Search Results (12,386)

The preparation of the novel optically active sulfoxides (-)-(S)-1,1,1,3,3,3-hexafluoro-2-[o-(p-tolylsulfinyl)phenyl]propan-2-ol 1, (-)-(S)-1,1,1,3,3,3-hexafluoro-2-[o-(methylsulfinyl)phenyl]propan-2-ol 2 and (-)-(S)-1,1,1,3,3,3-hexafluoro-2-[o-(t-butyl-sulfinyl)phenyl]propan-2-ol 3 according to the Andersen methodology and their spectroscopic characterization is presented. The NMR and CD spectroscopic evidence of the existence of the equilibrium between sulfoxide and hypervalent sulfurane forms of these compounds in solution and attempts at the isolation of corresponding sulfuranes are shown. For compound 3, the unprecedented subsequent irreversible transformation in solution into corresponding cyclic sulfinate ester–sultine 17 was established on the basis of NMR spectroscopy measurements. The mechanism of this transformation was investigated by means of GC-MS analysis and confirmed on the basis of synthesized long alkyl chain analog 23 transformation in solution. Moreover, the oxidation properties of obtained sulfoxides 2 and 3 for the selected compounds are described. Full article

Amaranth oil (AMO) and its topical formulation enriched with rose oil (AMOR) were evaluated for anti-inflammatory and cytotoxic properties in skin-relevant models. Two complementary inflammation models were used to assess immunomodulatory potential, (i) LPS-stimulated macrophages and (ii) TNF-α/IFN-γ-stimulated immortalized HaCaT keratinocytes, while cytotoxicity and selectivity were tested on human HaCaT keratinocytes and melanoma cell lines (A375, HTB140). GC-MS and FTIR analyses were performed to confirm the presence of key bioactive compounds (squalene, fatty acids, phenolics). AMOR showed significantly higher polyphenol and palmitic acid content than AMO. In both inflammation models, AMOR more effectively reduced IL-6, IL-1β, and TNF-α release. Cytotoxicity assays revealed that both oils were safe for normal keratinocytes, while selectively cytotoxic to melanoma cells, with AMOR demonstrating greater potency (IC₅₀ A375 = 3.8 μg/mL and HTB140 = 18.9 μg/mL). Albumin-binding studies showed that AMOR had stronger interactions with these proteins, which may enhance delivery and tissue retention. In conclusion, both oils exhibit promising topical safety, but AMOR provides enhanced anti-inflammatory and cytotoxic effects due to its enriched composition. This study supports the therapeutic potential of amaranth oil in different skin diseases, especially when combined with essential oils of complementary bioactivity. Full article

This study examines the effects of flower storage duration and harvest time on the yield and evolution of the volatile composition of ylang-ylang (Cananga odorata forma genuina) essential oil. Oils were obtained from flowers by hydrodistillation immediately or after storage (4 h, 8 h, 24 h and 30 h) to investigate the effect of storage duration and from flowers picked at different schedules (07:00 a.m., 11:00 a.m. and 03:00 p.m.) to investigate the effect of the time of flower harvesting. The ylang-ylang oils were by analyzed by GC–MS. Storage duration had no significant effect on yield up to 8 h, whereas significant decreases occurred after 24 and 30 h. The amount of aromatic compounds decreased markedly with storage, from 73.66% in fresh petals to 57.02% after prolonged storage. Harvest time also influenced the distribution of oxygenated compounds, terpene hydrocarbons and several key volatiles. Overall, oils distilled within 0–8 h after harvest and obtained from flowers collected at 07:00 a.m. or 3:00 p.m. exhibited superior yields and chemical profiles compared with delayed distillation or midday harvest (11:00 a.m.). These results underline the importance of rapid processing and optimized harvest timing to preserve oxygenated fractions and essential-oil quality. Full article

Ripened Pu-erh tea (RPT) experiences notable aroma transformations during industrial pile fermentation, yet the stage-dependent evolution of key aroma compounds remains poorly understood. This study analyzed two independent industrial batches of RPT across three fermentation stages: raw material (RM), intermediate fermentation (IF), and final fermentation (FF). Using HS-SPME/GC-MS coupled with multivariate statistical analysis and relative odor activity values (rOAVs), 134 volatile organic compounds (VOCs) were identified, with hydrocarbons, alcohols, and esters as predominant classes. In total, 13 key aroma-active compounds (rOAVs > 1) were found to be major contributors to RPT’s characteristic aroma. During early fermentation, relative levels of VOCs responsible for fresh and green aromas (e.g., linalool, D-limonene) diminished, while those for woody and minty aromas (e.g., isophorone, methyl salicylate) increased. A flavor wheel was developed to illustrate the dynamic shifts in aroma profiles. This stage-resolved analysis offers new mechanistic insights into aroma formation, aiding in the optimization of aroma quality control and process standardization for RPT production. Full article

