RESUMEN
Importance: Immune checkpoint inhibitors (ICIs) have yielded conflicting results in hepatocellular carcinoma (HCC). The overall effect of ICIs compared with standard therapies in unresectable HCC requires more research. Objective: To estimate the efficacy and safety associated with ICIs compared with standard therapies in patients with unresectable HCC. Data Sources: PubMed, Cochrane Library, Web of Science, Latin American and Caribbean Health Sciences Literature, and American Society of Clinical Oncology and European Society of Medical Oncology meeting proceedings were systematically searched. Reference lists from studies selected by electronic searching were manually searched to identify additional relevant studies. The search included literature published or presented from February 2010 to February 2020. Study Selection: From December 2019 to February 2020, independent reviewers evaluated each database, scanning the title, abstract, and keywords of every record retrieved. Full articles were further assessed if the information given suggested that the study was a randomized clinical trial (RCT) comparing ICIs vs standard therapies in the treatment of unresectable HCC. Data Extraction and Synthesis: The full text of the resulting studies and extracted data were reviewed independently according to PRISMA guidelines. Summary hazard ratios (HRs) of overall survival (OS) and progression-free survival (PFS) were calculated by a random-effects model. The likelihood of ICIs being associated with overall response rate (ORR) and treatment-related adverse events (TRAEs) was expressed by odds ratios (ORs) using a random-effects model. Main Outcomes and Measures: The main outcomes were OS, PFS, ORR, and TRAEs. Results: Of 1836 studies yielded by the search, 3 were retained, totaling 1657 patients (985 treated with ICIs vs 672 receiving standard treatment). Two studies evaluated ICIs as monotherapy, and 1 study investigated the combination of ICIs with bevacizumab. Compared with standard therapies (sorafenib in first-line therapy or placebo in second-line therapy), ICIs were associated with significantly improved OS (HR, 0.75; 95% CI, 0.62-0.92; P = .006), PFS (HR, 0.74; 95% CI, 0.56-0.97; P = .03), and ORR (OR, 2.82; 95% CI 2.02-3.93; P < .001). The probability of grade 3 or 4 TRAEs was lower with ICIs than with sorafenib (OR, 0.44; 95% CI, 0.20-0.96; P = .04). Conclusions and Relevance: This meta-analysis found superior efficacy and safety associated with ICIs compared with standard therapies and highlights the survival benefit associated with the combination of antiangiogenic therapy with ICIs in first-line systemic therapy of unresectable HCC.
Asunto(s)
Carcinoma Hepatocelular/tratamiento farmacológico , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/epidemiología , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Inmunoterapia/efectos adversos , Neoplasias Hepáticas/tratamiento farmacológico , Carcinoma Hepatocelular/mortalidad , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/etiología , Humanos , Neoplasias Hepáticas/mortalidad , Supervivencia sin Progresión , Ensayos Clínicos Controlados Aleatorios como Asunto , Sorafenib/uso terapéutico , Resultado del TratamientoRESUMEN
In this practice-oriented program review, a mindfulness-based, trauma-informed parent intervention, called Safe, Secure and Loved™ (SSL), designed to strengthen nurturing parenting and children's resilience, was implemented in an underserved Latino community. Across 5 years, a volunteer community workforce of promotoras transformed an academic-community research partnership into a community-led program partnership and established sustainable agency parent education programming. To better understand this transformation, we used a modified implementation science (IS) framework to structure interviews from members of the academic-community research partnership. Findings suggest that the commitment and cultural expertise of the volunteer community workforce acted as the major leadership drivers to create the community-led program partnership. Employing mindfulness-based, trauma-informed parent education designed to promote nurturing parenting and children's resilience may be an effective training model to engage and mobilize a volunteer community workforce from an underserved community.
