RESUMO
Elongating RNA polymerase II (Pol II) can be paused or arrested by a variety of obstacles. These obstacles include DNA lesions, DNA-binding proteins, and small molecules. Hairpin pyrrole-imidazole (Py-Im) polyamides bind to the minor groove of DNA in a sequence-specific manner and induce strong transcriptional arrest. Remarkably, this Py-Im-induced Pol II transcriptional arrest is persistent and cannot be rescued by transcription factor TFIIS. In contrast, TFIIS can effectively rescue the transcriptional arrest induced by a nucleosome barrier. The structural basis of Py-Im-induced transcriptional arrest and why TFIIS cannot rescue this arrest remain elusive. Here we determined the X-ray crystal structures of four distinct Pol II elongation complexes (Pol II ECs) in complex with hairpin Py-Im polyamides as well as of the hairpin Py-Im polyamides-dsDNA complex. We observed that the Py-Im oligomer directly interacts with RNA Pol II residues, introduces compression of the downstream DNA duplex, prevents Pol II forward translocation, and induces Pol II backtracking. These results, together with biochemical studies, provide structural insight into the molecular mechanism by which Py-Im blocks transcription. Our structural study reveals why TFIIS fails to promote Pol II bypass of Py-Im-induced transcriptional arrest.
Assuntos
DNA/química , Conformação de Ácido Nucleico , RNA Polimerase II/metabolismo , Transcrição Gênica , Sequência de Bases , Imidazóis/química , Modelos Moleculares , Pirróis/química , Fatores de Elongação da Transcrição/metabolismoRESUMO
Reactive functional groups, such as N-nitrosamines, impart unique bioactivities to the natural products in which they are found. Recent work has illuminated enzymatic N-nitrosation reactions in microbial natural product biosynthesis, motivating interest in discovering additional metabolites constructed using such reactivity. Here, we use a genome mining approach to identify over 400 cryptic biosynthetic gene clusters (BGCs) encoding homologues of the N-nitrosating biosynthetic enzyme SznF, including the BGC for chalkophomycin, a CuII-binding metabolite that contains a C-type diazeniumdiolate and N-hydroxypyrrole. Characterizing chalkophomycin biosynthetic enzymes reveals previously unknown enzymes responsible for N-hydroxypyrrole biosynthesis, including the first prolyl-N-hydroxylase, and a key step in the assembly of the diazeniumdiolate-containing amino acid graminine. Discovery of this pathway enriches our understanding of the biosynthetic logic employed in constructing unusual heteroatom-heteroatom bond-containing functional groups, enabling future efforts in natural product discovery and biocatalysis.
Assuntos
Pirróis , Pirróis/metabolismo , Pirróis/química , Família Multigênica , Streptomyces/enzimologia , Streptomyces/metabolismo , Streptomyces/genéticaRESUMO
Antibody-drug conjugates (ADCs) for the treatment of cancer aim to achieve selective delivery of a cytotoxic payload to tumor cells while sparing normal tissue. In vivo, multiple tumor-dependent and -independent processes act on ADCs and their released payloads to impact tumor-versus-normal delivery, often resulting in a poor therapeutic window. An ADC with a labeled payload would make synchronous correlations between distribution and tissue-specific pharmacological effects possible, empowering preclinical and clinical efforts to improve tumor-selective delivery; however, few methods to label small molecules without destroying their pharmacological activity exist. Herein, we present a bioorthogonal switch approach that allows a radiolabel attached to an ADC payload to be removed tracelessly at will. We exemplify this approach with a potent DNA-damaging agent, the pyrrolobenzodiazepine (PBD) dimer, delivered as an antibody conjugate targeted to lung tumor cells. The radiometal chelating group, DOTA, was attached via a novel trans-cyclooctene (TCO)-caged self-immolative para-aminobenzyl (PAB) linker to the PBD, stably attenuating payload activity and allowing tracking of biodistribution in tumor-bearing mice via SPECT-CT imaging (live) or gamma counting (post-mortem). Following TCO-PAB-DOTA reaction with tetrazines optimized for extra- and intracellular reactivity, the label was removed to reveal the unmodified PBD dimer capable of inducing potent tumor cell killing in vitro and in mouse xenografts. The switchable antibody radio-drug conjugate (ArDC) we describe integrates, but decouples, the two functions of a theranostic given that it can serve as a diagnostic for payload delivery in the labeled state, but can be switched on demand to a therapeutic agent (an ADC).
