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1.
J Assoc Physicians India ; 62(1): 50-1, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25327094

RESUMO

Variations in the renal vessels and supernumerary renal arteries have been observed frequently, either in routine dissections or in clinical practice which warrants considerations in a variety of urologic, renal transplantation, laparoscopic surgeries and retroperitoneal operations. The variations of renal arteries are considered critical issues that surgeons should have thorough envision and appreciation of the condition. Renal artery variations including their number source and course are very common. But more than 6 renal arteries on either side is rare and we present a case of multiple renal arteries in an asymptomatic young hypertensive and to our knowledge it is the first of its kind reported in literature.


Assuntos
Hipertensão/patologia , Artéria Renal/anormalidades , Adulto , Doenças Assintomáticas , Humanos , Hipertensão/diagnóstico , Rim/irrigação sanguínea , Masculino
2.
Heliyon ; 7(7): e07634, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34381897

RESUMO

The research received a great deal of worldwide attention due to the nature of interpretation before the experimental process. Based on the systematic process the structure of thiazole -pyrazole compound 4-[{2-[3-(4-chlorophenyl)-5-(4-propan-2-yl) phenyl)-4, 5-dihydro- 1H- pyrazol-1-yl]-4-oxo-1, 3- thiazol-5(4H)-ylidene} methyl] benzonitrile [CPTBN] was investigated. In the first level, the spectral statistics on experimental FT-IR and FT- Raman was reported. At the next level, geometrical parameters was theoretically acquired from density functional theory (DFT) using B3LPY/6-31G and 6-311G basis set. The computed Wavenumber were collected and compared with the experimental data. The vibrational modes were interpreted in terms of potential energy distribution (PED) results. The FMO, MEP, and NBO analysis further validated the electrophilic and nucleophilic interaction in the molecular systems. Two grams-positive bacteria: staphylococcus aureus, Bacillus subtilis and two gram-negative bacteria: Esherichia coli, Pseudomonas aeruginosa was performed for antibacterial activity. Two fungal strain Candida albicans and Aspergillus Niger was carried out against a ligand using anti-fungal activity. The molecular docking analysis explores the antimicrobial and selective potential inhibitory nature of the binding molecule. Besides, RDG and ELF analysis were also performed to show the nature of interactions between the molecule.

3.
Nat Commun ; 12(1): 3044, 2021 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-34031415

RESUMO

Unlike other malignancies, therapeutic options in pancreatic ductal adenocarcinoma (PDAC) are largely limited to cytotoxic chemotherapy without the benefit of molecular markers predicting response. Here we report tumor-cell-intrinsic chromatin accessibility patterns of treatment-naïve surgically resected PDAC tumors that were subsequently treated with (Gem)/Abraxane adjuvant chemotherapy. By ATAC-seq analyses of EpCAM+ PDAC malignant epithelial cells sorted from 54 freshly resected human tumors, we show here the discovery of a signature of 1092 chromatin loci displaying differential accessibility between patients with disease free survival (DFS) < 1 year and patients with DFS > 1 year. Analyzing transcription factor (TF) binding motifs within these loci, we identify two TFs (ZKSCAN1 and HNF1b) displaying differential nuclear localization between patients with short vs. long DFS. We further develop a chromatin accessibility microarray methodology termed "ATAC-array", an easy-to-use platform obviating the time and cost of next generation sequencing. Applying this methodology to the original ATAC-seq libraries as well as independent libraries generated from patient-derived organoids, we validate ATAC-array technology in both the original ATAC-seq cohort as well as in an independent validation cohort. We conclude that PDAC prognosis can be predicted by ATAC-array, which represents a low-cost, clinically feasible technology for assessing chromatin accessibility profiles.


