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1.
An Acad Bras Cienc ; 93(suppl 4): e20200591, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34730615

RESUMEN

We investigated ten honey samples from the Discovery Coast of Bahia, Brazil, to confirm the three predominant flower sources indicated by regional beekeepers: Brazilian peppertree - Schinus terebinthifolia Raddi; eucalyptus - Eucalyptus L'Hér. spp.; and velame - Croton L. spp.. The honeys were collected in five Southern Bahia municipalities - Belmonte, Eunápolis, Guaratinga, Itabela and Porto Seguro. The samples underwent acetolysis and, after slides mounting, the pollen types were identified and counted to determine the frequency classes. The pollen spectra revealed 31 pollen types in 27 genera and 17 families. The palynological analysis confirmed the predominant eucalyptus flower source indicated for four honey samples from Belmonte, Eunápolis, Itabela and Porto Seguro. Three honey samples previously indicated with predominant eucalyptus and velame flower sources had no predominant pollen. Eucalyptus predominated as the main flower source for another three samples previously indicated by beekeepers as Brazilian peppertree and velame. We conclude that regional honeys marketed as having a predominant flower source may have distinct botanical origin. This demands further research aimed at reviewing which bee plants provide resources for monofloral, bifloral and plurifloral honeys in the Bahian Discovery Coast.


Asunto(s)
Anacardiaceae , Croton , Eucalyptus , Miel , Animales , Abejas , Flores , Miel/análisis , Polen
2.
Huan Jing Ke Xue ; 42(11): 5440-5449, 2021 Nov 08.
Artículo en Chino | MEDLINE | ID: mdl-34708983

RESUMEN

Eucalyptus biochar(BC) was prepared and potassium permanganate was used to modify the biochar(KBC). Static adsorption experiments on Pb(Ⅱ) in aqueous solution were carried out to investigate the effects of pH, adsorbent dosing, adsorption time, temperature, and initial concentration on the adsorption of Pb(Ⅱ). The results showed that the optimum pH was 5 while the adsorption reached saturation after 6 h. When the temperature was 25℃, the initial concentration of Pb(Ⅱ) was 100 mg·L-1 with an adsorbent dosage of 0.06 g; the maximum adsorption of Pb(Ⅱ) by KBC was 83.059 mg·g-1, with a removal rate of 99.67%. The adsorption of Pb(Ⅱ) by KBC followed the pseudo-second-order kinetic model and the Langmuir isothermal adsorption model, which is a monolayer adsorption occurring on a homogeneous surface. The adsorbents were characterized using the BET method, scanning electron microscopy and energy dispersive spectroscopy(SEM-EDS), X-ray diffraction(XRD), Fourier transformed infrared(FT-IR) and X-ray photoelectron spectroscopy(XPS). The adsorption mechanism of Pb(Ⅱ) by KBC oxygen-containing and manganese-containing groups was through complexation and precipitation, and the formation of -O-Pb-O- bidentate complexes on the surface of the biochar. Therefore, potassium permanganate-modified BC can be used as a good Pb(Ⅱ) adsorbent.


Asunto(s)
Eucalyptus , Contaminantes Químicos del Agua , Adsorción , Carbón Orgánico , Concentración de Iones de Hidrógeno , Cinética , Plomo , Permanganato de Potasio , Espectroscopía Infrarroja por Transformada de Fourier , Contaminantes Químicos del Agua/análisis
3.
PLoS One ; 16(10): e0258568, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34648559

