High Degree Of Unsaturation Research Articles

Synthesis and Chemical Characterization of Alkyd Resins Using Maleic and Phthalic Anhydrides and Seed oil of Luffa aegyptiaca

The study aimed to provide sustainable alternatives to reduce industries’ over-reliance on edible vegetable oil for alkyd resin preparation as applicable in paint production. Alkyd resins were synthesized and characterized from sponge (Luffa aegyptiaca) seed oil. Condensation polymerization of monoglyceride with phthalic and maleic anhydride was carried out, and physico-chemical parameters such as drying time, total solids, viscosity, and chemical resistance were investigated following standard procedures. UV–visible, FT-IR, 1H, and 13C NMR spectroscopies were used to characterize the prepared alkyd resins. Sponge seed oil alkyd resins prepared with maleic anhydride (SPOMA) had a higher percentage yield (77.56%) than sponge seed oil prepared using phthalic anhydride (SPOPA) with 64.44%. The two alkyd resins showed a better drying time of 40 – 50 min than their commercial counterparts (70 min). This was attributed to the high degree of unsaturation of the seed oil due to the considerable proportion of linoleic acid in the seed oil. The alkyd resins were largely stable in 0.1 M HCl, 5% NaCl, and 0.1 M KOH, which caused the alkyd resins to whiten and shrink. The resins were generally soluble in xylene, kerosene, and petroleum ether. The nature of the alkyd resin can be described as nonpolar. This observation was consistent with the literature report. This study concluded that quality or industrial-grade alkyd resins could be prepared from sponge seed oil and thereby serve as a cheap and viable replacement for edible oils used in industries.

Solid–Liquid Phase Transitions of Triglycerides in Griebenschmalz, Smalec, and Fedt Studied Using 13C Solid-State NMR with Dynamics-Based Spectral Filtering

The consumer satisfaction of lard-based bread spreads depends on a delicate balance between a liquid fat phase, allowing the spread to flow, and solid fat crystals, providing the product with substance sometimes further enhanced by crispy pork cracklings. Here we apply 13C solid-state NMR with dynamics-based spectral filtering to characterize and follow the temperature dependence of the co-existing solid and liquid triglyceride phases in commercial German Griebenschmalz and Polish smalec, both containing cracklings, as well as home-made Danish fedt and, as a chemically more pure reference, German Schweineschmalz intended for baking. The NMR method allows detection of carbon atoms representative of saturated, unsaturated, and polyunsaturated acyl chains in both solid and liquid states. The results show that the solid comprises multiple crystal forms with different melting temperatures, while the liquid is at low temperature enriched in triglycerides with shorter acyl chains and higher degree of unsaturation, which become diluted with long-chain saturated triglycerides as the solids are melting. The obtained deeper understanding of the concomitant aspects of the phase transitions may pave the way for future efforts of rational optimization of fat blend composition to extend the temperature range over which the product contains sufficient amounts of both solids and liquids to give texture properties appealing to consumers.

Metabolic remission precedes possible weight regain after gastric bypass surgery.

Some patients regain weight to a variable extent from 1 year after Roux-en-Y gastric bypass surgery (RYGB), though rarely reaching preoperative values. The aim of the present study was to investigate whether, when, and to what extent metabolic remission occurs. Fasting metabolite and lipid profiles were determined in blood plasma collected from a nonrandomized intervention study involving 148 patients before RYGB and at 2, 12, and 60 months post RYGB. Both short-term and long-term alterations in metabolism were assessed. Anthropometric and clinical variables were assessed at all study visits. This study found that the vast majority of changes in metabolite levels occurred during the first 2 months post RYGB. Notably, thereafter the metabolome started to return toward the presurgical state. Consequently, a close-to-presurgical metabolome was observed at the time when patients reached their lowest weight and glucose level. Lipids with longer acyl chains and a higher degree of unsaturation were altered more dramatically compared with shorter and more saturated lipids, suggesting a systematic and reversible lipid remodeling. Remission of the metabolic state was observed prior to notable weight regain. Further and more long-term studies are required to assess whether the extent of metabolic remission predicts future weight regain and glycemic deterioration.