Assuntos
Sequenciamento de Cromatina por Imunoprecipitação/métodos , Cromatina , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/genética , Biomarcadores Tumorais , Carcinoma Ductal Pancreático/diagnóstico , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/metabolismo , Núcleo Celular , Fator 1-beta Nuclear de Hepatócito/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Fatores de Transcrição Kruppel-Like/genética , Neoplasias Pancreáticas/metabolismo , Prognóstico , Fatores de Transcrição , Transcriptoma , Neoplasias Pancreáticas
4.
J Cancer Res Clin Oncol ; 146(11): 2897-2911, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32748119

RESUMO

Advances in surgery, peri-operative care and systemic chemotherapy have not significantly improved the prognosis of pancreatic cancer for several decades. Early clinical trials of immunotherapy have yielded disappointing results proposing other means by which the tumour microenvironment serves to decrease the immune response. Additionally, the emergence of various subtypes of pancreatic cancer has emerged as a factor for treatment responses with immunogenic subtypes carrying a better prognosis. Herein we discuss the reasons for the poor response to checkpoint inhibitors and outline a rationale why combination treatments are likely to be most effective. We review the therapies which could provide optimal synergistic effects to immunotherapy including chemotherapy, agents targeting the stroma, co-stimulatory molecules, vaccinations and methods of immunogenic tumour priming including radiofrequency ablation. Finally, we discuss reasons why peri-operative and in particular neoadjuvant combination treatments are likely to be most effective and should be considered for early clinical trials.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma Ductal Pancreático/terapia , Terapia Combinada/métodos , Imunoterapia/métodos , Neoplasias Pancreáticas/terapia , Animais , Humanos
5.
Artigo em Inglês | MEDLINE | ID: mdl-19196545

RESUMO

The solid phase FTIR and FT-Raman spectra of 1,5-dinitronaphthalene (DNN) have been recorded in the regions 4000-50 and 3500-100cm(-1), respectively. The spectra were interpreted with the aid of normal coordinate analysis following full structure optimization and force field calculation based on density functional theory using standard B3LYP/6-31G* and B3LYP/6-311+G** methods and basis set combinations and was scaled using various scale factors yielding fairly good agreement between observed and calculated frequencies. Based on the present good quality scaled quantum mechanical force field, a reliable description of the fundamentals was provided and the assignments have been proposed with the help of normal coordinate analysis. The infrared and Raman spectra were also predicted from the calculated intensities. Comparison of the simulated spectra with the experimental spectra provides important information about the ability of the computational method to describe the vibrational modes.


Assuntos
Naftalenos/química , Nitrocompostos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Simulação por Computador , Estrutura Molecular , Teoria Quântica , Vibração
6.
Artigo em Inglês | MEDLINE | ID: mdl-28898821

RESUMO

Experimental FT-IR and FT-Raman spectra of 2-methylphenylacetic acid (MPA) were recorded and theoretical values are also analyzed. The non-linear optical (NLO) properties were evaluated by determination of first (5.5053×10-30 e.s.u.) and second hyper-polarizabilities (7.6833×10-36 e.s.u.) of the title compound. The Multiwfn package is used to find the weak non-covalent interaction (Van der Wall interaction) and strong repulsion (steric effect) of the molecule and examined by reduced density gradient. The molecular electrostatic potential (MEP) analysis used to find the most reactive sites for the electrophilic and nucleophilic attack. The chemical activity (electronegativity, hardness, chemical softness and chemical potential) of the title compound was predicted with the help of HOMO-LUMO energy values. The natural bond orbital (NBO) has been analyzed the stability of the molecule arising from the hyper-conjugative interaction. DSSCs were discussed in structural modifications that improve the electron injection efficiency of the title compound (MPA). The Fukui functions are calculated in order to get information associated with the local reactivity properties of the title compound. The binding sites of the two receptors were reported by molecular docking field and active site bond distance is same 1.9Å. The inhibitor of the title compound forms a stable complex with 1QYV and 2H1K proteins at the binding energies are -5.38 and -5.85 (∆G in kcal/mol).