RESUMEN

Urea is the most popular and widely used nitrogenous fertilizer. High soil urease activity rapidly hydrolyses applied urea to ammonia which contributes to soil nitrogen (N) losses and reduces N use efficiency of crop plants. The ammonia losses can be minimized by the inhibition of soil urease activity which has been explored using various potential chemical inhibitors. However, the soil urease activity inhibition potential of plant extracts is rarely explored to date. In the present study, extracts of 35 plant materials were taken and evaluated against jack bean urease. Eleven extracts, showing >50% jack bean urease inhibition, were selected and further investigated in 13 soils collected from various districts of Punjab, Pakistan. Interestingly, except Capsicum annum, Melia azedarach, Citrus reticulata and Quercus infectoria, the plant extracts showed urease inhibition activities in soils, the extent of which was lower as compared to that observed in jack bean urease though. Maximum urea hydrolysis inhibition (70%) was noted with Vachellia nilotica which was 40% more than that of hydroquinone (50%) followed by that of Eucalyptus camaldulensis (24%). The extracts of V. nilotica and E. camaldulensis were coated on urea and applied to soil in the next step. At 21st day, 239% and 116% more urea-N was recovered from soil treated with V. nilotica and E. camaldulensis extracts coated urea, respectively, as compared to uncoated urea. Conclusively, these results indicated that the coating of V. nilotica and E. camaldulensis extracts on urea prills prolonged urea persistence in soil owing to minimum urea hydrolysis, probably, the extracts of V. nilotica and E. camaldulensis showed their urease inhibition potential. The results of this study provide a base line for the identification of new soil urease inhibitor compounds from plant materials in future.


Asunto(s)
Extractos Vegetales/química , Suelo/química , Ureasa/metabolismo , Eucalyptus/química , Eucalyptus/metabolismo , Extractos Vegetales/metabolismo , Hojas de la Planta/química , Hojas de la Planta/metabolismo , Tabaco/química , Tabaco/metabolismo , Urea/metabolismo , Ureasa/antagonistas & inhibidores
4.
An Acad Bras Cienc ; 93(suppl 3): e20201351, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34468491

RESUMEN

Obesity is a major risk factor for type 2 diabetes mellitus development and is characterized by an abnormal expansion of adipose tissue and low-grade chronic inflammation that contribute to insulin resistance. Although there are multiple treatments, most therapies can produce undesirable side effects and therefore, new and effective treatments with fewer side effects are necessary. Previously, we demonstrated that a natural extract from the leaves of Eucalyptus tereticornis (OBE100) has anti-inflammatory, hypoglycemic and hypolipidemic activities. The major compounds identified in OBE100 were three pentacyclic triterpenoids, ursolic acid, oleanolic acid, and ursolic acid lactone. Triterpenoids have shown multiples biological activities. This current study compared the biological effect produced by OBE100 with five different reconstituted mixtures of these triterpenoids. Different cell lines were used to evaluate cytotoxicity, reactive oxygen species production, inflammatory cytokine expression, glucose uptake induction, leptin and adiponectin expression, and lipid accumulation. OBE100 treatment was the most efficacious and none of the formulated triterpenoid mixtures significantly improved on this. Moreover, OBE100 was less toxic and reduced reactive oxygen species production. Our study showed that the proven beneficial properties of triterpenoids may be enhanced due to the interaction with minor secondary metabolites present in the natural extract improving their anti-inflammatory properties.


Asunto(s)
Diabetes Mellitus Tipo 2 , Eucalyptus , Resistencia a la Insulina , Triterpenos , Extractos Vegetales/farmacología , Triterpenos/farmacología
5.
Biomacromolecules ; 22(10): 4365-4372, 2021 10 11.
Artículo en Inglés | MEDLINE | ID: mdl-34506709

RESUMEN

The electron beam irradiation (EBI) of native lignin has received little attention. Thus, its potential use in lignin-based biorefineries is not fully understood. EBI was applied to selected lignin samples and the structural and chemical changes were analyzed, revealing the suitability, limitations, and potential purpose of EBI in wood biorefineries. Isolated milled wood, kraft, and sulfite lignin from beech and eucalyptus were subjected to up to 200 kGy of irradiation. The analysis included gel permeation chromatography for molar masses, heteronuclear single quantum coherence (HSQC)- and 31P NMR and headspace gas chromatography-mass spectrometry for functional groups, and thermogravimetric analysis for thermal stability. Most samples resisted irradiation. Subtle changes occurred in the molecular weight distribution and thermal stability of milled wood lignin. EBI was found to be a suitable pretreatment method for woody biomass if the avoidance of lignin condensation and chemical modification is a high priority.