Asunto(s)
Investigación Participativa Basada en la Comunidad , Hispánicos o Latinos , Responsabilidad Parental , Padres/educación , Voluntarios , Recursos Humanos , Preescolar , Participación de la Comunidad , Femenino , Humanos , Ciencia de la Implementación , Lactante , Recién Nacido , Masculino , Atención Plena , Resiliencia Psicológica , Bienestar Social , Poblaciones VulnerablesRESUMEN
El presente trabajo de titulación, compara y analiza similitudes y diferencias entre el modelo sanitario actual y el anterior. La metodología usada para este propósito, fue una revisión bibliográfica de ambos modelos, se empleó como instrumentos el análisis de contenido y una matriz de vaciado para mostrar de manera resumida los hallazgos. El nuevo modelo, avanza en todas las características analizadas a una salud más humanitaria y moderna, convergiendo a los tres principios irrenunciables de este según la OPS: centrado en el usuario, integral y continuo; es decir, se centra en la persona y su entorno, a diferencia del modelo biomédico que se preocupaba más de la enfermedad, abarca desde la promoción hasta la rehabilitación e incluye todo el ciclo vital, evitando lagunas en la atención del paciente. Además, el énfasis en la promoción y prevención son claves para retrasar la aparición de la enfermedad y tener una mejor calidad de vida en la vejez. El modelo sanitario implementado, recoge las recomendaciones de la OPS y OMS y los avances en Canadá e Inglaterra en medicina familiar, fortaleciendo la Atención Primaria en Salud acordada en la Conferencia de Alma-Ata en 1978.
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Humanos , Atención Integral de Salud , Chile , Salud HolísticaRESUMEN
Trastuzumab emtansina (T-DM1) is an antibody-drug conjugate directed against the HER2 for the treatment of HER2+ mestastatic breast cancer (MBC), who has previously received trastuzumab plus a taxane. According to the results of the EMILIA trial versus lapatinib plus capecitabine T-DM1 shows an improvement in progression-free survival (PFS) and the overall survival (OS). It has a favorable profile reducing the incidence of grade 3-4 adverse reactions such as hand-foot syndrome and diarrhea. On the contrary increases significantly severe thrombocytopenia; bleeding risk and liver function should also be monitored. With the current import price T-DM1 has a cost per QALY of over 120,000 Euros. The price of the drug for the Spanish NHS has not yet been established. Drug cost would be the key factor in the sensitivity analysis and a 50% reduction in the price of the drug would place it close to the threshold of cost-effectiveness usually considered in our midst. According to the budget impact model used, a maximum of 1,218 patients / year and the budgetary impact throughout the Spanish state would be at 70,490,850 Euros. In the initial analysis no advantage was found for T-DM1 in those patients without visceral involvement. Although a subsequent re-analysis of the results of PFS in which the definition of visceral involvement was specified a significant benefit was shown in this subgroup. We believe that this approach introduces a high degree of uncertainty, which does not guarantee the benefit achieved for this subgroup of patients (AU)
T-DM1 es un conjugado anticuerpo-fármaco dirigido contra el HER2 para el tratamiento del cáncer de mama metastásico (CMM) HER2 +, que ha recibido previamente trastuzumab más un taxano. De acuerdo con los resultados del ensayo EMILIA frente a lapatinib más capecitabina T-DM1 muestra una mejora en la supervivencia libre de progresión (SLP) y la supervivencia global (SG). Tiene un perfil favorable reducir la incidencia de reacciones adversas grado 3-4 tales como el síndrome mano-pie y la diarrea. Sin embargo, aumenta significativamente el riesgo de trombocitopenia grave y debe monitorizarse el riesgo de hemorragia y la función hepática. Con el precio de importación actual T-DM1 tiene un coste por AVAC de más de 120.000 Euros. El precio del fármaco para el Sistema Nacional de Salud en España aún no ha sido establecido. El precio del fármaco sería el factor clave en el análisis de sensibilidad y una reducción del 50% en el precio lo situaría cerca del umbral de coste-efectividad generalmente considerada en nuestro medio como aceptable. De acuerdo con el modelo de impacto presupuestario utilizado, se trataría un máximo de 1.218 pacientes / año y el impacto presupuestario de todo el estado español estaría entorno a 70.490.850 Euros para este volumen de pacientes. En el análisis inicial no se encontró ninguna ventaja para T-DM1 en aquellos pacientes sin afectación visceral. Aunque un re-análisis posterior de los resultados de SLP en el que se especifica la definición de la afectación visceral se muestra un beneficio significativo en este subgrupo. Creemos que este enfoque presenta un alto grado de incertidumbre, y no garantiza el beneficio logrado para este subgrupo de pacientes (AU)
Asunto(s)
Humanos , Neoplasias de la Mama/tratamiento farmacológico , Genes erbB-2 , Anticuerpos Monoclonales/uso terapéutico , Antineoplásicos/uso terapéutico , Terapia Biológica , 50303RESUMEN
19-OH-(-)-eburnamonine 1 is a new indole alkaloid isolated from Bonafusia macrocalyx. A natural derivative from (-)-eburnamonine for which absolute configuration and conformation has been determined by making use of residual dipolar couplings enhanced NMR, circular dichroism spectra and high-level computations.
