Search Results (9)

This study aimed to characterize the metabolomic profile of monofloral honey from Eucryphia cordifolia (ulmo) and evaluate the potential transfer of bioactive compounds from the plant parts, including the leaves and flowers, to the honey. Using UHPLC/Q-TOF-MS analysis, various flavonoids and phenolic acids were identified and quantified in extracts from the leaves, flowers, and honey from E. cordifolia. Given their rich polyphenolic composition, E. cordifolia leaves were included in this study to assess their potential contribution to the antioxidant properties and chemical markers of ulmo honey. Additionally, the polyphenolic compounds in honey samples were quantified. Chromatographic analysis via UHPLC-MS/MS revealed that ulmo honey contains phenolic acids such as gallic, syringic, ferulic, chlorogenic, caffeic, and coumaric acid, as well as flavonoids including pinocembrin, quercetin, luteolin, kaempferol, epicatechin, apigenin, and isorhamnetin. The results indicate that pinocembrin and gallic acid are the main chemical markers of ulmo honey, while isorhamnetin could complement its characterization as a complementary marker. UHPLC/Q-TOF-MS analysis was also utilized to compare the compounds present in the honey with those found in the plant parts (leaves and flowers), respectively. A total of 10 shared compounds were identified, 9 of which were preliminarily identified, while 1 remains unknown. Notably, dihydroquercetin 3-O-rhamnoside, quercetin 3-O-rhamnoside, cyanidin 3-(p-coumaroyl)-glucoside, and eupatorin were detected in ulmo honey for the first time. Along with gallic acid, pinocembrin, and isorhamnetin, these compounds could contribute to a characteristic fingerprint for identifying the botanical origin of the honey. Overall, these findings provide valuable insights into the chemical composition of ulmo honey and its potential application as a functional product with antioxidant properties. Full article

This study explores the potential probiotic properties of yeasts isolated from various Chilean honeys, focusing on Ulmo, Quillay, and Mountain honeys. Six yeast strains were identified, including Zygosaccharomyces rouxii, Candida sp., Schizosaccharomyces pombe, Rhodosporidiobolus ruineniae, Clavispora lusitaniae, and Metschnikowia chrysoperlae. Phenotypic characterization involved assessing their fermentative performance, ethanol and hops resistance, and cross-resistance. Ethanol concentration emerged as a limiting factor in their fermentative performance. The probiotic potential of these yeasts was evaluated based on resistance to high temperatures, low pH, auto-aggregation capacity, survival in simulated in vitro digestion (INFOGEST method), and antimicrobial activity against pathogens like Escherichia coli, Staphylococcus aureus, and Salmonella enteritidis. Three yeasts, Zygosaccharomyces rouxii, Schizosaccharomyces pombe, and Metschnikowia chrysoperlae, exhibited potential probiotic characteristics by maintaining cell concentrations exceeding 10⁶ CFU/mL after in vitro digestion. They demonstrated fermentative abilities and resistance to ethanol and hops, suggesting their potential as starter cultures in beer production. Despite revealing promising probiotic and technological aspects, further research is necessary to ascertain their viability in producing fermented foods. This study underscores the innovative potential of honey as a source for new probiotic microorganisms and highlights the need for comprehensive investigations into their practical applications in the food industry. Full article

Honey is a mixture of compounds produced by bees that has been appreciated by humanity since the creation of the oldest civilizations. It has multiple uses and can be a highly nutritional and healing substance. It has been used in traditional medicine as a natural alternative for the treatment of diverse clinical conditions. This is due to its reported bioactive properties. The objective of this article is to exhibit and analyze the biological properties of different types of honey originating from Chile based on their antimicrobial, antioxidant, and anti-inflammatory activities, focusing primarily on recompiling experimental studies made on monofloral honey of plant species present in the Chilean territory. The result of this bibliographical review shows that Chilean honey possesses remarkable bioactive properties, mainly antimicrobial and antioxidant activities, with a few studies on its anti-inflammatory activity. Most of these results were attributed to monofloral honey belonging to ulmo (Eucryphia cordifolia) and quillay (Quillaja saponaria Molina) plant species. These properties are related to the presence of several bioactive components, such as phenolic components (mainly flavonoids), hydrogen peroxide (H₂O₂), enzymes, proteins, and carbohydrates. The biodiversity of the flora and the environmental conditions of the Chilean territory are responsible for the wide range of bioactive compounds and biological properties found in Chilean honey. Further studies must be made to uncover the medicinal potential of these native honeys. Full article