Asunto(s)
Eucalyptus , Lignina , Biomasa , Electrones , Madera
6.
Nature ; 597(7876): 366-369, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34526704

RESUMEN

Southeast Australia experienced intensive and geographically extensive wildfires during the 2019-2020 summer season1,2. The fires released substantial amounts of carbon dioxide into the atmosphere3. However, existing emission estimates based on fire inventories are uncertain4, and vary by up to a factor of four for this event. Here we constrain emission estimates with the help of satellite observations of carbon monoxide5, an analytical Bayesian inversion6 and observed ratios between emitted carbon dioxide and carbon monoxide7. We estimate emissions of carbon dioxide to be 715 teragrams (range 517-867) from November 2019 to January 2020. This is more than twice the estimate derived by five different fire inventories8-12, and broadly consistent with estimates based on a bottom-up bootstrap analysis of this fire episode13. Although fires occur regularly in the savannas in northern Australia, the recent episodes were extremely large in scale and intensity, burning unusually large areas of eucalyptus forest in the southeast13. The fires were driven partly by climate change14,15, making better-constrained emission estimates particularly important. This is because the build-up of atmospheric carbon dioxide may become increasingly dependent on fire-driven climate-carbon feedbacks, as highlighted by this event16.


Asunto(s)
Dióxido de Carbono/análisis , Imágenes Satelitales , Incendios Forestales/estadística & datos numéricos , Atmósfera/química , Australia , Teorema de Bayes , Monóxido de Carbono/análisis , Cambio Climático , Eucalyptus , Bosques , Pradera , Incertidumbre
7.
J Environ Manage ; 299: 113676, 2021 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-34526275

RESUMEN

During the past few decades, commercial silvopastoral systems (SPS) with exotic Eucalyptus (hybrid) trees have become popular in the Brazilian Cerrado (savanna). With the increasing awareness about the role of carbon (C) storage in soils as a climate-change mitigation strategy and the relationship between the nature of soil aggregates and the soil's carbon sequestration potential, it is important to understand the influence of such SPS systems on soil organic carbon (SOC) storage. We studied C content in three aggregate size classes in six land-use systems on Oxisols in Minas Gerais, Brazil. The systems were planted forest, native secondary forest, managed pasture, and three 8-year-old SPS, differing in their tree-planting configurations. Eucalyptus hybrid was the tree in SPS and planted forest treatments, and Urochloa decumbens was the grass in SPS and pasture treatments. From each treatment, replicated soil samples were collected from four depth-classes (0-10, 10-30, 30-60, and 60-100 cm), fractionated by wet sieving into the three aggregate-size classes, 2000 to 250 µm, 250 to 53 µm, and <53 µm size classes representing macroaggregates, microaggregates, and silt + clay, respectively, and their C contents determined. Down to 1 m, total SOC stock values ranged from 260 Mg ha-1 under pasture to 167 Mg ha-1 under native forest, with 174 Mg ha-1 for Eucalyptus plantation and about 195 Mg ha-1 for the three SPS. Compared to the degraded native forest, the pasture system had significantly higher SOC in the whole soil and the aggregate size fractions, especially in the lower soil-depth classes. The lower SOC stock of Eucalyptus hybrid SPS compared to open pasture differs from the general trend of SPS having higher stock. Given that the Cerrado biome is a biodiversity hotspot, the use of native nitrogen-fixing trees, of which there are several, is worth investigating. In addition, the conversion from Eucalyptus monocultures to SPS could be considered as a strategy to increase the SOC stock.


Asunto(s)
Eucalyptus , Suelo , Agricultura , Biodiversidad , Carbono , Secuestro de Carbono
8.
Molecules ; 26(18)2021 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-34577065

RESUMEN

Green composites, composed of bio-based matrices and natural fibers, are a sustainable alternative for composites based on conventional thermoplastics and glass fibers. In this work, micronized bleached Eucalyptus kraft pulp (BEKP) fibers were used as reinforcement in biopolymeric matrices, namely poly(lactic acid) (PLA) and poly(hydroxybutyrate) (PHB). The influence of the load and aspect ratio of the mechanically treated microfibers on the morphology, water uptake, melt flowability, and mechanical and thermal properties of the green composites were investigated. Increasing fiber loads raised the tensile and flexural moduli as well as the tensile strength of the composites, while decreasing their elongation at the break and melt flow rate. The reduced aspect ratio of the micronized fibers (in the range from 11.0 to 28.9) improved their embedment in the matrices, particularly for PHB, leading to superior mechanical performance and lower water uptake when compared with the composites with non-micronized pulp fibers. The overall results show that micronization is a simple and sustainable alternative for conventional chemical treatments in the manufacturing of entirely bio-based composites.


