•Croton is a large genus of Euphorbiaceae used medicinally in many tropical countries of the new and old worlds.•Chemical analyses and antiproliferative activity of extracts of Croton sphaerogynus ...were investigated.•Important diterpenes, previously recognized as possessing antitumor activity, were detected.•The results suggest promising use of extracts and substances of C. sphaerogynus in the control of malignant processes.
Several Croton species have been used in traditional medicine and contain substances active against cancer, such as diterpenoids and alkaloids. Croton sphaerogynus is a shrub from the Atlantic Rain Forest in southeastern Brazil. The main goal of this study was to characterize the main constituents of the leaf extracts of C. sphaerogynus and evaluate their in vitro antiproliferative activity against tumor cell lines. Hexane, dichloromethane and methanol extracts of leaves were analyzed by GC/MS and evaluated for their in vitro antiproliferative activity on the cell lines 786-0 (kidney), HT-29 (colon), K562 (leukemia), NCI-ADR/RES (drug resistant ovary), NCI-H460 (lung), MCF-7 (mammary), PC-3 (prostate), OVCAR-3 (ovary), U251 (glioma) and UACC-62 (melanoma). Relevant constituents in dichloromethane and hexane extracts were abietane, podocarpane and clerodane type furano diterpenes. Dicloromethane and hexane extracts exhibited activity against NCI-H460 (GI50 0.26μg/mL and 0.33μg/mL, respectively) and K562 (GI50 0.60μg/mL and <0.25μg/mL, respectively). Taking into account all cell lines tested, the dichloromethane extract was shown to have higher activity (mean log GI50 0.86) than hexane and methanol extracts (mean log GI50 1.26 and 1.49, respectively). The antiproliferative activity observed in the present work is probably accounted for by the abietane and/or podocarpane diterpenes.
The Simons Observatory (SO) is an upcoming polarization-sensitive cosmic microwave background experiment on the Cerro Toco Plateau (Chile) with large overlap with other optical and infrared surveys ...(e.g., DESI, LSST, HSC). To enable the readout of
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(10,000) detectors in each of the four telescopes of SO, we will employ the microwave SQUID multiplexing technology. With a targeted multiplexing factor of
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(1000), microwave SQUID multiplexing has never been deployed on the scale needed for SO. Here we present the design of the cryogenic coaxial cable and RF component chain that connects room temperature readout electronics to superconducting resonators that are coupled to transition edge sensor bolometers operating at sub-Kelvin temperatures. We describe design considerations including cryogenic RF component selection, system linearity, noise, and thermal power dissipation.
The cattle tick Rhipicephalus microplus is widely distributed in tropical and subtropical regions, causing high economic impact on cattle production. The control of tick infestations is regarded ...worldwide as critical and has been based on the use of organophosphates, synthetic pyretroids, amitraz and recently ivermectin and fipronil. The present study reports the analysis by gas chromatography/mass spectrometry of the constituents of leaf extracts of Croton sphaerogynus and results of acaricidal activity against the cattle tick R. microplus. The larval package test using the serial dilutions 0.625%, 1.25%, 2.5%, 5.0%, 10.0% and 20.0% (v/v) gave mortality rates 2.25%, 8.26%, 8.81%, 24.80%, 83.66% and 99.32%, respectively. Relevant constituents identified were abietanes, podocarpenes and clerodane type furano diterpenes. The present work may represent a possibility of attainment of natural substances useful for the control of R. microplus.
Croton sphaerogynus is a shrub from the Atlantic Rain Forest in southeastern Brazil. A lyophilized crude EtOH extract from leaves of C. sphaerogynus, obtained by maceration at room temperature (seven ...days), was suspended in methanol and partitioned with hexane. The purified MeOH phase was fractionated over Sephadex LH-20 yielding five fractions (F1–F5) containing flavonoids, as characterized by HPLC-DAD and HPLC-MS analyses. The antiproliferative activity of the crude EtOH extract, MeOH and hexane phases, and fractions F1–F5 was evaluated on in vitro cell lines NCI-H460 (nonsmall cell lung), MCF-7 (breast cancer), and U251 (glioma). The MeOH phase showed activity (mean log GI50 0.54) higher than the hexane phase and EtOH extract (mean log GI50 1.13 and 1.19, resp.). F1 exhibited activity against NCI-H460 (nonsmall cell lung) (GI50 1.2 μg/mL), which could be accounted for the presence of flavonoids and/or diterpenes. F4 showed moderate activity (mean log GI50 1.05), while F5 showed weak activity (mean log GI50 1.36). It is suggested that the antiproliferative activity of the crude EtOH extract and MeOH phase is accounted for a synergistic combination of flavonoids and diterpenes.
