Search Results (2,815)

Tuanao, a traditional Northern Thai fermented soybean product, was profiled with an integrated multi-omics workflow to clarify how microbes and metabolites co-evolve during household fermentation. Soybeans were fermented spontaneously for three days; samples from four time points were analyzed by shotgun metagenomics alongside 1H-NMR and UHPLC-ESI-QTOF-MS/MS metabolomics. Bacillus spp. (phylum Bacilliota) quickly supplanted early Enterobacterales and dominated the mature microbiome. The rise of Bacillus coincided with genes for peptide and carbohydrate utilization and with the accumulation of acetate, free amino acids (glutamine, leucine, alanine, valine) and diverse oligopeptides, whereas citrate and glucose-1-phosphate were depleted. This Bacillus-linked metabolic shift indicates that Tuanao is a promising source of probiotics and bioactive compounds. Our study provides the first system-level view of Tuanao fermentation and offers molecular markers to guide starter-culture design and quality control. Full article

This study characterized the physicochemical properties of cocoa butter (CB) extracted from cocoa beans of the Criollo Nativo (Peru), Criollo (Mexico), and Forastero (Brazil) varieties subjected to spontaneous fermentation under traditional local conditions in each country. Cocoa samples were collected at 24-h intervals, and CB was extracted to evaluate its lipid composition through fatty acid profiling and spectroscopic techniques (FT-IR and NMR). Also, the thermal and structural properties via differential scanning calorimetry (DSC), including melting and crystallization profiles, crystallization kinetics, and polymorphism, were determined. The results revealed that stearic, oleic, and palmitic acids were predominant in all varieties, while trace levels of myristic and pentadecanoic acids contributed to molecular packing. FT-IR identified bands associated with glycerol chain formation in TAGs, which were confirmed by NMR through chemical shifts linked to the distribution of POS, SOS, and POP species. CB exhibited melting temperatures between 19.6 and 20.5 °C, favoring polymorphic transitions toward more stable forms. Form I (γ) predominated during early fermentation, while Forms II (α) and III (β′₂) were subsequently identified, particularly in Criollo varieties. These findings demonstrate that fermentation time significantly influences the chemical composition, oxidative stability, and crystalline structure of CB, providing valuable insights for optimizing cocoa processing and the development of high-quality chocolate products. Full article

Background: Vandetanib is a clinically approved epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) used in the treatment of medullary thyroid cancer. Recent studies have also suggested potential activity against the SARS-CoV-2 main protease (Mpro), indicating dual therapeutic relevance. However, its clinical use is limited by photosensitivity side effects, the molecular basis of which remains poorly understood. This study aims to elucidate the conformational, spectroscopic, and electronic properties of vandetanib underlying its photoreactivity. Methods: Density functional theory (DFT) was employed to explore vandetanib’s conformational landscape, electronic structure, and spectroscopic behavior. Low-energy conformers were identified and compared with experimental crystal and NMR data. Time-dependent DFT (TD-DFT) calculations were used to simulate UV–Vis absorption spectra and assign key electronic transitions. Results: Eight low-energy conformer clusters, including the global minimum structure, were identified. The global minimum was validated by consistency with crystal and experimental NMR data, emphasizing the role of conformational averaging. TD-DFT simulations successfully reproduced the two main UV–Vis absorption bands, with the primary band (~339 nm) assigned to a HOMO–1 → LUMO charge-transfer excitation between the N-methyl piperidine and quinazoline rings, pinpointing a structural contributor to photoreactivity. Additionally, the N-methyl piperidine ring was identified as a major metabolic hotspot, undergoing multiple biotransformations potentially linked to phototoxicity. Conclusions: This study provides molecular-level insights into the structural and photophysical origins of vandetanib’s photosensitivity. The findings improve understanding of its adverse effects and can inform the safer design of EGFR-targeting drugs with reduced phototoxic risks. Full article

