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1.
Int J Mol Sci ; 25(17)2024 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-39273338

RESUMO

The pyrimidine heterocycle plays an important role in anticancer research. In particular, the pyrimidine derivative families of uracil show promise as structural scaffolds relevant to cervical cancer. This group of chemicals lacks data-driven machine learning quantitative structure-activity relationships (QSARs) that allow for generalization and predictive capabilities in the search for new active compounds. To achieve this, a dataset of pyrimidine and uracil compounds from ChEMBL were collected and curated. A workflow was developed for data-driven machine learning QSAR using an intuitive dataset design and forwards selection of molecular descriptors. The model was thoroughly externally validated against available data. Blind validation was also performed by synthesis and antiproliferative evaluation of new synthesized uracil-based and pyrimidine derivatives. The most active compound among new synthesized derivatives, 2,4,5-trisubstituted pyrimidine was predicted with the QSAR model with differences of 0.02 compared to experimentally tested activity.


Assuntos
Antineoplásicos , Proliferação de Células , Pirimidinas , Relação Quantitativa Estrutura-Atividade , Uracila , Uracila/química , Uracila/análogos & derivados , Uracila/farmacologia , Uracila/síntese química , Pirimidinas/química , Pirimidinas/farmacologia , Pirimidinas/síntese química , Humanos , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Proliferação de Células/efeitos dos fármacos , Aprendizado de Máquina , Linhagem Celular Tumoral
2.
Int J Mol Sci ; 23(21)2022 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-36362178

RESUMO

Seven pyridoxal dioxime quaternary salts (1-7) were synthesized with the aim of studying their interactions with human acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). The synthesis was achieved by the quaternization of pyridoxal monooxime with substituted 2-bromoacetophenone oximes (phenacyl bromide oximes). All compounds, prepared in good yields (43-76%) and characterized by 1D and 2D NMR spectroscopy, were evaluated as reversible inhibitors of cholinesterase and/or reactivators of enzymes inhibited by toxic organophosphorus compounds. Their potency was compared with that of their monooxime analogues and medically approved oxime HI-6. The obtained pyridoxal dioximes were relatively weak inhibitors for both enzymes (Ki = 100-400 µM). The second oxime group in the structure did not improve the binding compared to the monooxime analogues. The same was observed for reactivation of VX-, tabun-, and paraoxon-inhibited AChE and BChE, where no significant efficiency burst was noted. In silico analysis and molecular docking studies connected the kinetic data to the structural features of the tested compound, showing that the low binding affinity and reactivation efficacy may be a consequence of a bulk structure hindering important reactive groups. The tested dioximes were non-toxic to human neuroblastoma cells (SH-SY5Y) and human embryonal kidney cells (HEK293).


Assuntos
Reativadores da Colinesterase , Neuroblastoma , Humanos , Butirilcolinesterase/metabolismo , Acetilcolinesterase/metabolismo , Reativadores da Colinesterase/farmacologia , Reativadores da Colinesterase/química , Simulação de Acoplamento Molecular , Inibidores da Colinesterase/farmacologia , Inibidores da Colinesterase/química , Células HEK293 , Oximas/farmacologia , Oximas/química , Piridoxal , Ligantes
3.
Int J Mol Sci ; 23(20)2022 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-36293089

RESUMO

Considering the enormous importance of protein turns as participants in various biological events, such as protein-protein interactions, great efforts have been made to develop their conformationally and proteolytically stable mimetics. Ferrocene-1,1'-diamine was previously shown to nucleate the stable turn structures in peptides prepared by conjugation with Ala (III) and Ala-Pro (VI). Here, we prepared the homochiral conjugates of ferrocene-1,1'-diamine with l-/d-Phe (32/35), l-/d-Val (33/36), and l-/d-Leu (34/37) to investigate (1) whether the organometallic template induces the turn structure upon conjugation with amino acids, and (2) whether the bulky or branched side chains of Phe, Val, and Leu affect hydrogen bonding. Detailed spectroscopic (IR, NMR, CD), X-ray, and DFT studies revealed the presence of two simultaneous 10-membered interstrand hydrogen bonds, i.e., two simultaneous ß-turns in goal compounds. A preliminary biological evaluation of d-Leu conjugate 37 showed its modest potential to induce cell cycle arrest in the G0/G1 phase in the HeLa cell line but these results need further investigation.


