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1.
Chem Pharm Bull (Tokyo) ; 68(2): 117-128, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32009078

RESUMO

The total syntheses of dimeric indole alkaloids, haplophytine, and T988s are described. These dimeric compounds comprising two structurally different indole units are ubiquitous in nature, and many possess pharmaceutically important activities. To realize an efficient chemical synthesis of these dimeric indole alkaloids, the establishment of convergent synthetic strategies and development of new coupling methods are indispensable. The linkage of two highly functionalized units at a late stage of the synthesis frequently induces synthetic problems such as chemoselectivity and steric repulsion. Moreover, although transition metal-catalyzed reactions are usually an effective method for the cross-coupling of two units, the application of these cross-coupling reactions to bond formation involving a sterically hindered C(sp3) is often difficult. Thus, even with precise modern synthetic methods, it is currently difficult to realize convergent syntheses of dimeric indole alkaloids possessing a quaternary carbon linking two units. To combat these synthetic problems, we developed a synthetic method to link two indole units using an Ag-mediated nucleophilic substitution reaction. In this review, we provide a detailed discussion of convergent synthetic strategies and coupling methods for dimeric indole alkaloids.


Assuntos
Técnicas de Química Sintética/métodos , Alcaloides Indólicos/síntese química , Dimerização , Alcaloides Indólicos/química , Piperazinas/síntese química , Piperazinas/química , Estereoisomerismo
2.
Eur J Med Chem ; 188: 111975, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31940507

RESUMO

Local changes in the structure of G-protein coupled receptors (GPCR) binders largely affect their pharmacological profile. While the sought efficacy can be empirically obtained by introducing local modifications, the underlining structural explanation can remain elusive. Here, molecular dynamics (MD) simulations of the eticlopride-bound inactive state of the Dopamine D3 Receptor (D3DR) have been clustered using a machine learning-based approach in the attempt to rationalize the efficacy change in four congeneric modulators. Accumulating extended MD trajectories of receptor-ligand complexes, we observed how the increase in ligand flexibility progressively destabilized the crystal structure of the inactivated receptor. To prospectively validate this model, a partial agonist was rationally designed based on structural insights and computational modeling, and eventually synthesized and tested. Results turned out to be in line with the predictions. This case study suggests that the investigation of ligand flexibility in the framework of extended MD simulations can assist and inform drug design strategies, highlighting its potential role as a powerful in silico counterpart to functional assays.


Assuntos
Carbamatos/metabolismo , Agonistas de Dopamina/metabolismo , Antagonistas de Dopamina/metabolismo , Piperazinas/metabolismo , Receptores de Dopamina D3/metabolismo , Animais , Sítios de Ligação , Células CHO , Carbamatos/química , Cricetulus , Agonistas de Dopamina/química , Antagonistas de Dopamina/química , Desenho de Drogas , Humanos , Ligantes , Aprendizado de Máquina , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Piperazinas/química , Conformação Proteica , Receptores de Dopamina D3/química , Salicilamidas/metabolismo
3.
Eur J Med Chem ; 186: 111878, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31757524

RESUMO

We have previously disclosed compound 3 (CZh-226), a potent and selective PAK4 inhibitor, but its development was delayed due to poor oral pharmacokinetics. In an attempt to improve this issue, we synthesised a series of prodrugs by masking its terminal nitrogen of the piperazine moiety. Most synthesised prodrugs of 3 have low or no inhibition of PAK4 activity. The stability of synthetic prodrugs was evaluated in PBS, SGF, SIF, rat plasma and liver S9 fraction. Of these, prodrug 19 was not only stable under both acidic and neutral conditions but also could be quickly converted to parent drug 3 in rat plasma and liver S9 fraction. Such effective conversion into parent drug 3 was observed in rats, providing higher exposure of 3 compared to its direct administration. When given via oral route at daily doses of 25 and 50 mg/kg, the prodrug 19 was effective and well tolerated in mouse model of HCT-116 and B16F10.