Brazil nuts (Bertholletia excelsa), mainly from the Amazon, are notable for their exceptionally high selenium (Se) content and are widely consumed as a natural dietary supplement. They also contain potentially harmful elements, including barium (Ba), and exhibit an unusual capacity to accumulate radioactive radium (Ra). In this study, we quantified the concentrations of Se, Ba, strontium (Sr), lanthanum (La), europium (Eu), and the radionuclides ²²⁶Ra and ²²⁸Ra, and assessed their in vitro bioaccessibility—data largely unavailable for these elements to date. Se was highly bioaccessible (≈85%), whereas Ba and Ra, both chemo- and/or radiotoxic, exhibited low bioaccessibility (≈2% each). Nuclear magnetic resonance (NMR) spectroscopy revealed Se to occur predominantly as selenomethionine (SeMet), alongside phytate, amino acids, peptides, and other polar low-molecular-weight compounds. The influence of Brazil nut flour (BNF) on Eu(III) speciation in simulated gastrointestinal fluids, and the effect of chelating agents such as ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), and the hydroxypyridinone 3,4,3-LI(1,2-HOPO) were investigated using time-resolved laser-induced fluorescence spectroscopy (TRLFS). Results indicate that the food matrix has only a minor impact on the decorporation efficacy of these chelators. These findings provide novel insights into the bioaccessibility and chemical speciation of nutritionally and toxicologically relevant elements in Brazil nuts. Full article

Although coagulation can enhance sludge dewatering performance, it often leads to dense flocs, hindered water release, and secondary pollution of the sludge cake. In this study, three types of biochar-based skeleton materials, tea waste-derived biochar (TB), PAC sludge-derived biochar (PB), and their mixture (MB), were employed in combination with polyaluminum chloride (PAC) to improve sludge permeability and water release capacity. The results showed that PAC alone reduced the water content (Wc) and capillary suction time (CST) of raw sludge (RS) from 79.07% and 97.45 s to 69.45% and 42.30 s, respectively. In contrast, biochar–PAC composite conditioning achieved further enhancement. Among them, the TBP group (10% DS TB + 4% DS PAC) exhibited the best performance, with Wc and CST reduced to 58.73% and 55.65 s, reaching the threshold for deep dewatering (Wc < 60%). Low-field nuclear magnetic resonance (LF-NMR) analysis revealed an enhanced transformation from bound to free water, improving water mobility. Zeta potential and particle size analysis indicated that biochar promoted electrostatic neutralization and adsorption bridging. Rheological and EPS measurements demonstrated significant reductions in yield stress and apparent viscosity, alongside the enhanced release of proteins and polysaccharides into soluble EPS (S-EPS). Scanning electron microscopy and pore structure analysis further confirmed that biochar formed a stable porous skeleton (pore diameter up to 1.365 μm), improving sludge cake permeability. In summary, biochar synergizes with PAC through a “skeleton support–charge neutralization–adsorption bridging” mechanism, reconstructing sludge microstructure and significantly improving deep dewatering performance. Full article

Magnetic resonance techniques are powerful, nondestructive, non-invasive tools with broad applications in radiation dosimetry. Electron paramagnetic resonance (EPR) enables direct quantification of dose-dependent radiation-induced paramagnetic defects, while nuclear magnetic resonance (NMR) reflects the influence of such defects through changes in line width and nuclear spin relaxation. To date, these methods have typically been applied independently. Their combined use to probe radiation damage in the same material offers new opportunities for comprehensive characterization and preferred dosimetry techniques. In this work, we apply both EPR and NMR to investigate radiation damage in lithium carbonate (Li₂CO₃). A detailed EPR analysis of γ-irradiated samples shows that the concentration of paramagnetic defects increases with dose, following two distinct linear regimes: 10–100 Gy and 100–1000 Gy. A gradual decay of the EPR signal was observed over 40 days, even under cold storage. In contrast, ⁷Li NMR spectra and spin–lattice relaxation times in Li₂CO₃ exhibit negligible sensitivity to radiation doses up to 1000 Gy, while ¹H NMR results remain inconclusive. Possible mechanisms underlying these contrasting behaviors are discussed. Full article

