RESUMO
N-Acyl-phosphatidylethanolamine hydrolyzing phospholipase D (NAPE-PLD) is a zinc metallohydrolase that hydrolyzes N-acyl-phosphatidylethanolamines (NAPEs) to form N-acyl-ethanolamines (NAEs) and phosphatidic acid. Several lines of evidence suggest that reduced NAPE-PLD activity could contribute to cardiometabolic diseases. For instance, NAPEPLD expression is reduced in human coronary arteries with unstable atherosclerotic lesions, defective efferocytosis is implicated in the enlargement of necrotic cores of these lesions, and NAPE-PLD products such as palmitoylethanolamide and oleoylethanolamide have been shown to enhance efferocytosis. Thus, enzyme activation mediated by a small molecule may serve as a therapeutic treatment for cardiometabolic diseases. As a proof-of-concept study, we sought to identify small molecule activators of NAPE-PLD. High-throughput screening followed by hit validation and primary lead optimization studies identified a series of benzothiazole phenylsulfonyl-piperidine carboxamides that variably increased activity of both mouse and human NAPE-PLD. From this set of small molecules, two NAPE-PLD activators (VU534 and VU533) were shown to increase efferocytosis by bone-marrow derived macrophages isolated from wild-type mice, while efferocytosis was significantly reduced in Napepld-/- BMDM or after Nape-pld inhibition. Together, these studies demonstrate an essential role for NAPE-PLD in the regulation of efferocytosis and the potential value of NAPE-PLD activators as a strategy to treat cardiometabolic diseases.
Assuntos
Doenças Cardiovasculares , Fosfolipase D , Camundongos , Humanos , Animais , Fosfatidiletanolaminas/metabolismo , Encéfalo/metabolismo , Macrófagos/metabolismo , Doenças Cardiovasculares/metabolismoRESUMO
Consecutive oxygenation of arachidonic acid by 5-lipoxygenase and cyclooxygenase-2 yields the hemiketal eicosanoids, HKE2 and HKD2. Hemiketals stimulate angiogenesis by inducing endothelial cell tubulogenesis in culture; however, how this process is regulated has not been determined. Here, we identify vascular endothelial growth factor receptor 2 (VEGFR2) as a mediator of HKE2-induced angiogenesis in vitro and in vivo. We found that HKE2 treatment of human umbilical vein endothelial cells dose-dependently increased the phosphorylation of VEGFR2 and the downstream kinases ERK and Akt that mediated endothelial cell tubulogenesis. In vivo, HKE2 induced the growth of blood vessels into polyacetal sponges implanted in mice. HKE2-mediated effects in vitro and in vivo were blocked by the VEGFR2 inhibitor vatalanib, indicating that the pro-angiogenic effect of HKE2 was mediated by VEGFR2. HKE2 covalently bound and inhibited PTP1B, a protein tyrosine phosphatase that dephosphorylates VEGFR2, thereby providing a possible molecular mechanism for how HKE2 induced pro-angiogenic signaling. In summary, our studies indicate that biosynthetic cross-over of the 5-lipoxygenase and cyclooxygenase-2 pathways gives rise to a potent lipid autacoid that regulates endothelial cell function in vitro and in vivo. These findings suggest that common drugs targeting the arachidonic acid pathway could prove useful in antiangiogenic therapy.