Assuntos
Elétrons , Modelos Moleculares , Simulação de Acoplamento Molecular , Fenilacetatos/química , Energia Solar , Vibração , Domínio Catalítico , Humanos , Ligantes , Conformação Molecular , Dinâmica não Linear , Teoria Quântica , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade Estática , Termodinâmica
7.
Chem Cent J ; 11: 6, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28119762

RESUMO

BACKGROUND: Coumarin (2H-chromen-2-one) and its derivatives have a wide range of biological and pharmaceutical activities. They possess antitumor, anti-HIV, anticoagulant, antimicrobial, antioxidant, and anti-inflammatory activities. Synthesis and isolation of coumarins from different species have attracted the attention of medicinal chemists. Herein, we report the synthesis, molecular structure, dielectric, anticancer activity and docking studies with the potential target protein tankyrase. RESULTS: Molecular structure of (3E)-3-(4-methylbenzylidene)-3,4-dihydro-2H-chromen-2-one (MBDC) is derived from quantum chemical calculations and compared with the experimental results. Intramolecular interactions, stabilization energies, and charge delocalization are calculated by NBO analysis. NLO property and dielectric quantities have also been determined. It indicates the formation of a hydrogen bonding between -OH group of alcohol and C=O of coumarin. The relaxation time increases with the increase of bond length confirming the degree of cooperation and depends upon the shape and size of the molecules. The molecule under study has shown good anticancer activity against MCF-7 and HT-29 cell lines. Molecular docking studies indicate that the MBDC binds with protein. CONCLUSIONS: In this study, the compound (3E)-3-(4-methylbenzylidene)-3,4-dihydro-2H-chromen-2-one was synthesized and characterized by spectroscopic studies. The computed and experimental results of NMR study are tabulated. The dielectric relaxation studies show the existence of molecular interactions between MBDC and alcohol. Theoretical results of MBDC molecules provide the way to predict various binding sites through molecular modeling and these results also support that the chromen substitution is more active in the entire molecule. Molecular docking study shows that MBDC binds well in the active site of tankyrase and interact with the amino acid residues. These results are compared with the anti cancer drug molecule warfarin derivative. The results suggest that both molecules have comparable interactions and better docking scores. The results of the antiproliferative activity of MBDC and Warfarin derivative against MCF-7 breast cancer and HT-29 colon cancer cell lines at different concentrations exhibited significant cytotoxicity. The estimated half maximal inhibitory concentration (IC 50) value for MBDC and Warfarin derivative was 15.6 and 31.2 µg/ml, respectively. This enhanced cytotoxicity of MBDC in MCF-7 breast cancer and HT-29 colon cancer cell lines may be due to their efficient targeted binding and eventual uptake by the cells. Hence the compound MBDC may be considered as a drug molecule for cancer.Graphical abstractThe binding mode of the ligand MBDC at active site of protein and the graphical representation of cell inhibition for MCF-7 and HT-29 cell lines.

8.
Transplant Proc ; 38(10): 3384-7, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17175278

RESUMO

INTRODUCTION: Our center has recently observed foreign carbohydrate-appearing particles (FP) on transplant postreperfusion biopsy specimens: (PRBx). METHODS: To further characterize FPs, we reviewed all renal transplant RBx (30-45 minutes) performed between September 1, 2004 and December 3, 2005. Donor, preservation, and outcome variables were collected among patients with FP. RESULTS: A total of 135 PRBx were performed (45 deceased donors [DD] and 90 live donors [LD]). Fifteen PRBx demonstrated FP. All 15 cases were DD kidneys that underwent machine perfusion (MP) on the Waters RM3 (Waters Medical Systems, Rochester, Minn, United States) with Belzer MP solution (Trans Med, Elk River, Minn, United States). Donor age was 39.8 +/- 15.7 years. Terminal creatinine level was 1.45 +/- 0.8 mg/dL. Two of 15 were flushed in situ with HTK solution (no starch). Cold ischemia time was 28.8 +/- 9.1 hours with 14.3 +/- 5.1 hours of MP. In 13 of 15 patients, perfusion parameters were excellent (flow > 100 mL; resistance < .35). CHARACTERISTICS OF FP: Particles were 10-30 mu and globular in shape. FP were not visible on hematoxylin and eosin stain, but stained strongly periodic acid-Schiff-(PAS) positive and were refractile under polarized light. FP were seen segmentally within glomerular capillaries in all cases and in peritubular capillaries in 3. In 11 of the 15 cases with FP, focal glomerular fibrin thrombi or intracapillary neutrophil margination was seen. Ten of 15 patients with FP had a biopsy within the first week with no identifiable FP. OUTCOMES: Recipient age was 45.3 +/- 11.6 years. Eight patients (53.3%) had delayed graft function. Biopsy-proven rejection occurred in 3 patients (20%). Three-month creatinine level was 1.59 +/- 0.35 mg/dL. One graft was lost to early thrombosis in a patient with a hypercoagulable state and 1 patient died of sepsis at 2 months. All remaining 13 patients are alive with excellent graft function at a median follow-up of 6.7 months (range, 3-17 months). CONCLUSIONS: Microscopic intrarenal particles may be seen on DD kidney PRBx after MP. These FPs likely originate from surgical gloves. FPs are too small to be captured by standard filters but clear spontaneously and do not have deleterious effects on renal function or outcomes.


