RESUMEN
Iron is an essential metal for all organisms, yet disruption of its homeostasis, particularly in labile forms that can contribute to oxidative stress, is connected to diseases ranging from infection to cancer to neurodegeneration. Iron deficiency is also among the most common nutritional deficiencies worldwide. To advance studies of iron in healthy and disease states, we now report the synthesis and characterization of iron-caged luciferin-1 (ICL-1), a bioluminescent probe that enables longitudinal monitoring of labile iron pools (LIPs) in living animals. ICL-1 utilizes a bioinspired endoperoxide trigger to release d-aminoluciferin for selective reactivity-based detection of Fe2+ with metal and oxidation state specificity. The probe can detect physiological changes in labile Fe2+ levels in live cells and mice experiencing iron deficiency or overload. Application of ICL-1 in a model of systemic bacterial infection reveals increased iron accumulation in infected tissues that accompany transcriptional changes consistent with elevations in both iron acquisition and retention. The ability to assess iron status in living animals provides a powerful technology for studying the contributions of iron metabolism to physiology and pathology.
Asunto(s)
Infecciones por Acinetobacter/metabolismo , Anemia Ferropénica/metabolismo , Luciferina de Luciérnaga/análisis , Colorantes Fluorescentes/análisis , Sobrecarga de Hierro/metabolismo , Hierro/metabolismo , 2,2'-Dipiridil/farmacología , Infecciones por Acinetobacter/genética , Infecciones por Acinetobacter/microbiología , Infecciones por Acinetobacter/patología , Acinetobacter baumannii/patogenicidad , Acinetobacter baumannii/fisiología , Anemia Ferropénica/genética , Anemia Ferropénica/patología , Animales , Proteínas de Transporte de Catión/genética , Proteínas de Transporte de Catión/metabolismo , Cationes Bivalentes , Modelos Animales de Enfermedad , Compuestos Férricos/farmacología , Luciferina de Luciérnaga/análogos & derivados , Luciferina de Luciérnaga/síntesis química , Colorantes Fluorescentes/síntesis química , Regulación de la Expresión Génica , Hepcidinas/genética , Hepcidinas/metabolismo , Homeostasis/genética , Sobrecarga de Hierro/genética , Sobrecarga de Hierro/patología , Proteína 1 Reguladora de Hierro/genética , Proteína 1 Reguladora de Hierro/metabolismo , Proteína 2 Reguladora de Hierro/genética , Proteína 2 Reguladora de Hierro/metabolismo , Mediciones Luminiscentes , Ratones , Ratones Transgénicos , Compuestos de Amonio Cuaternario/farmacología , Receptores de Transferrina/genética , Receptores de Transferrina/metabolismo , Transducción de Señal , Transferrina/genética , Transferrina/metabolismoRESUMEN
Clinical development of the antimalarial artefenomel was recently halted due to formulation challenges stemming from the drug's lipophilicity and low aqueous solubility. The symmetry of organic molecules is known to influence crystal packing energies and by extension solubility and dissolution rates. Here we evaluate RLA-3107, a desymmetrized, regioisomeric form of artefenomel in vitro and in vivo, finding that the regioisomer retains potent antiplasmodial activity while offering improved human microsome stability and aqueous solubility as compared to artefenomel. We also report in vivo efficacy data for artefenomel and its regioisomer across 12 different dosing regimens.
RESUMEN
We have developed a phosphine-catalyzed (4+1) annulative rearrangement for the preparation of 3-pyrrolines from allenylic carbamates via phosphonium diene intermediates. We employed this methodology to synthesize an array of 1,3-disubstituted- and 1,2,3-trisubstituted-3-pyrrolines, including the often difficult to prepare 2-alkyl variants. A mechanistic investigation employing allenylic acetates and mononucleophiles unexpectedly unveiled that a phosphine-catalyzed (4+1) reaction for the construction of cyclopentene products, previously reported by Tong, might not occur through a phosphonium diene, as had been proposed, but rather through multiple mechanisms working in concert. Consequently, our phosphine-catalyzed rearrangement is most likely the first transformation to involve the unequivocal formation of a phosphonium diene intermediate along the reaction pathway. To demonstrate the synthetic utility of this newly developed reaction, we have completed concise formal syntheses of the pyrrolizidine alkaloids (±)-trachelanthamidine and (±)-supinidine.
