RESUMEN
A new antifungal compound, named N-demethyltyroscherin (1), was discovered from the static fungal cultured material of Scedosporium apiospermum FKJ-0499 isolated from a deep-sea sediment sample together with a known compound, tyroscherin (2). The structure of 1 was elucidated as a new analog of 2 by MS and NMR analyses. The absolute configuration of 1 was determined by chemical derivatization. Both compounds showed potent in vitro antifungal activity against clinically isolated Candida auris strains, with MIC values ranging from 0.0625 to 4 µg ml-1.
Asunto(s)
Antifúngicos , Epinefrina/análogos & derivados , Alcoholes Grasos , Scedosporium , Antifúngicos/farmacología , Antifúngicos/uso terapéutico , Candida auris , Pruebas de Sensibilidad Microbiana , HongosRESUMEN
Best treatments for initial presentation and relapses in children with nephrotic syndrome (NS) are still to be defined. The PROPINE study, published in this issue of Kidney International, demonstrates for relapse of childhood NS, the non-inferiority of a short taper (over 36 days) after remission with steroids. This study reinforces the need for more well-designed studies and the incorporation of predictive biomarkers, genetic studies, and other details to personalize treatment for each child with idiopathic NS.
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Síndrome Nefrótico , Niño , Epinefrina/análogos & derivados , Humanos , Síndrome Nefrótico/diagnóstico , Síndrome Nefrótico/tratamiento farmacológico , Prednisona , RecurrenciaRESUMEN
Corticosteroid-related toxicity in children with steroid-sensitive nephrotic syndrome is primarily related to the cumulative dose of prednisone. To optimize treatment of relapses, we conducted the PROPINE study, a multicentric, open-label, randomized, superiority trial. Seventy-eight relapsing children aged 3-17 years who had not received steroid-sparing medications during the previous 12 months were randomized to receive, from day five after remission, either 18 doses of 40 mg/m2 of prednisone on alternate days (short arm), or the same cumulative dose tapered over double the time (long arm). Patients were monitored with an ad-hoc smartphone application, allowing daily reporting. The primary outcome was the six-month relapse rate at which time, 23/40 and 16/38 patients had relapsed in the long and short arms, respectively (no significant difference). Additionally, 40/78 patients were also enrolled in a secondary crossover study and were allocated to the opposite arm. Altogether, at six months, the relapse rate was 32/40 and 28/40 in the long and short arms, respectively (no significant difference). A post-hoc analysis excluding 30 patients treated with low-dose prednisone maintenance therapy failed to show significant differences between the two arms. No differences in adverse events, blood pressure and weight gain were observed. Thus, our data do not support the prescription of prolonged tapering schedules for relapses of steroid-sensitive nephrotic syndrome in children.
Asunto(s)
Síndrome Nefrótico , Antiinflamatorios/uso terapéutico , Niño , Estudios Cruzados , Epinefrina/análogos & derivados , Glucocorticoides/uso terapéutico , Humanos , Inmunosupresores/uso terapéutico , Síndrome Nefrótico/tratamiento farmacológico , Prednisona/efectos adversos , RecurrenciaRESUMEN
Electrochemical sensors have shown great appeal for the simultaneous analysis of pharmaceutical compounds. In this way, the presence study described first electroanalytical sensor for simultaneous determination of adrenalone and folic acid. The two-amplified voltammetric sensor was developed by modifying carbon paste electrode (CPE) with NiO/SWCNTs composite and 1-butyl-3-methylimidazolium methanesulfonate (1B3MIMS) and used for simultaneous determination of adrenalone and folic acid. The NiO/SWCNTs was synthesised by a fast and low-cost precipitation strategy and then characterised by EDS, FESEM and XRD methods. The results confirmed a particle size range of â 26.93-33.87 nm for NiO nanoparticle decorated at SWCNTs. The cyclic voltammetric investigation showed that oxidation potentials of adrenalone and folic acid depend on changing the pH value. The maximum oxidation current for the simultaneous analysis of two compounds occurred at pH = 7.0. In this condition, the sensor showed linear dynamic range 0.01-400 µM and 0.3-350 µM for determination of adrenalone and folic acid, respectively. The NiO/SWCNTs/1B3MIMS/CPE was then used as an ultrasensitive electroanalytical sensor for determination of adrenalone and folic acid in injection samples with recovery ratio between 98.2-103.66 %.