Assuntos
Diaminas , Dipeptídeos , Humanos , Metalocenos/química , Ligação de Hidrogênio , Células HeLa , Cristalografia por Raios X , Estereoisomerismo , Dipeptídeos/química , Peptídeos/química , Aminoácidos/química , Conformação Proteica
4.
Int J Mol Sci ; 22(24)2021 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-34948332

RESUMO

The concept of peptidomimetics is based on structural modifications of natural peptides that aim not only to mimic their 3D shape and biological function, but also to reduce their limitations. The peptidomimetic approach is used in medicinal chemistry to develop drug-like compounds that are more active and selective than natural peptides and have fewer side effects. One of the synthetic strategies for obtaining peptidomimetics involves mimicking peptide α-helices, ß-sheets or turns. Turns are usually located on the protein surface where they interact with various receptors and are therefore involved in numerous biological events. Among the various synthetic tools for turn mimetic design reported so far, our group uses an approach based on the insertion of different ferrocene templates into the peptide backbone that both induce turn formation and reduce conformational flexibility. Here, we conjugated methyl 1'-aminoferrocene-carboxylate with homo- and heterochiral Pro-Ala dipeptides to investigate the turn formation potential and antiproliferative properties of the resulting peptidomimetics 2-5. Detailed spectroscopic (IR, NMR, CD), X-ray and DFT studies showed that the heterochiral conjugates 2 and 3 were more suitable for the formation of ß-turns. Cell viability study, clonogenic assay and cell death analysis showed the highest biological potential of homochiral peptide 4.


Assuntos
Ácidos Carboxílicos/química , Ácidos Carboxílicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Compostos Ferrosos/química , Compostos Ferrosos/farmacologia , Peptidomiméticos/química , Peptidomiméticos/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cristalografia por Raios X/métodos , Dipeptídeos/química , Dipeptídeos/farmacologia , Células HeLa , Humanos , Células MCF-7 , Peptídeos/química , Peptídeos/farmacologia , Estrutura Secundária de Proteína , Estereoisomerismo
5.
Molecules ; 25(20)2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-33092122

RESUMO

The effect of different hydrodistillation pretreatments, namely, reflux extraction, reflux extraction with the addition of cell wall-degrading enzymes, and ultrasound, on the yield and chemical composition of essential oils of sage, bay laurel, and rosemary was examined. All pretreatments improved essential oil yield compared to no-pretreatment control (40-64% yield increase), while the oil quality remained mostly unchanged (as shown by statistical analysis of GC-MS results). However, enzyme-assisted reflux extraction pretreatment did not significantly outperform reflux extraction (no-enzyme control), suggesting that the observed yield increase was mostly a consequence of reflux extraction and enzymatic activity had only a minute effect. Thus, we show that ultrasound and reflux extraction pretreatments are beneficial in the production of essential oils of selected Mediterranean plants, but the application of enzymes has to be carefully re-evaluated.


Assuntos
Óleos Voláteis/química , Folhas de Planta/química , Óleos de Plantas/isolamento & purificação , Rosmarinus/química , Cromatografia Gasosa-Espectrometria de Massas , Óleos Voláteis/isolamento & purificação , Óleos Voláteis/efeitos da radiação , Folhas de Planta/efeitos da radiação , Óleos de Plantas/química , Óleos de Plantas/efeitos da radiação , Rosmarinus/efeitos da radiação , Ondas Ultrassônicas
6.
Molecules ; 24(6)2019 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-30871137

