Search Results (113)

Oxygenated intermediate-volatility organic compounds (OIVOCs) represent an important but poorly constrained class of secondary organic aerosol (SOA) precursors due to analytical challenges in their molecular-level characterization. In this study, we conducted a systematic comparison of a non-polar gas chromatography column (HP-5MS) and a polar column (DB-Heavy WAX) for the measurement of atmospheric OIVOCs using thermal desorption–gas chromatography–mass spectrometry (TD–GC/MS). A set of 48 representative oxygenated standards together with urban ambient air samples was analyzed to evaluate chromatographic separation, compound identification, and quantitative responses. The developed analytical method demonstrated excellent linearity (R² > 0.90) and precision, with relative standard deviations (RSDs) typically below 10%. The polar WAX column provided improved chromatographic resolution and peak shapes for 39 oxygenated standards (e.g., ether alcohols, esters, diesters, and nitrogen-containing compounds) driven by strong intermolecular hydrogen bonding and dipole interactions, whereas the HP-5MS column showed stronger selectivity toward non-polar species such as long-chain siloxanes and branched alkanes. Application to urban ambient samples revealed that the WAX column increased the number of identifiable OIVOC species by 14.6% relative to the HP-5MS column. Furthermore, total OIVOC concentrations derived from the WAX column were 7% higher than those obtained using the HP-5MS column, while OIVOC-to-alkane ratios were 2–4 times greater. These differences demonstrate that chromatographic selectivity can influence the characterization of oxygenated compounds within the IVOC volatility range. The potential implications of these analytical differences were further illustrated through secondary organic aerosol formation potential (SOAFP) estimation, although the limited availability of experimental SOA yield data remains a major uncertainty. Overall, this study demonstrates that appropriate chromatographic method selection is essential for reducing analytical uncertainty and improving the molecular characterization of OIVOCs in complex environmental samples. Full article

Paraffin wax precipitation and deposition significantly hinder crude oil production and transportation by reducing flow efficiency, increasing operational downtime, and requiring costly remediation procedures. Conventional wax mitigation methods commonly rely on environmentally unfriendly chemicals and energy-intensive thermal or mechanical treatments. This study investigates the use of a natural polymer from Swietenia macrophylla (Mahogany), modified with metal nanoparticles (MNPs), namely silver oxide (Ag₂O), zinc oxide (ZnO), and silver-doped zinc oxide (Ag-ZnO), for petroleum wax inhibition. Material characterization was conducted using FTIR, TGA and GC-MS analyses, while performance evaluation employed rheological measurements, Cross-Polarized Microscopy (CPM), and pour point testing. GC-MS analysis revealed the presence of oxygenated fatty acid esters such as glycidyl oleate (59.61%) and glycidyl palmitate (16.86%). These compounds indicate the presence of hydrocarbon-compatible and surface-active constituents beneficial for wax crystal modification. FTIR spectra further confirmed carbonyl, aliphatic hydrocarbon, and ether functionalities associated with natural wax-mitigation compounds and effective MNP binding sites. The application of 2 wt% polymeric materials demonstrated significant wax inhibition performance. The unmodified polymer reduced the activation energy (Ea) for crude oil flow by 49.4 kJ·mol⁻¹ from the virgin crude oil value of 213.6 kJ·mol⁻¹. The polymer + ZnO formulation achieved the highest pour point reduction of 1.72 °C, while polymer + Ag-ZnO recorded the greatest viscosity reduction of 77.1% at 1 s⁻¹ and 91.6% at 200 s⁻¹. This study demonstrates, for the first time, the potential of Swietenia macrophylla-derived nanocomposite polymers as sustainable and effective wax mitigation agents for waxy crude oil systems. Full article