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Líquidos Iónicos , Carbono , Técnicas Electroquímicas , Electrodos , Epinefrina/análogos & derivados , Ácido FólicoRESUMEN
The degradation kinetics of an adrenaline (epinephrine) derivative, CpQ, was studied in solution in the pH range of 1-12 at 40-80 °C by high-performance liquid chromatography and ultraviolet-visible spectroscopy. The pH-rate profile exhibits a bell-shaped curve with two sigmoidal regions in the specific acid-catalyzed and specific base-catalyzed regions. The pH range of maximum stability was 2.5-4.5 with the main degradation pathway being the oxidative N-dealkylation of the aliphatic amino moiety followed by fast interconversion of the resulting fragments to stable degradation products. The autoxidation reaction was slower than the reaction of the oxygen reactive species. The chiral center underwent R to S racemization by a polar reaction mechanism under acidic conditions with a rate minimum at pH 4. The rates of degradation of the R and S enantiomers were similar across all pHs. CpQ degradation in the presence of hydrogen peroxide at 40 °C was significantly faster, and the extent of increases with pH. Metal ions bind to CpQ and catalyze its hydrolysis in the order Fe3+ > Fe2+ > Mg2+ > Mn2+ > Ti3+ > Sr2+ > Zn2+, with a rate enhancement of ≤1 order of magnitude at the studied pH values of 1 and 5. There was no buffer catalysis observed in the hydrolysis of the studied compound for maleate and phosphate but significant buffer catalysis in the case of citrate and malate.
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Epinefrina/análogos & derivados , Agua/química , Tampones (Química) , Remoción de Radical Alquila , Peróxido de Hidrógeno/química , Concentración de Iones de Hidrógeno , Hidrólisis , Cinética , Metales/química , Oxidación-Reducción , Estereoisomerismo , TemperaturaRESUMEN
Acinetobacter baumannii, an ESKAPE pathogen, causes various nosocomial infections and has capacity to produce biofilm. Biofilm produced by this bacterium is highly tolerant to environmental factors and different antibiotics. Biofilm-associated protein (Bap) plays a significant role in the biofilm formation by A. baumannii and found in the extra cellular matrix of the biofilm. Therefore, it becomes essential to find a potential drug against Bap that has capacity to inhibit biofilm formation by A. baumannii. In-silico screening, molecular mechanics and molecular dynamics studies identified ZINC00039089 (L-Adrenaline) as an inhibitor for Bap of A. baumannii. Recently, it is reported that Bap can form amyloid like structure; hence we have created dimer of Bap protein. This inhibitor can bind to dimeric Bap with good affinity. It confirms that ZINC00039089 (L-Adrenaline) can bind with Bap monomer as well as oligomeric Bap, responsible for amyloid formation and biofilm formation. Hence, we have tested Adrenaline as an anti-biofilm molecule and determined its IC50 value against biofilm. The result showed Adrenaline has anti-biofilm activity with IC50 value of 75µg/ml. Therefore; our finding suggests that L-Adrenaline can be developed to inhibit biofilm formation by carbapenem resistant strain of Acinetobacter baumannii.
