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1.
Nat Commun ; 15(1): 4525, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38806518

RESUMO

Medicinal compounds from plants include bicyclo[3.3.1]nonane derivatives, the majority of which are polycyclic polyprenylated acylphloroglucinols (PPAPs). Prototype molecules are hyperforin, the antidepressant constituent of St. John's wort, and garcinol, a potential anticancer compound. Their complex structures have inspired innovative chemical syntheses, however, their biosynthesis in plants is still enigmatic. PPAPs are divided into two subclasses, named type A and B. Here we identify both types in Hypericum sampsonii plants and isolate two enzymes that regiodivergently convert a common precursor to pivotal type A and B products. Molecular modelling and substrate docking studies reveal inverted substrate binding modes in the two active site cavities. We identify amino acids that stabilize these alternative binding scenarios and use reciprocal mutagenesis to interconvert the enzymatic activities. Our studies elucidate the unique biochemistry that yields type A and B bicyclo[3.3.1]nonane cores in plants, thereby providing key building blocks for biotechnological efforts to sustainably produce these complex compounds for preclinical development.


Assuntos
Hypericum , Hypericum/metabolismo , Hypericum/genética , Hypericum/química , Compostos Bicíclicos com Pontes/metabolismo , Compostos Bicíclicos com Pontes/química , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Simulação de Acoplamento Molecular , Floroglucinol/metabolismo , Floroglucinol/análogos & derivados , Floroglucinol/química , Alcanos/metabolismo , Alcanos/química , Domínio Catalítico , Terpenos/metabolismo , Terpenos/química , Modelos Moleculares
2.
Eur J Med Chem ; 265: 116068, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38141284

RESUMO

Thirteen new sirenin derivatives named eupenicisirenins C-O (1-13), along with a biosynthetically related known one (14), were isolated from the mangrove sediment-derived fungus Penicillium sp. SCSIO 41410. The structures, which possessed a rare cyclopropane moiety, were confirmed by extensive analyses of the spectroscopic data, quantum chemical calculations, and X-ray diffraction. Among them, eupenicisirenin C (1) exhibited the strongest NF-κB inhibitory activities, as well as suppressing effects on cGAS-STING pathway. Moreover, 1 showed the significant inhibitory effect on RANKL-induced osteoclast differentiation in bone marrow macrophages cells, and also displayed the therapeutic potential on prednisolone-induced zebrafish osteoporosis. Transcriptome analysis and the following verification tests suggested that its anti-osteoporotic mechanism is related to the extracellular matrix receptor interaction-related pathways. This study provided a promising marine-derived anti-osteoporotic agent for the treatment of skeletal disease.


Assuntos
Osteoporose , Penicillium , Animais , Fungos/metabolismo , Macrófagos , NF-kappa B/metabolismo , Osteoporose/tratamento farmacológico , Penicillium/química , Peixe-Zebra/metabolismo , Compostos Bicíclicos com Pontes/química
3.
Org Lett ; 24(6): 1268-1273, 2022 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-35014844

RESUMO

Acyl bicyclobutanes are shown to engage in strain-promoted cycloaddition reactions with a diverse array of triazolinedione reagents. The synthesis of an orthogonally protected urazole building block enabled the facile preparation of amino acid- and peptide-derived triazolinediones that undergo cycloaddition reactions to afford novel peptide conjugates. The additive-free and fully atom-economical nature of the transformation is a promising starting point for the generalization of this cycloaddition reaction for the functionalization of biomolecules.


Assuntos
Compostos Bicíclicos com Pontes/química , Peptídeos/química , Triazóis/química , Aminoácidos/química , Reação de Cicloadição , Estrutura Molecular
4.
J Am Chem Soc ; 144(2): 832-844, 2022 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-34985906

RESUMO

Owing to its roles in human health and disease, the modification of nuclear, cytoplasmic, and mitochondrial proteins with O-linked N-acetylglucosamine residues (O-GlcNAc) has emerged as a topic of great interest. Despite the presence of O-GlcNAc on hundreds of proteins within cells, only two enzymes regulate this modification. One of these enzymes is O-GlcNAcase (OGA), a dimeric glycoside hydrolase that has a deep active site cleft in which diverse substrates are accommodated. Chemical tools to control OGA are emerging as essential resources for helping to decode the biochemical and cellular functions of the O-GlcNAc pathway. Here we describe rationally designed bicyclic thiazolidine inhibitors that exhibit superb selectivity and picomolar inhibition of human OGA. Structures of these inhibitors in complex with human OGA reveal the basis for their exceptional potency and show that they extend out of the enzyme active site cleft. Leveraging this structure, we create a high affinity chemoproteomic probe that enables simple one-step purification of endogenous OGA from brain and targeted proteomic mapping of its post-translational modifications. These data uncover a range of new modifications, including some that are less-known, such as O-ubiquitination and N-formylation. We expect that these inhibitors and chemoproteomics probes will prove useful as fundamental tools to decipher the mechanisms by which OGA is regulated and directed to its diverse cellular substrates. Moreover, the inhibitors and structures described here lay out a blueprint that will enable the creation of chemical probes and tools to interrogate OGA and other carbohydrate active enzymes.