Assuntos
Antineoplásicos/farmacologia , Piperazinas/farmacologia , Pró-Fármacos/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Quinases Ativadas por p21/antagonistas & inibidores , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Células HCT116 , Humanos , Fígado/química , Fígado/metabolismo , Masculino , Melanoma Experimental/tratamento farmacológico , Melanoma Experimental/metabolismo , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Estrutura Molecular , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Piperazinas/síntese química , Piperazinas/química , Pró-Fármacos/síntese química , Pró-Fármacos/química , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Ratos , Ratos Wistar , Relação Estrutura-Atividade , Quinases Ativadas por p21/metabolismo
4.
Eur J Med Chem ; 186: 111896, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31784185

RESUMO

We report here a thorough structure-activity relationship (SAR) with piperazinylureido sulfamates as inhibitors of human (h) carbonic anhydrase (CA, EC 4.2.1.1). A SAR investigation over the structure of reported anti-cancer zinc-binder CAIs such as SLC-0111 and S4 was carried out by including the urea outer nitrogen atom into a substituted piperazine ring reducing the linker flexibility. The derivatives were assessed for the inhibition of CA I, II and IV (off-target isoforms) and the tumor-associated CA IX (anticancer drug target). CA I and IV were not effectively inhibited, whereas many low nanomolar inhibitors were evidenced against CA II (KIs in the range of 1.0-705.5 nM), and IX (KIs in the range of 0.91-155.9 nM). Interestingly, a subset of CA II/IX selective inhibitors was detected which might represent interesting lead for the development of new anticancer strategies.


Assuntos
Inibidores da Anidrase Carbônica/farmacologia , Anidrases Carbônicas/metabolismo , Piperazinas/farmacologia , Sulfonamidas/farmacologia , Ácidos Sulfônicos/farmacologia , Ureia/farmacologia , Inibidores da Anidrase Carbônica/síntese química , Inibidores da Anidrase Carbônica/química , Relação Dose-Resposta a Droga , Humanos , Isoenzimas/antagonistas & inibidores , Isoenzimas/metabolismo , Simulação de Acoplamento Molecular , Estrutura Molecular , Piperazinas/química , Relação Estrutura-Atividade , Sulfonamidas/química , Ácidos Sulfônicos/química , Ureia/análogos & derivados , Ureia/química
5.
Eur J Med Chem ; 186: 111905, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31785819

RESUMO

Farnesyl pyrophosphate synthase (FPPS) is known to participate in a variety of disease-related cell signaling pathway and bisphosphonates (BPs) are served as FPPS inhibitors. However, the high polarity of BPs often induces a series of side effects, limiting their applications. In the present study, novel non-BP FPPS inhibitors were discovered by in silico screening and experimental validation. From the structure-based virtual screening (SBVS) strategy combining molecular docking, pharmacophore and binding affinity prediction, 10 hits with novel scaffolds were filtered. The inhibition activity of hits against FPPS was identified and 7 hits showed comparable or higher inhibition activity than Zoledronate. The hit VS-4 with higher lipophilicity (XlogP = 1.81) and binding affinity (KD = 14.3 ± 2.63 µM) to FPPS was selected for further study on cancer cells with different FPPS expression level. Experimental results revealed that VS-4 could better target the FPPS high-expressing colon LoVo and HCT116 cancer cell lines with IC50 of 51.772 ± 0.473 and 43.553 ± 1.027 µM, respectively, whereas the IC50 value against FPPS low expressing MDA-MB-231 cells was >100 µM. The mechanism of VS-4 against colon cancer cells was investigated by flow cytometry and the results indicated that VS-4 induced cell apoptosis by increasing the intracellular reactive oxygen species (ROS) level. Taken together, the SBVS strategy could be used to discover promising non-BP FPPS inhibitors and the lead compound VS-4 might shed a light on designing more potent inhibitors as novel anticancer drugs.


Assuntos
Antineoplásicos/farmacologia , Inibidores Enzimáticos/farmacologia , Geraniltranstransferase/antagonistas & inibidores , Piperazinas/farmacologia , Sulfonamidas/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Geraniltranstransferase/metabolismo , Células HCT116 , Humanos , Células MCF-7 , Estrutura Molecular , Piperazinas/síntese química , Piperazinas/química , Relação Estrutura-Atividade , Sulfonamidas/síntese química , Sulfonamidas/química , Células Tumorais Cultivadas
6.
J Enzyme Inhib Med Chem ; 35(1): 96-108, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31690133

RESUMO

A series of analogues of Amb639752, a novel diacylglycerol kinase (DGK) inhibitor recently discovered by us via virtual screening, have been tested. The compounds were evaluated as DGK inhibitors on α, θ, and ζ isoforms, and as antagonists on serotonin receptors. From these assays emerged two novel compounds, namely 11 and 20, which with an IC50 respectively of 1.6 and 1.8 µM are the most potent inhibitors of DGKα discovered to date. Both compounds demonstrated the ability to restore apoptosis in a cellular model of X-linked lymphoproliferative disease as well as the capacity to reduce the migration of cancer cells, suggesting their potential utility in preventing metastasis. Finally, relying on experimental biological data, molecular modelling studies allow us to set a three-point pharmacophore model for DGK inhibitors.


