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1.
J Enzyme Inhib Med Chem ; 36(1): 1922-1930, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34425714

RESUMO

A rational-based process was adopted for repurposing pyrrolidine-based 3-deoxysphingosylphosphorylcholine analogs bearing variable acyl chains, different stereochemical configuration and/or positional relationships. Structural features were highly influential on activity. Amongst, enantiomer 1e having 1,2-vicinal relationship for the -CH2O- and the N-acyl moieties, a saturated palmitoyl chain and an opposite stereochemical configuration to natural sphingolipids was the most potent hit compound against promastigotes showing IC50 value of 28.32 µM. The corresponding enantiomer 1a was 2-fold less potent showing a eudismic ratio of 0.54 in promastigotes. Compounds 1a and 1e inhibited the growth of amastigotes more potently relative to promastigotes. Amongst, enantiomer 1a as the more selective and safer. In silico docking study using a homology model of Leishmania donovani inositol phosphoceramide synthase (IPCS) provided plausible reasoning for the molecular factors underlying the found activity. Collectively, this study suggests compounds 1a and 1e as potential hit compounds for further development of new antileishmanial agents.


Assuntos
Antiprotozoários/química , Leishmania donovani/efeitos dos fármacos , Fosforilcolina/química , Pirrolidinas/química , Amida Sintases/metabolismo , Antiprotozoários/farmacologia , Avaliação Pré-Clínica de Medicamentos , Humanos , Conformação Molecular , Simulação de Acoplamento Molecular , Palmitatos/química , Pirrolidinas/farmacologia , Esfingomielinas/química , Relação Estrutura-Atividade
2.
Molecules ; 26(16)2021 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-34443607

RESUMO

Cellular conformation of reduced pyridine nucleotides NADH and NADPH sensed using autofluorescence spectroscopy is presented as a real-time metabolic indicator under pressurized conditions. The approach provides information on the role of pressure in energy metabolism and antioxidant defense with applications in agriculture and food technologies. Here, we use spectral phasor analysis on UV-excited autofluorescence from Saccharomyces cerevisiae (baker's yeast) to assess the involvement of one or multiple NADH- or NADPH-linked pathways based on the presence of two-component spectral behavior during a metabolic response. To demonstrate metabolic monitoring under pressure, we first present the autofluorescence response to cyanide (a respiratory inhibitor) at 32 MPa. Although ambient and high-pressure responses remain similar, pressure itself also induces a response that is consistent with a change in cellular redox state and ROS production. Next, as an example of an autofluorescence response altered by pressurization, we investigate the response to ethanol at ambient, 12 MPa, and 30 MPa pressure. Ethanol (another respiratory inhibitor) and cyanide induce similar responses at ambient pressure. The onset of non-two-component spectral behavior upon pressurization suggests a change in the mechanism of ethanol action. Overall, results point to new avenues of investigation in piezophysiology by providing a way of visualizing metabolism and mitochondrial function under pressurized conditions.


Assuntos
NADP/química , NADP/metabolismo , NAD/química , NAD/metabolismo , Pressão , Fluorescência , Conformação Molecular
3.
Acta Crystallogr C Struct Chem ; 77(Pt 8): 490-495, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-34350847

RESUMO

Isopropyl 3-deoxy-α-D-ribo-hexopyranoside (isopropyl 3-deoxy-α-D-glucopyranoside), C9H18O5, (I), crystallizes from a methanol-ethyl acetate solvent mixture at room temperature in a 4C1 chair conformation that is slightly distorted towards the C5SC1 twist-boat form. A comparison of the structural parameters in (I), methyl α-D-glucopyranoside, (II), α-D-glucopyranosyl-(1→4)-D-glucitol (maltitol), (III), and 3-deoxy-α-D-ribo-hexopyranose (3-deoxy-α-D-glucopyranose), (IV), shows that most endocyclic and exocyclic bond lengths, valence bond angles and torsion angles in the aldohexopyranosyl rings are more affected by anomeric configuration, aglycone structure and/or the conformation of exocyclic substituents, such as hydroxymethyl groups, than by monodeoxygenation at C3. The structural effects observed in the crystal structures of (I)-(IV) were confirmed though density functional theory (DFT) calculations in computed structures (I)c-(IV)c. Exocyclic hydroxymethyl groups adopt the gauche-gauche (gg) conformation (H5 anti to O6) in (I) and (III), and the gauche-trans (gt) conformation (C4 anti to O6) in (II) and (IV). The O-glycoside linkage conformations in (I) and (III) resemble those observed in disaccharides containing ß-(1→4) linkages.