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Resonancia Magnética Nuclear Biomolecular/métodos , Alcaloides de la Vinca/química , Modelos Moleculares , Conformación MolecularRESUMEN
Treatment of diseases such as African sleeping sickness and leishmaniasis often depends on relatively expensive or toxic drugs, and resistance to current chemotherapeutics is an issue in treating these diseases and malaria. In this study, a new semi-synthetic berberine analogue, 5,6-didehydro-8,8-diethyl-13-oxodihydroberberine chloride (1), showed nanomolar level potency against in vitro models of leishmaniasis, malaria, and trypanosomiasis as well as activity in an in vivo visceral leishmaniasis model. Since the synthetic starting material, berberine hemisulfate, is inexpensive, 8,8-dialkyl-substituted analogues of berberine may lead to a new class of affordable antiprotozoal compounds.
Asunto(s)
Antiprotozoarios/farmacología , Antiprotozoarios/uso terapéutico , Berberina/farmacología , Parásitos/efectos de los fármacos , Infecciones por Protozoos/tratamiento farmacológico , Animales , Antiprotozoarios/síntesis química , Antiprotozoarios/química , Berberina/síntesis química , Berberina/química , Berberina/uso terapéutico , Chlorocebus aethiops , Modelos Animales de Enfermedad , Concentración 50 Inhibidora , Leishmania/efectos de los fármacos , Leishmaniasis/tratamiento farmacológico , Malaria/tratamiento farmacológico , Ratones , Modelos Moleculares , Plasmodium falciparum/efectos de los fármacos , Trypanosoma brucei brucei/efectos de los fármacos , Tripanosomiasis/tratamiento farmacológico , Células VeroRESUMEN
Greater left than right reductions of P3 amplitude in schizophrenia during auditory oddball tasks have been interpreted as evidence of left-lateralized dysfunction. However, the contributions of methodological factors (response mode, stimulus properties, recording reference), which affect event-related potential (ERP) topographies, remain unclear. We recorded 31-channel ERPs from 23 schizophrenic patients and 23 age- and gender-matched healthy controls (all right-handed) during tonal and phonetic oddball tasks, varying response mode (left press, right press, silent count) within subjects. Performance accuracy was high in both groups but patients were slower. ERP generator patterns were summarized by temporal Principal Components Analysis (PCA; unrestricted Varimax) from reference-free current source density (CSD; spherical spline Laplacians) waveforms, which sharpen scalp topographies. CSD represents the magnitude of the radial current flow entering (source) and leaving (sink) the scalp. Both patients and controls showed asymmetric frontolateral and parietotemporal N2 sinks peaking at 240 ms and asymmetric parietal P3 sources (355 ms) for targets (tonal R > L, phonetic L > R), but frontocentral N2 sinks and parietal P3 sources were bilaterally reduced in patients. A response-related midfrontal sink and accompanying centroparietal source (560 ms) were highly comparable across groups. However, a superimposed left temporal source was larger for silent count compared to button press, and this difference was smaller in patients. In both groups, left or right press produced opposite, region-specific asymmetries originating from central sites, modulating the N2/P3 complex. The results suggest bilaterally reduced neural generators of N2 and P3 in schizophrenia during auditory oddball tasks, but both groups showed comparable topographic effects of task and response mode. However, additional working memory demands during silent count may partially overlap in time the generation of the N2/P3 complex and differentially affect the asymmetry of P3 subcomponents, particularly when employing conventional ERP measures.
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Electroencefalografía , Potenciales Relacionados con Evento P300/fisiología , Lateralidad Funcional/fisiología , Esquizofrenia/fisiopatología , Estimulación Acústica/métodos , Adolescente , Adulto , Análisis de Varianza , Percepción Auditiva/fisiología , Estudios de Casos y Controles , Pruebas de Audición Dicótica , Potenciales Evocados Auditivos/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Fonética , Escalas de Valoración PsiquiátricaRESUMEN
We have determined the structure of a PNA-DNA duplex to 1.7 A resolution by multiple-wavelength anomalous diffraction phasing method on a zinc derivative. This structure represents the first high-resolution 3D view of a hybrid duplex containing a contiguous chiral PNA strand with complete gamma-backbone modification ("gammaPNA"). Unlike the achiral counterpart, which adopts a random-fold, this particular gammaPNA is already preorganized into a right-handed helix as a single strand. The new structure illustrates the unique characteristics of this modified PNA, possessing conformational flexibility while maintaining sufficient structural integrity to ultimately adopt the preferred P-helical conformation upon hybridization with DNA. The unusual structural adaptability found in the gammaPNA strand is crucial for enabling the accommodation of backbone modifications while constraining conformational states. In conjunction with NMR analysis characterizing the structures and substructures of the individual building blocks, these results provide unprecedented insights into how this new class of chiral gammaPNA is preorganized and stabilized, before and after hybridization with a cDNA strand. Such knowledge is crucial for the future design and development of PNA for applications in biology, biotechnology, and medicine.