Heliotropium procumbens, a Boraginaceae species native to Panama, has remained largely unexplored regarding its nitrogen-containing metabolites, including pyrrolizidine alkaloids (PAs). In the current study, a comprehensive phytochemical investigation of its aerial parts is presented using HPLC-DAD-IT-MS, UHPLC–HRMS, and GC-MS primarily to profile its PA composition. A total of twelve PAs and N-oxides (PANOs) were identified, along with two phenolamides—including N¹, N¹⁰-diferuloylspermidine, which is biosynthetically related to PAs—and the distinctive metabolite heliotropamide. The detected PAs included unsaturated necines, primarily monoesters of retronecine and heliotridine, as well as saturated PAs such as a platynecine-type PA and the less commonly encountered triol necines and their N-oxides. Among these, helifoline-N-oxide was isolated and structurally elucidated by NMR spectroscopy for the first time as a natural product. Comparison with the chemodiversity of PAs within the Heliotropium genus revealed a high degree of diversity in H. procumbens, which can be attributed both to the species’ inherent biosynthetic capacity for chemical variation and to the more comprehensive and extensive studies conducted on it, which naturally enrich the apparent diversity observed. This work expands the phytochemical knowledge of H. procumbens and contributes to a broader understanding of PA diversity in the genus, offering new insights into their potential ecological and toxicological significance. Full article

Polyscias fruticosa (L.) Harms, a Southeast Asian medicinal plant of the Araliaceae family, has gained increasing attention due to its rich phytochemical profile and potential pharmacological applications. This review provides an up-to-date synthesis of biotechnological strategies and chemical investigations related to this species. In vitro propagation methods, including somatic embryogenesis, adventitious root, and cell suspension cultures, are discussed with emphasis on elicitation and bioreactor systems to enhance the production of secondary metabolites. Phytochemical analyses using gas chromatography–mass spectrometry (GC-MS), high-performance liquid chromatography (HPLC), and nuclear magnetic resonance (NMR) have identified over 120 metabolites, including triterpenoid saponins, polyphenols, sterols, volatile terpenoids, polyacetylenes, and fatty acids. Several compounds, such as tocopherols, conjugated linoleic acids, and alismol, were identified for the first time in the genus. These constituents exhibit antioxidant, anti-inflammatory, antimicrobial, antidiabetic, anticancer, and neuroprotective activities, with selected saponins (e.g., chikusetsusaponin IVa, Polyscias fruticosa saponin [PFS], zingibroside R1) showing confirmed molecular mechanisms of action. The combination of biotechnological tools with phytochemical and pharmacological evaluation supports P. fruticosa as a promising candidate for further functional, therapeutic, and nutraceutical development. This review also identifies knowledge gaps related to compound characterization and mechanistic studies, suggesting future directions for interdisciplinary research. Full article

Background: Feces and cecum content are commonly involved in metabolomic analysis to understand the gut metabolic profile of the host, while, in fact, they are different. Feces represent the terminal excretory product after extensive host enzymatic digestion, absorption, and significant modification by the distal gut microbiota. In contrast, cecum content reflects the localized, in situ metabolic microenvironment at that specific site. However, it is worth noting that feces are the most accessible sample type for non-invasive studies, which could be considered proxies for cecum content in some specific cases. Unfortunately, the validity of fecal samples as an alternative to cecum content has rarely been assessed. Methods: The current study attempted to illustrate the distinct metabolomic and microbiota features of feces and cecum content in eight animals (mouse, pig, chicken, duck, rabbit, Gansu yak, Sichuan yak, and sheep) by means of ¹H-NMR and 16S rRNA, respectively. Results: A total of 116 molecules were characterized in feces and cecum content samples. Among them, 22 molecules were shared in all groups. Taking advantage of the univariate analysis, twenty-seven of the quantified molecules were significantly different between feces and cecum content, mainly pertaining to amino acids and organic acids. Moreover, in terms of mammals and non-mammals, short-chain fatty acids could be considered the main factor discriminating the metabolomic profiles between feces and cecum content. Furthermore, to better understand the mechanism of their metabolomic differences, 16S rRNA sequencing analysis was performed on feces and cecum content samples of mice, which is the most widely used animal model. The result showed that the Ace, Shannon, and Sobs indexes in feces were significantly higher than those of cecum content (p < 0.05). At the phylum and genus levels, the microbiota structures of feces and cecum content were similar, while the relative abundances of their microbiota exhibited distinct features. Conclusions: The present study could reduce this gap in information by characterizing, for the first time, the metabolomic differences between feces and cecum content using ¹H-NMR. Moreover, this study is meant as a reference guide for researchers wishing to apply a metabolomics approach to the gut of the host. Full article