RESUMO

The quaternization reactions of nicotinamide, with different electrophiles: methyl iodide and substituted 2-bromoacetophenones (4-Cl, 4-Br, 4-H, 4-CH3, 4-F, 4-OCH3, 4-Ph, 2-OCH3, 4-NO2) are reported. The preparations were carried out by conventional synthesis and under microwave irradiation in absolute ethanol and acetone. The synthesis performed by microwave dielectric heating significantly improved yield, up to 8 times, and shortened down the reaction time from ca. one day in conventional, to 10⁻20 min. The structures of the synthesized compounds were confirmed by IR, ¹H- and 13C-NMR spectroscopy, mass spectrometry and elemental analysis. The compounds have been screened for antifungal activities against Fusarium oxysporum, Fusarium culmorum, Macrophomina phaseolina and Sclerotinia sclerotiorum at concentrations of 10 µg/mL and 100 µg/mL. Six compounds showed the strong inhibition of mycelium growth at a concentration of 10 µg/mL. All tested compounds revealed the great inhibitory activities against S. sclerotiorum at a concentration of 100 µg/mL.


Assuntos
Antifúngicos/síntese química , Ascomicetos/efeitos dos fármacos , Fusarium/efeitos dos fármacos , Niacinamida/análogos & derivados , Piridinas/síntese química , Acetofenonas/química , Antifúngicos/química , Antifúngicos/farmacologia , Hidrocarbonetos Iodados/química , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Micro-Ondas , Estrutura Molecular , Niacinamida/química , Piridinas/química , Piridinas/farmacologia
7.
Molecules ; 23(12)2018 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-30545123

RESUMO

Thymoquinone (TQ), a natural compound with antimicrobial and antitumor activity, was used as the starting molecule for the preparation of 3-aminothymoquinone (ATQ) from which ten novel benzoxazole derivatives were prepared and characterized by elemental analysis, IR spectroscopy, mass spectrometry and NMR (¹H, 13C) spectroscopy in solution. The crystal structure of 4-methyl-2-phenyl-7-isopropyl-1,3-benzoxazole-5-ol (1a) has been determined by X-ray diffraction. All compounds were tested for their antibacterial, antifungal and antitumor activities. TQ and ATQ showed better antibacterial activity against tested Gram-positive and Gram-negative bacterial strains than benzoxazoles. ATQ had the most potent antifungal effect against Candida albicans, Saccharomyces cerevisiae and Aspergillus brasiliensis. Three benzoxazole derivatives and ATQ showed the highest antitumor activities. The most potent was 2-(4-fluorophenyl)-4-methyl-7-isopropyl-1,3-benzoxazole-5-ol (1f). Western blot analyses have shown that this compound inhibited phosphorylation of protein kinase B (Akt) and Insulin-like Growth Factor-1 Receptor (IGF1R ß) in HeLa and HepG2 cells. The least toxic compound against normal fibroblast cells, which maintains similar antitumor activities as TQ, was 2-(4-chlorophenyl)-4-methyl-7-isopropyl-1,3-benzoxazole-5-ol (1e). Docking studies indicated that 1e and 1f have significant effects against selected receptors playing important roles in tumour survival.


Assuntos
Benzoquinonas/química , Benzoxazóis , Anti-Infecciosos/síntese química , Anti-Infecciosos/química , Antineoplásicos/síntese química , Antineoplásicos/química , Benzoquinonas/síntese química , Benzoxazóis/síntese química , Benzoxazóis/metabolismo , Células HeLa , Células Hep G2 , Humanos , Simulação de Acoplamento Molecular
8.
Chemistry ; 23(43): 10372-10395, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28543826