Asunto(s)
Celulosa/análogos & derivados , Nanocompuestos/química , Eucalyptus/química , Hidroxibutiratos/química , Poliésteres/química , Resistencia a la Tracción , Humectabilidad
9.
G3 (Bethesda) ; 11(10)2021 09 27.
Artículo en Inglés | MEDLINE | ID: mdl-34568915

RESUMEN

Single-step GBLUP (HBLUP) efficiently combines genomic, pedigree, and phenotypic information for holistic genetic analyses of disjunct breeding populations. We combined data from two independent multigenerational Eucalyptus globulus breeding populations to provide direct comparisons across the programs and indirect predictions in environments where pedigreed families had not been evaluated. Despite few known pedigree connections between the programs, genomic relationships provided the connectivity required to create a unified relationship matrix, H, which was used to compare pedigree-based and HBLUP models. Stem volume data from 48 sites spread across three regions of southern Australia and wood quality data across 20 sites provided comparisons of model accuracy. Genotyping proved valuable for correcting pedigree errors and HBLUP more precisely defines relationships within and among populations, with relationships among the genotyped individuals used to connect the pedigrees of the two programs. Cryptic relationships among the native range populations provided evidence of population structure and evidence of the origin of landrace populations. HBLUP across programs improved the prediction accuracy of parents and genotyped individuals and enabled breeding value predictions to be directly compared and inferred in regions where little to no testing has been undertaken. The impact of incorporating genetic groups in the estimation of H will further align traditional genetic evaluation pipelines with approaches that incorporate marker-derived relationships into prediction models.


Asunto(s)
Eucalyptus , Eucalyptus/genética , Genoma , Genómica , Genotipo , Humanos , Modelos Genéticos , Fenotipo , Fitomejoramiento
10.
Physiol Plant ; 173(4): 2081-2090, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34523145

RESUMEN

Establishing drying-limits for mortality of different tree species and understanding the anatomical and physiological traits involved is crucial to predict forests' responses to climate change. The xylem of Eucalyptus camaldulensis presents a complex of solitary vessels surrounded by different imperforate tracheary elements and parenchyma that influence, in a poorly known way, its hydraulic functioning. We aimed at describing the dynamics of embolism propagation in this type of xylem, seeking any vessel-size pattern, and unraveling the threshold of xylem embolism leading to nonrecovery after drought in E. camaldulensis. We assigned potted saplings to a protracted water-stress for 70 days. We relied on colorimetric and hydraulic methods to test for links between xylem anatomy and embolism propagation in the main stem. On average, the occurrence of embolism was randomly distributed in the stem xylem, but the probability of embolized vessels was higher than predicted by chance in the narrowest vessels of individuals that experienced low to moderate water-stress. The saplings could recover from severe water-stress if their percentage loss of conductance (PLC) was <77%, but not when the PLC was ˃ 85%. We concluded that, contrary to results reported for most species, the narrowest vessels are the most vulnerable to cavitation in E. camaldulensis, suggesting a lack of tradeoff between xylem efficiency and safety (in response to drought) at the tissue level. These results challenge the well-established paradigm of the effect of vessel size on cavitation, which states that the widest conduits are the most vulnerable to both freeze-thaw and drought-induced cavitation.