Assuntos
Transplante de Rim/patologia , Preservação de Órgãos/métodos , Adulto , Biópsia , Cadáver , Carboidratos/análise , Creatinina/sangue , Seguimentos , Corpos Estranhos/patologia , Humanos , Glomérulos Renais/citologia , Glomérulos Renais/ultraestrutura , Transplante de Rim/fisiologia , Doadores Vivos , Pessoa de Meia-Idade , Fatores de Tempo , Doadores de Tecidos , Resultado do Tratamento
9.
Artigo em Inglês | MEDLINE | ID: mdl-15990355

RESUMO

FT-IR and FT-Raman spectra of 2-hydroxy-3-methoxy-5-nitrobenzaldehyde (HMN) and 2-methoxy-1-naphthaldehyde (MN) have been recorded in the regions 4000-400 cm(-1) and 3500-100 cm(-1), respectively. The molecular structure, conformational stability, geometry optimization, vibrational frequencies have been investigated. The total energy calculations of HMN and MN were tried for various possible conformers. The spectra were interpreted with the aid of normal coordinate analysis based on density functional theory (DFT) using B3LYP/6-31G* and B3LYP/6-311+G** level and basis set combinations and was scaled using various scale factors yielding good agreement between observed and calculated frequencies. The infrared and Raman spectra were also predicted from the calculated intensities. Comparison of the simulated spectra with the experimental spectra provides important information about the ability of the computational method to describe the vibrational modes.


Assuntos
Aldeídos/química , Benzaldeídos/química , Modelos Químicos , Naftalenos/química , Vibração , Conformação Molecular , Estrutura Molecular
10.
Artigo em Inglês | MEDLINE | ID: mdl-16330246

RESUMO

This work deals with the vibrational spectroscopy of 4-amino-2,6-dichloropyridine (ADCP) and 2-chloro-3,5-dinitropyridine (CDNP) by means of quantum chemical calculations. The mid and far FTIR and FT-Raman spectra were measured in the condensed state. The fundamental vibrational frequencies and intensity of vibrational bands were evaluated using density functional theory (DFT) with the standard B3LYP/6-31G(*) and B3LYP/6-311+G(**) methods and basis set combinations, and was scaled using various scale factors which yields a good agreement between observed and calculated frequencies. The vibrational spectra were interpreted with the aid of normal coordinate analysis based on scaled density functional force field. The results of the calculations were applied to simulated infrared and Raman spectra of the title compounds, which showed excellent agreement with the observed spectra.


Assuntos
Modelos Químicos , Piridinas/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Vibração , Carbono/química , Estrutura Molecular , Nitrogênio/química , Software , Análise Espectral Raman
11.
Artigo em Inglês | MEDLINE | ID: mdl-15683809

RESUMO

The geometry, frequency and intensity of the vibrational bands 5-fluoro, 5-chloro and 5-bromo-cytosines (5-FC, 5-ClC and 5-BrC) were obtained by the density functional theory (DFT) calculations with Becke3-Lee-Yang-Parr (B3LYP) functional and 6-31G* basis set. The effects of fluorine, chlorine and bromine substituents on the vibrational frequencies of cytosines have been investigated. The assignments have been proposed with the aid of the results of normal coordinate analysis. The observed and the calculated spectra are found to be in good agreement.