Assuntos
Antígenos de Neoplasias/metabolismo , Compostos Bicíclicos com Pontes/química , Inibidores Enzimáticos/química , Histona Acetiltransferases/metabolismo , Hialuronoglucosaminidase/metabolismo , Sequência de Aminoácidos , Encéfalo/metabolismo , Compostos Bicíclicos com Pontes/metabolismo , Domínio Catalítico , Cromatografia Líquida de Alta Pressão , Inibidores Enzimáticos/metabolismo , Histona Acetiltransferases/antagonistas & inibidores , Humanos , Hialuronoglucosaminidase/antagonistas & inibidores , Espectrometria de Massas , Peptídeos/análise , Peptídeos/química , Processamento de Proteína Pós-Traducional , Proteômica/métodos , Relação Estrutura-Atividade , Tiazolidinas/química , Tiazolidinas/metabolismo , Cadeia alfa da beta-Hexosaminidase/antagonistas & inibidores , Cadeia alfa da beta-Hexosaminidase/metabolismo
5.
Bioorg Med Chem ; 54: 116561, 2022 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-34920311

RESUMO

Chiral sp3-rich bicyclo[3.3.1]nonane scaffolds 10-12 were synthesized as single diastereomers from aldehyde 9, which was prepared from 4,4-dimethoxycyclohexa-2,5-dienone through a copper-catalyzed enantioselective reduction. Three different types of intramolecular addition reactions were studied: SmI2-mediated reductive cyclization, base-promoted aldol reaction, and one-pot Mannich reaction. We succeeded in introducing three side-chains to scaffold 11 and construct an sp3-rich compound library in both enantiomeric variants by simply changing the chirality of the ligands. The biological evaluation revealed that all synthesized compounds exhibited a concentration-dependent inhibition of hypoxia-inducible factor-1 (HIF-1) transcriptional activity, with IC50 values in the range of 17.2-31.7 µM, whereas their effects on cell viability were varied (IC50 = 3.5 to > 100 µM). The most active compound 16f inhibits the accumulation of HIF-1α protein and mRNA in hypoxia, indicating that it has a mechanism of action distinctly different from other known compounds bearing the common bicyclo[3.3.1]nonane skeleton.


Assuntos
Antineoplásicos/farmacologia , Compostos Bicíclicos com Pontes/farmacologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/antagonistas & inibidores , Antineoplásicos/síntese química , Antineoplásicos/química , Compostos Bicíclicos com Pontes/síntese química , Compostos Bicíclicos com Pontes/química , Hipóxia Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Células HeLa , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Ligantes , Modelos Moleculares , Estrutura Molecular , RNA Mensageiro/antagonistas & inibidores , RNA Mensageiro/metabolismo , Relação Estrutura-Atividade , Células Tumorais Cultivadas
6.
Artigo em Inglês | MEDLINE | ID: mdl-34507099

RESUMO

The synthesis of ß-ketophosphonates, linked by a methylene group to a bicyclo[3.3.0]octene fragment, was performed by the reaction of dimethyl methanephosphonate with the ester group of two intermediates with this scaffold. Starting from a diol, protected with good leaving groups (mesyl and tosyl), we performed a sequence of reactions with good yields: the carbon chain lengthening by reaction with KCN, the hydrolysis of the nitrile groups to carboxyl, the esterification of carboxyl to ester and finally the phosphonate synthesis, which gave one bis-ß-ketophosphonate and two mono ß-ketophosphonates. The new ß-ketophosphonates are key intermediates for obtaining new prostaglandin analogues with a bicyclo[3.3.0]octene fragment in the ω-side chain. The bicyclo[3.3.0]octane scaffold, found in natural products and in anticancer compounds, are expected to keep their activity in PG analogs; the bulky scaffold, separated by a methylene group from the C-15 carbon atom, is expected to diminish the inactivation of the PG analog by enzyme oxidation of 15α-OH oxidation to 15-Keto via PGDH pathway.