Assuntos
Imunoconjugados , Tomografia Computadorizada de Emissão de Fóton Único , Imunoconjugados/química , Humanos , Animais , Camundongos , Benzodiazepinas/química , Linhagem Celular Tumoral , Antineoplásicos/química , Antineoplásicos/farmacologia , Pirróis/químicaRESUMO
The viscosity that ensures the controlled diffusion of biomolecules in cells is a crucial biophysical parameter. Consequently, fluorescent probes capable of reporting viscosity variations are valuable tools in bioimaging. In this field, red-shifted probes are essential, as the widely used and gold standard probe remains green-emitting molecular rotors based on BODIPY. Here, we demonstrate that pyrrolyl squaraines, red-emissive fluorophores, exhibit high sensitivity over a wide viscosity range from 30 to 4890 mPa·s. Upon alkylation of the pyrrole moieties, the probes improve their sensitivity to viscosity through an enhanced twisted intramolecular charge transfer phenomenon. We utilized this scaffold to develop a plasma membrane probe, pSQ-PM, that efficiently stains the plasma membrane in a fluorogenic manner. Using fluorescence lifetime imaging, pSQ-PM enabled efficient sensing of viscosity variations in the plasma membrane under various conditions and in different cell lines (HeLa, U2OS, and NIH/3T3). Moreover, upon incubation, pSQ-PM stained the membrane of intracellular vesicles and suggested that the lysosomal membranes displayed enhanced fluidity.
Assuntos
Membrana Celular , Ciclobutanos , Corantes Fluorescentes , Imagem Óptica , Fenóis , Pirróis , Membrana Celular/química , Membrana Celular/metabolismo , Viscosidade , Corantes Fluorescentes/química , Camundongos , Animais , Humanos , Ciclobutanos/química , Pirróis/química , Fenóis/química , Células NIH 3T3 , Células HeLa , Estrutura MolecularRESUMO
Conductive polymers are recognized as ideal candidates for the development of noninvasive and wearable sensors for real-time monitoring of potassium ions (K+) in sweat to ensure the health of life. However, the low ion-to-electron transduction efficiency and limited active surface area hamper the development of high-performance sensors for low-concentration K+ detection in the sweat. Herein, a wearable K+ sensor is developed by tailoring the nanostructure of polypyrrole (PPy), serving as an ion-to-electron transduction layer, for accurately and stably tracing the K+ fluctuation in human sweat. The PPy nanostructures can be tailored from nanospheres to nanofibers by controlling the supramolecular assembly process during PPy polymerization. Resultantly, the ion-to-electron transduction efficiency (17-fold increase in conductivity) and active surface area (1.3-fold enhancement) are significantly enhanced, accompanied by minimized water layer formation. The optimal PPy nanofibers-based K+ sensor achieved a high sensitivity of 62 mV decade-1, good selectivity, and solid stability. After being integrated with a temperature sensor, the manufactured wearable sensor realized accurate monitoring of K+ fluctuation in the human sweat.
Assuntos
Nanofibras , Polímeros , Potássio , Pirróis , Dispositivos Eletrônicos Vestíveis , Nanofibras/química , Pirróis/química , Polímeros/química , Potássio/química , Potássio/análise , Humanos , Técnicas Biossensoriais/métodos , Elétrons , Íons , Suor/química , Condutividade ElétricaRESUMO
Ferroptosis is an emerging non-apoptotic death process, mainly involving lipid peroxidation (LPO) caused by iron accumulation, which is potentially lethal to the intrinsically apoptotic-resistant malignant tumor. However, it is still restricted by the inherent antioxidant systems of tumor cells and the poor efficacy of traditional iron-based ferroptosis initiators. Herein, the study develops a novel ferroptosis-inducing agent based on PEGylated Cu+/Cu2+-doped black phosphorus@polypyrrole heterojunction (BP@CPP), which is constructed by utilizing the phosphate on the surface of BP to chelate Cu ions and initiating subsequent in situ polymerization of pyrrole. As a novel Z-scheme heterojunction, BP@CPP possesses an excellent photocatalytic activity in which the separated electron-hole pairs under laser irradiation endow it with powerful oxidizing and reducing capacities, which synergy with Cu+/Cu2+ self-cycling catalyzing Fenton-like reaction to further strengthen reactive oxygen species (ROS) accumulation, glutathione (GSH) depletion, and glutathione peroxidase 4 (GPX4) inactivation, ultimately leading to efficient ferroptosis. Systematic in vitro and in vivo evaluations demonstrate that BP@CPP effectively inhibit tumor growth by inducing desired ferroptosis while maintaining a favorable biosafety in the body. Therefore, the developed BP@CPP-based ferroptosis initiator provides a promising strategy for ferroptosis-like cancer therapy.