Assuntos
Glucosídeos/química , Maltose/análogos & derivados , Álcoois Açúcares/química , Cristalografia por Raios X , Ligação de Hidrogênio , Maltose/química , Conformação Molecular
4.
J Phys Chem Lett ; 12(34): 8416-8422, 2021 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-34436909

RESUMO

Polyproline II (pPII) is a left-handed 31-helix conformation, which has been observed to be the most abundant secondary structure in unfolded peptides and proteins compared to α-helix and ß-sheet. Although pPII has been reported as the most stable conformation for several unfolded short chain peptides in aqueous solution, it is rarely observed in their solid state. Here, we show for the first time a glycine homopeptide (gly-gly-gly) adopting the pPII conformation in its crystalline dihydrate structure. The single crystal X-ray structure with molecular dynamic simulation suggests that a network of water and the charged carboxylate group is critical in stabilizing the pPII conformation in solid state, offering an insight into the structures of unfolded regions of proteins and the role of water in peptide crystallization.


Assuntos
Oligopeptídeos/química , Peptídeos/química , Água/química , Cristalização , Conformação Molecular
5.
Int J Mol Sci ; 22(16)2021 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-34445400

RESUMO

Alternariol (AOH) is an emerging mycotoxin produced by Alternaria molds. It occurs as a contaminant e.g., in oilseeds, cereals, grapes, and tomatoes. Chronic exposure to AOH may cause genotoxic and endocrine disruptor effects. Our recent studies demonstrated that the fluorescence signal of AOH can be strongly affected by the environmental pH as well as by the presence of serum albumin or cyclodextrins. In the current study, we aimed to characterize the most optimal circumstances regarding the highly sensitive fluorescent detection of AOH. Therefore, the further detailed investigation of the microenvironment on the fluorescence signal of the mycotoxin has been performed, including the effects of different buffers, organic solvents, detergents, and cations. Organic solvents (acetonitrile and methanol) caused only slight increase in the emission signal of AOH, while detergents (sodium dodecyl sulfate and Triton-X100) and Ca2+ induced considerably higher enhancement in the fluorescence of the mycotoxin. In addition, Mg2+ proved to be a superior fluorescence enhancer of the AOH. Spectroscopic and modeling studies suggest the formation of low-affinity AOH-Mg2+ complexes. The effect of Mg2+ was also tested in two HPLC assays: Our results show that Mg2+ can considerably increase the fluorescence signal of AOH even in a chromatographic system.


Assuntos
Alternaria/química , Lactonas/análise , Magnésio/química , Acetonitrilas/química , Cromatografia Líquida de Alta Pressão , Concentração de Íons de Hidrogênio , Lactonas/química , Metanol/química , Conformação Molecular , Estrutura Molecular , Octoxinol/química , Dodecilsulfato de Sódio/química , Espectrometria de Fluorescência
6.
Molecules ; 26(15)2021 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-34361624

RESUMO

Prediction of molecular properties plays a critical role towards rational drug design. In this study, the Molecular Topographic Map (MTM) is proposed, which is a two-dimensional (2D) map that can be used to represent a molecule. An MTM is generated from the atomic features set of a molecule using generative topographic mapping and is then used as input data for analyzing structure-property/activity relationships. In the visualization and classification of 20 amino acids, differences of the amino acids can be visually confirmed from and revealed by hierarchical clustering with a similarity matrix of their MTMs. The prediction of molecular properties was performed on the basis of convolutional neural networks using MTMs as input data. The performance of the predictive models using MTM was found to be equal to or better than that using Morgan fingerprint or MACCS keys. Furthermore, data augmentation of MTMs using mixup has improved the prediction performance. Since molecules converted to MTMs can be treated like 2D images, they can be easily used with existing neural networks for image recognition and related technologies. MTM can be effectively utilized to predict molecular properties of small molecules to aid drug discovery research.


