Search Results (104)

Microalgae have attracted the interest of researchers due to their high amounts of bioactive compounds with potential anti-obesity effects. In this context, the aim of this study is to analyse the effects of pigment extracts of Tetradesmus obliquus, Phaeodactylum tricornutum and Desmodesmus armatus on triglyceride accumulation in 3T3-L1 pre-adipocytes. Pigments were extracted and the chlorophyll and carotenoid profiles were analysed by HPLC-DAD-APCI-QTOF-MS analysis. Next, the three extracts were tested in maturing 3T3-L1 pre-adipocytes treated during 8 days at doses of 6.25, 12.5, 25 and 50 µg/mL. Cell viability was evaluated and triglyceride content of cells was measured by a commercial kit. Furthermore, adipogenic gene expression was measured in cells treated with the highest dose of the three extracts. The characterisation showed that the predominant pigments in each extract were different among the microalgae, with fucoxanthin being the main one in Phaeodactylum tricornutum and chlorophylls, lutein and violaxanthin/neoxanthin in the other two microalgae. All the tested microalgae extracts reduced triglyceride content of pre-adipocytes, although differing in the minimum effective dose. The underlying mechanism depends on the analysed extract, but the three extracts reduced adipogenesis via Pparg inhibition. In conclusion, the pigment extracts of the three microalgae exert anti-adipogenic effects in 3T3-L1 pre-adipocytes. Full article

Nitrosamines (NAs) pose a risk due to their carcinogenic properties, especially in processed and cured meats where nitrites and nitrates are widely used. The objective of this study was to develop an integrated Ultra-High-Performance Liquid Chromatography–High-Resolution Mass Spectrometry (UHPLC–HRMS) workflow for detecting both volatile (VNAs) and non-volatile (NVNAs) nitrosamines in meat matrices. Comparison of two ionization techniques showed that heated electrospray ionization (HESI) and atmospheric pressure chemical ionization (APCI) provided complementary coverage and sensitivity. Extraction and cleanup were optimized for meat, although recovery rates remained variable, underscoring the analytical complexity. The method was applied to raw, cooked, cured, and grilled meats, as well as to in vitro gastric digestion and co-digestion with spinach. Results revealed that some NAs were present even in untreated raw meat (≈3.0 µg/kg, N-nitrosodi-n-butylamine), while the addition of nitrites and nitrates significantly increased their levels (more than 10 µg/kg, N-nitrosodiethylamine, N-nitrosodimethylamine, N-nitrosodi-n-butylamine). Gastric digestion was the most critical condition, further promoting nitrosamine formation, particularly for N-nitrosodiethylamine, N-nitrosodi-n-butylamine, and N-nitrosopiperidine. Ascorbate exhibited a dual role, acting as an inhibitor at low nitrite concentrations but becoming pro-oxidant at high levels (300 mg/kg). Cooking alone had limited impact, whereas cooking combined with digestion yielded the highest and most consistent nitrosamine concentrations. The inclusion of spinach during digestion modestly altered nitrosamine levels, reflecting both its nitrate content and polyphenolic profile. Nonparametric ANOVA (aligned rank transform) confirmed that preservative treatment, rather than processing or interaction effects, was the main driver of variability (total nitrosamines: H = 24.15, p = 2.33 × 10⁻⁵), with the combination of preservative ascorbate plus nitrite producing significantly higher levels than other treatments (q = 0.000656). N-nitrosodimethylamine consistently emerged as the most relevant marker for dietary exposure, in agreement with EFSA guidance. Overall, this study underscores both the analytical and biochemical complexity of nitrosamine detection and formation in meat products, while highlighting the importance of preservative formulation and the potential role of dietary antioxidants in mitigating exposure. Full article