Assuntos
Cobre , Ferroptose , Oxirredução , Espécies Reativas de Oxigênio , Ferroptose/efeitos dos fármacos , Humanos , Espécies Reativas de Oxigênio/metabolismo , Cobre/química , Cobre/farmacologia , Animais , Linhagem Celular Tumoral , Polímeros/química , Polímeros/farmacologia , Pirróis/química , Pirróis/farmacologia , Neoplasias/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Camundongos , Glutationa/metabolismo , Fósforo/químicaRESUMO
Adoptive cellular therapy is a promising strategy for cancer treatment. However, the effectiveness of this therapy is limited by its intricate and immunosuppressive tumor microenvironment. In this study, a targeted therapeutic strategy for macrophage loading of drugs is presented to enhance anti-tumor efficacy of macrophages. K7M2-target peptide (KTP) is used to modify macrophages to enhance their affinity for tumors. Pexidartinib-loaded ZIF-8 nanoparticles (P@ZIF-8) are loaded into macrophages to synergistically alleviate the immunosuppressive tumor microenvironment synergistically. Thus, the M1 macrophages decorated with KTP carried P@ZIF-8 and are named P@ZIF/M1-KTP. The tumor volumes in the P@ZIF/M1-KTP group are significantly smaller than those in the other groups, indicating that P@ZIF/M1-KTP exhibited enhanced anti-tumor efficacy. Mechanistically, an increased ratio of CD4+ T cells and a decreased ratio of MDSCs in the tumor tissues after treatment with P@ZIF/M1-KTP indicated that it can alleviate the immunosuppressive tumor microenvironment. RNA-seq further confirms the enhanced immune cell function. Consequently, P@ZIF/M1-KTP has great potential as a novel adoptive cellular therapeutic strategy for tumors.
Assuntos
Macrófagos , Células Supressoras Mieloides , Osteossarcoma , Peptídeos , Microambiente Tumoral , Zeolitas , Animais , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Osteossarcoma/patologia , Osteossarcoma/tratamento farmacológico , Osteossarcoma/terapia , Microambiente Tumoral/efeitos dos fármacos , Peptídeos/química , Zeolitas/química , Camundongos , Células Supressoras Mieloides/efeitos dos fármacos , Células Supressoras Mieloides/metabolismo , Linhagem Celular Tumoral , Aminopiridinas/química , Aminopiridinas/farmacologia , Nanopartículas/química , Pirróis/química , Pirróis/farmacologia , Terapia de Imunossupressão , Sistemas de Liberação de Medicamentos , HumanosRESUMO
An efficient and biomimetic synthetic approach to 3,4-diindolylpyrrole-2,5-dicarboxylate derivatives, including lycogarubin C, lynamicin D and related analogues, was discovered. The crucial transformation included the one-pot formation of two C-N bonds and one C-C bond to construct characteristic pyrrole rings.
Assuntos
Biomimética , Pirróis , Pirróis/química , Indóis/químicaRESUMO
The synthesis of the ethyl ester analogue of the ultrapotent antitumour antibiotic seco-duocarmycin SA has been achieved in eleven linear steps from commercially available starting materials. The DSA alkylation subunit can be made in ten linear steps from the same precursor. The route involves C-H activation at the equivalent of the C7 position on indole leading to a borylated intermediate 9 that is stable enough for peptide coupling reactions but can be easily converted to the free hydroxyl analogue.