Difference analysis of dissolved gas in natural ester insulating fluids under typical electrical and thermal faults: An experimental study

AbstractNatural ester insulating oil is widely used in transformers due to its good fire resistance and biodegradability. It is mainly composed of triglycerides, and there are some differences in fatty acid composition and content among natural esters. Therefore, the fault diagnosis methods based on dissolved gas analysis are different. Three kinds of natural ester insulating oils are used to study the dissolved gas in oil under typical electrical and thermal faults of power transformers. Thermal faults from 200°C to 800°C and electrical faults with different discharge energies, which include partial discharge, breakdown discharge, and arc discharge, are simulated. The characteristic gases and their variation trends of natural esters under thermal and electrical faults are obtained through the experimental results. The gas generation characteristics of the three natural ester insulating oils under typical electrical and thermal faults are almost similar, but the relative percentages of characteristic gases have certain differences. Natural ester insulating oil with a higher unsaturation degree tends to produce more H2 and less C2H4. Finally, the fault diagnosis methods are used to determine the fault gas data, and the Duval pentagon is modified and improved according to the gas generation characteristics of natural esters.

Macadamia oil-based oleogels as cocoa butter alternatives: Physical properties, oxidative stability, lipolysis, and application

In this study, macadamia oil-based oleogels were prepared using monoglyceride stearate (MG) as a gelator with a low critical gelation concentration (3.0 wt%). The physical properties of the oleogels were evaluated by polarized light microscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, X-ray diffraction, texture and rheological analysis. And the lipid digestion and oxidative stability of the macadamia oil were determined by pH titration and accelerated oxidation test, respectively. The results showed that the hardness, oil binding capacity, and thermal stability of the oleogels increased with increasing MG concentration, which was attributed to the formation of a network of MG crystals held together by van der Waals interactions and hydrogen bonds. Rheological analysis indicated that all the oleogels exhibited a thermally reversible solid-to-liquid transition and viscoelastic behavior at ambient temperatures. Moreover, the formation of oleogels increased fatty acid release during in vitro lipid digestion and improved the oxidative stability of the macadamia oil. In addition, the potential application of these oleogels as replacements for saturated fats in foods was demonstrated by creating a chocolate product where the cocoa butter was replaced with macadamia oil-based oleogels with a high degree of unsaturation. These results can provide guidance for the preparation of macadamia oil-based oleogels, which may increase their application in foods.

Molecular properties and biotoxicity of dissolved organic matter leached from microplastic (MP-DOM) during typical hydrothermal treatment of sewage sludge

Microplastic-derived dissolved organic matter (MP-DOM) is crucial for assessing ecological and environmental impact of microplastics. However, the factors that influence the ecological effects of MP-DOM are yet to be determined. This study investigated the influence of plastic type and leaching conditions (thermal hydrolysis, TH; hydrothermal carbonization, HTC) on the molecular properties and toxicity of MP-DOM using spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). Results revealed that plastic type was the main factor affecting the chemodiversity of MP-DOM, compared to leaching conditions. Polyamide 6 (PA6) dissolved the largest number of DOM due to the presence of heteroatoms, followed by polypropylene (PP) and polyethylene (PE). From TH to HTC processes, the molecular composition of PA-DOM remained constant, with CHNO compounds being dominant, and labile compounds (lipids-like, and protein/amino sugar-like compounds) accounting for >90 % of the total compounds. In polyolefin-sourced DOM, CHO compounds were dominant, and the relative concentration of labile compounds decreased dramatically, resulting in the higher degree of unsaturation and humification than PA-DOM. The mass difference network analysis showed that the main reaction in PA-DOM and PE-DOM was oxidation while in PP-DOM, it was the carboxylic acid reaction. However, plastic type and leaching conditions jointly influenced the toxic effects of MP-DOM. PA-DOM was bioavailable, while polyolefin-sourced DOM leached under HTC treatment exhibited toxicity, with lignin/CRAM-like compounds being the dominant toxic compounds. Notably, the 2-fold higher relative intensity of the toxic compounds and the 6-fold higher abundance of highly unsaturated and phenolic-like compounds in PP-DOMHTC resulted in the higher inhibition rate than PE-DOMHTC. Toxic molecules in PE-DOMHTC mainly directly dissolved from PE polymers, while almost 20 % of toxic molecules in PP-DOMHTC resulted from molecular transformation, where dehydration (-H2O) was the core reaction. These findings offer advanced insights into the management and treatment of MPs in sludge.