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Proteínas Bacterianas/antagonistas & inhibidores , Biopelículas/efectos de los fármacos , Carbapenémicos/antagonistas & inhibidores , Epinefrina/química , Acinetobacter baumannii/efectos de los fármacos , Acinetobacter baumannii/patogenicidad , Proteínas Bacterianas/química , Carbapenémicos/química , Simulación por Computador , Epinefrina/análogos & derivados , Epinefrina/farmacología , Humanos , Simulación de Dinámica MolecularRESUMEN
Although, α2C adrenergic receptor (AR) mediates a number of physiological functions in vivo and has great therapeutic potential, the absence of its crystal structure is a major difficulty in the activation mechanism studies and drug design endeavors. Here, a homology model of α2C AR has been presented by means of multiple sequence alignment. The used templates were the latest crystal structures of the other ARs (Protein Data Bank IDs: 2R4R, 2RH1, 4GPO, 3P0G, 4BVN and 4LDO) that have 38.4% identity with the query. We then conducted docking simulations to understand and analyze the binding of noradrenaline (NOR), and its derivatives, namely arachidonoyl adrenalin (AA-AD) and arachidonoyl noradrenalin (AA-NOR) to the receptor. The existence of H-bonds between the ligands and SER218 residue implies the same binding site of derivatives with respect to the NOR. AA-AD and AA-NOR bind to the receptor with the larger binding affinities. The presence of salt bridge between ARG149 and GLU377 in the free receptor, obtained from molecular dynamics studies proved that the receptor still is in its basal state before binding process take places. The activation process is characterized by increasing in the RMSD values of the backbone receptor in the bound state, increasing the RMSF of the transmembrane involved in the activation process and the disappearance of the ARG149-GLU377 salt bridge.
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Epinefrina/análogos & derivados , Simulación del Acoplamiento Molecular , Norepinefrina/análogos & derivados , Receptores Adrenérgicos alfa 2/metabolismo , Ácido Araquidónico , Sitios de Unión , Bases de Datos de Proteínas , Epinefrina/metabolismo , Humanos , Simulación de Dinámica Molecular , Norepinefrina/metabolismo , Unión Proteica , Alineación de Secuencia , Homología Estructural de ProteínaRESUMEN
Stress conditions are correlated with tumor growth, progression and metastasis. We hypothesized that stress signals might affect tumor progression via epigenetic control of gene expression and investigated the effects of stress signals on the expression levels of histone deacetylases (HDACs) and the underlying mechanisms of these effects in lung cancer cells. Treatment with isoproterenol (ISO), an analog of the stress signal epinephrine, increased the expression of HDAC6 protein and mRNA in H1299 lung cancer cells. ISO caused the deacetylation of α-tubulin and stimulated cell migration in an HDAC6-dependent manner. HDAC6 expression was increased by treatment with selective activators of cAMP-dependent protein kinase (PKA) or exchange protein activated by cAMP (Epac). ISO activated Rap1 via Epac, and constitutively active Rap1A increased the HDAC6 level; however, the knockdown of Rap1A decreased the 8-(4-cholorophenylthio)-2'-O-methyl-cAMP-induced increase in HDAC6 expression. Both PKA and Rap1A decreased c-Raf activation to inhibit extracellular signal-regulated kinase (ERK) signaling. Inhibition of ERK caused an increase in HDAC6 expression, and constitutively active MEK1 decreased the ISO-induced HDAC6 expression. We concluded that ISO increases HDAC6 expression via a PKA/Epac/ERK-dependent pathway that stimulates the migration of lung cancer cells. This study suggests that stress signals can stimulate the migration of cancer cells by inducing HDAC6 expression in lung cancer cells.
Asunto(s)
Movimiento Celular , Regulación Neoplásica de la Expresión Génica , Histona Desacetilasa 6/genética , Neoplasias Pulmonares/etiología , Transducción de Señal , Estrés Fisiológico , Células A549 , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Epinefrina/análogos & derivados , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Factores de Intercambio de Guanina Nucleótido/metabolismo , Humanos , Isoproterenol/efectos adversos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Simpatomiméticos/efectos adversosRESUMEN
In this paper, we present a class of bio-dots, polyepinephrine (PEP)-based fluorescent organic dots (PEP-FODs) for selective and sensitive detection of Fe(2+), Fe(3+), and Cu(2+). The PEP-FODs were derived from epinephrine via self-polymerization at relatively low temperature down to 60°C with low cytotoxicity and relative long lifetime (7.24ns). The surface morphology and optical properties of the synthesized PEP-FODs were characterized. We found that the diameters of PEP-FODs were mainly distributed in the narrow range of 2-4nm with an average diameter of 2.9nm. An optimal emission peak located at 490nm was observed when the green light-emitting PEP-FODs were excited at 400nm. It is discovered that Fe(2+), Fe(3+), and Cu(2+)can strongly quench the fluorescence of PEP-FODs through the nonradiative electron-transfer. The detection limit of 0.16, 0.67, and 0.15µM was obtained for Fe(2+), Fe(3+), and Cu(2+), respectively. The independent sensing platform of Fe(2+), Fe(3+), and Cu(2+)could be established by using NaF as a complexing agent and by regulating the reaction time between NaF and metal ions. Cell viability studies reveal that the as-prepared PEP-FODs possess good solubility and biocompatibility, making it as excellent imaging nanoprobes for intracellular Fe(2+), Fe(3+), and Cu(2+)sensing. The developed PEP-FODs might hold great promise to broaden applications in nanotechnology and bioanalysis.