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ADN/química , Ácidos Nucleicos de Péptidos/química , Resonancia Magnética Nuclear Biomolecular , Conformación de Ácido Nucleico , TermodinámicaRESUMEN
Examining visual word recognition memory (WRM) with nose-referenced EEGs, we reported a preserved ERP 'old-new effect' (enhanced parietal positivity 300-800 ms to correctly-recognized repeated items) in schizophrenia ([Kayser, J., Bruder, G.E., Friedman, D., Tenke, C.E., Amador, X.F., Clark, S.C., Malaspina, D., Gorman, J.M., 1999. Brain event-related potentials (ERPs) in schizophrenia during a word recognition memory task. Int. J. Psychophysiol. 34(3), 249-265.]). However, patients showed reduced early negative potentials (N1, N2) and poorer WRM. Because group differences in neuronal generator patterns (i.e., sink-source orientation) may be masked by choice of EEG recording reference, the current study combined surface Laplacians and principal components analysis (PCA) to clarify ERP component topography and polarity and to disentangle stimulus- and response-related contributions. To investigate the impact of stimulus modality, 31-channel ERPs were recorded from 20 schizophrenic patients (15 male) and 20 age-, gender-, and handedness-matched healthy adults during parallel visual and auditory continuous WRM tasks. Stimulus- and response-locked reference-free current source densities (spherical splines) were submitted to unrestricted Varimax-PCA to identify and measure neuronal generator patterns underlying ERPs. Poorer (78.2+/-18.7% vs. 87.8+/-11.3% correct) and slower (958+/-226 vs. 773+/-206 ms) performance in patients was accompanied by reduced stimulus-related left-parietal P3 sources (150 ms pre-response) and vertex N2 sinks (both overall and old/new effects) but modality-specific N1 sinks were not significantly reduced. A distinct mid-frontal sink 50-ms post-response was markedly attenuated in patients. Reductions were more robust for auditory stimuli. However, patients showed increased lateral-frontotemporal sinks (T7 maximum) concurrent with auditory P3 sources. Electrophysiologic correlates of WRM deficits in schizophrenia suggest functional impairments of posterior cortex (stimulus representation) and anterior cingulate (stimulus categorization, response monitoring), primarily affecting memory for spoken words.
Asunto(s)
Percepción Auditiva/fisiología , Variación Contingente Negativa/fisiología , Reconocimiento Visual de Modelos/fisiología , Reconocimiento en Psicología/fisiología , Esquizofrenia/fisiopatología , Vocabulario , Estimulación Acústica/métodos , Adulto , Análisis de Varianza , Mapeo Encefálico , Estudios de Casos y Controles , Electroencefalografía/métodos , Femenino , Humanos , Masculino , Estimulación Luminosa/métodos , Análisis de Componente Principal , Psicofísica/métodos , Tiempo de Reacción/fisiología , Adulto JovenRESUMEN
The chemical study of Heterothalamus alienus gave rutin, spathulenol (1), (1R,7S)-germacra-4(15),5,10(14)-trien-1beta-ol (2), sakuranetin (3), padmatin 3-acetate (4), (2R,3R)-dihydroquercetin-7,3',4'-trimethyl ether (5), (2R,3R)-dihydroquercetin-7,4'-dimethyl ether (6), (2R,3R)-3-acetoxy-5,7,4'-trihydroxyflavanone (7), as the main components of an antifungal extract of the aerial parts of the plant. Compound 2 showed moderate activity, with Epidermophyton floccosum being the most susceptible species (MIC = 100 microg/mL); compound 3 showed the best antifungal behavior having a broad spectrum of action and the lowest MICs. This flavanone along with flavanolol 5 showed very good activity against standardized (MIC = 31.2 microg/mL) as well as clinical isolates of Trichophyton rubrum and T. mentagrophytes (MIC ranges 31.2-62.5 microg/mL and 31.2-125 microg/mL, respectively) and demonstrated not only fungistatic but also fungicide properties. Flavanolol 6 was active against all the dermatophytes tested with MICs of 62.5-250 microg/mL. Rutin, spathulenol (1) and the 3-acetylated flavanones 4 and 7 were inactive or marginally active against the fungal panel.