Maize bran is an abundant cereal byproduct and a promising source of ferulated arabinoxylan biopolymers (FAXs). In this study, alkaline hydrolysis was optimized for FAX extraction from maize bran using a design-of-experiments approach evaluating alkali concentration, extraction time, and temperature. Purified FAXs were characterized for their chemical composition, phenolic and ferulic acid content, antioxidant activity, microstructure, and functional properties using GC–MS, HPLC, FT-IR, SEM, and standard antioxidant and functional assays. The FAX yields ranged from 14.7 to 18.9%, producing arabinose- and xylose-rich polymers (A/X ratio 0.68–0.74) with a high proportion of bound ferulic acid. Antioxidant assays (FRAP, ABTS, and DPPH) showed that alkaline-extracted and bound phenolic fractions exhibited substantially higher antioxidant capacity (p ≤ 0.05) than free phenolics, highlighting the importance of phenolic association with the arabinoxylan backbone. The FAX 3 extract also showed high activity in both the alkaline-extracted phenolic compounds (905.0 μg/g TE) and fraction II (286.5 μg/g TE), indicating that specific structural features may contribute to its bioactivity. In addition, FAXs demonstrated high water-holding capacity and favorable emulsifying properties. These results support the recovery of maize bran-derived FAXs as functional, antioxidant-active ingredients for food and related applications. Full article

Coke, as an essential metallurgical raw material, is widely used in iron and steel production. To investigate the pyrolysis behavior and cross-linking reactions during the pyrolysis of coking coal, pyrolysis experiments were conducted in a quartz-tube fixed-bed reactor placed in an electric furnace. The yields and compositions of the pyrolysis products were systematically analyzed. Gaseous and tar components generated at different pyrolysis stages were characterized using gas chromatography (GC) and gas chromatography–mass spectrometry (GC–MS). The semi-coke was examined by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The results indicated that the yields of tar from coking coal pyrolysis have a notable impact on the cross-linking reactions occurring during the coal pyrolysis process. The structural differences between Malan coal (ML) and Tunlan coal (TL) coals underlie their distinct behaviors in cross-linking intensity, tar evolution profiles, and coke-forming properties. For high-volatile, highly fluid ML coal, the release of the aliphatic compounds in tar volatiles remains relatively low at the temperature of maximum fluidity, which is beneficial to the cross-linking reactions. In contrast, for TL coal with lower volatility and fluidity, substantial H₂ emission during the early pyrolysis stage promotes cross-linking reactions. This study provides new insights into the temperature-dependent evolution of cross-linking reactions during coking coal pyrolysis. Full article

The environmental persistence of post-consumer plastics remains a critical challenge due to their chemical stability, the presence of additives, and prior environmental weathering. This study evaluates the partial biodegradation and chemical transformation of post-consumer low-density polyethylene (LDPE) and expanded polystyrene (EPS) by Tenebrio molitor larvae under uncontrolled environmental conditions. Four diets were tested, including LDPE+S and EPS+S (polymers supplemented with wheat bran), to assess the influence of a co-substrate on larval performance and polymer transformation. Fourier-transform infrared spectroscopy (FTIR) revealed the emergence of oxygen-containing functional groups (–OH and C=O) in the frass, which were absent or negligible in pristine materials, indicating oxidative modification of the polymer matrix. Gel permeation chromatography (GPC) revealed pronounced reductions in number-average molecular weight (Mn) and increased polydispersity for EPS-derived fractions, consistent with heterogeneous chain scission and partial depolymerization. For LDPE, GPC evidenced the formation of THF-soluble, low-molecular-weight polymer-derived fragments, indicating fragmentation despite the inability to quantify pristine LDPE due to its insolubility in the mobile phase. Gas chromatography–mass spectrometry (GC–MS) identified aromatic hydrocarbons, phthalate esters, organosiloxanes, and fatty acid derivatives, reflecting both degradation intermediates and migrated additives from post-consumer plastics. Together, these results provide integrated evidence that Tenebrio molitor can induce chemical transformation of post-consumer LDPE and EPS under non-controlled environmental conditions, offering mechanistic insight into a biologically mediated degradation pathway that is directly relevant to realistic plastic waste scenarios. Full article