Assuntos
Organofosfonatos/síntese química , Prostaglandinas Sintéticas/síntese química , Compostos Bicíclicos com Pontes/química , Cetonas/síntese química , Cetonas/química , Organofosfonatos/química , Compostos Organofosforados/química
7.
J Toxicol Environ Health A ; 84(19): 783-799, 2021 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-34196263

RESUMO

A convenient fluorometrical test method to identify skin sensitizers in chemico was developed using reactivity with glutathione (GSH), a low molecular weight endogenous substance. Following incubation of test chemicals with GSH, the remaining GSH was quantitated fluorometrically by using monobromobimane (mBBr), a thiol-detecting agent, for determining % depletion of this endogenous substance by test chemicals. The experimental conditions optimized were: (1) reactivity of thiol compounds including GSH with mBBr, (2) effects of vehicles on reactivity, (3) molar ratios of GSH to test chemicals, and (4) reactivity of endogenous substance with test substances under different incubation times. When an optimized condition with DMSO as a vehicle for test chemicals and in 1:60 ratio for 24 hr at 4°C was applied to classify 48 well-known skin sensitizers and non-sensitizers, the predictive capacity was as follows: 88.2% sensitivity, 78.6% specificity, and 85.4% accuracy with 95.8% consistency of three trials when 10.3% depletion of GSH was used as a cutoff value. Because the present method employed relatively simple GSH as an acceptor for sensitizers and/or a relatively convenient fluorometric detection system in 96-well plates for a high throughput test, it would be a useful test tool for screening skin sensitization potential of test chemicals.


Assuntos
Alternativas aos Testes com Animais/métodos , Compostos Bicíclicos com Pontes/química , Fluorometria/métodos , Glutationa/análise , Pele/efeitos dos fármacos , Pele/fisiopatologia
8.
Molecules ; 26(11)2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34205933

RESUMO

Biothiols are extremely powerful antioxidants that protect cells against the effects of oxidative stress. They are also considered relevant disease biomarkers, specifically risk factors for cardiovascular disease. In this paper, a new procedure for the simultaneous determination of human serum albumin and low-molecular-weight thiols in plasma is described. The method is based on the pre-column derivatization of analytes with a thiol-specific fluorescence labeling reagent, monobromobimane, followed by separation and quantification through reversed-phase high-performance liquid chromatography with fluorescence detection (excitation, 378 nm; emission, 492 nm). Prior to the derivatization step, the oxidized thiols are converted to their reduced forms by reductive cleavage with sodium borohydride. Linearity in the detector response for total thiols was observed in the following ranges: 1.76-30.0 mg mL-1 for human serum albumin, 0.29-5.0 nmol mL-1 for α-lipoic acid, 1.16-35 nmol mL-1 for glutathione, 9.83-450.0 nmol mL-1 for cysteine, 0.55-40.0 nmol mL-1 for homocysteine, 0.34-50.0 nmol mL-1 for N-acetyl-L-cysteine, and 1.45-45.0 nmol mL-1 for cysteinylglycine. Recovery values of 85.16-119.48% were recorded for all the analytes. The developed method is sensitive, repeatable, and linear within the expected ranges of total thiols. The devised procedure can be applied to plasma samples to monitor biochemical processes in various pathophysiological states.


Assuntos
Compostos Bicíclicos com Pontes/química , Albumina Sérica Humana/análise , Compostos de Sulfidrila/análise , Cromatografia de Fase Reversa , Humanos , Peso Molecular , Oxirredução , Albumina Sérica Humana/química , Compostos de Sulfidrila/química
9.
Chem Biol Drug Des ; 98(3): 305-322, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34047462

RESUMO

Bacterial infections can cause serious problems that threaten public health over a long period of time. Moreover, the continuous emergence of drug-resistant bacteria necessitates the development of novel antibacterial agents. D-alanyl-D-alanine ligase (Ddl) is an indispensable adenosine triphosphate-dependent bacterial enzyme involved in the biosynthesis of peptidoglycan precursor, which catalyzes the ligation of two D-alanine molecules into one D-alanyl-D-alanine dipeptide. This dipeptide is an essential component of the intracellular peptidoglycan precursor, uridine diphospho-N-acetylmuramic acid (UDP-MurNAc)-pentapeptide, that maintains the integrity of the bacterial cell wall by cross-linking the peptidoglycan chain, and is crucial for the survival of pathogens. Consequently, Ddl is expected to be a promising target for the development of antibacterial agents. In this review, we present a brief introduction regarding the structure and function of Ddl, as well as an overview of the various Ddl inhibitors currently being used as antibacterial agents, specifically highlighting their inhibitory activities, structure-activity relationships and mechanisms of action.