Background/Objectives: Animal and fungal sterols and stanols exhibit remarkable structural diversity, driven by variations in the number and position of C=C bonds within the steroidal tetracyclic core and side chain, along with diverse branching patterns of the latter. Similarly to phytosterols, these metabolites produce highly complex tandem mass spectra, whose interpretation has so far been limited. To address this gap, the fragmentation behavior of selected animal/fungal sterols and stanols was studied in this paper. Methods: Higher-Collisional-energy Dissociation–High-resolution tandem mass spectrometry (HCD-HRMS/MS) of protonated/dehydrated species generated via atmospheric pressure chemical ionization (APCI) was performed on structurally diverse compounds, including lathosterol, desmosterol, zymosterol, lanosterol, ergosterol, chalinasterol, and the stanols coprostanol and cholestanol. Results: Structurally diagnostic product ions originating from the side chains were unveiled, shedding light on the intramolecular migration of positive charge from the initial ionization site at C3 to alternative stable sites across the molecular structure, which is a typical mechanism also noted in cholesterol and phytosterols. In addition, characteristic fragmentation patterns related to the steroidal backbone were found and discussed for Δ⁷, Δ^5,7 and Δ⁸-sterols, and a novel elucidation of the fragmentation behavior of 4,4-dimethyl-Δ⁸-sterols, based on lanosterol as a model compound, was achieved. The relative intensities of diagnostic product ions allowed a correlation with specific structural motifs, and “cholesterol-like” and “stigmasterol-like” fragmentations pathways were recognized. These findings were integrated with prior data on cholesterol and plant sterol fragmentation acquired under identical analytical conditions. Moreover, as a proof of its relevance for novel sterol identification, MS/MS-related information was successfully applied to the identification of a positional isomer (Δ⁷) of zymosterol in baker’s yeast extract, along with typical fungal major sterols. Conclusions: The comprehensive archive of sterol/stanol fragmentations obtained by APCI-HCD-MS/MS might prove very useful for the future characterization of novel sterol/stanol species in complex matrices. Full article

Rosa rugosa is an important ornamental and edible species that is valued for its floral colors and essential oils in the cosmetic and pharmaceutical industries. Carotenoids, beyond their health-promoting roles, function as accessory pigments that influence petal coloration, flower quality, and stress responses. However, their accumulation patterns and molecular biosynthesis in R. rugosa remain poorly understood. Here, UPLC-APCI-MS/MS analysis across three developmental stages (bud, semi-open, and full bloom) revealed stage-specific carotenoid accumulation, with phytoene and phytofluene markedly increasing at the semi-open stage. In total, 11 carotenoids were identified, comprising four carotenes and seven xanthophylls. Differential accumulation of metabolites (DAMs) analysis indicated shifts in compounds, including (E/Z)-phytoene, phytofluene, and β-carotene across stages. Genetic complementation assays in Escherichia coli and transient overexpression in rose petals confirmed that RrPSY1 functions as a phytoene synthase. qRT-PCR results showed its upregulation under salt treatment, suggesting a role in enhancing stress tolerance through carotenoid-mediated antioxidant protection. Furthermore, sub-cellular localization experiments confirmed plastid targeting of RrPSY1. Together, these findings clarify the role of RrPSY1 in carotenoid biosynthesis and provide a foundation for future studies on metabolic regulation and biosynthesis of carotenoids in R. rugosa. Full article

In recent years, numerous studies have emerged on the biological activities of endemic berries from the Valdivian Forest and their potential for therapeutic use. However, some species appear to have been relatively neglected. The objective of this study was to conduct, for the first time, a phytochemical composition analysis of a hydroalcoholic extract of Luzuriaga radicans Ruiz & Pav. and to evaluate its potential as an antioxidant and as an enzyme inhibitor in relation to chronic non-communicable diseases. The berries were collected in the Saval Park in Valdivia and were subsequently extracted via sonication in ethanol/water. UHPLC-DAD, HPLC-APCI (+)-MS, and UHPLC-ESI (+)-TOF-MS analysis allowed for the identification of several carotenoid ester species. According to UHPLC-DAD, the sum of carotenoids yielded was 983.4 ± 26.3 mg/kg DW, while the concentration of the phenolic compounds was 9.33 ± 0.01 mg GAE/g dry fruit. The extract exhibited antioxidant properties by scavenging DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2-azinobis-(3-ethylbenzothioazolin-6-sulfonic acid)) radicals, and ferric reducing antioxidant power (FRAP). It also demonstrated cholinesterase enzyme inhibitor capacities (AChE and BuChE—IC₅₀: 6.904 ± 0.42 and 18.38 ± 0.48 µg/mL, respectively). Docking calculations were additionally performed for a selection of compounds in the berries. The data obtained suggest that the hydroalcoholic extract of L. radicans possesses significant potential as a natural antioxidant and for the inhibition of enzymes, making it a promising candidate for the development of phytotherapeutic and nutraceutical products, especially as a supplement against chronic diseases. Full article