Assuntos
Araquidonato 5-Lipoxigenase , Receptor 2 de Fatores de Crescimento do Endotélio Vascular , Camundongos , Humanos , Animais , Ciclo-Oxigenase 2/metabolismo , Ácido Araquidônico , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Neovascularização Fisiológica , Células Endoteliais da Veia Umbilical Humana/metabolismo , Inibidores da Angiogênese/farmacologia , Movimento Celular , Proliferação de CélulasRESUMO
development of antibiotics, antineoplastics, and therapeutics for other diseases. Natural products are unique among all other small molecules in that they are produced by dedicated enzymatic assembly lines that are the protein products of biosynthetic gene clusters. As the products of chiral macromolecules, natural products have distinct three-dimensional shapes and stereochemistry is often encoded in their structures through the presence of stereocenters, or in the case of molecules that lack a stereocenter, the presence of an axis or plane of chirality. In the latter forms of chirality, if the barrier to rotation about the chiral axis or chiral plane is sufficiently high, stable conformers may exist allowing for isolation of discrete conformers, also known as atropisomers. Importantly, the diverse functions and biological activities of natural products are contingent upon their structures, stereochemistry and molecular shape. With continued innovation in methods for natural products discovery, synthetic chemistry, and analytical and computational tools, new insights into atropisomerism in natural products and related scaffolds are being made. As molecular complexity increases, more than one form of stereoisomerism may exist in a single compound (for example, point chirality, chiral axes, and chiral planes), sometimes creating atypical or noncanonical atropisomers, a term used to distinguish physically noninterconvertable atropisomers from typical atropisomers.Here we provide an account of the discovery and unusual structural and stereochemical features of the chrysophaentins, algal derived inhibitors of the bacterial cytoskeletal protein FtsZ and its associated protein partners. Eleven members of the chrysophaentin family have been discovered to date; seven of these are macrocyclic bis-bibenzyl ethers wherein the site of the ether linkage yields either a symmetrical or asymmetrical macrocyclic ring system. The asymmetrical ring system is highly strained and corresponds to the compounds having the most potent antimicrobial activity among the family. We review the structure elucidation and NMR properties that indicate restricted rotation between axes of two biaryl ethers, and the plane represented by the substituted 2-Z-butene bridge common to all of the macrocycles. Computational studies that corroborate high barriers to rotation about one representative plane, on the order of 20+ kcal/mol are presented. These barriers to rotation fix the conformation of the macrocycle into a bowl-like structure and suggest that an atropisomer should exist. Experimental evidence for atropisomerism is presented, consistent with computational predictions. These properties are discussed in the context of the total synthesis of 9-dechlorochrysophaenin A and its ring C isomers. Last, we discuss the implications for the presence of enantiomers in the biological activity and macrocyclization of the natural product.
Assuntos
Produtos Biológicos , Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas do Citoesqueleto/metabolismo , Estereoisomerismo , ÉteresRESUMO
Cancer cells have long been recognized to exhibit unique bioenergetic requirements. The apoptolidin family of glycomacrolides are distinguished by their selective cytotoxicity towards oncogene-transformed cells, yet their molecular mechanism remains uncertain. We used photoaffinity analogs of the apoptolidins to identify the F1 subcomplex of mitochondrial ATP synthase as the target of apoptolidin A. Cryogenic electron microscopy (cryo-EM) of apoptolidin and ammocidin-ATP synthase complexes revealed a novel shared mode of inhibition that was confirmed by deep mutational scanning of the binding interface to reveal resistance mutations which were confirmed using CRISPR-Cas9. Ammocidin A was found to suppress leukemia progression in vivo at doses that were tolerated with minimal toxicity. The combination of cellular, structural, mutagenesis, and in vivo evidence defines the mechanism of action of apoptolidin family glycomacrolides and establishes a path to address oxidative phosphorylation-dependent cancers.
Assuntos
Leucemia , Neoplasias , Trifosfato de Adenosina , Humanos , Leucemia/tratamento farmacológico , Macrolídeos , ATPases Mitocondriais Próton-Translocadoras/química , Neoplasias/tratamento farmacológicoRESUMO
Lactate dehydrogenase (LDH) is a critical enzyme in the glycolytic metabolism pathway that is used by many tumor cells. Inhibitors of LDH may be expected to inhibit the metabolic processes in cancer cells and thus selectively delay or inhibit growth in transformed versus normal cells. We have previously disclosed a pyrazole-based series of potent LDH inhibitors with long residence times on the enzyme. Here, we report the elaboration of a new subseries of LDH inhibitors based on those leads. These new compounds potently inhibit both LDHA and LDHB enzymes, and inhibit lactate production in cancer cell lines.
Assuntos
Compostos de Anilina/farmacologia , Antineoplásicos/farmacologia , Desenho de Fármacos , Éteres/farmacologia , L-Lactato Desidrogenase/antagonistas & inibidores , L-Lactato Desidrogenase/metabolismo , Compostos de Anilina/química , Antineoplásicos/química , Linhagem Celular Tumoral , Éteres/química , Humanos , L-Lactato Desidrogenase/químicaRESUMO
Lactate dehydrogenase (LDH) catalyzes the conversion of pyruvate to lactate, with concomitant oxidation of reduced nicotinamide adenine dinucleotide as the final step in the glycolytic pathway. Glycolysis plays an important role in the metabolic plasticity of cancer cells and has long been recognized as a potential therapeutic target. Thus, potent, selective inhibitors of LDH represent an attractive therapeutic approach. However, to date, pharmacological agents have failed to achieve significant target engagement in vivo, possibly because the protein is present in cells at very high concentrations. We report herein a lead optimization campaign focused on a pyrazole-based series of compounds, using structure-based design concepts, coupled with optimization of cellular potency, in vitro drug-target residence times, and in vivo PK properties, to identify first-in-class inhibitors that demonstrate LDH inhibition in vivo. The lead compounds, named NCATS-SM1440 (43) and NCATS-SM1441 (52), possess desirable attributes for further studying the effect of in vivo LDH inhibition.