Asunto(s)
Antifúngicos/farmacología , Asteraceae/química , Extractos Vegetales/farmacología , Antifúngicos/química , Epidermophyton/efectos de los fármacos , Flavanonas/química , Flavanonas/farmacología , Flavonoides/química , Flavonoides/farmacología , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Extractos Vegetales/química , Sesquiterpenos/química , Sesquiterpenos/farmacología , Trichophyton/efectos de los fármacosRESUMEN
Seven new withanolides (1-7) were isolated from the aerial parts of Jaborosa caulescens var. caulescens and Jaborosa caulescens var. bipinnatifida. Three of the new compounds are related to jaborosalactones R, S, and T with a delta-lactone side chain and a hemiketal (or ketal) ring formed between a 21-hydroxyl and a 12-ketone (1-3). Compounds 4-7 are trechonolide-type withanolides with a gamma-lactone side chain and a hemiketal (or ketal) ring formed between a 22-hydroxyl and a 12-ketone. Compounds 4 and 5 also contain a hydroxyl group at C-21. Compounds 1, 2, and 7 showed selective phytotoxicity toward monocotyledonous and dicotyledonous species.
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Ergosterol , Herbicidas , Plantas Medicinales/química , Solanaceae/química , Argentina , Avena/efectos de los fármacos , Ergosterol/análogos & derivados , Ergosterol/química , Ergosterol/aislamiento & purificación , Ergosterol/farmacología , Germinación/efectos de los fármacos , Herbicidas/química , Herbicidas/aislamiento & purificación , Herbicidas/farmacología , Lactuca/efectos de los fármacos , Estructura Molecular , Plantones/efectos de los fármacosRESUMEN
The peroxyl radical scavenging activity of a dry methanol extract of Misodendrum punctulatum was determined by means of luminol-enhanced chemiluminescence assay, allowing to calculate the total reactive antioxidant potential (TRAP) index equal to 239 +/- 26 microm, expressed in Trolox equivalents. The flavan-3-ol catechin (1) and the phenylbutanone derivative myzodendrone (2) were identified through assay-guided fractionation as active metabolites present in the extract, and their structures were elucidated by chemical and spectroscopic analysis. Three other structurally related synthetic phenols, dehydrozingerone (3), zingerone (4) and myzodendrone aglycone (5), were also analysed using this method. Compounds 1 and 2 were highly effective as free radical scavengers (TRAP = 1257 microm and 1018 microm, respectively) when compared with Trolox (TRAP = 144 microm), used as a standard. Compounds 3 and 5 were also active showing TRAP values of 229 microm and 219 microm, respectively, similarly to that observed for the dry extract. On the other hand, 4 was inactive. Catechin (1) also reduced the production of thiobarbituric acid reactive substances (TBARS) in rat liver homogenates, with IC50 = 26 microg/mL, superior to that obtained for Trolox, IC50 = 73 microg/mL. Compounds 2 and 5 showed IC50 values > 1000 microg/mL, while no activity could be observed for 3, 4, or the extract.