Assuntos
Antibacterianos/química , Descoberta de Drogas , Inibidores Enzimáticos/química , Peptídeo Sintases/química , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Compostos Bicíclicos com Pontes/química , Compostos Bicíclicos com Pontes/metabolismo , Compostos Bicíclicos com Pontes/farmacologia , Inibidores Enzimáticos/metabolismo , Compostos Heterocíclicos com 1 Anel/química , Compostos Heterocíclicos com 1 Anel/metabolismo , Compostos Heterocíclicos com 1 Anel/farmacologia , Peptídeo Sintases/metabolismo , Peptidoglicano/biossíntese , Relação Estrutura-Atividade
10.
Bioorg Chem ; 111: 104828, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33895605

RESUMO

Marine natural products derived from special or extreme environment provide an important source for the development of anti-tumor drugs due to their special skeletons and functional groups. In this study, based on our previous work on the total synthesis and structure revision of the novel marine natural product Chrysamide B, a group of its derivatives were designed, synthesized, and subsequently of which the anti-cancer activity, structure-activity relationships and cellular mechanism were explored for the first time. Compared with Chrysamide B, better anti-cancer performance of some derivatives against five human cancer cell lines (SGC-7901, MGC-803, HepG2, HCT-116, MCF-7) was observed, especially for compound b-9 on MGC-803 and SGC-7901 cells with the IC 50 values of 7.88 ± 0.81 and 10.08 ± 1.08 µM, respectively. Subsequently, cellular mechanism study suggested that compound b-9 treatment could inhibit the cellular proliferation, reduce the migration and invasion ability of cells, and induce mitochondrial-dependent apoptosis in gastric cancer MGC-803 and SGC-7901 cells. Furthermore, the mitochondrial-dependent apoptosis induced by compound b-9 is related with the JAK2/STAT3/Bcl-2 signaling pathway. To conclude, our results offer a new structure for the discovery of anti-tumor lead compounds from marine natural products.


Assuntos
Amidas/farmacologia , Antineoplásicos/farmacologia , Compostos Bicíclicos com Pontes/farmacologia , Desenho de Fármacos , Amidas/síntese química , Amidas/química , Antineoplásicos/síntese química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Compostos Bicíclicos com Pontes/síntese química , Compostos Bicíclicos com Pontes/química , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Relação Estrutura-Atividade , Células Tumorais Cultivadas
11.
J Med Chem ; 64(10): 6670-6695, 2021 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-33724031

RESUMO

The adenosine A1 receptor (A1AR) is a G-protein-coupled receptor (GPCR) that provides important therapeutic opportunities for a number of conditions including congestive heart failure, tachycardia, and neuropathic pain. The development of A1AR-selective fluorescent ligands will enhance our understanding of the subcellular mechanisms underlying A1AR pharmacology facilitating the development of more efficacious and selective therapies. Herein, we report the design, synthesis, and application of a novel series of A1AR-selective fluorescent probes based on 8-functionalized bicyclo[2.2.2]octylxanthine and 3-functionalized 8-(adamant-1-yl) xanthine scaffolds. These fluorescent conjugates allowed quantification of kinetic and equilibrium ligand binding parameters using NanoBRET and visualization of specific receptor distribution patterns in living cells by confocal imaging and total internal reflection fluorescence (TIRF) microscopy. As such, the novel A1AR-selective fluorescent antagonists described herein can be applied in conjunction with a series of fluorescence-based techniques to foster understanding of A1AR molecular pharmacology and signaling in living cells.


Assuntos
Antagonistas do Receptor A1 de Adenosina/síntese química , Corantes Fluorescentes/química , Receptor A1 de Adenosina/química , Antagonistas do Receptor A1 de Adenosina/metabolismo , Compostos Bicíclicos com Pontes/química , Desenho de Fármacos , Transferência Ressonante de Energia de Fluorescência , Corantes Fluorescentes/metabolismo , Células HEK293 , Humanos , Cinética , Ligantes , Octanos/química , Receptor A1 de Adenosina/metabolismo , Relação Estrutura-Atividade , Xantina/química , Xantina/metabolismo
12.
Molecules ; 26(4)2021 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-33673007

RESUMO

Malaria remains a significant cause of morbidity and mortality in Sub-Saharan Africa and South Asia. While clinical antimalarials are efficacious when administered according to local guidelines, resistance to every class of antimalarials is a persistent problem. There is a constant need for new antimalarial therapeutics that complement parasite control strategies to combat malaria, especially in the tropics. In this work, nopol-based quinoline derivatives were investigated for their inhibitory activity against Plasmodium falciparum, one of the parasites that cause malaria. The nopyl-quinolin-8-yl amides (2-4) were moderately active against the asexual blood stage of chloroquine-sensitive strain Pf3D7 but inactive against chloroquine-resistant strains PfK1 and PfNF54. The nopyl-quinolin-4-yl amides and nopyl-quinolin-4-yl-acetates analogs were generally less active on all three strains. Interesting, the presence of a chloro substituent at C7 of the quinoline ring of amide 8 resulted in sub-micromolar EC50 in the PfK1 strain. However, 8 was more than two orders of magnitude less active against Pf3D7 and PfNF54. Overall, the nopyl-quinolin-8-yl amides appear to share similar antimalarial profile (asexual blood-stage) with previously reported 8-aminoquinolines like primaquine. Future work will focus on investigating the moderately active and selective nopyl-quinolin-8-yl amides on the gametocyte or liver stages of Plasmodium falciparum and Plasmodium vivax.