Assuntos
Inibidores Enzimáticos/farmacologia , L-Lactato Desidrogenase/antagonistas & inibidores , Pirazóis/farmacologia , Animais , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacocinética , Meia-Vida , Humanos , Camundongos , Relação Estrutura-Atividade , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The mitotic spindle is a microtubule-based machine that segregates a replicated set of chromosomes during cell division. Many cancer drugs alter or disrupt the microtubules that form the mitotic spindle. Microtubule-dependent molecular motors that function during mitosis are logical alternative mitotic targets for drug development. Eg5 (Kinesin-5) and Kif15 (Kinesin-12), in particular, are an attractive pair of motor proteins, as they work in concert to drive centrosome separation and promote spindle bipolarity. Furthermore, we hypothesize that the clinical failure of Eg5 inhibitors may be (in part) due to compensation by Kif15. In order to test this idea, we screened a small library of kinase inhibitors and identified GW108X, an oxindole that inhibits Kif15 in vitro. We show that GW108X has a distinct mechanism of action compared with a commercially available Kif15 inhibitor, Kif15-IN-1 and may serve as a lead with which to further develop Kif15 inhibitors as clinically relevant agents.
Assuntos
Inibidores Enzimáticos/farmacologia , Cinesinas/antagonistas & inibidores , Sondas Moleculares/farmacologia , Oxindóis/farmacologia , Quinazolinonas/farmacologia , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Humanos , Cinesinas/metabolismo , Sondas Moleculares/síntese química , Sondas Moleculares/química , Estrutura Molecular , Oxindóis/síntese química , Oxindóis/química , Quinazolinonas/síntese química , Quinazolinonas/química , Relação Estrutura-AtividadeRESUMO
We report the discovery and medicinal chemistry optimization of a novel series of pyrazole-based inhibitors of human lactate dehydrogenase (LDH). Utilization of a quantitative high-throughput screening paradigm facilitated hit identification, while structure-based design and multiparameter optimization enabled the development of compounds with potent enzymatic and cell-based inhibition of LDH enzymatic activity. Lead compounds such as 63 exhibit low nM inhibition of both LDHA and LDHB, submicromolar inhibition of lactate production, and inhibition of glycolysis in MiaPaCa2 pancreatic cancer and A673 sarcoma cells. Moreover, robust target engagement of LDHA by lead compounds was demonstrated using the cellular thermal shift assay (CETSA), and drug-target residence time was determined via SPR. Analysis of these data suggests that drug-target residence time (off-rate) may be an important attribute to consider for obtaining potent cell-based inhibition of this cancer metabolism target.
Assuntos
Inibidores Enzimáticos/farmacologia , L-Lactato Desidrogenase/antagonistas & inibidores , Pirazóis/farmacologia , Tiazóis/farmacologia , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Cristalografia por Raios X , Descoberta de Drogas , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacocinética , Ensaios de Triagem em Larga Escala , Humanos , Masculino , Membranas Artificiais , Camundongos , Microssomos Hepáticos/efeitos dos fármacos , Permeabilidade , Pirazóis/síntese química , Pirazóis/química , Pirazóis/farmacocinética , Ratos , Solubilidade , Relação Estrutura-Atividade , Tiazóis/síntese química , Tiazóis/química , Tiazóis/farmacocinéticaRESUMO
The rising problem of antimicrobial resistance in Staphylococcus aureus necessitates the discovery of novel therapeutic targets for small-molecule intervention. A major obstacle of drug discovery is identifying the target of molecules selected from high-throughput phenotypic assays. Here, we show that the toxicity of a small molecule termed '882 is dependent on the constitutive activity of the S. aureus virulence regulator SaeRS, uncovering a link between virulence factor production and energy generation. A series of genetic, physiological, and biochemical analyses reveal that '882 inhibits iron-sulfur (Fe-S) cluster assembly most likely through inhibition of the Suf complex, which synthesizes Fe-S clusters. In support of this, '882 supplementation results in decreased activity of the Fe-S cluster-dependent enzyme aconitase. Further information regarding the effects of '882 has deepened our understanding of virulence regulation and demonstrates the potential for small-molecule modulation of Fe-S cluster assembly in S. aureus and other pathogens.
Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Proteínas Ferro-Enxofre/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologia , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/efeitos dos fármacos , Fatores de Virulência/metabolismo , Aconitato Hidratase/metabolismo , Antibacterianos/química , Descoberta de Drogas , Humanos , Proteínas Quinases/metabolismo , Transdução de Sinais/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/química , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus aureus/metabolismo , Fatores de Transcrição/metabolismo , Virulência/efeitos dos fármacosRESUMO
The apoptolidins are glycomacrolide microbial metabolites reported to be selectively cytotoxic against tumor cells. Using fluorescently tagged active derivatives we demonstrate selective uptake of these four tagged glycomacrolides in cancer cells over healthy human blood cells. We also demonstrate the utility of these five fluorescently tagged glycomacrolides in fluorescent flow cytometry to monitor cellular uptake of the six glycomacrolides and cellular response.
Assuntos
Macrolídeos/metabolismo , Células A549 , Transporte Biológico , Linhagem Celular Tumoral , Citometria de Fluxo , Corantes Fluorescentes , Humanos , Macrolídeos/química , Coloração e RotulagemRESUMO
Hedgehog (Hh) signaling plays an integral role in vertebrate development, and its dysregulation has been accepted widely as a driver of numerous malignancies. While a variety of small molecules target Smoothened (Smo) as a strategy for Hh inhibition, Smo gain-of-function mutations have limited their clinical implementation. Modulation of targets downstream of Smo could define a paradigm for treatment of Hh-dependent cancers. Here, we describe eggmanone, a small molecule identified from a chemical genetic zebrafish screen, which induced an Hh-null phenotype. Eggmanone exerts its Hh-inhibitory effects through selective antagonism of phosphodiesterase 4 (PDE4), leading to protein kinase A activation and subsequent Hh blockade. Our study implicates PDE4 as a target for Hh inhibition, suggests an improved strategy for Hh-dependent cancer therapy, and identifies a unique probe of downstream-of-Smo Hh modulation.
Assuntos
Proteínas Quinases Dependentes de AMP Cíclico/biossíntese , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/metabolismo , Inibidores da Fosfodiesterase 4/administração & dosagem , Pirimidinonas/química , Receptores Acoplados a Proteínas G/genética , Tiofenos/química , Proteínas de Peixe-Zebra/genética , Animais , Proteínas Quinases Dependentes de AMP Cíclico/genética , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/química , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/genética , Proteínas Hedgehog/antagonistas & inibidores , Proteínas Hedgehog/genética , Inibidores da Fosfodiesterase 4/química , Inibidores da Fosfodiesterase 4/isolamento & purificação , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/administração & dosagem , Bibliotecas de Moléculas Pequenas/química , Receptor Smoothened , Ativação Transcricional/efeitos dos fármacos , Peixe-Zebra , Proteínas de Peixe-Zebra/antagonistas & inibidoresRESUMO
Apoptolidinâ A has been described among the top 0.1% most-cell-selective cytotoxic agents to be evaluated in the NCI 60 cell line panel. The molecular structure of apoptolidinâ A consists of a 20-membered macrolide with mono- and disaccharide moieties. In contrast to apoptolidinâ A, the aglycone (apoptolidinone) shows no cytotoxicity (>10â µM) when evaluated against several tumor cell lines. Apoptolidinâ H, the C27 deglycosylated analogue of apoptolidinâ A, displayed sub-micromolar activity against H292 lung carcinoma cells. Selective esterification of apoptolidinsâ A and H with 5-azidopentanoic acid afforded azido-functionalized derivatives of potency equal to that of the parent macrolide. They also underwent strain-promoted alkyne-azido cycloaddition reactions to provide access to fluorescent and biotin-functionalized probes. Microscopy studies demonstrate apoptolidinsâ A and H localize in the mitochondria of H292 human lung carcinoma cells.