Lipid Membrane Remodeling by the Micellar Aggregation of Long-Chain Unsaturated Fatty Acids for Sustainable Antimicrobial Strategies.

Antimicrobial fatty acids derived from natural sources and renewable feedstocks are promising surface-active substances with a wide range of applications. Their ability to target bacterial membrane in multiple mechanisms offers a promising antimicrobial approach for combating bacterial infections and preventing the development of drug-resistant strains, and it provides a sustainable strategy that aligns with growing environmental awareness compared to their synthetic counterparts. However, the interaction and destabilization of bacterial cell membranes by these amphiphilic compounds are not yet fully understood. Here, we investigated the concentration-dependent and time-dependent membrane interaction between long-chain unsaturated fatty acids-linolenic acid (LNA, C18:3), linoleic (LLA, C18:2), and oleic acid (OA, C18:1)-and the supported lipid bilayers (SLBs) using quartz crystal microbalance-dissipation (QCM-D) and fluorescence microscopy. We first determined the critical micelle concentration (CMC) of each compound using a fluorescence spectrophotometer and monitored the membrane interaction in real time following fatty acid treatment, whereby all micellar fatty acids elicited membrane-active behavior primarily above their respective CMC values. Specifically, LNA and LLA, which have higher degrees of unsaturation and CMC values of 160 µM and 60 µM, respectively, caused significant changes in the membrane with net |Δf| shifts of 23.2 ± 0.8 Hz and 21.4 ± 0.6 Hz and ΔD shifts of 5.2 ± 0.5 × 10-6 and 7.4 ± 0.5 × 10-6. On the other hand, OA, with the lowest unsaturation degree and CMC value of 20 µM, produced relatively less membrane change with a net |Δf| shift of 14.6 ± 2.2 Hz and ΔD shift of 8.8 ± 0.2 × 10-6. Both LNA and LLA required higher concentrations than OA to initiate membrane remodeling as their CMC values increased with the degree of unsaturation. Upon incubating with fluorescence-labeled model membranes, the fatty acids induced tubular morphological changes at concentrations above CMC. Taken together, our findings highlight the critical role of self-aggregation properties and the degree of unsaturated bonds in unsaturated long-chain fatty acids upon modulating membrane destabilization, suggesting potential applications in developing sustainable and effective antimicrobial strategies.

Structural Impact of Selected Retinoids on Model Photoreceptor Membranes

Photoreceptor membranes have a unique lipid composition. They contain a high level of polyunsaturated fatty acids including the most unsaturated fatty acid in nature, docosahexaenoic acid (22:6), and are enriched in phosphatidylethanolamines. The phospholipid composition and cholesterol content of the subcellular components of photoreceptor outer segments enables to divide photoreceptor membranes into three types: plasma membranes, young disc membranes, and old disc membranes. A high degree of lipid unsaturation, extended exposure to intensive irradiation, and high respiratory demands make these membranes sensitive to oxidative stress and lipid peroxidation. Moreover, all-trans retinal (AtRAL), which is a photoreactive product of visual pigment bleaching, accumulates transiently inside these membranes, where its concentration may reach a phototoxic level. An elevated concentration of AtRAL leads to accelerated formation and accumulation of bisretinoid condensation products such as A2E or AtRAL dimers. However, a possible structural impact of these retinoids on the photoreceptor-membrane properties has not yet been studied. In this work we focused just on this aspect. The changes induced by retinoids, although noticeable, seem not to be significant enough to be physiologically relevant. This is, however, an positive conclusion because it can be assumed that accumulation of AtRAL in photoreceptor membranes will not affect the transduction of visual signals and will not disturb the interaction of proteins engaged in this process.

Urban particulate water-soluble organic matter in winter: Size-resolved molecular characterization, role of the S-containing compounds on haze formation