Lipolytic and esterase-like enzymes are crucial in the food industry for flavor production and ester hydrolysis. This study presents an exploratory, baseline feasibility approach to evaluate esterase-like enzyme production by Serratia marcescens 11E via a sustainable co-valorization matrix, where vegetable wax residues serve as structural solid support and cheese whey acts as the primary lipid nutritional source. Under fixed 48-h screening conditions, the recovered cell-free extract exhibited a distinct catalytic preference for short-chain esters, showing higher specific activity toward 4-nitrophenyl acetate (0.743 U/mg) than 4-nitrophenyl palmitate (0.125 U/mg), confirming a predominant carboxylesterase-like profile. Biochemical characterization revealed an initial optimal activity at pH 9.0 and 30 °C, along with a noteworthy bimodal catalytic behavior featuring a secondary activity peak at 70 °C. Size-exclusion chromatography resolved the extract into two distinct active elution pools (17.8 and 26.2 U/mg), which corresponded to candidate protein bands of 35–40 kDa on SDS-PAGE. Although definitive molecular identification remains subject to ongoing zymographic and proteomic characterization, these foundational findings demonstrate the potential of co-valorizing lipid- and carbohydrate-rich industrial wastes to produce resilient proteins with esterase-like activity at elevated temperatures. Full article

In the performed studies, microsomal fractions from Arabidopsis plants were used as a source of enzymes that esterify free fatty acids to free alcohols (both fatty alcohols and short-chain alcohols). The existence of two isoforms of tested enzymes is postulated. These putative isoforms, characterized by apparent peak activities at pH 6.0 and pH 7.2, respectively, appeared to differ in their responses to environmental conditions, e.g., in their temperature dependence; in their responses to calcium and magnesium ions’ presence in assays; or in retaining activity after membrane solubilization with 4% detergent CHAPS (only the postulated isoforms most active at pH 6.0 kept their activity). Differences were also annotated in the preferences of the apparent enzymatic activities toward different fatty alcohols (although both putative isoforms showed the highest activity toward phytol) and different fatty acids (in reactions with both fatty alcohols and short-chain alcohols). Two apparent enzymatic activities were inhibited by tetrahydrolipstatin, which may suggest their lipase nature. Based on the high activity of the tested enzymes in the membrane of the microsomal fractions, the authors speculate that their physiological function might be associated with maintaining membrane integrity against the harmful effects of excess free fatty acids and/or free fatty alcohols. Full article

Background/Objectives: Beeswax, a complex natural secretion primarily derived from Apis mellifera and Apis cerana, has evolved from an ancient remedy into a multifunctional excipient and bioactive material in modern pharmaceutical sciences. This review evaluates its physicochemical properties, pharmaceutical applications, and emerging biomedical potential, while addressing current quality and regulatory challenges. Methods: A narrative review was conducted by analyzing literature on the chemical composition, functional properties, conventional uses, advanced drug delivery applications, pharmacological activities, and quality control of beeswax, emphasizing structural characteristics, formulation roles, and integration into innovative delivery technologies. Results: Beeswax is a lipid-based matrix composed of over 300 constituents, including wax esters, hydrocarbons, and free fatty acids, conferring thermoplasticity, biocompatibility, and structural stability. Traditionally, it functions as a stiffening agent, viscosity modifier, and emulsion stabilizer in topical formulations, forming an occlusive barrier that enhances skin hydration. In advanced systems, it serves as a solid lipid matrix in nanostructured lipid carriers (NLCs), microspheres, and 3D-printed tablets, enabling controlled drug release and improved bioavailability of lipophilic compounds. It also exhibits antimicrobial, anti-inflammatory, and wound-healing activities, while beeswax-derived policosanols show potential cardiovascular and gastroprotective benefits. However, concerns regarding paraffin adulteration and pesticide contamination highlight the need for stringent analytical and regulatory oversight. Conclusions: With rigorous quality control and sustainable sourcing, beeswax remains a versatile, eco-friendly material bridging traditional medicine and advanced pharmaceutical innovation. Full article

This study investigates the potential of Fischer–Tropsch (FT) waxes, synthesized from natural gas, as high-performance and sustainable alternatives to conventional ester waxes in cosmetic applications. To evaluate their technical viability, a series of FT waxes with varying hydrocarbon chain lengths were synthesized and characterized. Safety was rigorously assessed through human patch tests and irritation surveys, while sensory attributes, including gloss and transparency, were compared against beeswax and carnauba wax. Furthermore, the impact on the skin barrier was analyzed using Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) spectroscopy to determine lipid packing characteristics. The results demonstrated that FT waxes possess an excellent safety profile with irritation levels comparable to traditional waxes. Sensory evaluations revealed that adjusting the hydrocarbon chain length allows for precise control over melting points and texture, offering significant formulation flexibility. Crucially, lipid packing analysis indicated that FT waxes promote an orthorhombic organization, effectively mimicking and reinforcing the native crystalline structure of the human skin barrier. These findings conclude that FT waxes provide both superior sensory properties and functional skin-barrier benefits, positioning them as versatile and innovative ingredients for advanced dermo-cosmetic formulations. Full article