Assuntos
Desenho de Fármacos , Descoberta de Drogas/métodos , Algoritmos , Conformação Molecular , Redes Neurais de Computação , Relação Estrutura-Atividade
7.
Nat Commun ; 12(1): 4966, 2021 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-34404784

RESUMO

Although chirality is an ever-present characteristic in biology and some artificial molecules, controlling the chirality and demystifying the chirality origin of complex assemblies remain challenging. Herein, we report two homochiral Ag14 nanoclusters with inherent chirality originated from identical rotation of six square faces on a Ag8 cube driven by intra-cluster π···π stacking interaction between pntp- (Hpntp = p-nitrothiophenol) ligands. The spontaneous resolution of the racemic (SD/rac-Ag14a) to homochiral nanoclusters (SD/L-Ag14 and SD/R-Ag14) can be realized by re-crystallizing SD/rac-Ag14a in acetonitrile, which promotes the homochiral crystallization in solid state by forming C-H···O/N hydrogen bonds with nitro oxygen atoms in pntp- or aromatic hydrogen atoms in dpph (dpph = 1,6-bis(diphenylphosphino)hexane) on Ag14 nanocluster. This work not only provides strategic guidance for the syntheses of chiral silver nanoclusters in an all-achiral environment, but also deciphers the origin of chirality at molecular level by identifying the special effects of intra- and inter-cluster supramolecular interactions.


Assuntos
Cristalização , Compostos Organometálicos/química , Fenômenos Físicos , Prata/química , Acetonitrilas/química , Cristalografia por Raios X , Hexanos , Hidrogênio , Ligação de Hidrogênio , Modelos Moleculares , Conformação Molecular , Oxigênio , Rotação
8.
J Gen Virol ; 102(8)2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34424155

RESUMO

Infectious bronchitis virus (IBV) is an economically important coronavirus, causing damaging losses to the poultry industry worldwide as the causative agent of infectious bronchitis. The coronavirus spike (S) glycoprotein is a large type I membrane protein protruding from the surface of the virion, which facilitates attachment and entry into host cells. The IBV S protein is cleaved into two subunits, S1 and S2, the latter of which has been identified as a determinant of cellular tropism. Recent studies expressing coronavirus S proteins in mammalian and insect cells have identified a high level of glycosylation on the protein's surface. Here we used IBV propagated in embryonated hens' eggs to explore the glycan profile of viruses derived from infection in cells of the natural host, chickens. We identified multiple glycan types on the surface of the protein and found a strain-specific dependence on complex glycans for recognition of the S2 subunit by a monoclonal antibody in vitro, with no effect on viral replication following the chemical inhibition of complex glycosylation. Virus neutralization by monoclonal or polyclonal antibodies was not affected. Following analysis of predicted glycosylation sites for the S protein of four IBV strains, we confirmed glycosylation at 18 sites by mass spectrometry for the pathogenic laboratory strain M41-CK. Further characterization revealed heterogeneity among the glycans present at six of these sites, indicating a difference in the glycan profile of individual S proteins on the IBV virion. These results demonstrate a non-specific role for complex glycans in IBV replication, with an indication of an involvement in antibody recognition but not neutralisation.


Assuntos
Coronavirus/fisiologia , Polissacarídeos/metabolismo , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/metabolismo , Alcaloides/química , Alcaloides/farmacologia , Sequência de Aminoácidos , Animais , Sítios de Ligação , Células Cultivadas , Cromatografia Líquida , Biologia Computacional/métodos , Coronavirus/efeitos dos fármacos , Infecções por Coronavirus/veterinária , Regulação Viral da Expressão Gênica , Glicosilação/efeitos dos fármacos , Vírus da Bronquite Infecciosa/fisiologia , Modelos Moleculares , Conformação Molecular , Peso Molecular , Testes de Neutralização , Oligossacarídeos/química , Oligossacarídeos/metabolismo , Polissacarídeos/química , Doenças das Aves Domésticas/virologia , Transporte Proteico , Espectrometria de Massas por Ionização por Electrospray , Glicoproteína da Espícula de Coronavírus/genética , Relação Estrutura-Atividade , Replicação Viral/efeitos dos fármacos
9.
Proc Natl Acad Sci U S A ; 118(36)2021 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-34426525