Assuntos
Citosina/análogos & derivados , Citosina/química , Flucitosina/química , Modelos Moleculares , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman
12.
Spectrochim Acta A Mol Biomol Spectrosc ; 61(11-12): 2510-25, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16043043

RESUMO

The FT-IR and FT-Raman spectra of 4-hydroxy-3-methylacetophenone (HMA) and 4-hydroxy-3-methoxyacetophenone (HMOA) have been recorded. The total energy calculations of HMA and HMOA were tried for various possible conformers. The spectra were interpreted with the aid of normal coordinate analysis based on density functional theory (DFT) using standard B3LYP/6-31G* and B3LYP/6-311+G** methods and basis sets combinations for the most optimized geometries. Normal coordinate calculations were performed with the DFT force field corrected by a recommended set of scaling factors yielding fairly good agreement between observed and calculated frequencies. On the basis of the comparison between calculated and experimental results, assignments of fundamental modes were examined.


Assuntos
Acetofenonas/química , Conformação Molecular , Estrutura Molecular , Espectrofotometria Infravermelho , Análise Espectral Raman , Vibração
13.
Artigo em Inglês | MEDLINE | ID: mdl-15863052

RESUMO

The FTIR and FT-Raman spectra of 2,6-dibromo-4-nitroaniline (2,6-DB4NA) in solid phase and 2-(methylthio)aniline (2-MTA) in liquid phase were measured. The geometry and normal vibrations have been obtained from the density functional theory (DFT) with the B3LYP method employing the 6-31G* basis set. Scale factors, which bring computational frequencies in closer agreement with the experimental data, have been calculated for predominant vibrational motions of the normal modes. The effects of the amino, bromine, nitro, thio and methyl substituents on vibrational frequencies have been investigated. The infrared and Raman spectra were also predicted from the calculated intensities. The observed and the calculated spectra were found to be in good agreement.


Assuntos
Compostos de Anilina/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Análise Espectral Raman/métodos , Bromo/química , Modelos Químicos , Conformação Molecular , Estrutura Molecular , Software
14.
Spectrochim Acta A Mol Biomol Spectrosc ; 62(4-5): 918-25, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15951230

RESUMO

Fourier transform infrared (FT-IR) spectra of phthalimide and N-bromophthalimide have been recorded in the range of 4000-400 cm-1. With the hope of providing more and effective information on the fundamental vibrations, a normal coordinate analysis has been performed on phthalimide and N-bromophthalimide, by assuming C2v symmetry. Density functional theory (DFT)-Beck3-Lee-Yang-Parr (B3LYP) levels with 6-31G* and 6-311+G** basis sets have been employed in quantum chemical analysis. The computational frequencies are in good agreement with the observed results. The theoretical spectra obtained along with intensity data agree well with the observed spectra.


Assuntos
Ftalimidas/química , Modelos Químicos , Estrutura Molecular , Espectroscopia de Infravermelho com Transformada de Fourier , Vibração
15.
Spectrochim Acta A Mol Biomol Spectrosc ; 135: 321-34, 2015 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-25084238

RESUMO

Experimental FTIR and FT-Raman spectroscopic analysis of 1-Amino-4-methylpiperazine (1A4MP) have been performed. A detailed quantum chemical calculations have been carried out using ab initio HF and density functional theory calculations (B3LYP) with 6-311+G(d,p) basis set. The atomic charges, electronic exchange interaction and charge delocalization of the molecule have been performed by natural bond orbital (NBO) analysis. Electron density distribution and frontier molecular orbitals (FMOs) have been constructed at B3LYP/6-311+G(d,p) level to understand the electronic properties. The charge density distribution and site of chemical reactivity of the molecule have been obtained by mapping electron density isosurface with electrostatic potential surfaces (ESP). The electronic properties, HOMO and LUMO energies were measured by time-dependent TD-DFT approach. The dipole moment (µ), polarizability (α), anisotropy polarizability (Δα) and hyperpolarizability (ß) of the molecule have been reported.