Assuntos
Duocarmicinas , Indóis , Irídio , Catálise , Indóis/química , Indóis/síntese química , Irídio/química , Estrutura Molecular , Pirróis/química , Pirróis/síntese química , Compostos de Boro/química , Compostos de Boro/síntese químicaRESUMO
Development of biocompatible nanomaterials with mitochondria-targeting and multimodal therapeutic activities is important for cancer treatment. Herein, we designed and synthesized a multifunctional pyrrole-based nanomaterial with photothermal effects and mitochondria-targeting properties from polypyrrole and the pro-apoptotic peptide KLA. Different from traditional strategies for the preparation of PPy nanoparticles, we innovatively used the KLA peptide as the template and CuCl2 as the catalyst to trigger the oxidative polymerization of pyrrole for PPy-KLA-Cu nanoparticle formation. Besides, due to the presence of mixed-valence Cu(I)/Cu(II) states, PPy-KLA-Cu nanoparticles also exhibited multienzyme-like activities, such as peroxidase, ascorbate oxidase and glutathione peroxidase activities, which can be exploited to elevate the intracellular ROS level and simultaneously consume GSH in cancer cells. More importantly, the heat generated by PPy-KLA-Cu nanoparticles from NIR irradiation could enhance the nanozymatic activities for ROS elevation and increase the KLA-induced anticancer activity via mitochondrial dysfunction, realizing multimodal treatment of cancer cells with improved therapeutic efficacy.
Assuntos
Antineoplásicos , Apoptose , Mitocôndrias , Polímeros , Pirróis , Pirróis/química , Pirróis/farmacologia , Pirróis/síntese química , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Humanos , Polímeros/química , Polímeros/farmacologia , Polímeros/síntese química , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Apoptose/efeitos dos fármacos , Catálise , Peptídeos/química , Peptídeos/farmacologia , Peptídeos/síntese química , Espécies Reativas de Oxigênio/metabolismo , Cobre/química , Cobre/farmacologia , Nanoestruturas/química , Ensaios de Seleção de Medicamentos Antitumorais , Linhagem Celular Tumoral , Neoplasias/tratamento farmacológico , Neoplasias/patologiaRESUMO
A structure-activity relationship study performed on 1H-pyrrolo[3,2-g]isoquinoline scaffold identified new haspin inhibitors with nanomolar potencies and selectivity indices (SI) over 6 (inhibitory potency evaluated against 8 protein kinases). Compound 22 was the most active of the series (haspin IC50 = 76 nM). Cellular evaluation of 22 confirmed its activity for endogenous haspin in U-2 OS cells and its anti-proliferative activity against various cell lines. In addition, the binding mode of analog 22 in complex with haspin was determined by X-ray crystallography.
Assuntos
Inibidores de Proteínas Quinases , Proteínas Serina-Treonina Quinases , Pirróis , Inibidores de Proteínas Quinases/química , Pirróis/química , Relação Estrutura-Atividade , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Isoquinolinas/química , Isoquinolinas/farmacologiaRESUMO
PURPOSE: The DNA recognition peptide compounds pyrrole-imidazole (PI) polyamides bind to the minor groove and can block the binding of transcription factors to target sequences. To develop more PI polyamides as potential treatments for fibrotic diseases, including chronic renal failure, we developed multifunctional PI polyamides that increase hepatocyte growth factor (HGF) and decrease transforming growth factor (TGF)-ß1. METHODS: We designed seven PI polyamides (HGF-1 to HGF-7) that bind to the chicken ovalbumin upstream promoter transcription factor-1 (COUP-TF1) binding site of the HGF promoter sequence. We selected PI polyamides that increase HGF and suppress TGF-ß1 in human dermal fibroblasts (HDFs). FINDINGS: Gel shift assays showed that HGF-2 and HGF-4 bound the appropriate dsDNAs. HGF-2 and HGF-4 significantly inhibited the TGF-ß1 mRNA expression in HDFs stimulated by phorbol 12-myristate 13-acetate. HGF-2 and HGF-4 significantly inhibited the TGF-ß1 protein expression in HDFs with siRNA targeting HGF, indicating that HGF-2 and HGF-4 directly inhibited the expression of TGF-ß1. CONCLUSION: The designed and synthetic HGF PI polyamides targeting the HGF promoter, which increased the expression of HGF and suppressed the expression of TGF-ß, will be a potential practical medicine for fibrotic diseases, including progressive renal diseases.