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has killed more than 4 million humans globally, but there is no bona fide Food and Drug Administration-approved drug-like molecule to impede the COVID-19 pandemic. The sluggish pace of traditional therapeutic discovery is poorly suited to producing targeted treatments against rapidly evolving viruses. Here, we used an affinity-based screen of 4 billion DNA-encoded molecules en masse to identify a potent class of virus-specific inhibitors of the SARS-CoV-2 main protease (Mpro) without extensive and time-consuming medicinal chemistry. CDD-1714, the initial three-building-block screening hit (molecular weight [MW] = 542.5 g/mol), was a potent inhibitor (inhibition constant [K i] = 20 nM). CDD-1713, a smaller two-building-block analog (MW = 353.3 g/mol) of CDD-1714, is a reversible covalent inhibitor of Mpro (K i = 45 nM) that binds in the protease pocket, has specificity over human proteases, and shows in vitro efficacy in a SARS-CoV-2 infectivity model. Subsequently, key regions of CDD-1713 that were necessary for inhibitory activity were identified and a potent (K i = 37 nM), smaller (MW = 323.4 g/mol), and metabolically more stable analog (CDD-1976) was generated. Thus, screening of DNA-encoded chemical libraries can accelerate the discovery of efficacious drug-like inhibitors of emerging viral disease targets.


Assuntos
Proteases 3C de Coronavírus/antagonistas & inibidores , Proteases 3C de Coronavírus/genética , Descoberta de Drogas/métodos , Inibidores de Proteases/química , Inibidores de Proteases/farmacologia , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/genética , Animais , COVID-19/tratamento farmacológico , COVID-19/virologia , Células Cultivadas , Proteases 3C de Coronavírus/metabolismo , Relação Dose-Resposta a Droga , Ativação Enzimática , Engenharia Genética , Humanos , Modelos Moleculares , Conformação Molecular , Estrutura Molecular , SARS-CoV-2/metabolismo , Relação Estrutura-Atividade , Replicação Viral
10.
Cell Rep ; 36(9): 109650, 2021 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-34433083

RESUMO

Coronaviruses have evolved elaborate multisubunit machines to replicate and transcribe their genomes. Central to these machines are the RNA-dependent RNA polymerase subunit (nsp12) and its intimately associated cofactors (nsp7 and nsp8). We use a high-throughput magnetic-tweezers approach to develop a mechanochemical description of this core polymerase. The core polymerase exists in at least three catalytically distinct conformations, one being kinetically consistent with incorporation of incorrect nucleotides. We provide evidence that the RNA-dependent RNA polymerase (RdRp) uses a thermal ratchet instead of a power stroke to transition from the pre- to post-translocated state. Ultra-stable magnetic tweezers enable the direct observation of coronavirus polymerase deep and long-lived backtracking that is strongly stimulated by secondary structures in the template. The framework we present here elucidates one of the most important structure-dynamics-function relationships in human health today and will form the grounds for understanding the regulation of this complex.


Assuntos
COVID-19/virologia , RNA-Polimerase RNA-Dependente de Coronavírus/fisiologia , Nucleotídeos/metabolismo , RNA Viral/biossíntese , SARS-CoV-2/fisiologia , RNA-Polimerase RNA-Dependente de Coronavírus/química , Ensaios de Triagem em Larga Escala , Humanos , Modelos Moleculares , Conformação Molecular , Nucleotídeos/química , RNA Viral/química , Imagem Individual de Molécula , Proteínas não Estruturais Virais/química , Proteínas não Estruturais Virais/fisiologia
11.
Chem Pharm Bull (Tokyo) ; 69(8): 802-805, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34334525