RESUMO

A series of peptides that contain homo- and heterochiral Ala-Pro sequences attached to the turn-inducing ferrocene-1,1'-diamine scaffold were synthesized. The effects of the backbone chirality and the N-terminal group (Boc/Ac) on the conformational properties of the novel peptidomimetics were thoroughly explored by IR, NMR, and CD spectroscopy and the experimental observations were corroborated by DFT studies in solution. The most stable conformers of the homochiral peptides adopted the interstrand hydrogen-bond patterns, realized through ten- and thirteen-membered rings. The common feature of the most stable conformers of the heterochiral peptides was the adoption of the turn-like structures that feature the simultaneous intra- (seven-membered) and interstrand (sixteen-membered) hydrogen-bonded rings. An exchange of two N-terminal groups had a somewhat larger influence on the distribution of the hydrogen-bond patterns in homochiral than in heterochiral derivatives. The homochiral peptides that contain pyridine moieties as metal coordination sites formed 1:1 complexes with divalent metal ions, which included Zn2+ , Cd2+ , Cu2+ and Fe2+ .


Assuntos
Compostos Ferrosos/química , Metalocenos/química , Peptídeos/química , Sequência de Aminoácidos , Sítios de Ligação , Dicroísmo Circular/métodos , Cristalografia por Raios X/métodos , Dipeptídeos/química , Compostos Ferrosos/síntese química , Ligação de Hidrogênio , Metalocenos/síntese química , Metais/química , Modelos Moleculares , Ressonância Magnética Nuclear Biomolecular/métodos , Peptídeos/síntese química , Ligação Proteica , Estrutura Secundária de Proteína , Piridinas/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Estereoisomerismo , Relação Estrutura-Atividade
9.
Molecules ; 19(8): 12852-80, 2014 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-25153883

RESUMO

Our previous studies showed that alteration of dipeptides Y-Fca-Ala-OMe (III) into Y-Ala-Fca-OMe (IV) (Y=Ac, Boc; Fca=1'-aminoferrocene-1-carboxylic acid) significantly influenced their conformational space. The novel bioconjugates Y-Fca-Pro-OMe (1, Y=Ac; 2, Y=Boc) and Y-Pro-Fca-OMe (3, Y=Boc; 4, Y=Ac) have been prepared in order to investigate the influence of proline, a well-known turn-inducer, on the conformational properties of small organometallic peptides with an exchanged constituent amino acid sequences. For this purpose, peptides 1-4 were subjected to detailed spectroscopic analysis (IR, NMR, CD spectroscopy) in solution. The conformation of peptide 3 in the solid state was determined. Furthermore, the ability of the prepared conjugates to inhibit the growth of estrogen receptor-responsive MCF-7 mammary carcinoma cells and HeLa cervical carcinoma cells was tested.


Assuntos
Antineoplásicos/farmacologia , Ácidos Carboxílicos/química , Compostos Ferrosos/química , Oligopeptídeos/farmacologia , Prolina/análogos & derivados , Prolina/síntese química , Antineoplásicos/química , Sobrevivência Celular/efeitos dos fármacos , Dicroísmo Circular , Cristalografia por Raios X , Ensaios de Seleção de Medicamentos Antitumorais , Células HeLa , Humanos , Ligação de Hidrogênio , Concentração Inibidora 50 , Células MCF-7 , Oligopeptídeos/química , Prolina/farmacologia , Estrutura Secundária de Proteína
10.
Technol Health Care ; 32(4): 2673-2684, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38306075

RESUMO

BACKGROUND: Computational research plays an important role in predicting the chemical and physical properties of biologically active compounds important in future structural modifications to improve or modify biological activity. OBJECTIVE: This research focuses on quantum chemical and spectroscopic investigations properties of synthesized 4-hydroxycoumarin derivatives. METHODS: Quantum chemical calculations were obtained using B3LYP, HF, and M06-2x level methods with the 6-31++G (d,p) basis set. Afterward, IR, 1H, 13C, UV-Visible experimentally parameters were compared with the results obtained using the B3LYP/6-31+G*(d) basis set of the molecules to be able to characterize the structures. RESULTS: Based on the quantum chemical calculations compound with acetamido group on the phenyl ring is the most reactive, and compound with nitro substituent is the least reactive and the the strongest electrophile among tested compounds. With the exception of compounds with dimethylamino group, all other compounds have a pronounced tautomer between OH and C = O group. The calculated and experimental values are in agreement with each other. CONCLUSION: The molecular structure in the ground state of six 3-cinnamoyl 4-hydroxycoumarin derivatives was optimized using density functional theory. The observed and computed values were compared and it can be concluded that the theoretical results were in good linear agreement with the experimental data.