In this article, we report a comprehensive analysis of the chemical composition and biological activity of Dysphania ambrosioides essential oil (DA-EO) originating from Bulgaria. Gas chromatography–mass spectrometry (GC–MS) analysis led to the identification of 53 constituents, revealing a complex phytochemical profile. The results classify the investigated oil as a thymol–carvacrol chemotype, dominated by oxygenated monoterpenes (56.79%), with thymol (19.45%) and carvacrol (14.30%) as the major components. This compositional profile differs markedly from the ascaridole-rich chemotypes commonly reported in the literature. The biological activity of DA-EO was evaluated through its antimicrobial, antioxidant, and anti-inflammatory properties. The oil exhibited broad-spectrum antimicrobial activity against pathogenic microorganisms such as S. aureus, E. coli, and L. monocytogenes. Antioxidant assays (HPSA, HRSA) indicated moderate activity, closely associated with the terpenoid composition of the oil. The anti-inflammatory potential, assessed via inhibition of albumin denaturation (IAD), was analyzed using nonlinear four-parameter (4PL) and five-parameter (5PL) logistic models. The obtained IC₅₀ values (67.0–77.0 µg/mL) were comparable to those of the reference drug ibuprofen, highlighting the significant potential of DA-EO as a natural therapeutic agent. Full article

Essential oils (EOs) from combined plant materials offer a promising alternative to conventional extraction by enhancing chemical diversity and bioactivity. This study evaluated the chemical composition and insecticidal properties of individual and combined plant EOs from Cymbopogon citratus, Eucalyptus camaldulensis, Eucalyptus lehmannii, Salvia rosmarinus and Thymus vulgaris were evaluated against aphids. Binary and ternary combinations were prepared in equal proportions prior to hydrodistillation. GC-MS analysis revealed significant compositional shifts in EOs from combined plant materials. Major compounds in individual oils included citral (53.11%) and neral (29.14%) in C. citratus, thymol (70.84%) in T. vulgaris, and eucalyptol as the predominant compound in E. camaldulensis (66.51%), E. lehmannii (56.99%) and S. rosmarinus (46.56%), respectively. In the combined oils, the relative abundance of these constituents was altered, and in some cases new constituents were introduced. Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) revealed that combined plant EOs clustered near their parental oils, indicating compositional inheritance. Contact toxicity assay against Aphis fabae demonstrated enhanced efficacy of the combined oils, with reduced LC₅₀ values (1.39 µL mL⁻¹ for E. camaldulensis + T. vulgaris) and synergistic interactions, indicated by a co-toxicity coefficient (CTC) of 221.58 and elevated synergistic factors. Pearson correlation analysis and Partial Least Squares (PLS) regression jointly identified Acorenone B and thymol as negatively, and caryophyllene as positively correlated compounds, all with relatively high contribution to insecticidal activity, ranking highest with a Variable Importance in Projection (VIP) scores > 1.0. While PLS model had modest predictive power, the integration of these statistical approaches supports the insecticidal potential of combined plant-derived EOS in laboratory bioassays and indicates their relevance to sustainable crop protection. Full article

Species of the genus Stachys (Lamiaceae) are recognized for their ethnobotanical importance and chemical diversity. In this study, the essential oil (EOS) and solvent extracts of the endemic species Stachys sparsipilosa were investigated using integrated GC–MS and LC–ESI–QTOF/MS approaches. GC–MS analysis showed that identified constituents accounted for 94.62% of the total oil, with caryophyllene oxide, kauran-16-ol, and cubebol as major components. Targeted LC–MS analysis quantified prominent phenolic compounds, including chlorogenic acid, rutin, and hesperidin, while untargeted metabolomics tentatively annotated 168 metabolites belonging to phenolics, terpenoids, and other classes. Antioxidant capacity was evaluated using complementary in vitro assays, and enzyme inhibitory activities against α-amylase, α-glucosidase, tyrosinase, acetylcholinesterase, and butyrylcholinesterase were assessed in comparison with standard inhibitors. The extracts demonstrated measurable but generally moderate activities relative to the corresponding positive controls. The essential oil exhibited moderate, non-selective cytotoxic effects at relatively high concentrations, whereas solvent extracts showed limited activity within the tested range. Molecular docking analyses were performed as supportive tools to explore possible enzyme–ligand interactions. Overall, S. sparsipilosa displays a chemically diverse metabolite profile associated with composition-dependent bioactivities, providing a basis for further mechanistic and in vivo studies. Full article