Assuntos
Nylons , Fator de Crescimento Transformador beta1 , Humanos , Nylons/química , Nylons/farmacologia , Fator de Crescimento de Hepatócito , Fator de Crescimento Transformador beta/genética , Pirróis/farmacologia , Pirróis/química , Imidazóis/farmacologia , Imidazóis/químicaRESUMO
Highly porous light absorbers are fabricated based on polypyrrole (PPy)-coated carbon nanotube (CNT). Carbon nanotube sponge (CNTS) or carbon nanotube array (CNTA) with three-dimensional (3D) network structure is the framework of porous light absorbers. Both PPy@CNTS and PPy@CNTA composites exhibit excellent light absorption of the full solar spectrum. The CNTS and CNTA with porous structures have extremely large effective surface area for light absorption and for water evaporation that has great practical benefit to the solar-driven vapor generation. The PPy layer on CNT sidewalls significantly improves the hydrophilicity of porous CNTS and CNTA. The good wettability of water on CNT sidewalls makes water transport in porous CNT materials highly efficient. The PPy@CNTS and PPy@CNTA light absorbers achieve high water evaporation rates of 3.35 and 3.41 kg m-2 h-1, respectively, under 1-sun radiation. The orientation of nano channels in CNTA-based light absorbers also plays an important role in the solar-driven vapor generation. The water transport and vapor escape are more efficient in CNTA-based light absorbers as compared to the CNTS-based light absorbers due to the relatively short path for the water transport and the vapor escape in CNTA-based light absorbers.
Assuntos
Nanotubos de Carbono , Polímeros , Pirróis , Nanotubos de Carbono/química , Polímeros/química , Pirróis/química , Energia Solar , Luz Solar , Porosidade , Água/química , Propriedades de Superfície , Tamanho da PartículaRESUMO
Pyrrole-based polymers (PBPs), a type of fascinating functional polymers, play a crucial role in materials science. However, efficient synthetic strategies of PBPs with diverse structures are mainly focused on conjugated polypyrroles and still remain challenging. Herein, an atom and step economy protocol is described to access various 2,4-disubstituted PBPs by in situ formation of pyrrole core structure via copper-catalyzed [3+2] polycycloaddition of dialkynones and diisocyanoacetates. A series of PBPs is prepared with high molecular weight (Mw up to 18 200 Da) and moderate to good yield (up to 87%), which possesses a fluorescent emission located in the green to yellow light region. Blending the PBPs with polyvinyl alcohol, the stretchable composite films exhibit a significant strengthening of the mechanical properties (tensile stress up to 59 MPa, elongation at break >400%) and an unprecedented stress-responsive luminescence enhancement that over fourfold fluorescent emission intensity is maintained upon stretching up to 100%. On the basis of computational studies, the unique photophysical and mechanical properties are attributed to the substitution of carbonyl chromophores on the pyrrole unit.
Assuntos
Cobre , Polímeros , Pirróis , Pirróis/química , Cobre/química , Catálise , Polímeros/química , Polímeros/síntese química , Estrutura Molecular , Reação de CicloadiçãoRESUMO
Autoimmune inflammatory diseases, such as rheumatoid arthritis (RA) and ulcerative colitis, are associated with an uncontrolled production of cytokines leading to the pronounced inflammatory response of these disorders. Their therapy is currently focused on the inhibition of cytokine receptors, such as the Janus kinase (JAK) protein family. Tofacitinib and peficitinib are JAK inhibitors that have been recently approved to treat rheumatoid arthritis. In this study, an in-depth analysis was carried out through quantum biochemistry to understand the interactions involved in the complexes formed by JAK1 and tofacitinib or peficitinib. Computational analyses provided new insights into the binding mechanisms between tofacitinib or peficitinib and JAK1. The essential amino acid residues that support the complex are also identified and reported. Additionally, we report new interactions, such as van der Waals; hydrogen bonds; and alkyl, pi-alkyl, and pi-sulfur forces, that stabilize the complexes. The computational results revealed that peficitinib presents a similar affinity to JAK1 compared to tofacitinib based on their interaction energies.