Background: Wax synthase/diacylglycerol acyltransferases (WS/DGATs), often referred to as WSD proteins, represent a class of key enzymes that catalyze the biosynthesis of wax esters in plants and other organisms. However, the WSD gene family in wheat (Triticum aestivum) has not been systematically characterized. Methods: A comprehensive genome-wide identification and bioinformatic characterization of the WSD gene family were conducted in wheat, followed by an analysis of chromosomal locations, gene structures, conserved motifs, phylogenetic relationships, expression profiles, and cis-element predictions. Results: In this study, a total of 43 TaWSDs were identified through genome-wide analysis in wheat. All identified TaWSD members exhibit highly conserved structural features and contain the core catalytic motif HHXXXDG. Phylogenetic analysis of WSD proteins from 63 species revealed that WSDs in Triticeae, including wheat, were mainly clustered into four distinct clades. Furthermore, sequence divergence among TaWSDs from different clades was primarily localized to the N-terminal region. Notably, expression profile analysis demonstrated that TaWSD genes display organ-specific expression patterns in wheat. Among them, 12 TaWSDs showed the highest expression levels in the leaf lamina joint, implying their potential involvement in the regulation of leaf angle formation. Additionally, 27 transcription factors were computationally predicted as putative regulators of TaWSDs, although their exact roles require further experimental confirmation. Conclusions: Our findings provide novel insights into the biological functions of the wheat WSD gene family and offer new perspectives for elucidating their molecular mechanisms underlying plant architecture regulation. Full article

Solar energy, as a clean and renewable resource, plays a pivotal role in advancing sustainable energy technologies. The efficiency of front-side silver paste is critical for the photovoltaic performance of Tunnel Oxide Passivated Contact (TOPCon) solar cells. In this study, we comprehensively investigated how the composition of organic vehicles in conductive pastes influences both printing rheological properties and electrical performance. Through rheological characterization, contact angle measurements, and Three-Interval Thixotropy Tests (3ITT), we examined the effects of varying solvent, binder, and thixotropic agent ratios on paste properties. The optimized formulation—a solvent mixture of lauryl alcohol ester (TE), butyl carbitol (DGME), butyl carbitol acetate (BCA), and dibutyl phthalate (DBP) in a 3:4:2:1 ratio, with ethyl cellulose (EC) STD10 as the binder and a polyamide wax (PAW)–hydrogenated castor oil (HCO) thixotropic agent at a 3:1 mass ratio—demonstrated superior viscosity control and rapid structural recovery. Printed grid lines achieved a height-to-width ratio (H/W) of 0.35 and a sheet resistance (Rs) of 1.43 Ω/□. These findings reveal direct relationships between organic vehicle composition, paste rheology, and functional performance, providing practical guidance for the design and optimization of high-performance conductive pastes for c-Si solar cells. This work establishes a foundation for improving both the efficiency and reliability of next-generation silver paste formulations in photovoltaic applications. Full article

In this paper, batch stirred-tank alcoholysis reactions of used and refined sunflower oils were performed with n-octyl, myristyl, cetyl, oleyl, and stearyl alcohols using immobilized lipases Novozym 435 and Lipozyme IM as catalysts. Alcohol conversions ranged from 74% to 94%, with slight differences between used frying sunflower oil and refined sunflower oil. The resulting wax esters were purified via stepwise column chromatography. The different regioselectivity of the biocatalysts led to distinct reaction pathways, and Novozym 435 proved to be the most effective enzyme, providing higher conversions and no detectable by-products. This study demonstrates the valorization of waste frying oils into high-value wax esters through enzymatic alcoholysis, comparing two industrially relevant immobilized lipases and achieving high conversion across multiple long-chain alcohols. The results highlight a sustainable alternative to conventional chemical catalysis and extend biocatalytic applications beyond traditional biodiesel production. By incorporating waste lipids into value-added products, the overall sustainability and circularity of the system are improved, contributing to green and sustainable chemistry. Full article