RESUMO

A new rearranged nitrogenous bisabolone-type sesquiterpene, halichonic acid B (1), was isolated from a marine sponge Axinyssa sp. together with halichonic acid (2) and (6R,7S)-7-amino-7,8-dihydro-α-bisabolene (3). The structure of 1 was determined by extensive NMR and MS analyses, revealing an unprecedented carbon framework, and its absolute configuration was elucidated by time-dependent density-functional theory (TDDFT)-based electronic circular dichroism (ECD) spectrum calculation. We propose that 1 and 2 may be biosynthesized in the same pathway, involving the reaction between farnesyl pyrophosphate and glycine, followed by cyclization.


Assuntos
Poríferos/química , Sesquiterpenos/química , Animais , Dicroísmo Circular , Teoria da Densidade Funcional , Conformação Molecular , Sesquiterpenos/isolamento & purificação , Fatores de Tempo
12.
Molecules ; 26(16)2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34443312

RESUMO

Subcritical water extraction of Himanthalia elongata and the subsequent acetone fractionation to precipitate crude fucoidans generated a liquid phase which was used to recover alginates with a wide range of viscoelastic features and other soluble extracts with potential biological activities. The precipitated alginate was converted to sodium alginate using an environmentally friendly treatment before being characterized by Fourier transform infrared attenuated total reflectance, nuclear magnetic resonance, high performance size exclusion chromatography and rheological measurements. The cell viability of three human cell lines (A549, HCT-116, T98G) in the presence of the extracts obtained before and after acetone fractionation was assessed. Fractionation with different acetone volumes showed a slight effect in the behavior of the different tested cell lines. Results also indicated a notable effect of the processing conditions on the block structure and molar mass of the extracted biopolymer, with the subsequent impact on the rheological properties of the corresponding gelled matrices.


Assuntos
Alginatos/isolamento & purificação , Feófitas/química , Água/química , Alginatos/química , Alginatos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Humanos , Conformação Molecular , Reologia , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura
13.
Molecules ; 26(16)2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34443314

RESUMO

Despite the common use of salens and hydroxyquinolines as therapeutic and bioactive agents, their metal complexes are still under development. Here, we report the synthesis of novel mixed-ligand metal complexes (MSQ) comprising salen (S), derived from (2,2'-{1,2-ethanediylbis[nitrilo(E) methylylidene]}diphenol, and 8-hydroxyquinoline (Q) with Co(II), Ni(II), Cd(II), Al(III), and La(III). The structures and properties of these MSQ metal complexes were investigated using molar conductivity, melting point, FTIR, 1H NMR, 13C NMR, UV-VIS, mass spectra, and thermal analysis. Quantum calculation, analytical, and experimental measurements seem to suggest the proposed structure of the compounds and its uncommon monobasic tridentate binding mode of salen via phenolic oxygen, azomethine group, and the NH group. The general molecular formula of MSQ metal complexes is [M(S)(Q)(H2O)] for M (II) = Co, Ni, and Cd or [M(S)(Q)(Cl)] and [M(S)(Q)(H2O)]Cl for M(III) = La and Al, respectively. Importantly, all prepared metal complexes were evaluated for their antimicrobial and anticancer activities. The metal complexes exhibited high cytotoxic potency against human breast cancer (MDA-MB231) and liver cancer (Hep-G2) cell lines. Among all MSQ metal complexes, CoSQ and LaSQ produced IC50 values (1.49 and 1.95 µM, respectively) that were comparable to that of cisplatin (1.55 µM) against Hep-G2 cells, whereas CdSQ and LaSQ had best potency against MDA-MB231 with IC50 values of 1.95 and 1.43 µM, respectively. Furthermore, the metal complexes exhibited significant antimicrobial activities against a wide spectrum of both Gram-positive and -negative bacterial and fungal strains. The antibacterial and antifungal efficacies for the MSQ metal complexes, the free S and Q ligands, and the standard drugs gentamycin and ketoconazole decreased in the order AlSQ > LaSQ > CdSQ > gentamycin > NiSQ > CoSQ > Q > S for antibacterial activity, and for antifungal activity followed the trend of LaSQ > AlSQ > CdSQ > ketoconazole > NiSQ > CoSQ > Q > S. Molecular docking studies were performed to investigate the binding of the synthesized compounds with breast cancer oxidoreductase (PDB ID: 3HB5). According to the data obtained, the most probable coordination geometry is octahedral for all the metal complexes. The molecular and electronic structures of the metal complexes were optimized theoretically, and their quantum chemical parameters were calculated. PXRD results for the Cd(II) and La(III) metal complexes indicated that they were crystalline in nature.