Based on the qualities of Ulmo honey (Eucryphia cordifolia), a medical-grade honey (Ulmoplus^®) has been developed. Relevant to this, the use of copper represents an emerging therapy for the treatment of wounds. Therefore, the aim of this study was to see how this medical-grade honey with copper nanoparticles (CuNPs) helped to heal infected or non-infected wounds. Twenty-four guinea pigs (Cavia porcellus) were divided into four groups for phase 1 (without and with infection, U + F₁ and U + F₂), and two groups for phase 2 (selected formulation, without and with infection, U + F₂NI and U + F₂I). Bacteriological and histopathological studies, collagen fibers content evaluation, and stereological analysis were performed. The selected formulation displayed the same antibacterial potency as Ulmoplus^®, indicating that this medical-grade honey by itself can be used as an antibacterial agent. However, the evaluation of collagen content demonstrated a significant increase in fibroblast and type III collagen fibers for infected and uninfected groups, which correlated with the histopathological study. Therefore, it is correct to affirm that adding CuNPs to Ulmoplus^® improved the maturation of collagen fibers. Finally, polymorphonuclear cells presented similar values between experimental groups, which would indicate that the formulation under study was able to regulate the inflammatory process despite their infectious condition. Full article

Precious metal-based materials such as commercial Pt/C are available electrocatalysts for redox reactions in Zn-air batteries. However, their commercial use is still limited by slow kinetics and restricted stability. In this work, we highlight a facial urea-assisted sol-gel method to synthesize A-site vacancy in LaMnO_3+δ oxide for boosting its catalytic activity and further explore the effect of the amount of urea on the A-site LaMnO₃. The A-site vacancy in LMO was confirmed by XRD, TEM, and XPS, which revealed that the urea-assisted sol-gel method mitigated the A-site vacancy in LaMnO_3+δ and increased its surface area, thus ultimately accelerating its redox reaction kinetics. The half-wave potential and current density of the resultant 3.0U-LMO electrocatalyst were 0.74 V and 5.74 mA cm⁻², respectively. It is worth noting that the assembled Zn-air battery with the 3.0U-LMO catalyst presented a power output of 130.04 mW cm⁻² at 0.51 V and a promising energy efficiency of 58.4% after 150 cycles. This protocol might offer an efficient approach for developing new defect-regulated perovskites for electrocatalysis. Full article

Drought is one of the most complex climate-related phenomena and is expected to progressively affect our lives by causing very serious environmental and socioeconomic damage by the end of the 21st century. In this study, we have extracted a dataset of exceptional meteorological drought events between 1975 and 2019 at the country and subregional scales. Each drought event was described by its start and end date, intensity, severity, duration, areal extent, peak month and peak area. To define such drought events and their characteristics, separate analyses based on three drought indices were performed at 12-month timescale: the Standardized Precipitation Index (SPI), the Standardized Precipitation Evapotranspiration Index (SPEI), and the Reconnaissance Drought Index (RDI). A multivariate combined drought index (DXI) was developed by merging the previous three indices for more understanding of droughts’ features at the country and subregional levels. Principal component analysis (PCA) was used to identify five different drought subregions based on DXI-12 values for 312 Mediterranean stations and a new special score was defined to classify the multi-subregional exceptional drought events across the Mediterranean Basin (MED). The results indicated that extensive drought events occurred more frequently since the late 1990s, showing several drought hotspots in the last decades in the southeastern Mediterranean and northwest Africa. In addition, the results showed that the most severe events were more detected when more than single drought index was used. The highest percentage area under drought was also observed through combining the variations of three drought indices. Furthermore, the drought area in both dry and humid areas in the MED has also experienced a remarkable increase since the late 1990s. Based on a comparison of the drought events during the two periods—1975–1996 and 1997–2019—we find that the current dry conditions in the MED are more severe, intense, and frequent than the earlier period; moreover, the strongest dry conditions occurred in last two decades. The SPEI-12 and RDI-12 have a higher capacity in providing a more comprehensive description of the dry conditions because of the inclusion of temperature or atmospheric evaporative demand in their scheme. A complex range of atmospheric circulation patterns, particularly the Western Mediterranean Oscillation (WeMO) and East Atlantic/West Russia (EATL/WRUS), appear to play an important role in severe, intense and region-wide droughts, including the two most severe droughts, 1999–2001 and 2007–2012, with lesser influence of the NAO, ULMO and SCAND. Full article