Assuntos
Indóis/farmacologia , Lipase Lipoproteica/antagonistas & inibidores , Piperazinas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células HEK293 , Humanos , Indóis/síntese química , Indóis/química , Lipase Lipoproteica/metabolismo , Linfócitos/efeitos dos fármacos , Células MCF-7 , Modelos Moleculares , Estrutura Molecular , Monócitos/efeitos dos fármacos , Piperazinas/síntese química , Piperazinas/química , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Relação Estrutura-Atividade , Linfócitos T/efeitos dos fármacos
7.
Eur J Med Chem ; 185: 111840, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31711794

RESUMO

In recent years, human adenovirus (HAdV) infections have shown a high clinical impact in both immunosuppressed and immunocompetent patients. The research into specific antiviral drugs for the treatment of HAdV infections in immunocompromised patients constitutes a principal objective for medicinal chemistry due to the lack of any specific secure drug to treat these infections. In this study, we report a small-molecule library (67 compounds) designed from an optimization process of piperazine-derived urea privileged structures and their biological evaluation: antiviral activity and cytotoxicity. The active compounds selected were further evaluated to gain mechanistic understanding for their inhibition. Twelve derivatives were identified that inhibited HAdV infections at nanomolar and low micromolar concentrations (IC50 from 0.6 to 5.1 µM) with low cytotoxicity. In addition, our mechanistic assays suggested differences in the way the derivatives exert their anti-HAdV activity targeting transcription, DNA replication and later steps in the HAdV replication cycle. Furthermore, eight of the 12 studied derivatives blocked human cytomegalovirus (HCMV) DNA replication at low micromolar concentrations. The data provided herein indicates that the 12 thiourea/urea piperazine derivatives studied may represent potential lead compounds for clinical evaluation and development of new anti-HAdV drugs.


Assuntos
Adenovírus Humanos/efeitos dos fármacos , Antivirais/farmacologia , Piperazinas/farmacologia , Ureia/farmacologia , Células A549 , Antivirais/síntese química , Antivirais/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Replicação do DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Piperazinas/síntese química , Piperazinas/química , Relação Estrutura-Atividade , Ureia/análogos & derivados , Ureia/química
8.
Eur J Med Chem ; 187: 111970, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31881454

RESUMO

Amongst the fluoroquinolone antibacterials, the 7-piperazinyl containing chemotypes such as norfloxacin, enoxacin, ciprofloxacin, pefloxacin, lomefloxacin, enrofloxacin, ofloxacin, levofloxacin, gatifloxacin and sparfloxacin have been shown to possess non-classical activities including cytotoxicity against different cancer cell lines, induction of apoptosis, and cell cycle arrest at the S/G2 stage. Additionally, piperazinylquinolones (PQs) have enough flexibility for chemical modification via their N-4 of piperazine ring and carboxylic acid at C-3. Therefore, PQs have been considered as a starting point for design and development of new anticancer agents. This review has focused on the recent synthetic modifications of PQs which led to N-substituted and/or C-3 modified PQs with potential anticancer activity.


Assuntos
Antibacterianos/farmacologia , Antineoplásicos/farmacologia , Bactérias/efeitos dos fármacos , Piperazinas/farmacologia , Quinolonas/farmacologia , Animais , Antibacterianos/síntese química , Antibacterianos/química , Antineoplásicos/síntese química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Testes de Sensibilidade Microbiana , Piperazinas/síntese química , Piperazinas/química , Quinolonas/síntese química , Quinolonas/química
9.
Chem Commun (Camb) ; 55(95): 14351-14354, 2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31720601

RESUMO

We present the first application of hydrophobic tagging to a non-covalent inhibitor of protein-protein interactions. Nutlin-3a-HT, created by fusing the hydrophobic tag HyT13 to the MDM2-p53 interaction inhibitor Nutlin-3a, prevented cellular accumulation of MDM2 upon p53 reactivation, and had a stronger effect on cell viability and the induction of apoptosis than Nutlin-3a.