Assuntos
Antibacterianos/farmacologia , Complexos de Coordenação/síntese química , Complexos de Coordenação/farmacologia , Teoria da Densidade Funcional , Etilenodiaminas/síntese química , Simulação de Acoplamento Molecular , Oxiquinolina/síntese química , Oxiquinolina/farmacologia , Antibacterianos/química , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Complexos de Coordenação/química , Etilenodiaminas/química , Etilenodiaminas/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Concentração Inibidora 50 , Ligantes , Testes de Sensibilidade Microbiana , Conformação Molecular , Oxiquinolina/química , Difração de Pó , Espectroscopia de Prótons por Ressonância Magnética , Espectrometria de Massas por Ionização por Electrospray , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria
14.
Molecules ; 26(16)2021 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-34443508

RESUMO

INTRODUCTION: Chemotherapy with anti-cancer drugs is considered the most common approach for killing cancer cells in the human body. However, some barriers such as toxicity and side effects would limit its usage. In this regard, nano-based drug delivery systems have emerged as cost-effective and efficient for sustained and targeted drug delivery. Nanotubes such as carbon nanotubes (CNT) and boron nitride nanotubes (BNNT) are promising nanocarriers that provide the cargo with a large inner volume for encapsulation. However, understanding the insertion process of the anti-cancer drugs into the nanotubes and demonstrating drug-nanotube interactions starts with theoretical analysis. METHODS: First, interactions parameters of the atoms of 5-FU were quantified from the DREIDING force field. Second, the storage capacity of BNNT (8,8) was simulated to count the number of drugs 5-FU encapsulated inside the cavity of the nanotubes. In terms of the encapsulation process of the one drug 5-FU into nanotubes, it was clarified that the drug 5-FU was more rapidly adsorbed into the cavity of the BNNT compared with the CNT due to the higher van der Waals (vdW) interaction energy between the drug and the BNNT. RESULTS: The obtained values of free energy confirmed that the encapsulation process of the drug inside the CNT and BNNT occurred spontaneously with the free energies of -14 and -25 kcal·mol-1, respectively. DISCUSSION: However, the lower value of the free energy in the system containing the BNNT unraveled more stability of the encapsulated drug inside the cavity of the BNNT comparing the system having CNT. The encapsulation of Fluorouracil (5-FU) anti-cancer chemotherapy drug (commercial name: Adrucil®) into CNT (8,8) and BNNT (8,8) with the length of 20 Å in an aqueous solution was discussed herein applying molecular dynamics (MD) simulation.


Assuntos
Antineoplásicos/farmacologia , Compostos de Boro/química , Composição de Medicamentos , Fluoruracila/farmacologia , Nanotubos de Carbono/química , Estabilidade de Medicamentos , Fluoruracila/química , Conformação Molecular , Simulação de Dinâmica Molecular , Termodinâmica
15.
Molecules ; 26(16)2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34443545

RESUMO

Carthamin potassium salt isolated from Carthamus tinctorius L. was purified by an improved traditional Japanese method, without using column chromatography. The 1H and 13C nuclear magnetic resonance (NMR) signals of the pure product were fully assigned using one- and two-dimensional NMR spectroscopy, while the high purity of the potassium salt and deprotonation at the 3' position of carthamin were confirmed by atomic adsorption spectroscopy and nano-electrospray ionization mass spectrometry.