The growing demand for sustainable soil management strategies has intensified interest in hydrochar (HC), a waste-derived amendment produced via hydrothermal carbonization (HTC). This review synthesizes recent advances in HC production, characterization, and agri-environmental applications within a waste-to-resource framework. It covers studies conducted mainly over the last decade, encompassing a wide range of feedstocks, including agricultural residues, sewage sludge, animal manures, and food waste. HTC is typically performed at 130–280 °C under autogenous pressure (2–15 MPa), generating HCs with low intrinsic surface area (<50 m²g⁻¹) and oxygen-containing functional groups that govern nutrient dynamics and soil interactions. Reported application rates vary broadly between 10 and 60 t ha⁻¹, with most experiments conducted under greenhouse conditions. Positive effects on soil pH, cation exchange capacity, water retention, and phosphorus availability are frequently observed. However, plant responses vary according to the type of stimulation promoted by HC, as well as its processing conditions, application rates, and the soil characteristics in which it is applied. Advanced molecular-level analyses (e.g., FT-ICR-MS, GC-MS, and ¹³C-NMR) have provided mechanistic insights into carbon stability, nutrient release, and interaction with soil organic matter. Reusing HTC process water offers an additional pathway for nutrient recovery, although concerns about phytotoxic compounds remain. Despite promising short-term results, long-term field evaluations and standardized assessment protocols are still limited. This review integrates structural, functional and agri-environmental perspectives to identify critical knowledge gaps and guide the optimized and context specific use of hydrochar in sustainable agricultural systems. At the same time, it emphasizes its role in advancing carbon sequestration and in operationalizing resource-circular strategies, thereby underscoring its broader practical and strategic relevance. Full article

Lignin valorization is a central objective of modern biorefinery research. This study investigates the catalytic depolymerization of two technical lignins, kraft lignin from beech hardwood and natron lignin from annual plants, via two complementary routes: analytical catalytic pyrolysis (Py-GC/MS, 300–600 °C) and hydrogenolysis (250–310 °C, Ru/C, isopropanol/H₂). In Py-GC/MS experiments, noble-metal catalysts on carbon supports (Ru/C, Pd/C, RuPd/C) were screened. Relative compound distributions revealed phenolic derivatives as the dominant products, with Ru/C yielding the highest conversion for lignin from annual plants at 500 °C and Pd/C proving most selective for hardwood lignin at 400 °C. Hydrogenolysis was optimized through a five-level, three-factor central composite design, varying temperature, residence time, and catalyst loading. Lignin conversion ranged from 64 to 83 wt% and bio-oil yield from 69 to 89 wt%. A regression model identified optimal conditions at 295 °C, 32 min, and 17 wt% Ru/C. Catalyst regeneration via solvent washing, H₂O₂ oxidation, and controlled thermal treatment resulted in only an 8% decrease in lignin conversion. The results demonstrate that lignin origin, catalyst type, and depolymerization pathway jointly govern product selectivity, highlighting clear strategies for targeted phenolic compound production. Full article

In recent years, the recording of fish with vertebral malformations has attracted growing interest worldwide, as these malformations may be associated with exposure to xenobiotics. This study aimed to determine the presence and concentrations of pesticide residues (organochlorines and organophosphates) in coastal fish in Nayarit, Mexico, and to assess their potential association with vertebral malformations. From November 2013 to September 2021, 32 fish, with visible malformations were conveniently collected, an equal number of healthy specimens per species was selected for comparative analysis. The fish exhibited vertebral malformations of the following types: kyphosis, lordosis, and scoliosis in 9, 8 and 6 species, respectively, while the total number of malformations was higher across the sampled organisms. Furthermore, pesticide residues were detected in both healthy and malformed fish using gas chromatography coupled with tandem mass spectrometry (GC-MS/MS). The samples analyzed contained at least one pesticide, with the group of healthy fish showing greater diversity of organochlorine compounds. The most frequent of these were p,p’-DDE, followed by p,p’-DDT (41%), p,p’-DDD (25%), and endrin (25%). The species C. raredonae and A. seemanni exhibited the greatest number of pesticides. The pesticides observed in malformed fish samples were p,p’-DDE (100%), p,p’-DDD (97%), p,p’-DDT (97%), endrin (50%), and BHC delta (31%). Chlorpyrifos was present (56% and 100% in healthy and malformed fish), with the highest frequency observed in A. seemanni and B. panamensis. The highest concentrations were observed in the DDT group. An association was also observed between vertebral malformations and concentrations of p,p’-DDE and chlorpyrifos in the species C. raredonae and A. guatemalensis. Multivariate analysis revealed a clear separation between malformed and healthy fish based on contaminant profiles. Full article