Assuntos
Adamantano/análogos & derivados , Janus Quinase 1 , Niacinamida , Niacinamida/análogos & derivados , Piperidinas , Pirimidinas , Pirimidinas/química , Pirimidinas/farmacologia , Piperidinas/química , Piperidinas/farmacologia , Piperidinas/uso terapêutico , Niacinamida/química , Janus Quinase 1/antagonistas & inibidores , Janus Quinase 1/metabolismo , Janus Quinase 1/química , Humanos , Teoria Quântica , Doenças Autoimunes/tratamento farmacológico , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Ligação de Hidrogênio , Inibidores de Janus Quinases/química , Inibidores de Janus Quinases/uso terapêutico , Inibidores de Janus Quinases/farmacologia , Adamantano/química , Pirróis/química , Pirróis/farmacologia , Simulação de Acoplamento MolecularRESUMO
Pyrrole-containing natural products form a large group of structurally diverse compounds that occur in both terrestrial and marine organisms. In the present study the formation of trideuteromethylated artifacts of pyrrole-containing natural products was investigated, focusing on the discorhabdins. Three deuterated discorhabdins, 1, 3, and 5, were identified to be isolation procedure artifacts caused by the presence of DMSO-d6 during NMR sample preparation and handling. Three additional semisynthetic derivatives, 7-9, were made during the investigation of the mechanism of formation, which was shown to be driven by trideuteromethyl radicals in the presence of water, methanol, TFA, and traces of iron in the deuterated solvent. Generation of trideuteromethylated artifacts was also confirmed for other classes of pyrrole-containing metabolites, namely, makaluvamines, tambjamines, and dibromotryptamines, which had also been dissolved in DMSO-d6 during the structure elucidation process. Semisynthetic discorhabdins were assessed for antiproliferative activity against a panel of human tumor cell lines, and 14-trideuteromethyldiscorhabdin L (3) averaged low micromolar potency.
Assuntos
Produtos Biológicos , Dimetil Sulfóxido , Humanos , Dimetil Sulfóxido/química , Pirróis/química , Produtos Biológicos/farmacologia , Artefatos , Solventes/químicaRESUMO
The title marine natural products have been prepared by total synthesis and in the case of congeners 3, 6, and 7 for the first time. Each of these was obtained by manipulation of readily prepared denigrin B (2). The structure, 3, assigned to denigrin C is shown to be incorrect. Reaction of compound 2 with DDQ has led, in high yield, to the related natural product spirodactylone (16), while treating the corresponding permethyl ether 15 with PIFA/BF3·Et2O provides compound 20, embodying an isomeric framework.
Assuntos
Alcaloides , Pirróis , Pirrolidinonas , Estrutura Molecular , Alcaloides/química , Alcaloides/síntese química , Pirróis/síntese química , Pirróis/química , Pirrolidinonas/química , Pirrolidinonas/síntese química , Produtos Biológicos/química , Produtos Biológicos/síntese química , Biologia Marinha , Estereoisomerismo , AnimaisRESUMO
In the current study, a series of new pyrrolizine-5-carboxamide derivatives (5-8, 9a-d, 10a-d, 11a,b and 12a,b) were developed, synthesized and evaluated in terms of in vitro COX-2 enzyme inhibition. The in vivo anti-inflammatory evaluation was conducted on the most selective compounds (9a,b,d, 10b,c and 11a,b). For the most active five compounds (9a, 10b,c and 11a,b), ulcerogenic liability, histopathological examinations, physicochemical properties study and antioxidant activity were investigated. Also, nitric oxide donor activity was evaluated for compounds (6, 7, 10a-d and 12a,b), while, compounds (10c,d and 12a,b) showed a high significant result relative to the normal control. According to the findings of this study, 2,3-dihydro-1H-pyrrolizine-5-carboxamide (9a) demonstrated high antioxidant (highest beta-carotene concentration (10.825 µg/ml)) and anti-inflammatory activity (EIP = 63.6 %) with lower ulcerogenicity (ulcer index 13.67), presenting it as a promising candidate for treating inflammatory diseases which are complicated by oxidative tissue damage. Furthermore, MOE software tools docking software was used to carry out the in silico studies. Docking study for the most active compounds showed that all compounds made three to four H-bond interactions in COX-2 active site adopting excellent docking scores.