Assuntos
4-Hidroxicumarinas , 4-Hidroxicumarinas/química , Teoria da Densidade Funcional , Estrutura Molecular , Teoria Quântica
11.
Spectrochim Acta A Mol Biomol Spectrosc ; 318: 124528, 2024 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-38801789

RESUMO

The need for a systematic approach in developing new metal-based drugs with dual anticancer-antimicrobial properties is emphasized by the vulnerability of cancer patients to bacterial infections. In this context, a novel organometallic assembly was designed, featuring ruthenium(II) coordination with p-cymene, one chlorido ligand, and a bidentate neutral Schiff base derived from 4-methoxybenzaldehyde and N,N-dimethylethylenediamine. The compound was extensively characterized in both solid-state and solution, employing single crystal X-ray diffraction, nuclear magnetic resonance, infrared, ultraviolet-visible spectroscopy, and density functional theory, alongside Hirshfeld surface analysis. The hydrolysis kinetic was thoroughly investigated, revealing the important role of the chloro-aqua equilibrium in the dynamics of binding with deoxyribonucleic acid and bovine serum albumin. Notably, the aqua species exhibited a pronounced affinity for deoxyribonucleic acid, engaging through electrostatic and hydrogen bonding interactions, while the chloro species demonstrated groove-binding properties. Interaction with albumin revealed distinct binding mechanisms. The aqua species displayed covalent binding, contrasting with the ligand-like van der Waals interactions and hydrogen bonding observed with the chloro specie. Molecular docking studies highlighted site-specific interactions with biomolecular targets. Remarkably, the compound exhibited wide spectrum moderate antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans, coupled with low micromolar cytotoxic activity against human colorectal adenocarcinoma cells and significant activity against human leukemic monocyte lymphoma cells. The presented findings encourage further development of this compound, promising avenues for its evolution into a versatile therapeutic agent targeting both infectious diseases and cancer.


Assuntos
Anti-Infecciosos , Antineoplásicos , DNA , Rutênio , Bases de Schiff , Soroalbumina Bovina , Bases de Schiff/química , Bases de Schiff/farmacologia , Antineoplásicos/farmacologia , Antineoplásicos/química , Rutênio/química , Rutênio/farmacologia , DNA/metabolismo , DNA/química , Humanos , Soroalbumina Bovina/química , Soroalbumina Bovina/metabolismo , Hidrólise , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Etilenodiaminas/química , Etilenodiaminas/farmacologia , Compostos Organometálicos/farmacologia , Compostos Organometálicos/química , Água/química , Animais , Linhagem Celular Tumoral , Testes de Sensibilidade Microbiana , Solubilidade , Ligação Proteica , Simulação de Acoplamento Molecular , Bactérias/efeitos dos fármacos
12.
J Inorg Biochem ; 258: 112637, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38876026

RESUMO

Wet synthesis approach afforded four new heteroleptic mononuclear neutral diamagnetic oxidovanadium(V) complexes, comprising salicylaldehyde-based 2-furoic acid hydrazones and a flavonol coligand of the general composition [VO(fla)(L-ONO)]. The complexes were comprehensively characterized, including chemical analysis, conductometry, infrared, electronic, and mass spectroscopy, as well as 1D 1H and proton-decoupled 13C(1H) NMR spectroscopy, alongside extensive 2D 1H1H COSY, 1H13C HMQC, and 1H13C HMBC NMR analyses. Additionally, the quantum chemical properties of the complexes were studied using Gaussian at the B3LYP, HF, and M062X levels on the 6-31++g(d,p) basis sets. The interaction of these hydrolytically inert vanadium complexes and the BSA was investigated through spectrofluorimetric titration, synchronous fluorimetry, and FRET analysis in a temperature-dependent manner, providing valuable thermodynamic insights into van der Waals interactions and hydrogen bonding. Molecular docking was conducted to gain further understanding of the specific binding sites of the complexes to BSA. Complex 2, featuring a 5-chloro-substituted salicylaldehyde component of the hydrazone, was extensively examined for its biological activity in vivo. The effects of complex administration on biochemical and hematological parameters were evaluated in both healthy and diabetic Wistar rats, revealing antihyperglycemic activity at millimolar concentration. Furthermore, histopathological analysis and bioaccumulation studies of the complex in the brain, kidneys, and livers of healthy and diabetic rats revealed the potential for further development of vanadium(V) hydrazone complexes as antidiabetic and insulin-mimetic agents.