Assuntos
Interações Hidrofóbicas e Hidrofílicas , Imidazóis/farmacologia , Piperazinas/farmacologia , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células HCT116 , Humanos , Imidazóis/química , Estrutura Molecular , Piperazinas/química , Ligação Proteica/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-mdm2/química , Relação Estrutura-Atividade , Proteína Supressora de Tumor p53/química
10.
Nature ; 574(7779): 581-585, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31645725

RESUMO

The tricarboxylic acid cycle intermediate succinate is involved in metabolic processes and plays a crucial role in the homeostasis of mitochondrial reactive oxygen species1. The receptor responsible for succinate signalling, SUCNR1 (also known as GPR91), is a member of the G-protein-coupled-receptor family2 and links succinate signalling to renin-induced hypertension, retinal angiogenesis and inflammation3-5. Because SUCNR1 senses succinate as an immunological danger signal6-which has relevance for diseases including ulcerative colitis, liver fibrosis7, diabetes and rheumatoid arthritis3,8-it is of interest as a therapeutic target. Here we report the high-resolution crystal structure of rat SUCNR1 in complex with an intracellular binding nanobody in the inactive conformation. Structure-based mutagenesis and radioligand-binding studies, in conjunction with molecular modelling, identified key residues for species-selective antagonist binding and enabled the determination of the high-resolution crystal structure of a humanized rat SUCNR1 in complex with a high-affinity, human-selective antagonist denoted NF-56-EJ40. We anticipate that these structural insights into the architecture of the succinate receptor and its antagonist selectivity will enable structure-based drug discovery and will further help to elucidate the function of SUCNR1 in vitro and in vivo.


Assuntos
Compostos de Bifenilo/química , Compostos de Bifenilo/farmacologia , Piperazinas/química , Piperazinas/farmacologia , Receptores Acoplados a Proteínas-G/antagonistas & inibidores , Receptores Acoplados a Proteínas-G/química , Animais , Apoproteínas/antagonistas & inibidores , Apoproteínas/química , Apoproteínas/metabolismo , Cristalografia por Raios X , Humanos , Modelos Moleculares , Ratos , Receptores Acoplados a Proteínas-G/metabolismo , Receptores Purinérgicos P2Y1/química , Transdução de Sinais , Anticorpos de Domínio Único/química , Especificidade da Espécie , Ácido Succínico/metabolismo
11.
Eur J Med Chem ; 183: 111674, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31518969

RESUMO

Polypharmacology approaches may help the discovery of pharmacological tools for the study or the potential treatment of complex and multifactorial diseases as well as for addictions and also smoke cessation. In this frame, following our interest in the development of molecules able to modulate either the endocannabinoid or the dopaminergic system, and given the multiple and reciprocal interconnections between them, we decided to merge the pharmacophoric elements of some of our early leads for identifying new molecules as tools able to modulate both systems. We herein describe the synthesis and biological characterization of compounds 5a-j inspired by the structure of our potent and selective fatty acid amide hydrolase (FAAH) inhibitors (3a-c) and ligands of dopamine D2 or D3 receptor subtypes (4a,b). Notably, the majority of the new molecules showed a nanomolar potency of interaction with the targets of interest. The drug-likeliness of the developed compounds (5a-j) was investigated in silico while hERG affinity, selectivity profile (for some proteins of the endocannabinoid system), cytotoxicity profiles (on fibroblast and astrocytes), and mutagenicity (Ames test) were experimentally determined. Metabolic studies also served to complement the preliminary drug-likeliness profiling for compounds 3a and 5c. Interestingly, after assessing the lack of toxicity for the neuroblastoma cell line (IMR 32), we demonstrated a potential anti-inflammatory profile for 3a and 5c in the same cell line.