Assuntos
Antimaláricos/farmacologia , Compostos Bicíclicos com Pontes/farmacologia , Plasmodium/efeitos dos fármacos , Quinolinas/farmacologia , Antimaláricos/síntese química , Antimaláricos/química , Compostos Bicíclicos com Pontes/síntese química , Compostos Bicíclicos com Pontes/química , Células Hep G2 , Humanos , Quinolinas/síntese química , Quinolinas/química
13.
J Biochem Mol Toxicol ; 35(4): e22713, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33501774

RESUMO

This study was performed to evaluate the antioxidant, anticancer, and toxicity properties of ferutinin, a phytoestrogen derived from Ferula species. The human Michigan Cancer Foundation-7 (MCF-7) breast cancer cell line and normal human fibroblast (HDF) were cultured and treated with different ferutinin concentrations. The cell viability was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and cell death-defining tests (a comparative real-time polymerase chain reaction [for Bax and Bcl-2 genes], flow cytometry, and acridine orange/propidium iodide cell staining). Moreover, 15 white male balb/c mice were divided into three groups of five (one untreated control group and two groups), which received different doses of ferutinin-supplemented water (500 and 1000 µg/kg mice weight) to check the mice liver and kidney pathomorphological alterations and to determine the antioxidant enzymes' expression profile (superoxide dismutase [SOD], catalase [CAT], and glutathione peroxidase) in the mentioned tissues. Finally, the liver lipid peroxidation of mice was analyzed. The results of MTT and cell death-defining tests indicate the significant reduction in cell viability and induction of apoptotic death in MCF-7 cells (enhanced sub-G1 peaks, Bax overexpression, Bcl-2 downregulation, and increased apoptotic cells). The antioxidant enzymes (SOD and CAT) in the mice liver and kidney cells were found to be upregulated (p < .05) in response to the increasing doses of ferutinin. Besides, the lipid peroxidation of the liver tissue of mice was significantly reduced. According to the results, we suggest that ferutinin has the potential to be served as a selective anticancer compound for breast cancer treatment.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Antioxidantes/farmacologia , Benzoatos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Cicloeptanos/farmacologia , Ferula/química , Fitoestrógenos/farmacologia , Sesquiterpenos/farmacologia , Animais , Antineoplásicos Fitogênicos/química , Antioxidantes/química , Benzoatos/química , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Compostos Bicíclicos com Pontes/química , Compostos Bicíclicos com Pontes/farmacologia , Cicloeptanos/química , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Células MCF-7 , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Fitoestrógenos/química , Sesquiterpenos/química
14.
Acc Chem Res ; 54(3): 569-582, 2021 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-33448789

RESUMO

The field of total synthesis has reached a stage in which emphasis has been increasingly focused on synthetic efficiency rather than merely achieving the synthesis of a target molecule. The pursuit of synthetic efficiency, typically represented by step count and overall yield, is a rich source of inspiration and motivation for synthetic chemists to invent innovative strategies and methods. Among them, convergent strategy has been well recognized as an effective approach to improve efficiency. This strategy generally involves coupling of fragments with similar complexity to furnish the target molecule via subsequent cyclization or late-stage functionalization. Thus, methodologies that enable effective connection of fragments are critical to devising a convergent plan. In our laboratory, convergent strategy has served as a long-standing principle for pursuing efficient synthesis during the course of planning and implementing synthetic projects. In this Account, we summarize our endeavors in the convergent synthesis of natural products over the last ten years. We show how we identify reasonable bond disconnections and employ enabling synthetic methodologies to maximize convergency, leading to the efficient syntheses of over two-dozen highly complex molecules from eight disparate families.In detail, we categorize our work into three parts based on the diverse reaction types for fragment assembly. First, we demonstrate the application of a powerful single-electron reducing agent, SmI2, in a late-stage cyclization step, forging the polycyclic skeletons of structurally fascinating Galbulimima alkaloids and Leucosceptrum sesterterpenoids. Next, we showcase how three different types of cycloaddition reactions can simultaneously construct two challenging C-C bonds in a single step, providing concise entries to three distinct families, namely, spiroquinazoline alkaloids, gracilamine, and kaurane diterpenoids. In the third part, we describe convergent assembly of ent-kaurane diterpenoids, gelsedine-type alkaloids, and several drug molecules via employing some bifunctional synthons. To access highly oxidized ent-kaurane diterpenoids, we introduce the hallmark bicyclo[3.2.1]octane ring system at an early stage, and then execute coupling and cyclization by means of a Hoppe's homoaldol reaction and a Mukaiyama-Michael-type addition, respectively. Furthermore, we showcase how the orchestrated combination of an asymmetric Michael addition, a tandem oxidation-aldol reaction and a pinacol rearrangement can dramatically improve the efficiency in synthesizing gelsedine-type alkaloids, with nary a protecting group. Finally, to address the supply issue of several drugs, including anti-influenza drug zanamivir and antitumor agent Et-743, we exploit scalable and practical approaches to provide advantages over current routes in terms of cost, ease of execution, and efficiency.