Assuntos
Complexos de Coordenação , Diabetes Mellitus Experimental , Hidrazonas , Hipoglicemiantes , Simulação de Acoplamento Molecular , Vanádio , Animais , Hidrazonas/química , Hidrazonas/síntese química , Hidrazonas/farmacologia , Ratos , Diabetes Mellitus Experimental/tratamento farmacológico , Hipoglicemiantes/química , Hipoglicemiantes/síntese química , Hipoglicemiantes/farmacologia , Complexos de Coordenação/síntese química , Complexos de Coordenação/farmacologia , Complexos de Coordenação/química , Vanádio/química , Flavonóis/farmacologia , Flavonóis/química , Flavonóis/síntese química , Masculino , Ratos Wistar , Soroalbumina Bovina/química , Soroalbumina Bovina/metabolismo , Aldeídos
13.
J Inorg Biochem ; 244: 112232, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37084582

RESUMO

Solution synthesis afforded five novel neutral heteroleptic octahedral paramagnetic mononuclear oxidovanadium(IV) complexes of general composition [VO(bpy)L], where L is a dianionic tridentate ONO-donor hydrazone ligand derived from 2-furoic acid hydrazide and salicylaldehyde and its 5-substituted derivatives. Characterization was carried out by elemental analysis, mass spectrometry, infrared, electron, NMR, and EPR spectroscopy, cyclic voltammetry and conductometry. The molecular and crystal structure of the complex with 5-chloro-salicylaldehyde 2-furoic acid hydrazone (2) was determined. The quantum chemical properties of the vanadium complexes were studied at B3LYP and M062X levels with the lanl2dz basis set using Gaussian. Additionally, Swiss-ADME analysis was performed and complex (4), featuring a 5-nitro substituent on the hydrazone ligand, was selected for further investigation. The effects of the in vivo application of the complex on selected biochemical parameters in healthy and diabetic Wistar rats were investigated. Strong antidiabetic effect associated with moderate hypoalbuminemia was observed. Furthermore, the interaction of complexes with BSA was studied by spectrofluorimetry. A significant conformational change of BSA in the presence of vanadium complexes was found. Synchronous fluorescence spectra revealed significant changes in the tyrosine microenvironment of BSA. The FRET analysis was also used and the non-radiative process of energy transfer is elucidated. Thermodynamic data suggest van der Waals forces and hydrogen bonding as predominant binding modes of complexes to BSA.


Assuntos
Hidrazonas , Vanádio , Animais , Ratos , Vanádio/química , Hidrazonas/química , Hipoglicemiantes/farmacologia , Ligantes , Ratos Wistar
14.
Pharmaceuticals (Basel) ; 16(1)2022 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-36678546