For decades, palynologists working in tropical South America are using the genus Podocarpus as a climate indicator although without referring to any modern data concerning its distribution and ...limiting factors. With the aim to characterize the modern and past distribution of the southern conifer Podocarpus in Brazil and to obtain new information on the distribution of the Atlantic rainforest during the Quaternary, we examined herbarium data to locate the populations of three Brazilian endemic Podocarpus species: P. sellowii, P. lambertii, and P. brasiliensis, and extracted DNA from fresh leaves from 26 populations. Our conclusions are drawn in the light of the combination of these three disciplines: botany, palynology, and genetics. We find that the modern distribution of endemic Podocarpus populations shows that they are widely dispersed in eastern Brazil, from north to south and reveals that the expansion of Podocarpus recorded in single Amazonian pollen records may have come from either western or eastern populations. Genetic analysis enabled us to delimit regional expansion: between 5° and 15° S grouping northern and central populations of P. sellowii expanded c. 16,000 years ago; between 15° and 23° S populations of either P. lambertii or sellowii expanded at different times since at least the last glaciation; and between 23° and 30° S, P. lambertii appeared during the recent expansion of the Araucaria forest. The combination of botany, pollen, and molecular analysis proved to be a rapid tool for inferring distribution borders for sparse populations and their regional evolution within tropical ecosystems. Today the refugia of rainforest communities we identified are crucial hotspots to allow the Atlantic forest to survive under unfavourable climatic conditions and, as such, offer the only possible opportunity for this type of forest to expand in the event of a future climate change.
During embryogenesis and seed filling, developing seeds are metabolically highly active, while at the desiccation stage of tolerant seeds a decreased metabolism is expected. Seeds of Poincianella ...pluviosa present an extensive maturation cycle (11 months), longer than seed storability at room temperature (8 months). The metabolic profile of these seeds was characterized during maturation and drying, focusing in their role on seed behavior after shedding. Distinct responses of the embryonic axes and cotyledons to drying were observed depending on the developmental stage. Low proportions of tricarboxylic acids intermediaries until maturity indicated a low respiratory metabolism prior to the desiccation stage. Changes in shikimate, 4-coumarate, and quinate proportions suggest a metabolic shift towards the synthesis of chlorogenate isomers, found in high proportions in dispersed seeds. High proportions of lactate and glycerol were observed in immature seeds after artificial drying, but also in naturally dried axes of dispersed seeds. This suggests an active metabolism prior to drying and an osmotic stress under hypoxia, mechanisms that were never described before in desiccation-tolerant seeds. The results indicated that P. pluviosa seeds are dispersed with an incomplete metabolic switch-off, which can be related to their short lifespan.
Resumo: Durante a embriogênese e deposição de reservas, sementes em desenvolvimento apresentam metabolismo fortemente ativo, enquanto na fase de dessecação de sementes tolerantes é esperado metabolismo reduzido. Sementes de Poincianella pluviosa apresentam um ciclo de maturação extenso (11 meses), maior que sua longevidade à temperatura ambiente (8 meses). O perfil metabólico dessas sementes foi caracterizado durante a maturação e secagem, enfocando seus papéis no comportamento das sementes após dispersão. Respostas distintas de eixos embrionários e cotilédones à secagem foram observadas dependendo do estádio de desenvolvimento. Baixas proporções de intermediários de ácidos tricarboxílicos até a maturidade indicaram um baixo metabolismo respiratório anterior à fase de dessecação. Mudanças nas proporções de chiquimato, 4-cumarato e quinato sugerem uma alteração metabólica em direção a síntese de isômeros clorogenatos, encontrados em altas proporções em sementes dispersas. Altas proporções de lactato e glicerol foram observadas em sementes imaturas após secagem artificial, mas também em eixos naturalmente secos de sementes dispersas. Isso sugere um metabolismo ativo anterior à dessecação e um estresse osmótico sob hipóxia, mecanismos nunca descritos antes em sementes tolerantes à dessecação. Nossos resultados indicam que sementes de P. pluviosa podem ser dispersas com um desligamento metabólico incompleto, que pode estar relacionado à sua baixa longevidade.