Acromegaly is a rare endocrine disease characterized by multiple metabolic abnormalities and high cardiovascular risk. This cross-sectional study evaluated the lipidomic serum profile of 109 participants (59 acromegaly patients versus 50 healthy controls) via high-performance liquid chromatography combined with mass spectrometry (HPLC-MS). The lipidomic profile that differentiated acromegaly from controls included sphingomyelins (SMs), glycerophospholipids, glycerolipids, ceramides, fatty acids, wax esters (WEs), carnitines, and sterol (ST) lipids. SM 34:0;O2 and phosphorylcholine best distinguished acromegaly patients from controls (VIP > 2.49). SM 34:0;O2 levels were significantly elevated in treatment-naïve versus uncontrolled patients (p < 0.0001). Furthermore, SM 34:0;O2 positively correlated with random GH and IGF-1. Lack of therapy predicted SM 34:0;O2 serum titers in acromegaly. Profound alterations of glycerophospholipids and sphingolipids were detected in acromegaly patients with cardiovascular complications. ST 24:1;O3, ceramide (Cer) 38:0;O4, and WE 34:1 were significantly increased in both hypertensive acromegaly patients and those with heart failure in comparison to patients without cardiovascular impairment. In conclusion, SM 34:0;O2 and phosphorylcholine emerged as potential lipidomic biomarkers in acromegaly. Moreover, SM 34:0;O2 potentially reflects disease severity. Identifying lipidomic profile alterations in acromegaly patients with cardiac involvement may provide a basis for further insights into the cardiovascular pathogenesis of the disease. Full article

This study screens the permeability of volatile organic compounds (VOCs) through edible films made of candelilla wax and guar gum, offering new insights into their role as aroma and moisture barriers. Four formulations (0.2–0.4% wax, 0.4–0.8% gum, and 0.2–0.3% glycerol) were tested using a fractional factorial design. VOC fluxes (one ester, two aldehydes, two terpenes, and one lactone) were monitored via headspace solid-phase microextraction coupled to gas chromatography–mass spectrometry (HS-SPME/GC-MS) in a diffusion cell and modeled kinetically. Wax-rich matrices compacted the network, reducing initial VOC transmission by up to 60%, while glycerol fine-tuned micromobility and selectivity. The formulation containing 0.4% wax, 0.8% gum, and 0.2% glycerol minimized time-dependent flux acceleration and reduced the cumulative permeability of both polar (hexanal) and non-polar (limonene) markers by 80%. Aroma loss decreased across all blends, correlating with improved water vapor control. These results establish quantitative criteria for developing sustainable edible coatings that balance aroma retention, water-barrier performance, and mechanical flexibility. Full article

Increasing competition in the olive oil market and labor shortages have accelerated the use of mechanical harvesting, raising concerns about potential fruit damage and its impact on oil quality. This study examined how three harvesting methods: manual using hand-held combs (B-HH) and two mechanical, hand-held shaker rake (B-MH-1) and self-propelled trunk shaker (B-MH-2), affect the quality and composition of Buža variety virgin olive oil. The greatest damage to the fruits occurred in B-MH-1, whereas the least was observed in B-HH. Olives were processed within 24 h, and oils were analyzed for basic quality parameters, fatty acid ethyl esters (FAEE), waxes content, fatty acid composition, volatile and phenolic profiles, and sensory attributes. Harvesting method did not significantly affect acidity, peroxide value, UV indices, FAEE, waxes, and fatty acids. Analyses of volatile and phenolic compounds revealed only slight differences. Nevertheless, sensory assessment detected no defects, with only minor reductions in positive odor attributes in B-MH-1. Taste attributes remained unchanged, consistent with similar total phenolic content. Overall, when olives are promptly processed, all investigated harvesting methods result in high-quality Buža olive oil. Full article