Assuntos
Antioxidantes , Inibidores de Ciclo-Oxigenase 2 , Humanos , Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Ciclo-Oxigenase 2/metabolismo , Inibidores de Ciclo-Oxigenase 2/farmacologia , Simulação de Acoplamento Molecular , Estrutura Molecular , Relação Estrutura-Atividade , Úlcera , Pirróis/química , Pirróis/farmacologiaRESUMO
Twenty N-substituted pyrrolo[3,4-c]quinoline-1,3-diones 3a-t were synthesized by a cyclization reaction of Pfitzinger's quinoline ester precursor with the selected aromatic, heteroaromatic and aliphatic amines. The structures of all derivatives were confirmed by IR, 1H NMR, 13C NMR and HRMS spectra, while their purity was determined using HPLC techniques. Almost all compounds were identified as a new class ofpotent inhibitors against hDHODH among which 3a and 3t were the most active ones with the same IC50 values of 0.11 µM, about seven times better than reference drug leflunomide. These two derivatives also exhibited very low cytotoxic effects toward healthy HaCaT cells and the optimal lipophilic properties with logP value of 1.12 and 2.07 respectively, obtained experimentally at physiological pH. We further evaluated the comparative differences in toxicological impact of the three most active compounds 3a, 3n and 3t and reference drug leflunomide. The rats were divided into five groups and were treated intraperitoneally, control group (group I) with a single dose of leflunomide (20 mg/kg) group II and the other three groups, III, IV and V were treated with 3a, 3n and 3t (20 mg/kg bw) separately. The investigation was performed in liver, kidney and blood by examining serum biochemical parameters and parameters of oxidative stress.
Assuntos
Di-Hidro-Orotato Desidrogenase , Inibidores Enzimáticos , Oxirredutases atuantes sobre Doadores de Grupo CH-CH , Animais , Humanos , Masculino , Ratos , Linhagem Celular , Relação Dose-Resposta a Droga , Descoberta de Drogas , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Estrutura Molecular , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/antagonistas & inibidores , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismo , Pirróis/química , Pirróis/farmacologia , Pirróis/síntese química , Quinolinas/química , Quinolinas/farmacologia , Quinolinas/síntese química , Ratos Wistar , Relação Estrutura-Atividade , Quinolonas/síntese química , Quinolonas/química , Quinolonas/farmacologiaRESUMO
A new efficient and versatile one-pot three-component synthesis of substituted pyrrolo[1,2-a]thieno[3,2-e]pyrimidine derivatives has been developed. It is based on a multistep cascade reaction from 2-aminothiophenes and 2-hydroxy-4-oxobut-2-enoic acids, and derivatives of cyanoacetic acid catalyzed by diisopropylethylamine. As a result, novel pyrrolo[1,2-a]thieno[3,2-e]pyrimidine derivatives (21 compounds) were synthesized in a mild reaction conditions with a high yield. The structures of the developed compounds were confirmed by NMR and elemental analysis. The influence of electron-withdrawing or electron-donor substituents on the antitumor activity of the developed compounds has been identified. In vitro screening analysis of 21 compounds revealed six lead candidates (12aa, 12dc, 12hc, 12ic, 12lb, and 12mb) that demonstrated the most significant antitumor activity against B16-F10, 4T1 and CT26 cells. Necrosis/apoptosis assay showed that apoptosis was the predominant mechanism of cell death. Molecular docking analysis revealed several potential targets for tested compounds, i.e. phosphatidylinositol 5-phosphate 4-kinase (PI5P4K2C), proto-oncogene serine/threonine-protein kinase (Pim-1), nicotinamide phosphoribosyltransferase (NAMPT) and dihydrofolate reductase (DHFR). The lead compound (12aa) can effectively induce cell apoptosis, possesses a high yield (98 %) and requires low-cost starting chemicals for its synthesis. In vivo experiments with melanoma-bearing mice confirmed that 12aa compound resulted in the significant tumor inhibition on 15 d after the therapy. In particular, tumor volume was â¼0.19 cm3 for 50 mg/kg versus â¼2.39 cm3 in case of untreated mice and tumor weight was â¼71.6 mg for 50 mg/kg versus â¼452.4 mg when considered untreated mice. Thus, our results demonstrated the high potential of the 12aa compound in the treatment of melanoma and can be recommended for further preclinical studies.