Asunto(s)
Cobre/análisis , Epinefrina/análogos & derivados , Colorantes Fluorescentes/química , Hierro/análisis , Puntos Cuánticos/química , Espectrometría de Fluorescencia/métodos , Técnicas Biosensibles/métodos , Cationes/análisis , Epinefrina/química , Fluorescencia , Células HeLa , Humanos , Microscopía Confocal/métodos , Imagen Óptica/métodosRESUMEN
PURPOSE: To evaluate the effects of signals through adrenergic receptors on the changes in the aqueous flare and intraocular pressure (IOP) induced by topical prostaglandin E2 (PGE2) in pigmented rabbits. METHODS: Adrenergic agents were applied topically to pigmented Dutch rabbits, and PGE2 was then applied to induce an increase in the aqueous flare and IOP. The degree of aqueous flare was measured with a laser flare meter, and the IOP was measured with a rebound tonometer. Measurements were made every 30 min after the PGE2 had been applied for 2 h and at 4.0 and 4.5 h. Repeated measure analysis of variance and Dunnett's post hoc tests were used for the statistical analyses. RESULTS: The topical application of PGE-2 increased the aqueous flare for more than 4.5 h. The topical instillation of 1.0 % apraclonidine significantly inhibited the increase in the PGE2-induced aqueous flare by 75.1 %, of 0.1 % brimonidine by 57.2 %, of 0.04 % dipivefrin by 57.4 %, and a combination of 0.1 % brimonidine and 5 % phenylephrine by 78.9 %. Topical 5.0 % phenylephrine and 0.05 % isoproterenol had little effect on the aqueous flare elevation induced by PGE2. The IOP increased 0.5 h after the topical application of PGE-2. Topical 1.0 % apraclonidine, 0.1 % brimonidine, 0.1 % dipivefrin, and the combination of 0.1 % brimonidine and 5.0 % phenylephrine significantly inhibited the PGE2-induced IOP elevation. However, topical 5.0 % phenylephrine and 0.05 % isoproterenol did not significantly inhibit the IOP elevation caused by PGE2. CONCLUSIONS: Signaling by the α2 receptor inhibits both the PGE2-induced flare and IOP elevation caused by topical PGE2 application.
Asunto(s)
Agonistas Adrenérgicos/farmacología , Humor Acuoso/efectos de los fármacos , Barrera Hematoacuosa/efectos de los fármacos , Dinoprostona/farmacología , Presión Intraocular/efectos de los fármacos , Uveítis Anterior/prevención & control , Administración Tópica , Animales , Humor Acuoso/metabolismo , Tartrato de Brimonidina/farmacología , Clonidina/análogos & derivados , Clonidina/farmacología , Combinación de Medicamentos , Epinefrina/análogos & derivados , Epinefrina/farmacología , Masculino , Fenilefrina/farmacología , Conejos , Tonometría Ocular , Uveítis Anterior/inducido químicamente , Uveítis Anterior/metabolismoRESUMEN
Alcohol addiction is a problem of great societal concern, for which there is scope to improve current treatments. One potential new treatment for alcohol addiction is based on disrupting the reconsolidation of the maladaptive Pavlovian memories that can precipitate relapse to drug-seeking behavior. In alcohol self-administering rats, we investigated the effects of bidirectionally modulating adrenergic signaling on the strength of a Pavlovian cue-alcohol memory, using a behavioral procedure that isolates the specific contribution of one maladaptive Pavlovian memory to relapse, the acquisition of a new alcohol-seeking response for an alcohol-associated conditioned reinforcer. The ß-adrenergic receptor antagonist propranolol, administered in conjunction with memory reactivation, persistently disrupted the memory that underlies the capacity of a previously alcohol-associated cue to act as a conditioned reinforcer. By contrast, enhancement of adrenergic signaling by administration of the adrenergic prodrug dipivefrin at reactivation increased the strength of the cue-alcohol memory and potentiated alcohol seeking. These data demonstrate the importance of adrenergic signaling in alcohol-associated memory reconsolidation, and suggest a pharmacological target for treatments aiming to prevent relapse through the disruption of maladaptive memories.