RESUMEN
The emergence of artemisinin resistance, combined with certain suboptimal properties of ozonide agents arterolane and artefenomel, has necessitated the search for new drug candidates in the endoperoxide class. Our group has focused on trioxolane analogues with substitution patterns not previously explored. Here, we describe the enantioselective synthesis of analogues bearing a trans-3â³ carbamate side chain and find these to be superior, both in vitro and in vivo, to the previously reported amides. We identified multiple analogues that surpass the oral efficacy of arterolane in the Plasmodium berghei model while exhibiting drug-like properties (logD, solubility, metabolic stability) similar or superior to next-generation clinical candidates like E209 and OZ609. While the preclinical assessment of new analogues is still underway, current data suggest the potential of this chemotype as a likely source of future drug candidates from the endoperoxide class.
Asunto(s)
Antimaláricos , Preparaciones Farmacéuticas , Antimaláricos/farmacología , Plasmodium berghei , Plasmodium falciparumRESUMEN
The adenosinergic pathway represents an attractive new therapeutic approach in cancer immunotherapy. In this pathway, ecto-5-nucleotidase CD73 has the unique function of regulating production of immunosuppressive adenosine (ADO) through the hydrolysis of AMP. CD73 is overexpressed in many cancers, resulting in elevated levels of ADO that correspond to poor patient prognosis. Therefore, reducing the level of ADO via inhibition of CD73 is a potential strategy for treating cancers. Based on the binding mode of adenosine 5'-(α,ß-methylene)diphosphate (AOPCP) with human CD73, we designed a series of novel monophosphonate small-molecule CD73 inhibitors. Among them, OP-5244 (35) proved to be a highly potent and orally bioavailable CD73 inhibitor. In preclinical studies, 35 completely inhibited ADO production in both human cancer cells and CD8+ T cells. Furthermore, 35 lowered the ratio of ADO/AMP significantly and reversed immunosuppression in mouse models, indicating its potential as an in vivo tool compound for further development.
Asunto(s)
5'-Nucleotidasa/antagonistas & inhibidores , Adenosina/antagonistas & inhibidores , Inhibidores Enzimáticos/farmacología , Factores Inmunológicos/farmacología , Nucleósidos/farmacología , Organofosfonatos/farmacología , Administración Oral , Animales , Linfocitos T CD8-positivos/efectos de los fármacos , Línea Celular Tumoral , Perros , Inhibidores Enzimáticos/administración & dosificación , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacocinética , Proteínas Ligadas a GPI/antagonistas & inhibidores , Humanos , Factores Inmunológicos/administración & dosificación , Factores Inmunológicos/síntesis química , Factores Inmunológicos/farmacocinética , Macaca fascicularis , Ratones Endogámicos BALB C , Estructura Molecular , Nucleósidos/administración & dosificación , Nucleósidos/síntesis química , Nucleósidos/farmacocinética , Organofosfonatos/administración & dosificación , Organofosfonatos/síntesis química , Organofosfonatos/farmacocinética , Ratas , Estereoisomerismo , Relación Estructura-ActividadRESUMEN
Iron is essential to all life, and competition for this vital nutrient is central to host-pathogen interactions during infection. The opportunistic Gram-negative pathogen Pseudomonas aeruginosa utilizes a diverse array of iron-acquisition strategies, including those enabling import of extracellular ferrous iron. We hypothesize that soluble and redox-active ferrous iron can be employed to activate caged antibiotics at sites of infection in vivo. Here we describe new chemistry that expands the application of our laboratory's Fe2+-activated-prodrug chemistry to cage hydroxamic acids, a class of drugs that present manifold development challenges. We synthesize the caged form of a known LpxC inhibitor and show that it is efficacious in an acute P. aeruginosa mouse-lung infection model, despite showing little activity in cell-culture experiments. Overall, our results are consistent with the Fe2+-promoted uncaging of an antibacterial payload at sites of infection in an animal and lend support to recent reports indicating that extracellular pools of ferrous iron can be utilized by bacterial pathogens like P. aeruginosa during infection.