Assuntos
Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Carthamus tinctorius/química , Chalcona/análogos & derivados , Glucosídeos/análise , Espectroscopia de Prótons por Ressonância Magnética , Chalcona/análise , Chalcona/química , Chalcona/isolamento & purificação , Glucosídeos/química , Glucosídeos/isolamento & purificação , Conformação Molecular , Processamento de Sinais Assistido por Computador
16.
Molecules ; 26(16)2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34443416

RESUMO

Acylhydrazones are still an important framework to the design of new bioactive compounds. As treatment of chronic pain represents a clinical challenge, we decided to modify the structure of LASSBio-1514 (1), previously described as anti-inflammatory and analgesic prototype. Applying the homologation as a strategy for molecular modification, we designed a series of cyclopentyl- (2a-e), cyclobutyl- (3a-e), and cyclopropylacylhydrazones (4a-e) that were synthetized and evaluated in murine models of inflammation and pain. A comparison of their in silico physicochemical and drug-like profile was conducted, as well as their anti-inflammatory and analgesic effect. Compounds 4a (LASSBio-1755) and 4e (LASSBio-1757) displayed excellent in silico drug-like profiles and were identified as new analgesic lead-candidates in acute and chronic model of pain, through oral administration.


Assuntos
Simulação por Computador , Desenho de Fármacos , Hidrazonas/síntese química , Hidrazonas/farmacologia , Preparações Farmacêuticas/síntese química , Analgésicos/farmacologia , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Aspirina/farmacologia , Células CACO-2 , Humanos , Hidrazonas/química , Hiperalgesia/patologia , Indometacina/farmacologia , Masculino , Camundongos , Conformação Molecular , Peso Molecular , Preparações Farmacêuticas/química , Ratos Wistar
17.
Molecules ; 26(16)2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34443429

RESUMO

A series of 16 new derivatives of harmine N9-Cinnamic acid were synthesized and fully characterized using NMR and MS. The in vitro antibacterial evaluation revealed that most of the synthesized harmine derivatives displayed better antibacterial activities against Gram-positive strains (S. aureus, S. albus and MRSA) than Gram-negative strains (E. coli and PA). In particular, compound 3c showed the strongest bactericidal activity with a minimum inhibitory concentration of 13.67 µg/mL. MTT assay showed that compound 3c displayed weaker cytotoxicity than harmine with IC50 of 340.30, 94.86 and 161.67 µmol/L against WI-38, MCF-7 and HepG2 cell lines, respectively. The pharmacokinetic study revealed that the distribution and elimination of 3c in vivo were rapid in rats with an oral bioavailability of 6.9%.


Assuntos
Antibacterianos/síntese química , Antibacterianos/farmacocinética , Cinamatos/síntese química , Cinamatos/farmacocinética , Animais , Antibacterianos/administração & dosagem , Antibacterianos/química , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Cinamatos/administração & dosagem , Cinamatos/química , Feminino , Humanos , Injeções Intravenosas , Masculino , Testes de Sensibilidade Microbiana , Conformação Molecular , Ratos Sprague-Dawley , Fatores de Tempo
18.
Molecules ; 26(16)2021 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-34443452

RESUMO

The solvatomorphism of the anthelmintic drug moxidectin is investigated, and a new solvatomorph with nitromethane is reported. Moreover, the hitherto unknown crystal structures of the solvatomorphs with ethanol and 2-propanol are reported and discussed. The thermal characterization of these solvatomorphs through variable-temperature powder X-ray diffraction analysis (VT-PXRD) is also described, providing new insights into the crystallochemistry of this active pharmaceutical ingredient.


Assuntos
Macrolídeos/química , Solventes/química , Cristalografia por Raios X , Ligação de Hidrogênio , Conformação Molecular , Difração de Pó , Temperatura
19.
Molecules ; 26(16)2021 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-34443382