Asunto(s)
Condicionamiento Clásico/fisiología , Comportamiento de Búsqueda de Drogas/fisiología , Etanol/administración & dosificación , Consolidación de la Memoria/fisiología , Receptores Adrenérgicos beta/fisiología , Refuerzo en Psicología , Agonistas Adrenérgicos/administración & dosificación , Antagonistas Adrenérgicos beta/administración & dosificación , Animales , Condicionamiento Clásico/efectos de los fármacos , Señales (Psicología) , Comportamiento de Búsqueda de Drogas/efectos de los fármacos , Epinefrina/administración & dosificación , Epinefrina/análogos & derivados , Masculino , Consolidación de la Memoria/efectos de los fármacos , Nadolol/administración & dosificación , Propranolol/administración & dosificación , Ratas , AutoadministraciónRESUMEN
A computational approach to predict the main binding modes of two adrenalin derivatives, arachidonoyl adrenalin (AA-AD) and arachidonoyl noradrenalin (AA-NOR) with the ß-lactoglubuline (BLG) as a nano-milk protein carrier is presented and assessed by comparison to the UV-Vis absorption spectroscopic data using chemometric analysis. Analysis of the spectral data matrices by using the multivariate curve resolution-alternating least squares (MCR-ALS) algorithm led to the pure concentration calculation and spectral profiles resolution of the chemical constituents and the apparent equilibrium constants computation. The negative values of entropy and enthalpy changes for both compound indicated the essential role of hydrogen bonding and van der Waals interactions as main driving forces in stabilizing protein-ligand complex. Computational studies predicted that both derivatives are situated in the calyx pose and remained in that pose during the whole time of simulation with no any significant protein structural changes which pointed that the BLG could be considered as a suitable carrier for these catecholamine compounds.
Asunto(s)
Ácidos Araquidónicos/química , Epinefrina/análogos & derivados , Epinefrina/química , Lactoglobulinas/química , Norepinefrina/análogos & derivados , Norepinefrina/química , Ácido Araquidónico/química , Ácidos Araquidónicos/metabolismo , Sitios de Unión , Entropía , Epinefrina/metabolismo , Enlace de Hidrógeno , Lactoglobulinas/metabolismo , Simulación del Acoplamiento Molecular , Norepinefrina/metabolismo , Análisis de Componente Principal , Estructura Secundaria de Proteína , Estructura Terciaria de Proteína , Espectrofotometría UltravioletaRESUMEN
BACKGROUND: Post-transplant reinnervation is a unique model to study sympathetic neuronal regeneration in vivo. The differential role of subcellular mechanisms of catecholamine handling in nerve terminals has not been investigated. METHODS AND RESULTS: Three different carbon-11-labeled catecholamines were used for positron emission tomography of transport (C-11 m-hydroxyephedrine, HED), vesicular storage (C-11 epinephrine, EPI), and metabolic degradation (C-11 phenylephrine). A 2-day protocol was used, including quantification of myocardial blood flow by N-13 ammonia. Resting myocardial blood flow and EPI, HED and phenylephrine retention were homogeneous in healthy volunteers (n=7). Washout was only observed for phenylephrine (T(1/2) 49±6 min). In nonrejecting, otherwise healthy heart transplant recipients (>1 year after surgery, n=10), resting myocardial blood flow was also homogenous. Regional catecholamine uptake of varying degrees was observed in the anterior left ventricular wall and septum. Overall, 24±19% of left ventricle showed HED uptake levels comparable with healthy volunteers, whereas it was only 8±7% for EPI (P=0.004 versus HED). Phenylephrine washout was not different from healthy volunteers in the area with restored EPI and HED retention (T(1/2) 41±7 min; P>0.05), but was significantly enhanced in the EPI/HED mismatch area (T(1/2) 36±8 min; P=0.008), consistent with inefficient vesicular storage and enhanced metabolic degradation. CONCLUSIONS: Regeneration of subcellular components of sympathetic nerve terminal function does not occur simultaneously. In the reinnervating transplanted heart, a region with normal catecholamine transport and vesicular storage is surrounded by a borderzone, where transport is already restored but vesicular storage remains inefficient, suggesting that vesicular storage is a more delicate mechanism. This observation may have implications for other pathologies involving cardiac autonomic innervation.