RESUMO

Two newly synthesized coumarin-palladium(II) complexes (C1 and C2) were characterized using elemental analysis, spectroscopy (IR and 1H-13C NMR), and DFT methods at the B3LYP-D3BJ/6-311+G(d,p) level of theory. The in vitro and in silico cytotoxicity of coumarin ligands and their corresponding Pd(II) complexes was examined. For in vitro testing, five cell lines were selected, namely human cervical adenocarcinoma (HeLa), the melanoma cell line (FemX), epithelial lung carcinoma (A549), the somatic umbilical vein endothelial cell line (EA.hi926), and pancreatic ductal adenocarcinoma (Panc-1). In order to examine the in silico inhibitory potential and estimate inhibitory constants and binding energies, molecular docking studies were performed. The inhibitory activity of C1 and C2 was investigated towards epidermal growth factor receptor (EGFR), receptor tyrosine kinase (RTK), and B-cell lymphoma 2 (BCL-2). According to the results obtained from the molecular docking simulations, the inhibitory activity of the investigated complexes towards all the investigated proteins is equivalent or superior in comparison with current therapeutical options. Moreover, because of the low binding energies and the high correlation rate with experimentally obtained results, it was shown that, out of the three, the inhibition of RTK is the most probable mechanism of the cytotoxic activity of the investigated compounds.

15.
Food Chem ; 198: 93-100, 2016 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-26769509

RESUMO

Pectin was extracted from tomato waste using two different extraction methods to assess its potential utilization as an alternative source of commercial pectin production. Tomato waste was treated with ammonium oxalate/oxalic acid by conventional extraction (CE), under reflux and ultrasound assisted extraction (UAE) at 37 kHz and temperatures of 60 °C and 80 °C. The pectin obtained from these methods was analysed and compared in terms of yield, chemical properties and structure. Among examined methods, CE at 60 °C resulted with the highest yield, but UAE during 15 min of sonication produced the pectin of better quality (anhydrouronic acid, methoxy and calcium pectate contents and degree of esterification). NMR and FTIR spectroscopy of isolated pectins revealed predominantly esterified structure, irrespective of extraction conditions. The comparison of the pectin yields obtained after extraction at 80 °C, indicate that similar values were found at times of 24h and 15 min for CE and UAE, respectively. According to obtained results it can be concluded that main advantage of UAE is considerable shortening of extraction procedure with strong emphasis on environmental friendly processing approach. Therefore, these results suggested that UAE could be used as an efficient technique for the extraction of pectin from tomato waste and by-products.


Assuntos
Espectroscopia de Ressonância Magnética/métodos , Pectinas/química , Solanum lycopersicum/química , Sonicação/métodos , Ultrassom/métodos
16.
Dalton Trans ; 44(37): 16405-20, 2015 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-26308626

RESUMO

A novel synthetic approach toward a poorly explored bioorganometallic consisting of ferrocene-1,1'-diamine bearing structurally and chirally diverse amino acid sequences is reported. Until now, ferrocene-1,1'-diamine was suitable for accommodating only identical amino acid sequences at its N-termini, leading to the symmetrically disubstituted homochiral products stabilized through a 14-membered intramolecular hydrogen-bonded ring as is seen in antiparallel ß-sheet peptides. The key step of the novel synthetic pathway is the transformation of Ac-Ala-NH-Fn-COOH (5) (Fn = 1,1'-ferrocenylene) to orthogonally protected Ac-Ala-NH-Fn-NHBoc (7). The spectroscopic analysis (IR, NMR, CD) of the novel compounds, corroborated with DFT studies, suggests the interesting feature of the ferrocene-1,1'-diamine scaffold. The same hydrogen-bonding pattern, i.e. a 14-membered hydrogen-bonded ring, was determined both in solution and in the solid state, thus making them promising, yet simple scaffolds capable of mimicking ß-sheet peptides. In vitro screening of potential anticancer activity in Hep G2 human liver carcinoma cells and Hs 578 T human breast cancer cells revealed a cytotoxic pattern for novel compounds (150-500 µM) with significantly decreased cell proliferation.


Assuntos
Aminoácidos/química , Antineoplásicos/química , Diaminas/química , Compostos Ferrosos/química , Antineoplásicos/síntese química , Antineoplásicos/toxicidade , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cristalografia por Raios X , Células Hep G2 , Humanos , Ligação de Hidrogênio , Espectroscopia de Ressonância Magnética , Metalocenos , Conformação Molecular , Peptídeos/química
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