Assuntos
Amidoidrolases/antagonistas & inibidores , Dopamina/metabolismo , Endocanabinoides/metabolismo , Amidoidrolases/metabolismo , Ligação Competitiva , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Humanos , Ligantes , Piperazinas/química , Piperazinas/farmacologia , Pirróis/química , Pirróis/farmacologia
12.
Eur J Med Chem ; 183: 111707, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31561043

RESUMO

The diverse nature of Alzheimer's disease (AD) has prompted researchers to develop multi-functional agents. Herein, we have designed and synthesized molecular hybrids of 2-pyridylpiperazine and 5-phenyl-1,3,4-oxadiazoles. Biological activities of synthesized compounds suggested significant and balanced inhibitory potential against target enzymes. In particular, compound 49 containing 2,4-difluoro substitution at terminal phenyl ring considered as most potential lead with inhibition of acetylcholinesterase (hAChE, IC50 = 0.054 µM), butyrylcholinesterase (hBChE, IC50 = 0.787 µM) and beta-secretase-1 (hBACE-1, IC50 = 0.098 µM). The enzyme kinetics study of 49 against hAChE suggested a mixed type of inhibition (Ki = 0.030 µM). Also, 48 and 49 showed significant displacement of propidium iodide from the peripheral anionic site (PAS) of hAChE, excellent blood-brain barrier (BBB) permeability in parallel artificial membrane permeation assay (PAMPA), and neuroprotective ability against SH-SY5Y neuroblastoma cell lines. Further, 49 also exhibited anti-Aß aggregation activity in self- and AChE-induced thioflavin T assay, which was ascertained by morphological characterization by atomic force microscopy (AFM). Moreover, in vivo behavioral studies signified learning and memory improvement by compound 49 in scopolamine- and Aß-induced cognitive dysfunctions performed on Y-maze and Morris water maze. The ex vivo studies suggested decreased AChE activity and antioxidant potential of compound 49, with good oral absorption characteristics ascertained by pharmacokinetic studies.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Fármacos Neuroprotetores/química , Oxidiazóis/química , Piperazinas/química , Piridinas/química , Acetilcolinesterase/metabolismo , Doença de Alzheimer/psicologia , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Antioxidantes/química , Antioxidantes/farmacologia , Barreira Hematoencefálica/metabolismo , Butirilcolinesterase/metabolismo , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacocinética , Disfunção Cognitiva/tratamento farmacológico , Feminino , Humanos , Cinética , Simulação de Acoplamento Molecular , Fármacos Neuroprotetores/farmacocinética , Oxidiazóis/farmacocinética , Piperazinas/farmacocinética , Agregados Proteicos , Piridinas/farmacocinética , Ratos Wistar , Relação Estrutura-Atividade
13.
Malar J ; 18(1): 310, 2019 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-31521174

RESUMO

BACKGROUND: After years of efforts on the control of malaria, it remains as a most deadly infectious disease. A major problem for the available anti-malarial drugs is the occurrence of drug resistance in Plasmodium. Developing of new compounds or modification of existing anti-malarial drugs is an effective approach to face this challenge. Quantitative structure activity relationship (QSAR) modelling plays an important role in design and modification of anti-malarial compounds by estimation of the activity of the compounds. METHODS: In this research, the QSAR study was done on anti-malarial activity of 33 imidazolopiperazine compounds based on artificial neural networks (ANN). The structural descriptors of imidazolopiperazine molecules was used as the independents variables and their activity against 3D7 and W2 strains was used as the dependent variables. During modelling process, 70% of compound was used as the training and two 15% of imidazolopiperazines were used as the validation and external test sets. In this work, stepwise multiple linear regression was applied as the valuable selection and ANN with Levenberg-Marquardt algorithm was utilized as an efficient non-linear approach to correlate between structural information of molecules and their anti-malarial activity. RESULTS: The sufficiency of the suggested method to estimate the anti-malarial activity of imidazolopiperazine compounds at two 3D7 and W2 strains was demonstrated using statistical parameters, such as correlation coefficient (R2), mean square error (MSE). For instance R2train = 0.947, R2val = 0.959, R2test = 0.920 shows the potential of the suggested model for the prediction of 3D7 activity. Different statistical approaches such as and applicability domain (AD) and y-scrambling was also showed the validity of models. CONCLUSION: QSAR can be an efficient way to virtual screening the molecules to design more efficient compounds with activity against malaria (3D7 and W2 strains). Imidazolopiperazines can be good candidates and change in the structure and functional groups can be done intelligently using QSAR approach to rich more efficient compounds with decreasing trial-error runs during synthesis.