Polycyclic aromatic hydrocarbon (PAH) derivatives, specifically azaarenes and nitrated and oxygenated PAHs, are emerging contaminants of concern due to their increased toxicity and persistence compared to the parent PAHs. Despite their toxicity, their simultaneous analysis in complex matrices, such as in fumes emitted from bituminous mixtures, remains challenging due to limitations of conventional analytical techniques. To address this, an advanced methodology was developed using Ultra-High-Performance Liquid Chromatography coupled with High-Resolution Mass Spectrometry (UHPLC-HRMS Orbitrap Eclipse) equipped with an APCI source for the simultaneous identification and quantification of 14 PAH derivatives. Chromatographic and ionization parameters were optimized to ensure maximum sensitivity and selectivity. Following ICH Q2(R2) guidelines, the method was validated, demonstrating excellent linearity (R² > 0.99), high mass accuracy (≤5 ppm), strong precision (<15%), and excellent sensitivity. Limits of detection (LODs) ranged from 0.1 µg L⁻¹ to 0.6 µg L⁻¹ and limits of quantification (LOQs) ranged from 0.26 µg L⁻¹ to 1.87 µg L⁻¹. The validated method was successfully applied to emissions from asphalt pavement materials collected on quartz filters under controlled conditions, enabling the identification and quantification of all 14 targeted compounds. These results confirm the method’s robustness and suitability for trace-level analysis of PAH derivatives in complex environmental matrices. Full article

To address the need for improved nutritional value of organically grown wheat, this study investigated the impact of silicon treatments (AdeSil, ZumSil) on yield, health status, and bioactive compound content in spring wheat cultivars. The 2019–2020 research evaluated different application variants: seed dressing, foliar sprays, and their combinations. Comprehensive seed dressing combined with two foliar treatments, (variant B) and two foliar treatments (variant C), significantly increased yield (by an average of 8.9% and 7.6% vs. control, respectively). These variants beneficially affected fungal disease resistance mainly in the stressful 2019; in optimal 2020, they showed no clear advantage over the control, which performed similarly or better. Seed dressing (variant D) increased total phenolic acids (PAs) content and antioxidant activity, with the spelt cv. Wirtas exhibiting the highest levels. Silicon treatments modified alkylresorcinols (ARs) content, but effects depended on the year, cultivar, and application variant, not always exceeding the control. Silicon treatments, especially when applied in combination (seed dressing and foliar application), can improve spring wheat yield and favorably modify PAs content, enhancing grain nutritional value. However, the plant response regarding health status and ARs content is strongly conditioned by cultivar specificity and the prevailing environmental conditions of the growing year. Full article

Chlorothalonil and its toxic metabolite, 4-hydroxy-chlorothalonil, pose significant environmental and health risks. However, their simultaneous and accurate detection remains challenging due to their differing ionization efficiencies in mass spectrometry and the interference caused by enzymatic reactions in sulfur-rich vegetables. This study developed a UHPLC-MS/MS method for simultaneous detection of chlorothalonil and 4-hydroxy-chlorothalonil, using an atmospheric pressure chemical ionization (APCI) source, optimizing the probe temperature to 600 °C and a set of optimal chromatography parameters. A low-temperature and acidification synergistic enzyme inhibition strategy was developed, involving refrigerating samples and extraction reagents, acidifying with citric acid before sample homogenization, and extracting with formic acid/acetonitrile, significantly improving chlorothalonil recovery. Method validation demonstrated limits of detection (LOD) and quantification (LOQ) of 0.003 mg/kg and 0.01 mg/kg, respectively, with recoveries of 76.5–91.1% for chlorothalonil and 87.6–96.7% for 4-hydroxy-chlorothalonil. The method was successfully applied in monitoring the residue risks in sulfur-rich vegetables. Full article