Water-soluble organic matter (WSOM), as a group of ubiquitous components in atmospheric PM, plays a crucial role in global climate change and carbon cycle. In this study, the size-resolved molecular characterization of WSOM in the range of 0.010–18 μm PM was studied to gain insights into their formation processes. The CHO, CHNO, CHOS, CHNOS compounds were identified by the ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry in ESI source mode. A bimodal pattern of the PM mass concentrations was found in the accumulation and coarse mode. The increasing mass concentration of PM was mainly attributed to the growth of large-size PM with the occurrence of haze. Both Aiken-mode (70.5–75.6 %) and coarse-mode (81.7–87.9 %) particles were proven the main carriers of the CHO compounds, the majority of which were indicated to be the saturated fatty acids and their oxidized derivatives. The S-containing (CHOS and CHNOS) compounds in accumulation-mode (71.5–80.9 %) increased significantly in hazy days, where organosulfates (C11H20O6S, C12H22O7S) and nitrooxy-organosulfates (C9H19NO8S, C9H17NO8S) were confirmed in majority. The S-containing compounds in accumulation-mode particle with high oxygen content (6–8 oxygen atoms), unsaturation degree (DBE < 4), and reactivity could facilitate the particle agglomeration and accelerate the haze formation.

Semicrystalline IrOx with Abundant Boundaries for Overall Water Splitting.

Inorganic compounds with different crystalline and amorphous states may show distinct properties in catalytic applications. In this work, we control the crystallization level by fine thermal treatment and synthesize a semicrystalline IrOx material with the formation of abundant boundaries. Theoretical calculation reveals that the interfacial iridium with a high degree of unsaturation is highly active for the hydrogen evolution reaction compared to individual counterparts based on the optimal binding energy with hydrogen (H*). At the heat treatment temperature of 500 °C, the obtained IrOx-500 catalyst has dramatically promoted hydrogen evolution kinetics, endowing the iridium catalyst with a bifunctional activity for acidic overall water splitting with a total voltage of only 1.554 V at a current density of 10 mA cm-2. In light of the remarkable boundary-enhanced catalysis effects, the semicrystalline material should be further developed for other applications.

Molecular-level evidence of early lipid transformations throughout oceanic depths

Our understanding of lipid biogeochemistry of the ocean’s interior is still in its infancy. Here we focus on early lipid transformation and the formation of lipid degradation products in the NE Atlantic Ocean (49.0°N, 16.5°W). We employed high resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), a method that allows observation and elemental composition assignment of thousands of lipids in a single sample. Using these data, we infer molecular-level changes that occur during lipid transformation in the oceanic water column to shed new light on early lipid transformation processes and the formation of lipid decomposition intermediates, here termed CHO compounds (i.e., lipid-derived species that contain carbon, hydrogen and oxygen in their molecular formula). We considered the distribution of molecular rings and/or double bonds (DBE), H/C and O/C ratios, molecular diversity based on the number of mass spectral signals for monoisotopic species, and carbon number in CHO molecules. Data are elaborated for the four ocean zones, the epipelagic, mesopelagic, bathypelagic and abyssal. The highest molecular diversity characterizes CHO compounds associated with the epipelagic zone, which is explained by numerous and diverse planktonic communities inhabiting the epipelagic and by the effects of both biotic and abiotic processes on lipid transformation. Lipid transformations include crosslinking (condensation), partial degradation or fragmentation, double bond reduction, oxidation, hydrogenation, dehydrogenation and cyclization. Crosslinking likely results in a unimodal distribution of carbon number of CHO compounds, in contrast to cell lipids (referred to as Reported lipids based on the Lipid Maps Database), which have a bimodal distribution of carbon number. CHO compounds that appear to be formed by fragmentation (decrease of the number of C atoms) and ring/double bond reduction were more stable to further transformation and remained longer in the water column, i.e., these compounds were transferred deeper into the water column. Low unsaturation and fast transport to depth promotes CHO compound preservation in the water column. Dehydrogenation leads to increased unsaturation (average DBE up to 21.3), condensation, and cyclization, resulting in high molecular weight compounds with a high degree of unsaturation. Our data demonstrate that lipids with cyclic structures are more refractory than those with acyclic structures. The formation of aromatic structures is not a significant process during early lipid transformation in the oceanic water column.