Asunto(s)
Sequías , Eucalyptus , Congelación , Agua , Xilema
11.
Molecules ; 26(16)2021 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-34443612

RESUMEN

Eucalyptus leaves (ELE) and willow bark (WBE) extracts were utilized towards the formation of silver nanoparticles (AgNPs(ELE), AgNPs(WBE)). AgNPs(ELE) and AgNPs(WBE) were dispersed in polymer hydrogels to create pHEMA@AgNPs(ELE)_2 and pHEMA@AgNPs(WBE)_2 using hydroxyethyl-methacrylate (HEMA). The materials were characterized in a solid state by X-ray fluorescence (XRF) spectroscopy, X-ray powder diffraction analysis (XRPD), thermogravimetric differential thermal analysis (TG-DTA), differential scanning calorimetry (DTG/DSC) and attenuated total reflection spectroscopy (ATR-FTIR) and ultraviolet visible (UV-vis) spectroscopy in solution. The antimicrobial potential of the materials was investigated against the Gram-negative bacterial strain Pseudomonas aeruginosa (P. aeruginosa) and the Gram-positive bacterial strain of the genus Staphylococcus epidermidis (S. epidermidis) and Staphylococcus aureus (S. aureus), which are involved in microbial keratitis. The percentage of bacterial viability of P. aeruginosa and S. epidermidis upon their incubation over the pHEMA@AgNPs(ELE)_2 discs is interestingly low (28.3 and 6.8% respectively), while the inhibition zones (IZ) formed are 12.3 ± 1.7 and 13.2 ± 1.2 mm, respectively. No in vitro toxicity of this material towards human corneal epithelial cells (HCEC) was detected. Despite its low performance against S. aureus, pHEMA@AgNPs(ELE)_2 could be an efficient candidate towards the development of contact lenses that reduces microbial infection risk.


Asunto(s)
Lentes de Contacto/microbiología , Eucalyptus/química , Hidrogeles/química , Extractos Vegetales/química , Salix/química , Plata/farmacología , Antibacterianos/síntesis química , Antibacterianos/química , Antibacterianos/farmacología , Humanos , Nanopartículas del Metal , Pruebas de Sensibilidad Microbiana , Plata/química
12.
Bioresour Technol ; 341: 125757, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34411942

RESUMEN

Glycolic acid has chemical properties similar to those of formic acid. Therefore, similar to formic acid pretreatment, glycolic acid pretreatment has the separation effect of hemicellulose. In this study, eucalyptus hemicellulose was effectively separated by glycolic acid pretreatment. The effects of glycolic acid concentration, temperature and time on the separation of cellulose, hemicellulose and lignin were investigated. The optimum conditions were acid concentration 5.40%, temperature 140 °C, time 3.0 h. The highest yield of xylose was 56.72%. The recovery rate of glycolic acid was 91%. Compared to formic acid, the yield of xylose increased to 10.33% while that of lignin decreased to 11.08%. It showed high selectivity for hemicellulose separation, yielding 65.48% hemicellulose with 72.08% purity. The depolymerization and repolymerization of lignin were inhibited. The integrity of the cellulose structure was preserved. It provides theoretical support for the fractional separation and high-value transformation of lignocellulosic biomass.


Asunto(s)
Eucalyptus , Biomasa , Glicolatos , Hidrólisis , Lignina , Polisacáridos
13.
Afr Health Sci ; 21(1): 397-409, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34394322

RESUMEN

Background: Inflammation is an immune response characterized by swelling, redness, pain and heat. Inflammation is mainly managed using conventional medicines that are associated with many side effects. Plant-based remedies are considerably better alternative therapies for they have fewer side effects. Objective: This study aimed at determining the anti-inflammatory potential of dichloromethane (DCM) leaf extracts of Eucalyptus globulus and Senna didymobotrya in mice. Methods: Fresh leaves of these plants were harvested from Embu County, Kenya. Quantitative phytochemical analysis was done using Gas Chromatography-Mass Spectrometry (GC-MS). Anti-inflammatory test comprised nine groups of five animals each: normal, negative, positive controls and 6 experimental groups. Inflammation was induced with Carrageenan. One hour post-treatment, the different groups were intraperitoneally administered with the reference drug, diclofenac, 3% DMSO and six DCM leaf extracts at doses of 25, 50, 100, 150, 200 and 250mg/kgbw. Results: GC-MS results revealed α-phellandrene, camphene, terpinolene, and limonene among others. Anti-inflammatory effects showed that extract doses of 100,150,200 and 250mg/kg bw significantly reduced the inflamed paw. Doses of 200 and 250mg/kgbw in both plants were more potent and compared with diclofenac. E. globulus extract dose of 250mg kg bw reduced inflamed paw in the 1st, 2nd, 3rd and 4th hours, by 2.27,6.52,9.09 and 10.90% respectively while S.didymobotrya at similar dose ranges, inflamed paw reduced by 2.41, 5.43, 8.31 and 9.05% respectively. Conclusion: E. globulus and S. didymobotrya have potent anti-inflammatory activities, attributed to their constituent phytochemicals. This study confirms the traditional use of these plants in treating inflammation.