The meat industry is one of the main sources of organic waste in the food processing sector. Due to their high content of biodegradable organic matter, these wastes represent a potentially valuable resource for the development of recycling and valorization processes, particularly with regard to the circular economy and environmental sustainability. The present study aimed at assessing the potential of natural sheep casings waste (NSCW) as a source of nitrogen for promoting the growth and lipid production of Scenedesmus rubescens MDP19, a marine microalga isolated from the Mediterranean coastline of northern Morocco. For this purpose, we evaluated the effects of different NSCW concentrations (0.25–5 g L⁻¹) on the microalga growth, its ability to utilize organic waste components (proteins, amino acids, and carbohydrates) as nutrients, and its efficiency in eliminating nitrogen and phosphorus. Lipid and pigment contents were determined using colorimetric methods, and their composition was analyzed by high-performance liquid chromatography coupled with atmospheric pressure chemical ionization mass spectrometry (HPLC-APCI-MS/MS). The results showed that S. rubescens MDP19 achieved the highest biomass production of 1.737 g L⁻¹ at an NSCW concentration of 5 g L⁻¹. This strain removed 33.70–47.63% of protein, 71.84–87.62% of amino acids, 41.9–92.97% of carbohydrates, 59.72–99.30% of nitrogen, and 80.74–99.10% of phosphorus. Furthermore, S. rubescens MDP19 showed a significantly enhanced lipid content (68.11%) at an NSCW concentration of 0.5 g L⁻¹. At this concentration, the lipid composition of S. rubescens MDP19 was particularly complex, including monounsaturated and polyunsaturated fatty acids, digalactosyldiacylglycerols, sulfoquinovosyldiacylglycerols, phosphatidylglycerols, and acylglycerols. The pigment profile includes neoxanthin, canthaxanthin, lutein, chlorophyll a, geranylgeranyl chlorophyll a, chlorophyllide b, hydrochlorophyllide b, and pheophytin a. These results indicate that natural sheep casings waste represents a promising source of nitrogen, reducing the need for nutrient supplementation in microalgae production. This approach not only offers a sustainable and economical alternative for optimizing microalgae cultivation but also contributes to the valorization of organic waste, thus supporting more ecological and responsible practices. Full article

This study aimed to characterize carotenoid profiles and unravel the genetic mechanisms underlying flesh color variation in white and yellow-fleshed peaches, with a focus on the hybrid cultivar ‘ZY29’ derived from two white-fleshed parents (‘Yulu’ and ‘Hujing Honey Dew’). Using UPLC-APCI-MS/MS, we quantified carotenoids in the pericarp (exocarp) and flesh (mesocarp) of parental and hybrid fruits. Results showed that ‘ZY29’ accumulated significantly higher levels of β-carotene and lutein compared to its white-fleshed parents. Transcriptome analysis revealed upregulation of carotenoid biosynthesis genes (PSY, LCYB, and ZDS) and downregulation of the carotenoid cleavage gene CCD4 in ‘ZY29’, explaining enhanced carotenoid accumulation. Integrative metabolome-transcriptome analysis identified core regulatory networks associated with metabolic shifts, including transcription factors (MYB and WRKY). These findings provide novel insights into the molecular basis of yellow flesh formation in peaches, offering potential targets (PSY and LCYB) and metabolic markers (β-carotene and lutein) for breeding nutritionally enriched cultivars. These findings contribute to a better understanding of the genetic factors and parental regulatory mechanisms involved in the formation of yellow flesh color in peaches. Our results have important implications for breeding new peach varieties with desirable color and nutritional qualities and may provide valuable insights for future research in this area. Full article

Background/Objectives: Oxazolidinones are novel antimicrobial agents used to combat bacterial infections, particularly multidrug-resistant strains. However, the synthesis of oxazolidinone derivatives, such as linezolid, often involves the use of 3,4-difluoronitrobenzene (DFNB) as an initiator. Despite its effectiveness, residual DFNB in drug products raises significant health concerns due to its structural similarity to toxic and carcinogenic nitrobenzenes. This contamination is particularly concerning in pharmaceutical formulations, where it poses potential patient safety hazards. Therefore, strict concentration limits for this impurity are necessary. Methods: To ensure tight control of DFNB concentrations, this study established an 8.3 µg/g target limit. An advanced high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed to overcome current limitations in detecting trace DFNB. Under negative atmospheric pressure chemical ionization (APCI) conditions, DFNB exhibited characteristic ion formations, including [M]^•− through electron capture and [M − F + O]⁻ via substitution reactions. The quantitative method utilizes MS/MS ion transitions of the substitution product while optimizing chromatographic and spectrometric parameters to enhance both sensitivity and specificity. Conclusions: Validation tests confirm the efficiency, precision, and accuracy of this method, with a low limit of quantification (LOQ) of 5 ng/mL (0.83 µg/g). This technique enables accurate detection and quantification of DFNB in linezolid active pharmaceutical ingredient (API) and various formulations, providing a reliable tool for quality control. This method ensures the safe use of linezolid by effectively monitoring and minimizing the risks associated with DFNB contamination. Full article