Catalytic hydroprocessing of camelina oil/AGO mixtures over NiMoP/γ-Al2O3 catalysts

Inedible camelina oil (CSO) contains fatty acids with a high degree of unsaturation (1.8 double bonds per fatty acid on average). CSO was hydrotreated at temperatures 340–370 °C, pressures of 15–50 bar, and liquid hour space velocities (LHSVs) of 0.8–1.1 h-1 for the production of hydrocarbons that are usable as diesel components. First, hydrotreating pure CSO at 340–370 oC and low hydrogen pressures of 15–25 bar led to the formation of a mixture of n-/iso- alkanes, aromatics, and higher olefins. The presence of CC double bonds in the CSO molecule affected the progress of the side reactions and caused rapid deactivation and coking of the catalyst, especially at low hydrogen partial pressure. Hydrotreatment co-processing of polyunsaturated CSO and partially hydrogenated CSO was then done with two different gas oils or two paraffinic solvents in the range of concentration 5–20%. Co-hydrotreatment took place in a bench-scale trickle-bed reactor using commercial NiMoP/γ-Al2O3 catalysts (catalysts A and B) and a prepared catalyst, NiMoCuP/ZrO2-γ-Al2O3 (catalyst C). High triacylglyceride conversion to hydrocarbons was achieved when CSO was hydrogenated in a mixture with paraffinic solvents on NiMoP/γ-Al2O3 catalysts at hydrogen partial pressures above 30 bar and temperatures above 350 oC. CSO decarboxylation/decarbonylation reactions prevailed over hydrodeoxygenation. Hydrodeoxygenation (72%) was predominant for catalyst C with significant methanation of CO and CO2. There was a complete TAG conversion into hydrocarbons when co-processing a mixture of CSO and atmospheric gas oil at a temperature of 360 oC, LHSV of 0.8 h-1, a hydrogen pressure of 50 bar, and various ratios of hydrogen to raw material from 312 to 656 NL.L-1. The deoxygenation activity decreased in the order of catalysts C>B>A. Increasing the ratio of H2 to feed had a positive effect on the composition and properties of the liquid product. During experiments with catalyst C at 50 bar, 370 °C, and ratios of hydrogen to raw material of 293–656 NL.L-1, the cetane index increased from 46 to 58, and the polyaromatic content decreased from 12.5 to 4.4 wt%. The sulphur and nitrogen contents of the product (29.5 mg.kg-1 and 13.2 mg.kg-1) were higher than expected. In the case of catalyst C, the degree of desulphurization was lower than that of catalysts A and B.

Formulation, characterization, pharmacokinetics and antioxidant activity evaluation of Pinus koraiensis nuts oil based coenzyme Q10 loaded nanoemulsion

Coenzyme Q10(CoQ10) is a well-known lipophilic antioxidant with good prospects for practical application of different fields including foods and pharmaceutics but has the drawback of low oral bioavailability because of its water insolubility and instability. Pinus koraiensis nut oil(PNO) is excellent in nutritional content and contains a great amount of unsaturated fatty acids that are helpful to the human body. It is easily oxidized, however, due to the high degree of unsaturation in its own structure, which limits its application. The present study aimed to formulate and characterize a CoQ10 loaded nanoemulsion based on PNO to overcome these problems of CoQ10 and PNO. Simultaneously, the physiological effects of the CoQ10 and PNO can work together in a synergistic way. In this study, coenzyme Q10 nanoemulsion(CoQ10-NE) with good stability was prepared by high pressure homogenization(HPH) technology. The CoQ10-NE was evaluated by TEM, FTIR, encapsulation rate, stability and release behavior in vitro. The bioavailability and the relationship between cellular oxidative stress and anticancer of CoQ10-NE was studied by pharmacokinetic and activity of malondialdehyde(MDA), superoxidedismutase(SOD) and glutathione peroxidase(GPx) about mouse colon cancer cells(CT26. WT). The area under the curve(AUC0-ꝏ) of CoQ10-NE was 3.25 folds higher than that of CoQ10 suspension, indicating that the bioavailability and absorption of CoQ10-NE are greatly increased. Also, at the same time, CoQ10-NE has a protective effect on CT26. WT cell damage induced by H2O2 compared with CoQ10 suspension and blank nanoemulsion. The final formulation solved the insolubility and instability of CoQ10 during use, along with providing a new technology for preparing CoQ10-NE with a long-term stability and good antioxidants in the prevention of colon cancer.