Assuntos
Antineoplásicos/química , Corantes Fluorescentes/química , Macrolídeos/química , Antineoplásicos/toxicidade , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Peroxidação de Lipídeos/efeitos dos fármacos , Macrolídeos/toxicidade , Microscopia Confocal , Pironas/química , Pironas/toxicidadeRESUMO
The fosfomycin resistance enzymes, FosB, from Gram-positive organisms, are M(2+)-dependent thiol tranferases that catalyze nucleophilic addition of either L-cysteine (L-Cys) or bacillithiol (BSH) to the antibiotic, resulting in a modified compound with no bacteriacidal properties. Here we report the structural and functional characterization of FosB from Bacillus cereus (FosB(Bc)). The overall structure of FosB(Bc), at 1.27 Å resolution, reveals that the enzyme belongs to the vicinal oxygen chelate (VOC) superfamily. Crystal structures of FosB(Bc) cocrystallized with fosfomycin and a variety of divalent metals, including Ni(2+), Mn(2+), Co(2+), and Zn(2+), indicate that the antibiotic coordinates to the active site metal center in an orientation similar to that found in the structurally homologous manganese-dependent fosfomycin resistance enzyme, FosA. Surface analysis of the FosB(Bc) structures show a well-defined binding pocket and an access channel to C1 of fosfomycin, the carbon to which nucleophilic addition of the thiol occurs. The pocket and access channel are appropriate in size and shape to accommodate L-Cys or BSH. Further investigation of the structures revealed that the fosfomycin molecule, anchored by the metal, is surrounded by a cage of amino acids that hold the antibiotic in an orientation such that C1 is centered at the end of the solvent channel, positioning the compound for direct nucleophilic attack by the thiol substrate. In addition, the structures of FosB(Bc) in complex with the L-Cys-fosfomycin product (1.55 Å resolution) and in complex with the bacillithiol-fosfomycin product (1.77 Å resolution) coordinated to a Mn(2+) metal in the active site have been determined. The L-Cys moiety of either product is located in the solvent channel, where the thiol has added to the backside of fosfomycin C1 located at the end of the channel. Concomitant kinetic analyses of FosB(Bc) indicated that the enzyme has a preference for BSH over L-Cys when activated by Mn(2+) and is inhibited by Zn(2+). The fact that Zn(2+) is an inhibitor of FosB(Bc) was used to obtain a ternary complex structure of the enzyme with both fosfomycin and L-Cys bound.
Assuntos
Antibacterianos/química , Bacillus cereus/enzimologia , Proteínas de Bactérias/química , Fosfomicina/metabolismo , Transferases/química , Antibacterianos/metabolismo , Bacillus cereus/química , Bacillus cereus/genética , Bacillus cereus/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Cristalografia por Raios X , Cisteína/análogos & derivados , Cisteína/metabolismo , Fosfomicina/química , Glucosamina/análogos & derivados , Glucosamina/metabolismo , Cinética , Especificidade por Substrato , Transferases/genética , Transferases/metabolismoRESUMO
Bacillithiol (BSH) has been prepared on the gram scale from the inexpensive starting material, D-glucosamine hydrochloride, in 11 steps and 8-9% overall yield. The BSH was used to survey the substrate and metal-ion selectivity of FosB enzymes from four Gram-positive microorganisms associated with the deactivation of the antibiotic fosfomycin. The in vitro results indicate that the preferred thiol substrate and metal ion for the FosB from Staphylococcus aureus are BSH and Ni(II), respectively. However, the metal-ion selectivity is less distinct with FosB from Bacillus subtilis, Bacillus anthracis, or Bacillus cereus.