Assuntos
Elétrons , Modelos Moleculares , Piperazinas/química , Teoria Quântica , Análise Espectral Raman , Vibração , Acetona/química , Dimetil Sulfóxido/química , Conformação Molecular , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade Estática , Termodinâmica
16.
Spectrochim Acta A Mol Biomol Spectrosc ; 138: 406-23, 2015 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-25528503

RESUMO

The experimental and theoretical study on the structures and vibrations of 4-hexylacetophenone (abbreviated as 4HAP) are presented. The FT-IR and FT-Raman spectra of the title compound have been recorded in the region 4000-400cm(-1) and 3500-100cm(-1) respectively. The molecular structures, vibrational wavenumbers, infrared intensities and Raman activities were calculated using DFT (B3LYP and LSDA) method with 6-311++G(d,p) basis set. The most stable conformer of 4HAP is identified from the computational results. The assignments of the vibrational spectra have been carried out with the aid of normal coordinate analysis (NCA) following the scaled quantum mechanical force field methodology (SQMEF). The linear polarizability (α) and the first hyperpolarizability (ßtot) values of the investigated molecule have been computed using B3LYP and LSDA with 6-311++G(d,p) basis set. Stability of the molecule arising from hyper conjugative interaction and charge transfer delocalization has been analyzed using natural bond orbital (NBO) analysis. The molecule orbital contributions are studied by density of energy states (DOSs). UV-Vis spectrum and effects of solvents have been discussed effects of solvents have been discussed and the electronic properties such as HOMO and LUMO energies were determined by time-dependent TD-DFT approach. Fukui function and Mulliken analysis on atomic charges of the title compound have been calculated. Finally, electrophilic and nucleophilic descriptors of the title molecule have been calculated.


Assuntos
Acetofenonas/análise , Propiofenonas/análise , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Acetofenonas/química , Algoritmos , Ligação de Hidrogênio , Modelos Moleculares , Conformação Molecular , Estrutura Molecular , Óptica e Fotônica , Propiofenonas/química , Teoria Quântica , Software , Difração de Raios X
17.
Artigo em Inglês | MEDLINE | ID: mdl-25813164

RESUMO

Vibrational spectral analysis and quantum chemical computations based on density functional theory have been performed on the N-(2-cyanoethyl)-N-butylaniline. The geometry, structural properties, intermolecular hydrogen bond, and harmonic vibrational frequencies of the title molecule have been investigated with the help of DFT (B3LYP) and LC-DFT (CAM-B3LYP) method. Molecular electrostatic potential (MEP) have been performed. The various intramolecular interactions have been exposed by natural bond orbital analysis. The distribution of atomic charges and bending of natural hybrid orbitals also reflect the presence of intramolecular hydrogen bonding. Global reactivity and local reactivity descriptors of the title molecule have been calculated. The analysis of the electron density of HOMO and LUMO gives an idea of the delocalization and low value of energy gap indicated the electron transport in the molecule and thereby NLO activity. The effect of solvent on second-order NLO properties has been studied using polarized continuum model (PCM) in the tetrahydrofuran (THF) solution. The solvent leads to a slight enhancement of the NLO responses for the studied complexes relevant to their NLO responses in gas phase. The electronic absorption spectra were investigated by the TDDFT methods. The frequency-dependent first hyperpolarizabilities of the N-(2-cyanoethyl)-N-butylaniline were also evaluated. The (1)H and (13)C NMR chemical shifts have been calculated by gauge-indepedent atomic orbital (GIAO) method with B3LYP/6-311++G(d, p) approach.