We performed an out-of-distribution (OOD) analysis of ∼12,000,000 semi-independent 128 × 128 pixel${}^2$ sea surface temperature (SST) regions, which we define as cutouts, from all nighttime granules in the MODIS R2019 Level-2 public dataset to discover the most complex or extreme phenomena at the ocean’s surface. Our algorithm (ULMO) is a probabilistic autoencoder (PAE), which combines two deep learning modules: (1) an autoencoder, trained on ∼150,000 random cutouts from 2010, to represent any input cutout with a 512-dimensional latent vector akin to a (non-linear) Empirical Orthogonal Function (EOF) analysis; and (2) a normalizing flow, which maps the autoencoder’s latent space distribution onto an isotropic Gaussian manifold. From the latter, we calculated a log-likelihood (LL) value for each cutout and defined outlier cutouts to be those in the lowest 0.1% of the distribution. These exhibit large gradients and patterns characteristic of a highly dynamic ocean surface, and many are located within larger complexes whose unique dynamics warrant future analysis. Without guidance, ULMO consistently locates the outliers where the major western boundary currents separate from the continental margin. Prompted by these results, we began the process of exploring the fundamental patterns learned by ULMO thereby identifying several compelling examples. Future work may find that algorithms such as ULMO hold significant potential/promise to learn and derive other, not-yet-identified behaviors in the ocean from the many archives of satellite-derived SST fields. We see no impediment to applying them to other large remote-sensing datasets for ocean science (e.g., SSH and ocean color). Full article

Raulí (Nothofagus alpina (Poepp. & Endl.)) and Ulmo (Eucryphia cordifolia Cav.) are mid-tolerant tree species in the Coihue-Raulí-Tepa (ca. 0.55 mill ha) and Evergreen (ca. 4.1 mill ha) forest types in south-central Chile, respectively. These species have been selectively logged in old-growth forests especially during the 20th century, Raulí mostly for its highly valuable timber, and Ulmo for its highly demanded firewood and bark for the tannery industry. Natural regeneration of these species occurs mostly through canopy gaps, but it can be retarded, or even inhibited, when the cover of the understory vegetation becomes unusually dense, such as in high-graded forests. Although underplanting is possible for these species, the knowledge about their growth in forest understories is scarce, and necessary to inform restoration programs. Therefore, we evaluated short-term responses (two years) of underplanted containerized seedlings in root-collar diameter, height, stem volume, and in the slenderness index, as a function of canopy openness (%, continuous variable) and three restoration treatments (categorical variables, plus one control treatment) at two different sites with high-graded old-growth forests for each forest type. By using generalized linear mixed-effects models (GLMMs) we determined that Raulí was more sensitive to the influence of both canopy openness and restoration treatments, while Ulmo was mostly influenced by canopy openness. Specifically, Raulí was positively influenced by canopy openness and restoration treatments in all response variables except for the slenderness index. Conversely, Ulmo was influenced by canopy openness in all response variables except the slenderness index, which was influenced by both predictor variables (canopy openness and restoration treatments). Thus, prospects for restoration with these species are discussed, including possible ontogenetic changes in their responses to light that may demand continuous silvicultural operations to recover the productive and functional roles of these species in these forest ecosystems. Full article

The present study investigated the antioxidant potential and the ability to inhibit lipid and protein oxidation in bovine meat of four native Chilean species: canelo (Drimys winteri), nalca (Gunnera tinctoria), tiaca (Caldcluvia paniculata), and ulmo (Eucryphia cordifolia). Phenolic acids (gallic, chlorogenic, caffeic, and coumaric) and flavonoids (catechin, epicatechin, and rutin) were identified and quantified by HPLC-MS/MS. Drimys winteri extract exhibited the highest antioxidant capacity evaluated by oxygen radical absorption capacity-red pyrogallol method (ORAC-PGR) and ferric ion reducing antioxidant power (FRAP) assays. All extracts decreased lipid oxidation induced by 2,2’-azo-bis(2-amidinopropane) dihydrochloride (AAPH) derived peroxyl radicals by anywhere between 30% and 50% the. In addition, canelo and nalca extracts decreased spontaneous oxidation by around 57% and 37% in relation to the control group, being even more efficient than butylated hydroxyanisole (BHT) a synthetic antioxidant. Protein oxidation in the myofibrillar proteins was evaluated by the formation of protein carbonyls and loss of protein thiols. The canelo, ulmo, and nalca extracts decreased the formation of carbonyls by around 30%. Plant extracts and BHT did not show an antioxidant effect on protein thiol loss. However, tiaca and ulmo extracts exerted a pro-oxidant effect, favoring the oxidation of sulfhydryl groups. The oxidizing system induced structural changes in myofibrillar protein (SDS−PAGE). A protective effect on protein structure from the canelo extract can be observed during the incubation when compared to samples incubated with AAPH. Full article