This study aimed to optimize the extraction conditions for a valuable source of antioxidants: seaweed. Therefore, ten seaweed samples were subjected to a solid–liquid extraction (SLE), where the extraction conditions (biomass (g): solvent (mL) ratio, temperature, and time) were optimized using response surface methodology (RSM). The seaweeds were also subjected to subcritical water extraction (SWE) (140 and 190 °C) and ultrasound-assisted extraction (UAE) (10 and 20 min). The antioxidant capacity of the extracts was determined through the ferric-reducing antioxidant power and the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid). The total phenolic content revealed the significance of temperature and biomass; solvent ratio parameters in the extraction process with higher conditions generally promoting the release of phenolic compounds. Furthermore, applying RSM allowed for the identification of optimal conditions and the establishment of predictive models that can be valuable in industrial-scale extraction processes. The antioxidant potency composite index (APCI) shows that SWE at 190 °C stands out, with E. bicyclis reaching an APCI score of 46.27%. The AGREEprep evaluation showed that UAE is the most sustainable method, achieving the highest score (0.69). The results of this study contribute to the development of efficient and standardized extraction protocols for each seaweed species, allowing for the maximum yield of antioxidants. Full article

Triarylamine groups have been widely utilized in the development of high-performance charge-transporting or luminescent materials for fabricating organic light-emitting diodes (OLEDs). In this study, atmospheric pressure chemical ionization (APCI) Q-Orbitrap mass spectrometry was adopted to investigate the dissociation behaviors of these triarylamine derivatives. Specifically, taking [M+H]⁺ as the precursor ion, high-energy collision dissociation (HCD) experiments within the energy range from 0 to 80 eV were carried out. The results showed that triarylamine derivatives with specific structures exhibited distinct fragmentation patterns. For diarylamine, the formation of odd-electron ions was ascribed to the single-electron transfer (SET) reaction mediated by ion-neutral complexes (INCs). In the low-energy range (below 40 eV), proton transfer served as the predominant mechanism for generating even-electron ions. Conversely, in the high-energy range (60 eV and above), the INC-SET reaction dominated. The precursor ion’s structure affects compliance with the “even-electron rule”, which has exceptions. Here, even-electron ion fragmentation was energy-dependent and could deviate from the rule, yet did not conflict with its concept, reflecting dissociation complexity. This research provides insights for triarylamine-based OLED materials, facilitating analysis and identification, and is expected to aid OLED material development. Full article

This study presents a dynamic multi-factor correlation analysis method designed to predict provincial carbon dioxide emissions (CDE) within China’s Bohai Rim region, including Tianjin, Hebei, Shandong, and Liaoning. By employing the sliding window technique, dynamic correlation curves are computed between various influencing factors and CDE at different time intervals, thereby facilitating the identification of key feature attributes. A novel metric, the Consistency Index of Influencing Factors (CIIF), is introduced to evaluate the consistency of these factors across regions. Furthermore, the Accurate Predictive Capability Indicator (APCI) is defined to measure the impact of different feature categories on the prediction accuracy. The findings reveal that models relying on a single influencing factor exhibit limited accuracy, whereas combining multiple factors with diverse correlation features significantly improves the prediction accuracy. This study introduces a refined analytical framework and a comprehensive indicator system for CDE prediction. It enhances the understanding of the complex factors that influence CDE and provides a scientific rationale for implementing effective emission reduction strategies. Full article

Terpenes are plant secondary metabolites known for their anti-inflammatory and antioxidant activities. According to ethnobotanical knowledge, Rhododendron luteum Sweet was used in traditional medicine against inflammation. The present study was conducted to determine the triterpene profile and antioxidant and anti-inflammatory activity of supercritical CO₂ (SC-CO₂) extracts of Rhododendron luteum Sweet flower (RLF). An LC-APCI-MS/MS analysis showed the presence of eight pentacyclic triterpenes and one phytosterol in the extracts obtained with pure CO₂ as well as CO₂ with the addition of aqueous ethanol as a co-solvent. Among the compounds detected, oleanolic/ursolic acid, β-sitosterol and 3β-taraxerol were the most abundant. The extract obtained with pure SC-CO₂ was additionally subjected to HS-SPME-GC-FID-MS, which revealed more than 100 volatiles, mainly eugenol, β-phenylethanol, dodecane, β-caryophyllene, estragole and (Z)- and (E)-cinnamyl alcohol, followed by δ-cadinene. The extracts demonstrated significant hyaluronidase inhibition and exhibited varying modes of lipoxygenase and xanthine oxidase inhibitory activities. The studies of RLF have shown that their SC-CO₂ extracts can be a rich source of triterpenes with anti-inflammatory potential. Full article