This work examined the development of amylose–lipid complexes in green banana flour (Musa × paradisiaca) incorporated with virgin coconut oil (VCO), focusing on their spectral, thermal, and in vitro digestibility characteristics. Firstly, the native banana flour was analyzed for apparent amylose content using a spectrophotometric assay. To facilitate amylose–lipid complexation, both hot-pressed and cold-pressed VCO were incorporated into the banana flour under controlled thermal conditions, after which amylose–lipid interactions were characterized using Fourier-transform infrared and Raman spectroscopy for spectral features and differential scanning calorimetry for thermal behavior. The banana flour exhibited an AAC of 26.40 ± 0.002%. GCMS analysis of FAME derivatized VCO detected medium- to long-chain fatty acids, including octanoic (C8:0), decanoic (C10:0), dodecanoic (C12:0), tetradecanoic (C14:0), and hexadecanoic acids (C16:0) stearic acid (C18:0) and oleic acid (C18:1). FTIR coupled with multivariate analysis and Raman spectra confirmed lipid incorporation/retention in green banana flour through characteristic O–H, C–H, and C=O bands. While DSC revealed distinct endothermic transitions at 89.56 ± 2.17 °C (ΔHₘ = 0.8587 ± 0.1014 J g⁻¹) for hot-pressed VCO and 89.18 ± 0.98 °C (ΔHₘ = 0.6267 ± 0.0777 J g⁻¹) for cold-pressed VCO, consistent with the melting of V-type amylose–lipid complexes. Morphological analysis revealed that thermal treatment transformed native banana flour from irregular granular structures into an amorphous matrix via starch gelatinization, whereas subsequent incorporation of VCO promoted aggregation. In vitro enzymatic digestion showed a slight reduction in starch hydrolysis in VCO-treated samples. The incorporation of an exogenous lipid, such as VCO, into green banana flour promotes the formation of thermally stable amylose–lipid complexes that reduce enzymatic digestibility. Full article

High-amylose Lueang Patew Chumphon (LPC) rice, a Thai geographical indication variety, represents an underutilized resource for functional food development. This study investigated sweet fermented LPC rice (SFLPC) compared to conventional sweet fermented glutinous rice (SFGR) through comprehensive microbial, chemical, and nutritional characterization. Starter cakes contained Aspergillus sp., Rhizopus stolonifer, and Pediococcus pentosaceus (>99% similarity by ITS/16S rRNA sequencing and MALDI Biotyper). Both varieties demonstrated comparable fermentation with pH reductions to ~3.5 and lactic acid production (~6 g/L). GC-MS analysis with mass spectral library matching and Linear Retention Index (LRI) comparison tentatively annotated twelve volatile compounds. Absolute peak area analysis revealed distinct variety-specific profiles: SFGR was characterized by significantly higher ethyl palmitate (75.89 ± 19.30 vs. 16.80 ± 7.21 × 10⁶, p = 0.008) and isobutyl alcohol (33.09 ± 3.56 vs. 23.53 ± 1.71 × 10⁶, p = 0.014), exclusive ethyl dodecanoate (44.87 ± 20.60 × 10⁶), and exclusive 2,4-di-tert-butylphenol, while SFLPC showed exclusive ethyl acetate formation. Isoamyl alcohol was the dominant volatile in both varieties, with comparable absolute peak areas (273.91 ± 22.65 vs. 267.54 ± 28.78 × 10⁶, ns). SFLPC demonstrated superior mineral retention (2.1-fold phosphorus, 1.9-fold potassium and magnesium) and enhanced antioxidant capacity (IC₅₀: 3.30 vs. 5.20 μg/mL, representing 36% improvement). Degree of gelatinization analysis validated comparable starch gelatinization (32.5–40.1%) despite different cooking methods, confirming volatile differences arose from rice variety rather than processing. These findings demonstrate high-amylose LPC rice as a promising fermented food substrate offering enhanced nutritional properties and volatile compound profiles through traditional fermentation. Full article