Asunto(s)
Amidohidrolasas/antagonistas & inhibidores , Antibacterianos/uso terapéutico , Inhibidores Enzimáticos/uso terapéutico , Compuestos Ferrosos/uso terapéutico , Pseudomonas aeruginosa/efectos de los fármacos , Animales , Antibacterianos/química , Inhibidores Enzimáticos/química , Femenino , Compuestos Ferrosos/química , Bacterias Gramnegativas/efectos de los fármacos , Interacciones Huésped-Patógeno/efectos de los fármacos , Ácidos Hidroxámicos/metabolismo , Pulmón/microbiología , Ratones , Profármacos/administración & dosificación , Pseudomonas aeruginosa/patogenicidad , Infecciones del Sistema Respiratorio/tratamiento farmacológico , Infecciones del Sistema Respiratorio/microbiologíaRESUMEN
We describe the first systematic study of antimalarial 1,2,4-trioxolanes bearing a substitution pattern regioisomeric to that of arterolane. Conformational analysis suggested that trans-3â³-substituted trioxolanes would exhibit Fe(II) reactivity and antiparasitic activity similar to that achieved with canonical cis-4â³ substitution. The chiral 3â³ analogues were prepared as single stereoisomers and evaluated alongside their 4â³ congeners against cultured malaria parasites and in a murine malaria model. As predicted, the trans-3â³ analogues exhibited in vitro antiplasmodial activity remarkably similar to that of their cis-4â³ comparators. In contrast, efficacy in the Plasmodium berghei mouse model differed dramatically for some of the congeneric pairs. The best of the novel 3â³ analogues (e.g., 12i) outperformed arterolane itself, producing cures in mice after a single oral exposure. Overall, this study suggests new avenues for modulating Fe(II) reactivity and the pharmacokinetic and pharmacodynamic properties of 1,2,4-trioxolane antimalarials.
Asunto(s)
Antimaláricos/química , Compuestos Heterocíclicos con 1 Anillo/química , Peróxidos/química , Compuestos de Espiro/química , Animales , Antimaláricos/farmacología , Antimaláricos/uso terapéutico , Femenino , Compuestos Ferrosos/metabolismo , Compuestos Heterocíclicos con 1 Anillo/farmacología , Compuestos Heterocíclicos con 1 Anillo/uso terapéutico , Malaria/tratamiento farmacológico , Malaria/parasitología , Ratones , Peróxidos/farmacología , Peróxidos/uso terapéutico , Plasmodium berghei , Plasmodium falciparum/efectos de los fármacos , Plasmodium falciparum/metabolismo , Compuestos de Espiro/farmacología , Compuestos de Espiro/uso terapéutico , Estereoisomerismo , Relación Estructura-ActividadRESUMEN
An array of N-tosylated α-aminoalkylallenic esters was prepared and their cyclization under the influence of nucleophilic phosphine catalysts was explored. The α-aminoalkylallenic esters were prepared through aza-Baylis-Hillman reactions or novel DABCO-mediated decarboxylative rearrangements of allenylic carbamates. Conversion of these substrates to 3-carbethoxy-2-alkyl-3-pyrrolines was facilitated through Ph(3)P-catalyzed intramolecular γ-umpolung addition.
Asunto(s)
Fosfinas/química , Pirroles/química , Aminas/química , Catálisis , Ésteres , Isomerismo , Piperazinas/química , Pirroles/síntesis químicaRESUMEN
Glutamate carboxypeptidase II (GCP2) is a membrane-bound cell-surface peptidase which is implicated in several neurological disorders and is also over-expressed in prostate tumor cells. There is a significant interest in the inhibition of GCP2 as a means of neuroprotection, while GCP2 inhibition as a method to treat prostate cancer remains a topic of further investigation. The key zinc-binding functional group of the well-characterized classes of GCP2 inhibitors (phosphonates and phosphoramidates) is tetrahedral and negatively charged at neutral pH, while glutamyl urea class of inhibitors possesses a planar and neutral zinc-binding group. This study introduces a new class of GCP2 inhibitors, N-substituted glutamyl sulfonamides, which possess a neutral tetrahedral zinc-binding motif. A library containing 15 secondary sulfonamides and 4 tertiary (N-methyl) sulfonamides was prepared and evaluated for inhibitory potency against purified GCP2 enzyme activity. While most inhibitors lacked potency at 100 µm, short alkyl sulfonamides exhibited promising low micromolar potency, with the optimal inhibitor in this series being glutamyl N-(propylsulfonamide) (2g). Lastly, molecular docking was used to develop a model to formulate an explanation for the relative inhibitory potencies employed for this class of inhibitors.