Magnetic visible-light activated photocatalyst CuFe2O4/Bi2WO6/mpg-C3N4 for the treatment of natural organic matter

Despite growing interest in research on visible-light-driven photocatalysts, reusable photocatalysts have not been extensively developed for the treatment of natural organic matter (NOM), because such development requires an understanding of the complex NOM structures. In this study, we combined the individual benefits of CuFe2O4, Bi2WO6, and mesoporous graphitic carbon nitride (mpg-C3N4) to prepare a magnetic, visible-light-driven photocatalytic composite, CBC-5, for effectively removing NOM in a short period of time. The degradation mechanisms were further explored at the molecular level through ultra-high-resolution mass spectrometry. Broad light absorbance and charge transmission based on a dual S-scheme pathway allowed CBC-5 to generate multiple active agents, OH (49.7 %), O2− (27.6 %), and h+ (24.8 %), which ultimately led to the removal of 7.9 mgC of NOM per 0.9 g of CBC-5 in 6 h. Humic-like fluorophores were preferentially degraded, followed by the generation of simple phenolic components as by-products. Molecular-level investigation revealed that the NOM structures with high degree of unsaturation and functionalization were preferentially attacked by the radicals. Oxygenic groups were formed upon the oxidation of the unsaturated bonds and the functional groups having a low oxidation state of carbon (OSc) before the degradation of the carboxyl-rich alicyclic molecules. NOM degradation was prioritized in the following order: CHON > CHO > CHOS. Oxidative deamination is attributed to the preferential degradation of N-containing compounds, which are partially transformed to CHO compounds. CHOS compounds enriched with aliphatic organosulfates were recalcitrant to photocatalytic oxidation. Thus, CBC-5 demonstrated convenient magnetic recovery, stable performance, and high recyclability and can be applied as a promising NOM treatment agent.

Effect of ligand concentration and ultrasonic treatment on inclusion complexes of high amylose corn starch with chia seed oil fatty acids

Chia seed oil is rich in α-linolenic and linoleic fatty acids, which have multiple health benefits but are prone to oxidation due to their high degree of unsaturation. The linear component of starch, amylose, can interact with hydrophobic molecules (ligand) forming amylose inclusion complexes, which may potentially act as delivery systems of polyunsaturated fatty acids. Their physicochemical and functional properties are influenced by the conditions of formation. In the present study, it was investigated the effect of ultrasonic treatment and different ligand/starch ratios (10, 20, and 30% w/w) on the physicochemical properties of inclusion complexes formed between high amylose corn starch and enzymatically hydrolyzed chia seed oil. The increase in ligand/starch ratio, especially from 10 to 20%, yielded complexes with a higher content of α-linolenic acid. The effect of ultrasonic treatment on the acidic composition of complexes depended on the initial ligand concentration. All samples displayed a V-type X-ray diffraction pattern, indicating an effective complexation. Ultrasonically treated complexes showed a higher crystallinity than the untreated ones, suggesting that sonication promoted the fatty acid complexation. All samples displayed the same thermal behavior (Tp > 90 °C, ΔH = 7 J/g) and similar structural properties at the microscopic level. Thermogravimetric analysis showed that the untreated complexes formed with a 10% ligand/starch ratio effectively protected hydrolyzed chia seed oil from oxidative deterioration, suggesting an appropriate behavior as potential carrier agents of fatty acids from chia seed oil in food.

Metabolic Disorder Enhances Oxidative Stress after Exposure to Aromatic Components of Fine Particulate Matter

Metabolic disorder can exacerbate oxidative damage following exposure to fine particulate matter (PM2.5), but the role of chemical composition in this process remains unclear. This study comprehensively assessed the oxidative stress effect from the synergy of metabolic disorder and the organic components in PM2.5 as well as their molecular features. We high-throughput characterized 942 PM2.5 chemicals from an elderly urban population exposure and found the association between oxidative stress markers of exhaled nitric oxide (eNO) and urinary malondialdehyde (MDA) and 330 and 32 compounds, respectively, was enhanced by metabolic disorder. Most of these compounds were aromatics, including PAHs and their functionalized and oxidized products. The integrated explanatory random forest approach incorporating source tracers showed that primary aromatics arising from combustion with a high unsaturation degree, high logKOW, and low volatility were responsible for the increased eNO levels in participants with metabolic disorder, while compounds formed through atmospheric oxidation reactions with high numbers of carbonyl groups and oxygen atoms and relatively low logKOW were associated with elevated MDA in disordered individuals. This study provides the first evidence that metabolic disorder exacerbates oxidative stress after exposure to specific PM2.5 components, which could in turn exacerbate chronic diseases in the elderly population.