Assuntos
Compostos de Anilina/química , Modelos Químicos , Modelos Moleculares
18.
Spectrochim Acta A Mol Biomol Spectrosc ; 138: 283-95, 2015 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-25498825

RESUMO

The FT-IR and FT-Raman spectra of N-acetyl-l-phenylalanine were recorded and analyzed. Natural bond orbital analysis has been carried out for various intramolecular interactions that are responsible for the stabilization of the molecule. HOMO-LUMO energy gap has been computed with the help of density functional theory. The statistical thermodynamic functions (heat capacity, entropy, vibrational partition function and Gibbs energy) were obtained for the range of temperature 100-1000K. The polarizability, first hyperpolarizability, anisotropy polarizability invariant has been computed using quantum chemical calculations. The infrared and Raman spectra were also predicted from the calculated intensities. Comparison of the experimental and theoretical spectra values provides important information about the ability of the computational method to describe the vibrational modes.


Assuntos
Fenilalanina/análogos & derivados , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Algoritmos , Carbono/química , Simulação por Computador , Hidrogênio/química , Modelos Moleculares , Conformação Molecular , Distribuição Normal , Fenilalanina/química , Software , Espectrofotometria Infravermelho , Eletricidade Estática , Temperatura , Termodinâmica , Vibração
19.
Spectrochim Acta A Mol Biomol Spectrosc ; 141: 104-12, 2015 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-25677530

RESUMO

Thiophene derivatives have been focused in the past decades due to their remarkable biological and pharmacological activities. In connection with that the conformational stability, spectroscopic characterization, molecular (inter- and intra-) interactions, and molecular docking studies on thiophene-2-carboxylicacid have been performed in this work by experimental FT-IR and theoretical quantum chemical computations. Experimentally recorded FT-IR spectrum in the region 4000-400 cm(-1) has been compared with the scaled theoretical spectrum and the spectral peaks have been assigned on the basis of potential energy distribution results obtained from MOLVIB program package. The conformational stability of monomer and dimer conformers has been examined. The presence of inter- and intramolecular interactions in the monomer and dimer conformers have been explained by natural bond orbital analysis. The UV-Vis spectra of the sample in different solvents have been simulated and solvent effects were predicted by polarisable continuum model with TD-DFT/B3LYP/6-31+G(d,p) method. To test the biological activity of the sample, molecular docking (ligand-protein) simulations have been performed using SWISSDOCK web server. The full fitness (FF) score and binding affinity values revealed that thiophene-2-carboxylicacid can act as potential inhibitor against inflammation.


Assuntos
Simulação de Acoplamento Molecular , Tiofenos/química , Ácidos Carboxílicos , Dimerização , Ligação de Hidrogênio , Ácidos de Lewis/química , Bases de Lewis/química , Teoria Quântica , Solventes , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Termodinâmica , Vibração
20.
Spectrochim Acta A Mol Biomol Spectrosc ; 136 Pt B: 451-63, 2015 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-25448946

RESUMO

The optimized molecular structure and corresponding vibrational assignments of 2-tert-butyl-5-methyl anisole (TBMA) have been investigated using density functional theory (DFT)/B3LYP with 6-31G(d,p) and 6-311++G(d,p) basis sets investigation of the relative orientation of the methoxy group has shown two conformers (O-cis) and (O-trans) exist. The vibrational analysis of the stable conformer of the title compound is performed by means of infrared absorption and Raman spectroscopy in combination with theoretical simultaneously. The natural bond orbital (NBO) analysis is useful to understand the intra-molecular hyper conjugative interaction lone pair and π(∗)(C-C), σ(∗)(C-H) bond orbital. HOMO and LUMO energies show that charge transfer occurs in the molecule, therefore; HOMO, LUMO and molecular electrostatic potential (MEP) were calculated and analyzed. (1)H and (13)C NMR spectra by using gauge including atomic orbital (GIAO) method of studied compound were compared with experimental data. The thermodynamic functions of TBMA were calculated by B3LYP/6-311+G(d,p) basis set.


Assuntos
Anisóis/química , Elétrons , Modelos Moleculares , Teoria Quântica , Análise Espectral Raman , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Conformação Molecular , Espectroscopia de Prótons por Ressonância Magnética , Rotação , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade Estática , Termodinâmica , Vibração
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