Assuntos
Antimaláricos/química , Imidazóis/química , Piperazinas/química , Relação Quantitativa Estrutura-Atividade , Algoritmos , Modelos Lineares
14.
J Chromatogr A ; 1604: 460494, 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31488292

RESUMO

The objective of this study is to understand the behavior of a peptide in a medium containing supercritical carbon dioxide mixed with an alcohol (methanol) and acidic or basic additives in uncommonly high concentrations. Chirobiotic TAG is a chromatographic column made of silica bonded with a macrocyclic peptide, teicoplanin aglycone. With this stationary phase, two additives (trifluoroacetic acid and isopropylamine) were tested under extreme concentration conditions to observe the behavior of this peptide. Indeed, concentrations exceeding 1 M in the methanol co-solvent (>0.1 M overall concentration in the CO2-methanol mixture) were used whereas usual additive concentrations employed in supercritical fluid chromatography (SFC) rarely exceed 50 mM in the co-solvent. One purpose was to modify the apparent pH of the fluid, which is normally slightly acidic (around 5) and consequently possibly changing the ionization state of the peptide. Firstly, the effect of acidic and basic additives on the polarity and the apparent pH were evaluated with the help of color indicators. This served to assess the ionization state of the peptide under the selected operating conditions. Secondly, 54 achiral and 24 chiral molecules were injected in the chromatographic column at different levels of additives. The achiral species served at establishing retention models based on linear solvation energy relationships (LSER), while the chiral species were examined for their enantioresolution. From the LSER equations and observation of chromatograms, it appeared that specific interactions between the peptide-based stationary phase and the analytes evolved when increasing the concentration of additives, particularly hydrogen bonds and ionic interactions. A bare silica stationary phase (Acquity BEH) served as reference to deconvolute the contributions of silica support and bonded peptide. This study, with these extreme conditions of mobile phase, could be useful to understand the behavior of such peptides in SFC mobile phases and also improve the knowledge of the effects of additives in SFC, which should be helpful in the future prospect of analyzing large biomolecules in SFC.


Assuntos
Cromatografia com Fluido Supercrítico/métodos , Teicoplanina/análogos & derivados , Compostos Azabicíclicos/química , Ligações de Hidrogênio , Concentração de Íons de Hidrogênio , Íons , Metanol/química , Piperazinas/química , Solventes/química , Estereoisomerismo , Teicoplanina/química , Teicoplanina/isolamento & purificação , Ácido Trifluoracético/química
15.
Chem Biol Interact ; 311: 108787, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31400341

RESUMO

Antipsychotic drugs interfere with the antioxidant defense system provoking complex and often toxicological effects. Here we examined differences in plasma albumin reduced free thiol (SH) group content and its reactivity as a consequence of clozapine (CLZ) and ziprasidone (ZIP) binding. Chronic administration of CLZ reduced, whereas treatment with ZIP increased albumin-SH content in rats. Regardless of the ratio of stearic acid (SA) bound to protein, in vitro binding of ZIP to human serum albumin (HSA) increased both the SH group level and reactivity. In contrast, the effect of CLZ on HSA-SH reactivity was dependent on HSA to SA molar ratio. CLZ binding was accompanied by an increase in HSA-SH reactivity in samples with normal, but a reduction of its reactivity level with higher SA/HSA ratio, compared to drug-free samples. We demonstrate by steady-state fluorescence quenching studies that an increase in SA binding to HSA is associated with a significant reduction of binding constant for both antipsychotics. In addition, this is the first report of quantitative characterization of ZIP binding to HSA. Our findings suggest that albumin-SH content and reactivity is modulated by ZIP towards an increased antioxidant defense capacity in circulation, as opposed to CLZ, which can contribute to the safer, more effective treatment of schizophrenia.


Assuntos
Clozapina/química , Ácidos Graxos/química , Piperazinas/química , Albumina Sérica/química , Compostos de Sulfidrila/química , Tiazóis/química , Animais , Clozapina/metabolismo , Ácidos Graxos/metabolismo , Humanos , Masculino , Piperazinas/metabolismo , Ligação Proteica , Ratos , Ratos Wistar , Albumina Sérica/metabolismo , Espectrometria de Fluorescência , Espectrofotometria , Compostos de Sulfidrila/análise , Compostos de Sulfidrila/metabolismo , Tiazóis/metabolismo
16.
Acta Crystallogr C Struct Chem ; 75(Pt 8): 1031-1035, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31380784