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Catequina/farmacología , Depuradores de Radicales Libres/farmacología , Glucósidos/farmacología , Fenilpropionatos/farmacología , Extractos Vegetales/química , Animales , Catequina/química , Depuradores de Radicales Libres/química , Glucósidos/química , Peroxidación de Lípido/efectos de los fármacos , Masculino , Peróxidos/metabolismo , Fenoles/química , Fenoles/farmacología , Fenilpropionatos/química , Extractos Vegetales/farmacología , Ratas , Ratas Wistar , Relación Estructura-ActividadRESUMEN
Antioxidant-guided fractionation of Mammea americana L. seeds resulted in the identification of three new isoprenylated coumarins, mammea B/BA hydroxycyclo F (1), mammea E/BC (2), and mammea E/BD (3). In addition, twelve known isoprenylated coumarins, mammea A/AA (4), mammea A/AA cyclo D (5), mammea A/AA cyclo F (6), mammea A/AC cyclo D (7), mammea A/AD cyclo D (8), mammea B/BA (9), mammea B/BA cyclo F (10), mammea B/BB (11), mammea B/BC (12), mammea B/BD (13), mammea E/BA (14), and mammea E/BB (15), as well as two known flavanols, (+)-catechin (16) and (-)-epicatechin (17) were identified. The fifteen isoprenylated coumarins were screened for their cytotoxicity in the SW-480, HT-29, and HCT-116 human colon cancer cell lines and antioxidant capacities in the DPPH (1,1-diphenyl-2-picrylhydrazyl) free-radical assay. Compounds 1 - 15 exhibited significant cytotoxic activities in the SW-480, HT-29, and HCT-116 human colon cancer cell lines (IC50 ranges 13.9 - 88.1, 11.2 - 85.3, and 10.7 - 76.7 microM, in the three cell lines, respectively) at concentrations comparable to 5-fluorouracil (IC50 = 53.0, 46.1, and 45.1 microM), a drug frequently used for human colon cancer treatment. Compounds 2 - 4, 9, and 11 - 15 displayed high antioxidant activity in the DPPH assay (IC50 range 86 - 135 microM), compounds 1, 5 - 8, and 10, however, had no antioxidant activity (IC50 > 200 microg/mL) in the DPPH assay. The results of these assays were used to study the structure-activity relationships for this class of compounds. In the SW-480 cell line, the three new coumarins, 1 - 3, also exhibited dose-dependent increases in sub-diploid cells by flow cytometry, indicating that they induce apoptosis.
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Antineoplásicos Fitogénicos/farmacología , Antioxidantes/farmacología , Mammea , Fitoterapia , Extractos Vegetales/farmacología , Antineoplásicos Fitogénicos/administración & dosificación , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/uso terapéutico , Antioxidantes/administración & dosificación , Antioxidantes/química , Antioxidantes/uso terapéutico , Compuestos de Bifenilo , Línea Celular Tumoral/efectos de los fármacos , Cumarinas/administración & dosificación , Cumarinas/química , Cumarinas/farmacología , Cumarinas/uso terapéutico , Citometría de Flujo , Frutas , Humanos , Concentración 50 Inhibidora , Picratos/química , Extractos Vegetales/administración & dosificación , Extractos Vegetales/química , Extractos Vegetales/uso terapéutico , Prenilación de Proteína , Relación Estructura-ActividadRESUMEN
The MeOH extract of aerial parts of Flourensia riparia Grisebach (Asteraceae) afforded a sesquiterpene lactone, 4beta-hydroxy-4,10alpha-dimethyl-7alphaH,8alphaH-eudesman-11-ene-8,12-olide, together with septuplinolide, its isomer at positions C-5 and C-10. In addition, known flavonoids, p-hydroxyacetophenone derivatives, carabrone and isoalantolactone were identified. Three known flavonoids and a benzofuran were isolated from Flourensia campestris Wedd.
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Asteraceae/química , Asteraceae/clasificación , Benzofuranos/aislamiento & purificación , Flavonoides/aislamiento & purificación , Espectroscopía de Resonancia Magnética , Conformación Molecular , Estructura Molecular , Componentes Aéreos de las Plantas/química , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificaciónRESUMEN
Six new withanolides (1-6) were isolated from the aerial parts of Jaborosa bergii plants and characterized by spectroscopic methods (1D and 2D NMR, MS). Five of the new compounds presented a novel norbornane-type structure in ring D of the steroid nucleus (1-5), resulting from a carbon-carbon bond between C-15 and C-21. The sixth withanolide isolated was the 5alpha-chloro-6beta-hydroxy analogue (6) of 2,3-dehydrojaborosalactol M (7), previously isolated from this plant. Compound 1 showed selective phytotoxicity toward monocotiledoneous and dicotiledoneous species.
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Ergosterol , Plantas Medicinales/química , Solanaceae/química , Argentina , Relación Dosis-Respuesta a Droga , Ergosterol/análogos & derivados , Ergosterol/química , Ergosterol/aislamiento & purificación , Ergosterol/farmacología , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , EstereoisomerismoRESUMEN
Thirty-seven naturally occurring withanolides (1-37), previously isolated in our laboratories, were evaluated for their potential to induce quinone reductase with cultured murine hepatoma cells (Hepa 1c1c7). Spiranoid (29, 32) and 18-functionalized withanolides (2-5, 7-9, 24) were found to be potent inducers of the enzyme, while 5alpha-substituted derivatives exhibited weak activity. Preliminary studies were performed with compound 29 to evaluate enzyme-inducing capacity in multiple organ sites of BALB/c mice. Significant induction was observed in liver and colon, but not in lung, stomach, or mammary gland.