomethine nitrogen and carboxylate oxygen atom via deprotonation. The synthesized complexes have been characterized by elemental analysis, conductance measurements, and molecular weight determinations. The mode of bonding of the complexes has been suggested on the basis of infrared, UV-visible, and ¹H- and ¹³C-NMR spectroscopy, and probable structures have been assigned to these complexes. Few representative ligands and metal complexes have also been screened for their antifungal and antibacterial activities. Molecular modeling and analysis for bond lengths and bond angles have also been carried out for one of the representative compound, [Pb(L³)₂], to substantiate the proposed structures.     

Design,Synthesis, Photophysical Properties,Biological Estimation and Molecular Docking Studies of Novel Schiff Base Derivatives as Potential Urease Inhibitors

A quinoline functionalized two novel fluorescent Schiff bases, N-(quinolin-2-ylmethylene) anthracen-1-amine (SB1) and 2-(quinolin-2-ylmethyleneamino) benzene thiol (SB2) were synthesized and confirmed by using ¹H NMR, IR and GC-MS techniques. The spectroscopic properties were examined by absorption spectroscopy and fluorescence spectroscopy. The absorption and fluorescence spectra of the probes (SB1 and SB2) were measured in a variety of solvents. Both the compounds were tested for urease inhibitory activity. The synthesized compound SB2 proved to be the most effective screening for enzyme inhibitory activity with IC₅₀?=?0.111 μM than SB1 (IC₅₀?=?0.287 μM). Molecular docking studies were performed to delineate the binding affinity and conformational positions of chemical compounds within the active region of the target protein. In-vitro analysis depicts the potency of SB1 in free radical scavenging as compared to the reference drug vitamin C.     

Synthesis,Spectral Characterization,DNA/ Protein Binding,DNA Cleavage,Cytotoxicity, Antioxidative and Molecular Docking Studies of Cu(II)Complexes Containing Schiff Base-bpy/Phen Ligands

Ternary Cu(II) complexes [Cu(II)(L)(bpy)Cl] 1, [Cu(II)(L)(Phen)Cl] 2 [L = 2,3–dimethyl-1-phenyl-4(2 hydroxy-5-methyl benzylideneamino)-pyrazol-5-one, bpy = 2,2^′ bipyridine, phen =1,10 phenanthroline) were synthesized and characterized by elemental analyses, UV-Visible, FT-IR, ESR, Mass, thermogravimetric and SEM EDAX techniques. The complexes exhibit octahedral geometry. The interaction of the Cu(II) with cailf thymus DNA (CT-DNA) was explored by using absorption and fluorescence spectroscopic methods. The results revealed that the complexes have an affinity constant for DNA in the order of 10⁴ M^?1 and mode of interaction is intercalative mode. The DNA cleavage study showed that the complexes cleaved DNA without any external agent. The interaction of Cu(II) complexes with bovine serum albumin (BSA) was also studied using absorption and fluorescence techniques. The cytotoxic activity of the Cu(II) complexes was probed in HeLa (human breast adenocarcinoma cell line), B16F10 (Murine melanoma cell line) and HEPA1–6 celllines, complex 1 has good cytotoxic activity which is comparable with the doxarubicin drug, with IC₅₀ values ranging from 3 to 12.6 μM. A further molecular docking technique was employed to understand the binding of the complexes towards the molecular target DNA. Investigation of the antioxidative properties showed that the metal complexes have significant radical scavenging activity potency against DPPH radical.     

A Fluorescence Emission, FT-IR and UV-VIS Absorption Study of the Some Uranium (VI) Schiff Bases Complexes

The capacity of metallic ions to form complexes depends on the electric charge and its mass and on the ligands nature. In this study we followed the coordination capacity of the uranyl ion (UO2(2+)) with a series of Schiff bases. The Schiff bases have been obtained through the condensation of some salicylic aldehyde derivates with a series of diamines. As a result of the reaction between these substances and the uranyl ions the mono-, bi-, or poly-nuclear complexes, depend on the nature of the ligands. The forming of the complexes is highlighted through ultraviolet-visible, Fourier transform infrared (IR), and fluorescence spectroscopy. In the IR studies the forming of the complexes is highlighted by the apparition of a new band at approximately 920 cm(-1,) characteristic to the O=U=O group. Also modifications of valence vibrations appear characteristic to the azomethinic groups, nu(C=N,) and the apparition of some new bands in the 300-500 cm(-1) domain, characteristic to forming of some new bonds U-O and U-N. The formed complexes represent tetragonal bipyramidal geometry. The study of the capacity coordination of uranyl ions is important in determining, dozing and precipitin of the ions in diverse used waters.     