RESUMO

Mycobacterium tuberculosis (Mtb), the principal etiological agent of tuberculosis (TB), infects over one-quarter of humanity and is now the leading cause of infectious disease mortality by a single pathogen. Macozinone {2-[4-(cyclohexylmethyl)piperazin-1-yl]-8-nitro-6-(trifluoromethyl)-4H-1,3-benzothiazin-4-one, C20H23F3N4O3S} is a promising new drug for treating drug-sensitive and drug-resistant TB that has successfully completed phase I clinical trials. We report the complete spectroscopic and structural characterization by 1H NMR, 13C NMR, HRMS, IR, and X-ray crystallography. The cyclohexyl moiety is observed to be nearly perpendicular to the core formed by the 1,3-benzothiazin-4-one and piperazine groups. The central piperazine ring adopts a slightly distorted chair conformation caused by sp2-hybridization of the nitro N atom, which donates into the electron-deficient 1,3-benzothiazin-4-one group.


Assuntos
Antituberculosos/química , Piperazinas/química , Tiazinas/química , Antituberculosos/síntese química , Cristalografia por Raios X , Farmacorresistência Bacteriana , Ligações de Hidrogênio , Conformação Molecular , Piperazinas/síntese química , Tiazinas/síntese química , Tuberculose Pulmonar/tratamento farmacológico
17.
Drug Dev Ind Pharm ; 45(10): 1695-1706, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31418592

RESUMO

Objectives: Development and evaluation of rapidly dissolving film for intra-oral administration of naftopidil. Significance: Formulation of naftopidil in the form of rapidly dissolving buccal film can eliminate the dissolution problem of naftopidil and provide a greater chance for direct absorption into the systemic circulation bypassing the presystemic metabolism. This can improve the oral bioavailability. In addition, this film guarantees patient compliance and is suitable for geriatric patients. Methods: Rapidly dissolving film utilized hydroxypropyl methylcellulose E5 and polyvinylpyrrolidone K30 as the main components. The drug was loaded in pure form or after co-grinding with citric and/or tartaric acid. A solution of naftopidil in plurol oleique, labrasol, and tween 80 self-microemulsifying drug delivery systems (SMEDDS) was also loaded. The interactions of the drug with the excipients were monitored using thermal analysis, Fourier transform infrared spectroscopy, and X-ray diffraction. Naftopidil dissolution was monitored and selected films were used to assess the bioavailability after buccal administration to rabbit. Unprocessed drug suspension was administered orally and used as a reference. Results: Incorporation of naftopidil in the film developed a new crystalline structure. The crystallinity of drug was abolished in the presence of organic acids or SMEDDS. The rapidly dissolving films showed fast liberation of the drug irrespective to the composition. Those films enhanced the bioavailability of naftopidil compared to orally administered suspension with SMEDDS containing film being superior. Conclusion: The study introduced rapidly dissolving buccal film for enhanced dissolution and bioavailability of naftopidil.


Assuntos
Excipientes/química , Naftalenos/administração & dosagem , Naftalenos/química , Piperazinas/administração & dosagem , Piperazinas/química , Solubilidade/efeitos dos fármacos , Administração Bucal , Animais , Disponibilidade Biológica , Varredura Diferencial de Calorimetria/métodos , Química Farmacêutica/métodos , Sistemas de Liberação de Medicamentos/métodos , Derivados da Hipromelose/química , Povidona/química , Coelhos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Suspensões/química , Difração de Raios X/métodos
18.
Eur J Med Chem ; 181: 111590, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31408808

RESUMO

Hybridization strategy is an effective strategy to obtain multi-target inhibitors in drug design. In this study, we assembled the pharmacophores of momelotinib and tandutinib to get a series of 4-piperazinyl-2-aminopyrimidine derivatives. All compounds were tested for the inhibition of JAK2 and FLT3 enzymes, of which, compounds with potent enzyme activities were assayed for antiproliferative activities against three cancer cell lines (HEL, MV4-11, and HL60). The structure-activity relationship studies were conducted through variations in two regions, the "A" phenyl ring and "B" phenyl ring. Compound 14j showed the most balanced in vitro inhibitory activity against JAK2 and FLT3 (JAK2 IC50 = 27 nM, FLT3 IC50 = 30 nM), and it also showed potent inhibition against the above tested cell lines. In the cellular context, 14j strongly induced apoptosis by arresting cell cycle in the G1/S phase, and was selected as a promising JAK2/FLT3 dual inhibitor.