Assuntos
Produtos Biológicos/síntese química , Alcaloides/síntese química , Alcaloides/química , Produtos Biológicos/química , Compostos Bicíclicos com Pontes/química , Carbono/química , Ciclização , Reação de Cicloadição , Diterpenos do Tipo Caurano/síntese química , Diterpenos do Tipo Caurano/química , Octanos/química , Oxirredução , Sesterterpenos/síntese química , Sesterterpenos/química , Estereoisomerismo , Trabectedina/síntese química , Trabectedina/química , Zanamivir/síntese química , Zanamivir/química
15.
Acc Chem Res ; 54(3): 583-594, 2021 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-33448794

RESUMO

From the venerable Robinson annulation to the irreplaceable Diels-Alder cycloaddition, annulation reactions have fueled the progression of the field of natural product synthesis throughout the past century. In broader terms, the ability to form a cyclic molecule directly from two or more simpler fragments has transformed virtually every aspect of the chemical sciences from the synthesis of organic materials to bioconjugation chemistry and drug discovery. In this Account, we describe the evolution of our meroterpene synthetic program over the past five years, enabled largely by the development of a tailored anionic annulation process for the synthesis of hydroxylated 1,3-cyclohexanediones from lithium enolates and the reactive ß-lactone-containing feedstock chemical diketene.First, we provide details on short total syntheses of the prototypical polycyclic polyprenylated acylphloroglucinol (PPAP) natural products hyperforin and garsubellin A, which possess complex bicyclo[3.3.1]nonane architectures. Notably, these molecules have served as compelling synthetic targets for several decades and induce a number of biological effects of relevance to neuroscience and medicine. By merging our diketene annulation process with a hypervalent iodine-mediated oxidative ring expansion, bicyclo[3.3.1]nonane architectures can be easily prepared from simple 5,6-fused bicyclic diketones in only two chemical operations. Leveraging these two key chemical reactions in combination with various other stereoselective transformations allowed for these biologically active targets to be prepared in racemic form in only 10 steps.Next, we extend this strategy to the synthesis of complex fungal-derived meroterpenes generated biosynthetically from the coupling of 3,5-dimethylorsellinic acid (DMOA) and farnesyl pyrophosphate. A Ti(III)-mediated radical cyclization of a terminal epoxide was used to rapidly prepare a 6,6,5-fused tricyclic ketone which served as an input for our annulation/rearrangement process, ultimately enabling a total synthesis of protoaustinoid A, an important biosynthetic intermediate in DMOA-derived meroterpene synthesis, and its oxidation product berkeleyone A. Through a radical-based, abiotic rearrangement process, the bicyclo[3.3.1]nonane cores of these natural products could again be isomerized, resulting in the 6,5-fused ring systems of the andrastin family and ultimately delivering a total synthesis of andrastin D and preterrenoid. Notably, these isomerization transformations proved challenging when employing classic, acid-induced conditions for carbocation generation, thus highlighting the power of radical biomimicry in total synthesis. Finally, further oxidation and rearrangement allowed for access to terrenoid and the lactone-containing metabolite terretonin L.Overall, the merger of annulative diketene methodology with an oxidative rearrangement transformation has proven to be a broadly applicable strategy to synthesize bicyclo[3.3.1]nonane-containing natural products, a class of small molecules with over 1000 known members.


Assuntos
Produtos Biológicos/síntese química , Terpenos/síntese química , Produtos Biológicos/química , Compostos Bicíclicos com Pontes/química , Ciclização , Reação de Cicloadição , Conformação Molecular , Oxirredução , Floroglucinol/análogos & derivados , Floroglucinol/síntese química , Floroglucinol/química , Resorcinóis/síntese química , Resorcinóis/química , Estereoisomerismo , Terpenos/química
16.
Mol Biochem Parasitol ; 242: 111362, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33513391