Asunto(s)
Antiinflamatorios/farmacología , Eucalyptus/química , Inflamación/tratamiento farmacológico , Cloruro de Metileno/efectos adversos , Extractos Vegetales/farmacología , Hojas de la Planta/química , Animales , Humanos , Kenia , Masculino , Ratones
14.
World J Microbiol Biotechnol ; 37(10): 164, 2021 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-34458956

RESUMEN

Eucalyptus is the main species for the forestry industry in Brazil. Biotechnology and, more recently, gene editing offer significant opportunities for rapid improvements in Eucalyptus breeding programs. However, the recalcitrance of Eucalyptus species to in vitro culture is also a major limitation for commercial deployment of biotechnology techniques in Eucalyptus improvement. We evaluated various clones of Eucalyptus urophylla for their in vitro regeneration potential identified a clone, BRS07-01, with considerably higher regeneration rate (85%) in organogenesis, and significantly higher than most works described in literature. Endophytic bacteria are widely reported to improve in vitro plant growth and development. Hence, we believe that inclusion of endophytic plant growth promoting bacteria enhanced was responsible for the improved plantlets growth and development of this clone under in vitro culture. Metagenomic analysis was performed to isolate and characterize the prominent endophytic bacteria on BRS07-01 leaf tissue in vitro micro-cultures, and evaluate their impact on plant growth promotion. The analysis revealed the presence of the phyla Firmicutes (35%), Proteobacteria (30%) and much smaller quantities of Actinobacteria, Bacteroidetes, Gemmatimonadetes, Crenarchaeota, Euryarchaeota and Acidobacteria. Of the thirty endophytic bacterial strains isolated, eleven produced indole-3-acetic acid. Two of the isolates were identified as Enterobacter sp. and Paenibacillus polymyxa, which are nitrogen-fixing and capable of phosphate and produce ammonium. These isolates also showed similar positive effects on the germination of common beans (Phaseolus spp.). The isolates will now be tested as a growth promoter in Eucalyptus in vitro cultures. Graphical abstract for the methodology using cultivation independent and dependent methodologies to investigate the endophytic bacteria community from in vitro Eucalyptus urophylla BRS07-01.


Asunto(s)
Bacterias/aislamiento & purificación , Endófitos/aislamiento & purificación , Eucalyptus/microbiología , Bacterias/clasificación , Bacterias/genética , Bacterias/metabolismo , Brasil , ADN Bacteriano/genética , ADN Ribosómico/genética , Endófitos/clasificación , Endófitos/genética , Endófitos/metabolismo , Eucalyptus/crecimiento & desarrollo , Ácidos Indolacéticos/metabolismo , Metagenómica , Filogenia , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/microbiología , ARN Ribosómico 16S/genética
15.
Molecules ; 26(12)2021 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-34201300

RESUMEN

Eight polyhydroxy triterpenoid acids, hederagenin, (4α)-23-hydroxybetulinic acid, maslinic acid, corosolic acid, arjunolic acid, asiatic acid, caulophyllogenin, and madecassic acid, with 2, 3, and 4 hydroxyl substituents, were identified and quantified in the dichloromethane extract of Eucalyptus globulus wood by comparing their GC-retention time and mass spectra with standards. Two other triterpenoid acids were tentatively identified by analyzing their mass spectra, as (2α)-2-hydroxybetulinic acid and (2α,4α)-2,23-dihydroxybetulinic acid, with 2 and 3 hydroxyl substituents. Two MS detectors were used, a quadrupole ion trap (QIT) and a quadrupole mass filter (QMF). The EI fragmentation pattern of the trimethylsilylated polyhydroxy structures of these triterpenoid acids is characterized by the sequential loss of the trimethylsilylated hydroxyl groups, most of them by the retro-Diels-Alder (rDA) opening of the C ring with a π-bond at C12-C13. The rDA C-ring opening produces ions at m/z 320 (or 318) and m/z 278 (or 277, 276, 366). Sequential losses of the hydroxyl groups produce ions with m/z from [M - 90] to [M - 90*y], where y is the number of hydroxyl substituents present (from 2 to 4). Moreover, specific cleavage in ring E was observed, passing from m/z 203 to m/z 133 and conducting other major fragments such as m/z 189.