The determination of RNA secondary structure (RSS) could help understand RNA’s functional mechanisms, guiding the design of RNA-based therapeutics, and advancing synthetic biology applications. However, traditional methods such as NMR for determining RSS are typically time-consuming and labor-intensive. As a result, the accurate prediction of RSS remains a fundamental yet unmet need in RNA research. Various deep learning (DL)-based methods achieved improved accuracy over thermodynamic-based methods. However, the over-parameterization nature of DL makes these methods prone to overfitting and thus limits their generalizability. Meanwhile, the inconsistency of RSS predictions between these methods further aggravated the crisis of generalizability. Here, we propose TrioFold to achieve enhanced generalizability of RSS prediction by integrating base-pairing clues learned from both thermodynamic- and DL-based methods by ensemble learning and convolutional block attention mechanism. TrioFold achieves higher accuracy in intra-family predictions and enhanced generalizability in inter-family and cross-RNA-types predictions. Additionally, we have developed an online webserver equipped with widely used RSS prediction algorithms and analysis tools, providing an accessible platform for the RNA research community. This study demonstrated new opportunities to improve generalizability for RSS predictions by efficient ensemble learning of base-pairing clues learned from both thermodynamic- and DL-based algorithms. Full article

The gut microbiota plays a significant role in metabolic diseases such as obesity. We extracted and purified a new type of pectin polysaccharide (mango peel pectin, MPP) from mango (Mangifera indica L.) peel. The structural analysis results reveal that MPP has a molecular weight (Mw) of 6.76 × 10⁵ Da and the mass fractions of the main components were galacturonic acid (21.36%), glucose (8.85%), and arabinose (5.97%). The results of methylation and NMR analyses reveal that the backbone of MPP consisted of →6)-α-D-GalpAOMe-(1→ and →4)-β-D-Glcp-(1→ linkages. Based on the above structural analysis, we further explored the therapeutic effect of MPP on high-fat diet-induced obese mice. The results demonstrate that MPP significantly suppressed body weight and dyslipidemia, reduced liver damage and lipid accumulation, attenuated changes in adipocyte hypertrophy, and improved glucose homeostasis and insulin resistance, with fasting blood glucose (FBG) levels decreasing by more than 12.8%. Furthermore, the modulatory impact of MPP on gut microbiota composition was investigated. MPP treatment significantly enhanced the levels of short-chain fatty acids (SCFAs) by decreasing the amount of Bacillota and reducing the Bacillota/Bacteroidota ratio, especially with an increase in the total SCFA content of over 64%. Meanwhile, MPP treatment encouraged beneficial bacteria to grow (e.g., Bacteroidota, Akkermansia, and Nanasyncoccus), altered the gut microbiome profiles in mice, and decreased the abundance of harmful bacteria (e.g., Paralachnospira, Coproplasma, Pseudoflavonifractor, Parabacteroides, Acetatifactor, and Phocaeicola). Overall, the findings demonstrate for the first time that MPP treats obesity by alleviating dyslipidemia, improving insulin resistance, and regulating gut microbiota to improve the intestinal environment. Full article

In the quest for greener alternatives to conventional organic solvents, Deep Eutectic Solvents (DESs) have gained significant attention due to their sustainability, biodegradability, and tunability. The use of water as an active and genuine component has recently led to the emergence of water-based DESs (wb-DESs). Here, a careful experimental characterization was performed on choline acetate (ChAc)/water mixtures across a range of water:ChAc molar ratios (n = 2–6). Differential Scanning Calorimetry (DSC) revealed glass transitions between 150 and 180 K, with no first-order transitions, leading to a classification of these mixtures as Low Transition-Temperature Mixtures (LTTMs). Physicochemical measurements, including density, viscosity, electrical conductivity, and refractive index, were conducted over a broad temperature range. NMR analyses provided insights into dynamics and solvation environments, with ¹H T1_slow relaxation times reaching their lowest value at n = 2, consistent with the formation of a strong hydrogen-bonding network. The n = 2 mixture was further investigated using Small and Wide-Angle X-ray Scattering (S-WAXS) and ab initio molecular dynamics (AIMD). These studies, jointly with ¹H NMR choline diffusion coefficient, directly challenge previous claims of the existence of aggregation phenomena in wb-DES. The simulation revealed a well-organized solvation structure, where acetate and water synergistically stabilize the choline cation through a cooperative hydrogen-bonding network. These findings highlight the impact and significance of an integrated physicochemical study in guiding the rational development of new sustainable systems, such as wb-DESs. Full article