Transformation of dissolved organic matter in landfill leachate during a membrane bioreactor treatment

In this study, a cutting-edge mass spectrometry (MS) technique, Orbitrap fusion MS with ultrahigh resolution, was used to analyze the molecular composition, chemical properties, formation mechanism, and environmental impact of refractory dissolved organic matter (rDOM) in leachate. The results showed that the bioavailable DOM (bDOM) and rDOM constituents varied substantially during the biological treatment of landfill leachate. Compared with bDOM, the rDOM in leachate had a higher degree of unsaturation, aromaticity, and oxidation, and a larger molecular weight, and contained more organic matter with benzene ring and biphenyl structures. Using high-throughput 16S rRNA sequencing, metagenomics, the Kendrick mass defect (KMD), and a mass difference network (MDiN), it was found that rDOM in leachate is generated through carboxylation (+COO), dehydro-oligomerization (-H2), and chain scission (-CH2) pathways due to the activity of microbes such as Patescibacteria, Chloroflexi, and Proteobacteria. Compared with Suwannee River fulvic acid (SRFA), the rDOM in leachate contained more organics with nitrogen, sulfur, benzene rings, and biphenyls. If the rDOM in leachate enters the environment it will affect the composition of the original organic matter, and its biogeochemical transformation and environmental fate will then need to be monitored and may require special attention.

Liquid chromatography-dielectric barrier discharge ionization mass spectrometry for the analysis of neutral lipids of archaeological interest.

Dielectric barrier discharge ionization has gained attention in the last few years due to its versatility and the vast array of molecules that can be ionized. In this study, we report on the assessment of liquid chromatography coupled to dielectric barrier discharge ionization with mass spectrometry for neutral lipid analysis. A set of different neutral lipid subclasses (triacylglycerides, diacylglycerides, and sterols) were selected for the study. The main species detected from our ionization source were [M‐H2O+H]+, [M+H]+ or [M‐R‐H2O+H]+, attributed to sterol dehydration, protonation or the fragmentation of an acyl chain accompanied by a water loss of the glycerolipids, respectively. In terms of sensitivity, the dielectric barrier discharge displayed overall improved abundances and comparable or better limits of quantitation than atmospheric pressure chemical ionization for both acylglycerols and sterols. As a case study, different archaeological samples with variable content in neutral lipids, particularly triacylglycerides, were studied. The identification was carried out by combining accurate mass and the tentative formula associated with the exact mass, retention time matching with standards, and additional structural information from in‐source fragmentation. The high degree of unsaturation and the presence of sterols revealed the potential vegetal origin of the material stored in the analyzed samples.

Are n-3 PUFAs from Microalgae Incorporated into Membrane and Storage Lipids in Pig Muscle Tissues?-A Lipidomic Approach.

For the study of molecular mechanisms of to lipid transport and storage in relation to dietary effects, lipidomics has been rarely used in farm animal research. A feeding study with pigs (German Landrace sows) and supplementation of microalgae (Schizochytrium sp.) was conducted. The animals were allocated to the control group (n = 15) and the microalgae group (n = 16). Shotgun lipidomics was applied. This study enabled us to identify and quantify 336 lipid species from 15 different lipid classes in pig skeletal muscle tissues. The distribution of the lipid classes was significantly altered by microalgae supplementation, and ether lipids of phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidic acid (PA) were significantly decreased. The total concentration of triacylglycerides (TAGs) was not affected. TAGs with high degree of unsaturation (TAG 56:7, TAG 56:6, TAG 54:6) were increased in the microalgae group, and major abundant species like TAG 52:2 and TAG 52:1 were not affected by the diet. Our results confirmed that dietary DHA and EPA are incorporated into storage and membrane lipids of pig muscles, which further led to systemic changes in the lipidome composition.

Enzymatic method for obtaining fatty acid concentrate from fish oil

Fish oil, depending on the quality, is used for various industries. High-quality oils are used in the pharmaceutical and food industries. Changing the quality of fish oils are associated with the processes of hydrolysis and oxidation. Lower quality oils are used for fodder and technical purposes. One of the areas of fish oils technical use is the production of free fatty acids. Acids are obtained by oil hydrolysis. The enzymatic method of hydrolysis is considered to be promising. The method does not require high energy costs. The enzyme should be immobilized. This ensures the reusability of the enzyme in the technological process. Fish oil acids are distinguished by a high degree of unsaturation of their fatty acid composition. Therefore, these compounds can be used to obtain surface-active, film-forming and antifriction technical products.