Asunto(s)
Eucalyptus/química , Triterpenos/química , Madera/química , Cloruro de Metileno/química , Extractos Vegetales/química , Espectrometría de Masas en Tándem/métodos
16.
Ultrason Sonochem ; 76: 105654, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34198128

RESUMEN

Antioxidant products present a very high added value and are demanded in the market. The optimization of their extraction is a high-stakes matter for both economic and environmental points of view. Ultrasound extraction has been considered one of the most promising methods, so the relative importance of key parameters may have decisive economic significance. For this reason, different parameters that have influence on the extraction capacity such as ultrasound power, time, temperature, pH and % ethanol in water have been studied to know the relationships between the independent parameters and their influence on the extraction from Eucalyptus globulus leaves. An experimental Box-Behnken factorial design and subsequent analysis by neural networks have been used. The relative influence of each parameter varies according to the nature of the extracted compound. In this regard, the higher capacity of extraction of the selected antioxidant compounds by means of the variation of the operation conditions can be facilitated. For all the studied compounds, temperature has been the most important parameter for their extraction. The relative content (%) of bioactive compounds (terpenes) in the optimized Eucalyptus globulus extract has been performed by GC-MS analysis.


Asunto(s)
Antioxidantes/aislamiento & purificación , Antioxidantes/farmacología , Eucalyptus/química , Hojas de la Planta/química , Ondas Ultrasónicas , Antioxidantes/química , Concentración de Iones de Hidrógeno , Temperatura , Factores de Tiempo
17.
Sci Total Environ ; 794: 148723, 2021 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-34217075

RESUMEN

Providing a valuable application to the under-utilized solid residue of co-pyrolysis of biomass and plastics could substantially improve economic and environmental sustainability of the process, thereby fostering circular economy. This study focuses on the variation of thermal and physiochemical characteristics of solid char, produced from the co-pyrolysis of waste low-density polyethylene (WLDPE) and Eucalyptus wood with varying pyrolysis temperatures from 300 to 550 °C, residence times of 90-150 min, and relative percentage of 33% and 25% (w/w) WLDPE in the feedstock. The highest values of yield (37%), energy density (1.25) and high heat value (31 MJ/Kg) were observed with the char produced at 300 °C. The physical inhibition caused by the overlaying plastic coating on the surface of the char below 450 °C resulted in the same. However, with the increase in temperature, increase in fuel ratio by 78-79% and fixed carbon content by 68-69% were observed. The highest concentrations of fixed carbon (39%), fuel ratio (0.81) along with the lowest O/C and H/C ratios (0.07 and 0.13) were observed with the chars produced above 450 °C depicting their high degree of carbonization. The fuel value indices of all the chars were > 500 GJ/m3 indicating their suitability as high-quality fuels. Significant influences of residence time and feedstock ratio were also observed on properties of the char. The analysis of variance and principal component analysis also depicted significant variations in the properties of the char produced below and above the temperatures of 450 °C due to the inhibitory and synergetic effects. While the chars produced at 300-350 °C could be used for combustion/co-combustion in coal-fired boilers, chars produced above 450 °C can be opted as household fuel due to their low losses of energy, water vapour, and smoke during combustion.