Asunto(s)
Catecolaminas , Trasplante de Corazón , Corazón/inervación , Imagen Molecular/métodos , Regeneración Nerviosa , Tomografía de Emisión de Positrones , Radiofármacos , Sistema Nervioso Simpático/diagnóstico por imagen , Adulto , Estudios de Casos y Controles , Catecolaminas/farmacocinética , Efedrina/análogos & derivados , Epinefrina/análogos & derivados , Femenino , Humanos , Masculino , Persona de Mediana Edad , Imagen de Perfusión Miocárdica , Fenilefrina , Valor Predictivo de las Pruebas , Terminales Presinápticos/diagnóstico por imagen , Terminales Presinápticos/metabolismo , Radiofármacos/farmacocinética , Sistema Nervioso Simpático/metabolismo , Sistema Nervioso Simpático/fisiopatología , Resultado del TratamientoRESUMEN
Defense mutualisms between social insects and microorganisms have been described in the literature. The present article describes the discovery of a Pseudallescheria boydii strain isolated from Nasutitermes sp. The microbial symbiont produces two antifungal metabolites: tyroscherin and N-methyltyroscherin, a compound not previously described in the literature. Methylation of tyroscherin has confirmed the structure of N-methyltyroscherin. Both compounds are effective antifungal agents with favorable selectivity indices for Candida albicans and Trichophyton rubrum.
Asunto(s)
Antifúngicos/aislamiento & purificación , Antifúngicos/farmacología , Isópteros/microbiología , Pseudallescheria/química , Animales , Antifúngicos/química , Aspergillus fumigatus/efectos de los fármacos , Candida albicans/efectos de los fármacos , Ensayos de Selección de Medicamentos Antitumorales , Epinefrina/análogos & derivados , Epinefrina/química , Escherichia coli/efectos de los fármacos , Alcoholes Grasos/química , Humanos , Células KB , Miconazol/farmacología , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Trichophyton/efectos de los fármacosRESUMEN
Alkylative ring-opening reactions of stable 2-substituted N-methylaziridinium ions proceeded with various alkyl- or arylmagnesium bromides in the presence of CuI to yield synthetically valuable and optically pure alkylated acyclic amines in a completely regio- and stereoselective manner. This was applied to a formal synthesis of the cytotoxic natural product tyroscherin.
Asunto(s)
Aziridinas/química , Epinefrina/análogos & derivados , Alcoholes Grasos/síntesis química , Alquilación , Epinefrina/síntesis química , Iones/química , Metilación , Estructura MolecularRESUMEN
Color Doppler imaging (CDI) was carried out to evaluate the effects of anti-glaucoma drugs on ophthalmic circulation using CDI-derived resistive index (RI) values. CDI was performed on nine Beagle dogs, and RI values were calculated for the medial long posterior ciliary artery before and after the administration of anti-glaucoma drugs. A significant increase in RI values was found after topical administration of levobunolol (p < 0.05) or dipivefrin (p < 0.05). Pilocarpine showed no effects on RI values after topical administration. The results suggest that some anti-glaucoma drugs could affect ophthalmic blood flow.