Spectroscopic,Computational, Antimicrobial,DNA Interaction,In Vitro Anticancer and Molecular Docking Properties of Biochemically Active Cu(II) and Zn(II) Complexes of Pyrimidine-Ligand

Biochemically active Cu(II) and Zn(II) complexes [CuL(ClO₄)₂(1) and ZnL(ClO₄)₂(2)] have been synthesized from N,N donor Schiff base ligand L derived from4,6-dichloropyrimdine-5-carboxaldehyde with 4-(2-aminoethyl)morpholine. The L, complexes 1 and 2 have been structurally characterized by elemental analysis, ¹H-NMR, FTIR, MS, UV-Visible and ESR techniques. The results obtained from the spectral studies supports the complexes 1 and 2 are coordinated with L through square planar geometry. DFT calculations results supports, the ligand to metal charge transfer mechanism can occur between L and metal(II) ions. The antimicrobial efficacy results have been recommended that, complexes 1 and 2 are good anti-pathogenic agents than ligand L. The interaction of complexes 1 and 2 with calf thymus (CT) DNA has been studied by electronic absorption, viscometric, fluorometric and cyclic voltammetric measurements. The calculated K_b values for L, complexes 1 and 2 found from absorption titrations was 4.45?×?10⁴, L; 1.92?×?10⁵, 1 and 1.65?×?10⁵, 2. The Ksv values were found to be 3.0?×?10³, 3.68?×?10³and 3.52?×?10³ for L, complexes 1 and 2 by using competitive binding with ethidium bromide (EB). These results suggest that, the compounds are interacted with DNA may be electrostatic binding. The molecular docking studies have been carried out to confirm the interaction of compounds with DNA. Consequently, in vitro anticancer activities of L, complexes 1 and 2 against selected cancer (lung cancer A549, liver cancer HepG2 and cervical carcinoma HeLa) and normal (NHDF) cell lines were assessed by MTT assay.     

Radiotracer Studies on the Extraction of Metal Ions Part 10: Extraction of Calcium,Iron, Nickel,Copper, and Zinc with Some Aromatic Schiff Bases)

Using the radioactive indicators Ca ⁴⁵, Fe ⁵⁹, Ni ⁶³, Cu ⁶⁴, and Zn ⁶⁵ the yield of extraction (%E) of Ca(II), Fe(III), Ni(II), Cu(II), and Zn(II) with quadridentate Schiff bases, which are products of condensation of salicylaldehyde and its derivatives with ethylenediamine, 1,3-propylenediamine and o-phenylenediamine has been investigated as a function of the pH of the electrolyte.     

光谱法联合分子对接和等温滴定微量热法研究全氟壬酸与人血清白蛋白的相互作用

全氟壬酸(PFNA)是在血清中检测到第三多的全氟烷酸类(PFAAs)新型有毒环境污染物。目前PFNA对人血清白蛋白(HSA)结构甚至是功能的影响还处于起步阶段,借助于多光谱、分子对接和等温滴定微量热(ITC)技术研究了PFNA和HSA相互作用的结合机理。所有荧光数据均进行了内滤光校正以获得更准确的结合参数。荧光结果表明PFNA通过动静态猝灭方式可以猝灭HSA的内源荧光。取代实验和分子对接结果表明,PFNA主要通过极性键、疏水力和卤素键键合在HSA亚域ⅡA疏水腔中,最佳对接自由能为-26.54 kJ·mol-1,表明PFNA分子与HSA有较大的结合亲和力。ITC表明两者的结合属于两类结合位点模型并给出了相应的热力学参数：第一类结合位点有较大的亲和力,属于焓驱动,静电力和卤键作为主要驱动力;第二类结合位点亲和力较小,主要驱动力是疏水力。三维荧光光谱揭示PFNA与HSA生成复合物后,可以改变HSA的构象,引起Trp和Tyr残基微环境疏水性增强。圆二色谱(CD)定量测定了HSA与PFNA作用前后的二级结构含量：α-螺旋、β-折叠和β-转角含量分别降低14.3%,5.3%和3.5%,无规卷曲含量从14.4%增加到37.5%。以上结果表明,PFNA与HSA的结合可以改变HSA的二级结构,进而可能影响HSA的生理功能。结果阐述了PFNA与HSA相互作用机理,并且为PFNA在体内的运输和分配提供了可靠的生物物理和生物化学的相关依据。     

Combined Multispectroscopic and Molecular Docking Assessments to the Effect of an Anticonvulsant,Oxcarbazepine on Human Serum Albumin Conformation and its Binding Properties

Journal of Applied Spectroscopy - Elimination and distribution of drugs are affected by human serum albumin (HSA) interaction. In children and adults, specific types of seizures are controlled by...