The Advanced ACTPol (AdvACT) upgrade to the Atacama Cosmology Telescope (ACT) features arrays of aluminum manganese transition-edge sensors (TESes) optimized for ground-based observations of the ...cosmic microwave background (CMB). Array testing shows highly responsive detectors with anticipated in-band noise performance under optical loading. We report on TES parameters measured with impedance data taken on a subset of TESes. We then compare modeled noise spectral densities to measurements. We find excess noise at frequencies around 100 Hz, nearly outside of the signal band of CMB measurements. In addition, we describe full-array noise measurements in the laboratory and in the field for two new AdvACT mid-frequency arrays, sensitive at bands centered on 90 and 150 GHz, and data for the high-frequency array (150/230 GHz) as deployed.
The Simons Observatory is building both large (6 m) and small (0.5 m) aperture telescopes in the Atacama Desert in Chile to observe the cosmic microwave background CMB radiation with unprecedented ...sensitivity. Simons Observatory telescopes in total will use over 60,000 transition edge sensor (TES) detectors spanning center frequencies between 27 and 285 GHz and operating near 100 mK. TES devices have been fabricated for the Simons Observatory by NIST, Berkeley, and HYPRES/SeeQC corporation. Iterations of these devices have been tested cryogenically in order to inform the fabrication of further devices, which will culminate in the final TES designs to be deployed in the field. The detailed design specifications have been independently iterated at each fabrication facility for particular detector frequencies. We present test results for prototype devices, with emphasis on NIST high frequency detectors. A dilution refrigerator was used to achieve the required temperatures. Measurements were taken both with 4-lead resistance measurements and with a time-domain Superconducting Quantum Interference Device (SQUID) multiplexer system. The SQUID readout measurements include analysis of current versus voltage (IV) curves at various temperatures, square wave bias step measurements, and detector noise measurements. Normal resistance, superconducting critical temperature, saturation power, thermal and natural time constants, and thermal properties of the devices are extracted from these measurements.
The detection of marker compounds is a necessary step for chemical characterization and standardization of propolis. A thin-layer chromatography procedure is described for the detection of allyl ...3-prenylcinnamate, a volatile marker of Brazilian green propolis. The powdered sample is heated inside a petri dish and the material condensed on the dish cap is chromatographed on silica gel plates. The visualization may be done by spraying the plates with a solution of sodium fluorescein or a solution of sulphuric acid vanillin reagent.
The cuticular waxes of leaves of Coffea arabica cv. ‘Catuaí Vermelho’, C. arabica cv. ‘Obatã’, Coffea canephora cv. ‘Apoatã’, Coffea racemosa and two hybrids between C. arabica and C. racemosa were ...extracted by rapid washing of the surface with chloroform. The waxes were fractionated by thin layer chromatography over silicagel. The fractions of the constituent classes were characterized by infrared spectroscopy and the distribution of the homologs of the n-alkanes and n-primary alcohols was determined by GC/MS and GC/FID. Among the samples analyzed, leaves of C. racemosa have the highest content of foliar wax (22.9 μg cm−2). Most samples contain either n-alkanes (C. canephora and C. racemosa) or n-primary alcohols (C. arabica) as predominant wax constituents. The distribution of n-alkanes allowed the distinction of C. racemosa from the other samples; the distribution of alcohols allowed the distinction of the three species. The two hybrids have waxes similar to the wax of C. arabica.
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