Assuntos
Biocatálise , Cisteína/análogos & derivados , Glucosamina/análogos & derivados , Proteínas Proto-Oncogênicas c-fos/metabolismo , Staphylococcus aureus/metabolismo , Bacillus/metabolismo , Cisteína/síntese química , Cisteína/metabolismo , Fosfomicina/química , Fosfomicina/metabolismo , Glucosamina/síntese química , Glucosamina/metabolismo , Estrutura Molecular , Especificidade por SubstratoRESUMO
The apoptolidins are 20/21-membered macrolides produced by Nocardiopsis sp. FU40. Several members of this family are potent and remarkably selective inducers of apoptosis in cancer cell lines, likely via a distinct mitochondria associated target. To investigate the biosynthesis of this natural product, the complete genome of the apoptolidin producer Nocardiopsis sp. FU40 was sequenced and a 116 Kb region was identified containing a putative apoptolidin biosynthetic gene cluster. The apoptolidin gene cluster comprises a type I polyketide synthase, with 13 homologating modules, apparently initiated in an unprecedented fashion via transfer from a methoxymalonyl-acyl carrier protein loading module. Spanning approximately 39 open reading frames, the gene cluster was cloned into a series of overlapping cosmids and functionally validated by targeted gene disruption experiments in the producing organism. Disruption of putative PKS and P(450) genes delineated the roles of these genes in apoptolidin biosynthesis and chemical complementation studies demonstrated intact biosynthesis peripheral to the disrupted genes. This work provides insight into details of the biosynthesis of this biologically significant natural product and provides a basis for future mutasynthetic methods for the generation of non-natural apopotolidins.
RESUMO
Wnt/ß-catenin signaling is critically involved in metazoan development, stem cell maintenance and human disease. Using Xenopus laevis egg extract to screen for compounds that both stabilize Axin and promote ß-catenin turnover, we identified an FDA-approved drug, pyrvinium, as a potent inhibitor of Wnt signaling (EC(50) of â¼10 nM). We show pyrvinium binds all casein kinase 1 (CK1) family members in vitro at low nanomolar concentrations and pyrvinium selectively potentiates casein kinase 1α (CK1α) kinase activity. CK1α knockdown abrogates the effects of pyrvinium on the Wnt pathway. In addition to its effects on Axin and ß-catenin levels, pyrvinium promotes degradation of Pygopus, a Wnt transcriptional component. Pyrvinium treatment of colon cancer cells with mutation of the gene for adenomatous polyposis coli (APC) or ß-catenin inhibits both Wnt signaling and proliferation. Our findings reveal allosteric activation of CK1α as an effective mechanism to inhibit Wnt signaling and highlight a new strategy for targeted therapeutics directed against the Wnt pathway.
Assuntos
Caseína Quinase Ialfa/metabolismo , Proliferação de Células/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Compostos de Pirvínio/farmacologia , Transdução de Sinais/efeitos dos fármacos , Proteínas Wnt/antagonistas & inibidores , Proteínas Adaptadoras de Transdução de Sinal , Polipose Adenomatosa do Colo/genética , Polipose Adenomatosa do Colo/metabolismo , Animais , Proteína Axina , Caseína Quinase I/genética , Caseína Quinase I/metabolismo , Extratos Celulares , Linhagem Celular Tumoral , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Relação Dose-Resposta a Droga , Ativação Enzimática/efeitos dos fármacos , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Oócitos/citologia , Oócitos/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Proteínas Wnt/química , Proteínas Wnt/genética , Proteínas Wnt/metabolismo , Proteínas de Xenopus , Xenopus laevis , beta Catenina/genética , beta Catenina/metabolismoRESUMO
The isolation, characterization, and cytotoxicity against H292 cells of apoptolidin G are reported. Apoptolidin G is shown to be derived by a light-induced isomerization of the C2-C3 carbon-carbon double bond of apoptolidin A.
Assuntos
Macrolídeos/química , Pironas/química , Raios Ultravioleta , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Macrolídeos/isolamento & purificação , Macrolídeos/farmacologia , Conformação Molecular , Pironas/isolamento & purificação , Pironas/farmacologia , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
Synthetic efforts toward the cytotoxic peptides lucentamycins A-D are described that resulted in the total synthesis and biological evaluation of 8-epi-lucentamycin A in 15 steps with 2.2% overall yield. The key epi-nonproteogenic 3-methyl-4-ethylideneproline was synthesized via a titanium-mediated cycloisomerization reaction.
Assuntos
Oligopeptídeos/síntese química , Oligopeptídeos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Concentração Inibidora 50 , Conformação Molecular , Oligopeptídeos/química , Oligopeptídeos/toxicidade , EstereoisomerismoRESUMO
Glycosylation of a synthetic aglycone using precursor-directed biosynthesis is facilitated by a chemical ketosynthase "knockdown" of the apoptolidin producer Nocardiopsis sp. This synthetic approach facilitated the preparation of an unnatural disaccharide derivative of apoptolidin D that substantially restores cytotoxicity against H292 cells and deconvolutes the role of the decorating sugars in apoptolidin bioactivity.