Zeolites are widely used as adsorbents due to their porous structure and ion-exchange capabilities. However, their adsorption efficiency for heavy metal ions remains limited. To enhance their performance, the natural zeolite heulandite (Z) was functionalized with guanidine derivatives: N-[3-(triethoxysilyl)propyl]guanidine (1), -aminoguanidine (2), and -acetyl-guanidine (3). The resulting materials (Z1–Z3) were evaluated for their ability to adsorb Co²⁺, Cu²⁺, and Ni²⁺ from aqueous solutions. The composition and structure of silanes 1–3 were confirmed by FT-IR and ¹H and ¹³C NMR spectroscopy methods. The modified zeolites were characterized using nitrogen adsorption/desorption (BET) and SEM-EDX to confirm their functionalization and assess the structural changes. A TGA-DSC was used to determine the thermal stability. The adsorption experiments were conducted in single and multi-ionic aqueous solutions at pH 5.0 to evaluate metal uptake. Functionalization significantly improved the adsorption efficiency, with Z1–Z3 showing a three to six times greater adsorption capacity than the unmodified zeolite. The adsorption efficiency followed the trend Cu²⁺ > Co²⁺ > Ni²⁺, primarily due to chelate complex formation between the metal ions and guanidine groups. The SEM-EDX confirmed the co-localization of nitrogen atoms and metal ions. The functional materials (Z1–Z3) exhibited strong potential as adsorbents for noble, heavy, and toxic metal ions, and could find applications in industry, agriculture, ecology, medicine, chemistry, wastewater treatment, soil remediation, chemisorption, filtration, chromatography, etc. Full article

The degradation of modern and ancient permafrost-affected soils and organic-rich sediments and the release of relict soil organic matter from the frozen state are critical for understanding the global carbon cycle in a changing climate. The molecular structure of humic acids isolated from modern Cryosols and paleosoils from the Ice Complex deposits in the Batagay megaslump area was investigated. The elemental composition analysis was performed using a CHN analyzer, and molecular composition analysis was determined by CP/MAS ¹³C-NMR spectroscopy. Analysis of the molecular structure of humic acids showed that MIS 5e paleosoils are characterized by a relatively high content of aliphatic structural fragments (C,H-AL—29–36%) and a low content of aromatic structural fragments (AR/AL—0.49–0.43), which reveals low humification rates in this time period. The composition of humic acids from MIS 7 paleosoils shows a relatively high content of aromatic structural fragments compared to modern soils (AR/AL—0.47) and MIS 5e deposits (AR/AL—0.67–0.54), indicating a longer humification process in heterogenic conditions (warm and cold periods). The results indicate that the molecular structure of humic acids is a dynamic parameter of the environment that reflects the local conditions of pedogenesis and organic matter formation. Permafrost thawing leads to the release of organic matter (including matter that is relatively weakly resistant to biodegradation where aliphatic structural fragments dominate the composition of humic acids) that may strengthen the emission of climate-active gases into the atmosphere and boost climate change. Full article

In this study, the effects of non-thermal pretreatment such as corona discharge plasma (CDP-21 kV), dielectric barrier discharge plasma (DBDP-32 kV), and ultrasonic waves of different powers (US-180 W, 210 W, 240 W) on hot-air drying of ferruginous yam were compared. The regulatory effects of ultrasonic and cold plasma pretreatment on the drying characteristics and quality of yam were systematically evaluated by determining the drying kinetic parameters, physicochemical indexes, volatile components, and energy consumption. The results showed that ultrasonic pretreatment significantly improved the drying performance of yam compared with different cold plasma treatments, with the highest drying rate and effective moisture diffusion coefficient in the US-180 W group. In terms of quality, this treatment group exhibited better color retention, higher total phenol content (366 mg/100 g) and antioxidant activity, and optimal rehydration performance. Low-field nuclear magnetic resonance (NMR) analyses showed a more homogeneous water distribution, and gas chromatography–mass spectrometry (GC-MS) identified 55 volatile components. This study confirms that the US-180 W ultrasonic pretreatment technology can effectively improve the drying efficiency and product quality of yam and at the same time reduce the energy consumption. The results of this study provide a practical solution for the optimization of a process that can be replicated in the food drying industry. Full article