RESUMO

Plasmodium falciparum causes the deadliest form of malaria. Adequate redox control is crucial for this protozoan parasite to overcome oxidative and nitrosative challenges, thus enabling its survival. Sulfenylation is an oxidative post-translational modification, which acts as a molecular on/off switch, regulating protein activity. To obtain a better understanding of which proteins are redox regulated in malaria parasites, we established an optimized affinity capture protocol coupled with mass spectrometry analysis for identification of in vivo sulfenylated proteins. The non-dimedone based probe BCN-Bio1 shows reaction rates over 100-times that of commonly used dimedone-based probes, allowing for a rapid trapping of sulfenylated proteins. Mass spectrometry analysis of BCN-Bio1 labeled proteins revealed the first insight into the Plasmodium falciparum trophozoite sulfenylome, identifying 102 proteins containing 152 sulfenylation sites. Comparison with Plasmodium proteins modified by S-glutathionylation and S-nitrosation showed a high overlap, suggesting a common core of proteins undergoing redox regulation by multiple mechanisms. Furthermore, parasite proteins which were identified as targets for sulfenylation were also identified as being sulfenylated in other organisms, especially proteins of the glycolytic cycle. This study suggests that a number of Plasmodium proteins are subject to redox regulation and it provides a basis for further investigations into the exact structural and biochemical basis of regulation, and a deeper understanding of cross-talk between post-translational modifications.


Assuntos
Compostos Bicíclicos com Pontes/química , Sondas Moleculares/química , Plasmodium falciparum/metabolismo , Processamento de Proteína Pós-Traducional , Proteínas de Protozoários/metabolismo , Ácidos Sulfênicos/metabolismo , Trofozoítos/metabolismo , Células Cultivadas , Cisteína/metabolismo , Eritrócitos/parasitologia , Ontologia Genética , Glutationa/metabolismo , Humanos , Espectrometria de Massas , Anotação de Sequência Molecular , Compostos Nitrosos/metabolismo , Oxirredução , Plasmodium falciparum/genética , Proteínas de Protozoários/genética , Coloração e Rotulagem/métodos , Trofozoítos/genética
17.
Bioorg Med Chem Lett ; 33: 127738, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33316404

RESUMO

Through structural modification of an oxalamide derived chemotype, a novel class of highly potent, orally bioavailable IDO1-specific inhibitors was identified. Representative compound 18 inhibited human IDO1 with IC50 values of 3.9 nM and 52 nM in a cellular and human whole blood assay, respectively. In vitro assessment of the ADME properties of 18 demonstrated very high metabolic stability. Pharmacokinetic profiling in mice showed a significantly reduced clearance compared to the oxalamides. In a mouse pharmacodynamic model 18 nearly completely suppressed lipopolysaccharide-induced kynurenine production. Hepatocyte data of 18 suggest the human clearance to be in a similar range to linrodostat (1).


Assuntos
Amidas/farmacologia , Compostos Bicíclicos com Pontes/farmacologia , Descoberta de Drogas , Inibidores Enzimáticos/farmacologia , Indolamina-Pirrol 2,3,-Dioxigenase/antagonistas & inibidores , Ácido Oxâmico/farmacologia , Amidas/síntese química , Amidas/química , Animais , Compostos Bicíclicos com Pontes/síntese química , Compostos Bicíclicos com Pontes/química , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Cinurenina/antagonistas & inibidores , Cinurenina/biossíntese , Lipopolissacarídeos/antagonistas & inibidores , Lipopolissacarídeos/farmacologia , Camundongos , Estrutura Molecular , Ácido Oxâmico/síntese química , Ácido Oxâmico/química , Relação Estrutura-Atividade
18.
Eur J Med Chem ; 210: 112988, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33189438

RESUMO

The molecular chaperone heat shock protein 90 (Hsp90) is a promising target for cancer therapy. Natural product aconitine is a potential Hsp90 inhibitor reported in our previous work. In this study, we designed and synthesized a series of 2-((1-phenyl-1H-1,2,3-triazol-4-yl)methyl)-2-azabicyclo[3.2.1]octan-3-one derivatives as potent Hsp90 inhibitors by simplifying and modifying aconitine scaffold. Among these compounds, 14t exhibited an excellent antiproliferative activity against LoVo cells with an IC50 value of 0.02 µM and a significant Hsp90α inhibitory activity with an IC50 value of 0.71 nM. Molecular docking studies provided a rational binding model of 14t in complex with Hsp90α. The following cell cycle and apoptosis assays revealed that compound 14t could arrest cell cycle at G1/S phase and induce cell apoptosis via up-regulation of bax and cleaved-caspase 3 protein expressions while inhibiting the expressions of bcl-2. Moreover, 14t could inhibit cell migration in LoVo and SW620 cell lines. Consistent with in vitro results, 14t significantly repressed tumor growth in the SW620 xenograft mouse model.