RESUMO

The E-hook of ß-tubulin plays instrumental roles in cytoskeletal regulation and function. The last six C-terminal residues of the ßII isotype, a peptide of amino acid sequence EGEDEA, extend from the microtubule surface and have eluded characterization with classic X-ray crystallographic techniques. The band position of the characteristic amide I vibration of small peptide fragments is heavily dependent on the length of the peptide chain, the extent of intramolecular hydrogen bonding, and the overall polarity of the fragment. The dependence of the E residue's amide I ν(C=O) and the αCOO- terminal ν(C=O) bands on the neighboring side chain, the length of the peptide fragment, and the extent of intramolecular hydrogen bonding in the structure are investigated here via the EGEDEA peptide. The hexapeptide is broken down into fragments increasing in size from dipeptides to hexapeptides, including EG, ED, EA, EGE, EDE, DEA, EGED, EDEA, EGEDE, GEDEA, and, finally, EGEDEA, which are investigated with experimental Raman spectroscopy and density functional theory (DFT) computations to model the zwitterionic crystalline solids (in vacuo). The molecular geometries and Boltzmann sum of the simulated Raman spectra for a set of energetic minima corresponding to each peptide fragment are computed with full geometry optimizations and corresponding harmonic vibrational frequency computations at the B3LYP/6-311++G(2df,2pd) level of theory. In absence of the crystal structure, geometry sampling is performed to approximate solid phase behavior. Natural bond order (NBO) analyses are performed on each energetic minimum to quantify the magnitude of the intramolecular hydrogen bonds. The extent of the intramolecular charge transfer is dependent on the overall polarity of the fragment considered, with larger and more polar fragments exhibiting the greatest extent of intramolecular charge transfer. A steady blue shift arises when considering the amide I band position moving linearly from ED to EDE to EDEA to GEDEA and, finally, to EGEDEA. However, little variation is observed in the αCOO- ν(C=O) band position in this family of fragments.


Assuntos
Amidas/química , Teoria da Densidade Funcional , Ácido Glutâmico/química , Fragmentos de Peptídeos/química , Análise Espectral Raman , Simulação por Computador , Conformação Molecular , Estrutura Secundária de Proteína , Termodinâmica , Vibração
20.
Inorg Chem ; 60(16): 12172-12185, 2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34346215

RESUMO

Morpholine motif is an important pharmacophore and, depending on the molecular design, may localize in cellular acidic vesicles. To understand the importance of the presence of pendant morpholine in a metal complex, six bidentate N,O-donor ligands with or without a pendant morpholine unit and their corresponding ruthenium(II) p-cymene complexes (1-6) are synthesized, purified, and structurally characterized by various analytical methods including X-ray diffraction. Complexes 2-4 crystallized in the P21/c space group, whereas 5 and 6 crystallized in the P1̅ space group. The solution stability studies using 1H NMR support instantaneous hydrolysis of the native complexes to form monoaquated species in a solution of 3:7 (v/v) dimethyl sulfoxide-d6 and 20 mM phosphate buffer (pH* 7.4, containing 4 mM NaCl). The monoaquated complexes are stable for at least up to 24 h. The complexes display excellent in vitro antiproliferative activity (IC50 ca. 1-14 µM) in various cancer cell lines, viz., MDA-MB-231, MiaPaCa2, and Hep-G2. The presence of the pendant morpholine does not improve the dose efficacy, but rather, with 2-[[(2,6-dimethylphenyl)imino]methyl]phenol (HL1) and its pendant morpholine analogue (HL3) giving complexes 1 and 3, respectively, the antiproliferative activity was poorer with 3. MDA-MB-231 cells treated with the complexes show that the acidic vesicles remain acidic, but the population of acidic vesicles increases or decreases with time of exposure, as observed from the dispersed red puncta, depending on the complex used. The presence of the 2,6-disubstituted aniline and the naphthyl group seems to improve the antiproliferative dose. The complex treated MDA-MB-231 cells show that cathepsin D, which is otherwise present in the cytosolic lysosomes, translocates to the nucleus as a result of exposure to the complexes. Irrespective of the presence of a morpholine motif, the complexes do not activate caspase-3 to induce apoptosis and seem to favor the necrotic pathway of cell killing.


Assuntos
Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Complexos de Coordenação/síntese química , Complexos de Coordenação/farmacologia , Cimenos/química , Morfolinas/química , Rutênio/química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Técnicas de Química Sintética , Complexos de Coordenação/química , Humanos , Modelos Moleculares , Conformação Molecular
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