The lacquer tree (Toxicodendron vernicifluum) possesses significant economic value due to its capability to produce raw lacquer, lacquer wax, and lacquer oil. The fruit is the primary source of lacquer wax; the primary components of lacquer wax are fatty acids, yet the synthesis mechanisms of fatty acids and wax esters remain unclear. In this study, we employed RNA-seq to analyze differentially expressed genes (DEGs) across four developmental stages in the fruit of the lacquer tree. The results revealed that, compared to the T1 stage, there were 1736, 10,228, and 12,444 DEGs in the three developmental stages. Through KEGG enrichment analysis, DEGs associated with lacquer wax synthesis were found to be primarily enriched in fatty acid metabolism, degradation, and the biosynthesis of cutin, suberin, and wax esters pathways. Furthermore, analysis of DEGs expression patterns in fatty acid synthesis pathways revealed that ACC, KAS, KAR, FATB, and FAD were significantly differentially expressed. Additionally, LACS, WSD1, CER4, CER1, and MAH1 participated in wax biosynthesis. Moreover, one co-expression network among wax biosynthesis genes, hormone signal transduction genes, and transcription factors was established. These findings provide a theoretical foundation for identifying key genes involved in regulating fatty acid and lacquer wax synthesis in Toxicodendron vernicifluum. Full article

As a key medium in industry, lubricating oil plays a significant role in reducing friction, cooling sealing and transmitting power, which directly affects equipment life and energy efficiency. Traditional mineral-based lubricating oils rely on non-renewable petroleum, and they have high energy consumption and poor biodegradability (<30%) during the production process. They can easily cause lasting pollution after leakage and have a high carbon footprint throughout their life cycle, making it difficult to meet the “double carbon” goal. Bio-based lubricating oil uses renewable resources such as cottonseed oil and waste grease as raw materials. This material offers three significant advantages: sustainable sourcing, environmental friendliness, and adjustable performance. Its biodegradation rate is over 80%, and it reduces carbon emissions by 50–90%. Moreover, we can control its properties through processes like hydrogenation, isomerization, and transesterification to ensure it complies with ISO 6743 and other relevant standards. However, natural oils and fats have regular molecular structure, high freezing point (usually > −10 °C), and easy precipitation of wax crystals at low temperature, which restricts their industrial application. In recent years, a series of modification studies have been carried out around “pour point depression-viscosity preservation”. Catalytic isomerization can reduce the freezing point to −42 °C while maintaining a high viscosity index. Epoxidation–ring-opening modification introduces branched chains or ether bonds, taking into account low-temperature fluidity and oxidation stability. The deep dewaxing-isomerization dewaxing process improves the base oil yield, and the freezing point drops by 30 °C. The synergistic addition of polymer pour point depressant and nanomaterials can further reduce the freezing point by 10–15 °C and improve the cryogenic pumping performance. The life cycle assessment shows that using the “zero crude oil” route of waste oil and green hydrogen, the carbon emission per ton of lubricating oil is only 0.32 t, and the cost gradually approaches the level of imported synthetic esters. In the future, with the help of biorefinery integration, enzyme catalytic modification and AI molecular design, it is expected to realize high-performance, low-cost, near-zero-carbon lubrication solutions and promote the green transformation of industry. Full article

Meibum—a lipid-rich secretion produced by holocrine Meibomian glands (MG)—plays a central role in maintaining ocular surface homeostasis in humans. Previously, changes in MG lipidomes induced by inactivation of critical genes of meibogenesis, such as Elovl3, Soat1, Awat2, Sdr16c5/Sdr16c6, and others were shown to cause MG dysfunction (MGD) and dry eye in experimental animals. Here, we describe the impact of the changes in the lipid composition of meibum on its protective properties, specifically physiologically relevant thermotropic characteristics, using various mutant and wild-type animal models, and comparing them with healthy human subjects and patients with MGD. Meibum samples were analyzed using liquid chromatography/mass spectrometry (LC/MS) and differential scanning microcalorimetry (DSC). We found that any change in the balance between major lipid classes in meibum—wax esters, cholesteryl esters, triacylglycerols, and free cholesterol—cause detrimental changes in its thermotropic properties, loss of cohesiveness, and abnormal expressibility from MG, resulting in MGD-like phenotypes of the eyes and adnexa. We conclude that tested knockout mice can be valuable models for modeling and studying MGD. A combination of LC/MS and DSC can be a powerful diagnostic tool and may help to diagnose MGD and other pathologies, as well as determine their molecular mechanisms. Full article