Assuntos
Aconitina/farmacologia , Antineoplásicos/farmacologia , Descoberta de Drogas , Aconitina/síntese química , Aconitina/química , Antineoplásicos/síntese química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Compostos Aza/síntese química , Compostos Aza/química , Compostos Aza/farmacologia , Compostos Bicíclicos com Pontes/síntese química , Compostos Bicíclicos com Pontes/química , Compostos Bicíclicos com Pontes/farmacologia , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Humanos , Simulação de Acoplamento Molecular , Estrutura Molecular , Octanos/síntese química , Octanos/química , Octanos/farmacologia , Relação Estrutura-Atividade , Triazóis/síntese química , Triazóis/química , Triazóis/farmacologia
19.
Molecules ; 25(23)2020 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-33297504

RESUMO

The employment studies of natural extracts in the prevention and treatment of several diseases highlighted the role of different species of genus Ferula L., belonging to the Apiaceae family, dicotyledonous plants present in many temperate zones of our planet. Ferula communis L. is the main source of sesquiterpene ferutinin, a bioactive compound studied both in vitro and in vivo, because of different effects, such as phytoestrogenic, antioxidant, anti-inflammatory, but also antiproliferative and cytotoxic activity, performed in a dose-dependent and cell-dependent way. The present review will focus on the molecular mechanisms involved in the different activities of Ferutinin, starting from its antioxidant potential at low doses until its ionophoric property and the subsequent mitochondrial dysfunction induced through administration of high doses, which represent the key point of its anticancer action. Furthermore, we will summarize the data acquired from some experimental studies on different cell types and on several diseases. The results obtained showed an important antioxidant and phytoestrogenic regulation with lack of typical side effects related to estrogenic therapy. The preferential cell death induction for tumor cell lines suggests that ferutinin may have anti-neoplastic properties, and may be used as an antiproliferative and cytotoxic agent in an estrogen dependent and independent manner. Nevertheless, more data are needed to clearly understand the effect of ferutinin in animals before using it as a phytoestrogen or anticancer drug.


Assuntos
Antineoplásicos/farmacologia , Antioxidantes/farmacologia , Benzoatos/farmacologia , Cicloeptanos/farmacologia , Ferula/química , Extratos Vegetais/farmacologia , Sesquiterpenos/farmacologia , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Antioxidantes/química , Antioxidantes/uso terapêutico , Apoptose/efeitos dos fármacos , Benzoatos/química , Benzoatos/uso terapêutico , Compostos Bicíclicos com Pontes/química , Compostos Bicíclicos com Pontes/farmacologia , Compostos Bicíclicos com Pontes/uso terapêutico , Linhagem Celular Tumoral , Cicloeptanos/química , Cicloeptanos/uso terapêutico , Relação Dose-Resposta a Droga , Transporte de Elétrons/efeitos dos fármacos , Terapia de Reposição Hormonal , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Óxido Nítrico/metabolismo , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia , Fitoestrógenos/química , Fitoestrógenos/farmacologia , Extratos Vegetais/química , Extratos Vegetais/uso terapêutico , Espécies Reativas de Oxigênio/metabolismo , Sesquiterpenos/química , Sesquiterpenos/uso terapêutico
20.
Bioorg Med Chem ; 28(23): 115811, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-33069129

RESUMO

'precision medicine' is characterized by the selection of targeted drugs based on genetic characteristics of tumor from patients, and no longer selected basis on the type of cancer tissue. Among them, clinical trials on neurotrophin receptor tyrosine kinase genes (NTRK) have proven that great anti-cancer effects can be achieved in different cancer patients. In this paper, a novel total of twenty compounds in two categories have been designed and synthesized. Results of Kinase activity tests showed that I-9 (TRKA IC50 = 1.3 nM, TRKAG595R IC50 = 6.1 nM), and I-10 (TRKA IC50 = 1.1 nM, TRKAG595R IC50 = 5.3 nM) have significant inhibitory activity, and results of cell viability tests showed that I-9 and I-10 can maintain a great inhibitory effect in the Ba/F3-LMNA-NTRK1 cell line(IC50 = 81.1 nM and 41.7 nM, respectively), and in Ba/F3-LMNA-NTRK1-G595R cell line, I-9 and I-10 have better cell activity (IC50 was 495.3 nM, 336.6 nM, respectively) compared with the positive control drug LOXO-101. These results indicate that I-9 and I-10 are potential TRK inhibitors that can overcome drug resistance for further investigation.


Assuntos
Amidas/química , Compostos Bicíclicos com Pontes/química , Desenho de Fármacos , Inibidores de Proteínas Quinases/síntese química , Receptor trkA/antagonistas & inibidores , Amidas/metabolismo , Amidas/farmacologia , Sítios de Ligação , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Simulação de Acoplamento Molecular , Polimorfismo de Nucleotídeo Único , Inibidores de Proteínas Quinases/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Receptor trkA/genética , Receptor trkA/metabolismo , Relação Estrutura-Atividade
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