Asunto(s)
Arterias Ciliares/efectos de los fármacos , Arterias Ciliares/diagnóstico por imagen , Ojo/irrigación sanguínea , Glaucoma/tratamiento farmacológico , Ultrasonografía Doppler en Color/veterinaria , Resistencia Vascular , Agonistas Adrenérgicos/farmacología , Animales , Perros , Epinefrina/análogos & derivados , Epinefrina/uso terapéutico , Femenino , Levobunolol/uso terapéutico , Masculino , Fenómenos Fisiológicos Oculares , Pilocarpina/uso terapéuticoRESUMEN
Here we describe the concise syntheses of the 15 diastereomers and key analogs of the natural product tyroscherin. While systematic analysis of the analogs clearly demonstrated that the hydrocarbon tail is important for biological activity, structure-activity relationship studies of the complete tyroscherin diastereoarray revealed a surprisingly expansive stereochemical tolerance for the cytotoxic activity. Our results represent a departure from the tenet that biological activity is constrained to a narrow pharmacophore, and highlight the recently emerging appreciation for stereochemical flexibility in defining the essential structural elements of biologically active small molecules.
Asunto(s)
Antineoplásicos/síntesis química , Antineoplásicos/farmacología , Epinefrina/análogos & derivados , Alcoholes Grasos/síntesis química , Alcoholes Grasos/farmacología , Antineoplásicos/química , Neoplasias de la Mama/patología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Epinefrina/síntesis química , Epinefrina/química , Epinefrina/farmacología , Alcoholes Grasos/química , Femenino , Humanos , Concentración 50 Inhibidora , Estructura Molecular , Estereoisomerismo , Relación Estructura-ActividadRESUMEN
Color Doppler imaging (CDI) was carried out to evaluate the effects of anti-glaucoma drugs on ophthalmic circulation using CDI-derived resistive index (RI) values. CDI was performed on nine Beagle dogs, and RI values were calculated for the medial long posterior ciliary artery before and after the administration of anti-glaucoma drugs. A significant increase in RI values was found after topical administration of levobunolol (p < 0.05) or dipivefrin (p < 0.05). Pilocarpine showed no effects on RI values after topical administration. The results suggest that some anti-glaucoma drugs could affect ophthalmic blood flow.
Asunto(s)
Animales , Perros , Femenino , Masculino , Agonistas Adrenérgicos/farmacología , Arterias Ciliares/efectos de los fármacos , Epinefrina/análogos & derivados , Ojo/irrigación sanguínea , Glaucoma/tratamiento farmacológico , Levobunolol/uso terapéutico , Fenómenos Fisiológicos Oculares , Pilocarpina/uso terapéutico , Resistencia VascularRESUMEN
Short-step syntheses of (2RS,8R,10R)-YM-193221 (1) and tyroscherin (2), which are biologically active compounds isolated from Pseudallescheria sp., were accomplished in six and eight steps from L-tyrosine. The relative stereochemistry of natural YM-193221 was determined to be 8R*,10R*.
Asunto(s)
Productos Biológicos/química , Productos Biológicos/síntesis química , Epinefrina/análogos & derivados , Alcoholes Grasos/síntesis química , Cetonas/química , Cetonas/síntesis química , Fenetilaminas/química , Fenetilaminas/síntesis química , Pseudallescheria/química , Antifúngicos/síntesis química , Antifúngicos/química , Antineoplásicos/síntesis química , Epinefrina/síntesis químicaRESUMEN
The efficient synthesis and biological evaluation of both the reported and revised structures of tyroscherin have been achieved. Central to our synthesis is a cross metathesis reaction that generated the trans-olefin regioselectively. This synthetic strategy enabled the facile manipulation of tyroscherin stereochemistry, facilitating the generation of all 16 tyroscherin diastereomers and a photoactivatable tyroscherin-based affinity probe for future mode of action studies.