Asunto(s)
Eucalyptus , Pirólisis , Biomasa , Polietileno , Madera
18.
Food Chem ; 365: 130519, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34247044

RESUMEN

Thermal liquefaction is a conventional method used by beekeepers to liquefy crystallized honey. However, an abusive use of heat may affect its quality, chemical composition and bioactivity. The purpose of this study was to investigate the effect of thermal liquefaction on the quality, chemical composition and antibiofilm properties of eucalyptus honey. Thermal liquefaction (at 45 and 60 °C) did not affect the honey's quality; however, a significant reduction in the reducing capacity, total phenolic content and hydrogen peroxide content was observed. At 60 °C, a significant reduction in the honey's ability to inhibit biofilm formation was observed in Pseudomonas aeruginosa, as well as a reduction in its ability to remove preformed biofilms in both Staphylococcus aureus and Pseudomonas aeruginosa. Structural changes in biofilm architecture caused by honey were not affected by thermal treatment. Therefore, we recommend liquefaction at 45 °C as the most convenient for honey liquefaction without affecting its characteristics.


Asunto(s)
Eucalyptus , Miel , Antibacterianos/farmacología , Biopelículas , Humanos , Pruebas de Sensibilidad Microbiana , Pseudomonas aeruginosa , Staphylococcus aureus
19.
Phytother Res ; 35(9): 5282-5289, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34314073

RESUMEN

Tyrosyl-DNA phosphodiesterase 2 (TDP2) is a recently discovered DNA repair enzyme that can repair topoisomerase 2-mediated DNA damage, resulting in cancer cell resistance. In this study, two compounds, robustadial A and B, were isolated from a fraction of the ethyl acetate extract of Eucalyptus globulus Labill. fruits based on TDP2 inhibition screening. The biological experiments indicated that robustadial A and B have TDP2 inhibitory activity with EC50 values of 17 and 42 µM, respectively, but no tyrosyl-DNA phosphodiesterase 1 inhibition at 100 µM. Robustadial A showed significant synergistic effects with the anticancer drug etoposide in four human cancer cell lines, non-small cell lung cancer cell line (A549), prostate cancer cell line (DU145), breast cancer cell line (MCF-7), colorectal adenocarcinoma cell line (HCT-116), and chicken lymphoma cell line (DT40), and chicken lymphoma cell line complementation with human TDP2 (DT40 hTDP2) with combination index values ranging from 0.21 to 0.74. This work will facilitate future efforts for the development of robustadial A-based TDP2 selective inhibitors.


Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Eucalyptus , Neoplasias , Inhibidores de Fosfodiesterasa , Animales , Línea Celular Tumoral , Pollos , Proteínas de Unión al ADN , Eucalyptus/química , Humanos , Neoplasias/tratamiento farmacológico , Neoplasias/patología , Inhibidores de Fosfodiesterasa/farmacología , Hidrolasas Diéster Fosfóricas
20.
J Genet ; 1002021.
Artículo en Inglés | MEDLINE | ID: mdl-34282737

RESUMEN

Eucalyptus breeding programme mainly aims at increasing productivity associated with wood property traits which are suitable for different end uses. The principal challenge in this endeavor is to combine productivity with industrially relevant wood traits. In the present study, 23 hybrid clones derived from a biparental mapping population of Eucalyptus camaldulensis × E. tereticornis was assessed for six wood property traits across two sites in Tamil Nadu, India. The mean of most of the traits evaluated was consistently higher in Muthupettai, indicating significant site effect. Combined and location-wise analysis indicated additive genetic control of assessed traits. The stability of acoustic velocity in study sites, negligible G × E interaction and significant correlation with dynamic modulus of elasticity (DMoE) implies its use in selecting trees/logs for solid wood properties. Combined analysis of locations revealed low to moderate heritability (0.294-0.439) for all the traits with H2 being highest for cellulose per cent (0.439) followed by acoustic velocity (0.416). Genetic advance was calculated and was the highest for diameter (10.47%) followed by DMoE (9.19%). The two major chemical constituents of wood, namely total lignin and cellulose per cent showed 7.13% and 7.53% advancement in the hybrids. The out-performance of several hybrid clones when compared to the parents for different wood traits reiterates the use of Eucalyptus hybrids in plantation programmes to improve quality of raw material suitable for industrial application.


Asunto(s)
Eucalyptus/química , Hibridación Genética , Sitios de Carácter Cuantitativo/genética , Madera/genética , Eucalyptus/genética , India , Fenotipo , Fitomejoramiento , Polimorfismo de Nucleótido Simple/genética , Madera/química
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