Assuntos
Janus Quinase 2/antagonistas & inibidores , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/química , Pirimidinas/farmacologia , Tirosina Quinase 3 Semelhante a fms/antagonistas & inibidores , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Desenho de Drogas , Humanos , Janus Quinase 2/metabolismo , Simulação de Acoplamento Molecular , Neoplasias/tratamento farmacológico , Piperazinas/química , Piperazinas/farmacologia , Tirosina Quinase 3 Semelhante a fms/metabolismo
19.
Comput Biol Chem ; 83: 107109, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31445419

RESUMO

The binding affinity of a series of benzhydrylpiperazine δ opioid receptor agonists were pooled and evaluated by using 3D-QSAR and homology modeling/molecular docking methods. Ligand-based CoMFA and CoMSIA 3D-QSAR analyses with 46 compounds were performed on benzhydrylpiperazine analogues by taking the most active compound BW373U86 as the template. The models were generated successfully with q2 value of 0.508 and r2 value of 0.964 for CoMFA, and q2 value of 0.530 and r2 value of 0.927 for CoMSIA. The predictive capabilities of the two models were validated on the test set with R2pred value of 0.720 and 0.814, respectively. The CoMSIA model appeared to work better in this case. A homology model of active form of δ opioid receptor was established by Swiss-Model using a reported crystal structure of active µ opioid receptor as a template, and was further optimized using nanosecond scale molecular dynamics simulation. The most active compound BW373U86 was docked to the active site of δ opioid receptor and the lowest energy binding pose was then used to identify binding residues such as s Gln105, Lys108, Leu125, Asp128, Tyr129, Leu200, Met132, Met199, Lys214, Trp274, Ile277, Ile304 and Tyr308. The docking and 3D-QSAR results showed that hydrogen bond and hydrophobic interactions played major roles in ligand-receptor interactions. Our results highlight that an approach combining structure-based homology modeling/molecular docking and ligand-based 3D-QSAR methods could be useful in designing of new opioid receptor agonists.


Assuntos
Piperazinas/farmacologia , Relação Quantitativa Estrutura-Atividade , Receptores Opioides delta/agonistas , Cristalografia por Raios X , Humanos , Ligantes , Modelos Moleculares , Conformação Molecular , Piperazinas/química
20.
Cancer Sci ; 110(10): 3173-3182, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31464035

RESUMO

Ferroptosis is an iron-dependent, lipid peroxide-driven cell death caused by inhibition of the cystine/glutamate transporter, which is of importance for the survival of triple-negative breast cancer (TNBC) cells. Erastin is a low molecular weight chemotherapy drug that induces ferroptosis; however, poor water solubility and renal toxicity have limited its application. Exosomes, as drug delivery vehicles with low immunogenicity, high biocompatibility and high efficiency, have attracted increasing attention in recent years. Herein, we developed a formulation of erastin-loaded exosomes labeled with folate (FA) to form FA-vectorized exosomes loaded with erastin (erastin@FA-exo) to target TNBC cells with overexpression of FA receptors. The characterization, drug release, internalization and anti-tumor effect in vitro of erastin@FA-exo were determined. Erastin@FA-exo could increase the uptake efficiency of erastin into MDA-MB-231 cells; compared with erastin@exo and free erastin, erastin@FA-exo has a better inhibitory effect on the proliferation and migration of MDA-MB-231 cells. Furthermore, erastin@FA-exo promoted ferroptosis with intracellular depletion of glutathione and reactive oxygen species overgeneration. Western blot analyses revealed that erastin@FA-exo suppressed expression of glutathione peroxidase 4 (GPX4) and upregulated expression of cysteine dioxygenase (CDO1). We conclude that targeting and biocompatibility of exosome-based erastin preparations provide an innovative and powerful delivery platform for anti-cancer therapy.


Assuntos
Exossomos/química , Ácido Fólico/química , Piperazinas/farmacologia , Neoplasias de Mama Triplo Negativas/metabolismo , Morte Celular , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cisteína Dioxigenase/metabolismo , Sistemas de Liberação de Medicamentos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glutationa Peroxidase/metabolismo , Humanos , Piperazinas/química , Espécies Reativas de Oxigênio/metabolismo , Neoplasias de Mama Triplo Negativas/tratamento farmacológico
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