articles+ search results

ETHER lipids, MONOUNSATURATED fatty acids, SATURATED fatty acids, UNSATURATED fatty acids, LIPID peroxidation (Biology), LIPIDS, GLYCERYL ethers, and VINYL ethers

Ferroptosis is an iron-dependent form of regulated cell death associated with uncontrolled membrane lipid peroxidation and destruction. Previously, we showed that dietary dihomo-gamma-linolenic acid (DGLA; 20: 3(n-6)) triggers ferroptosis in the germ cells of the model organism, Caenorhabditis elegans. We also demonstrated that ether lipid-deficient mutant strains are sensitive to DGLA-induced ferroptosis, suggesting a protective role for ether lipids. The vinyl ether bond unique to plasmalogen lipids has been hypothesized to function as an antioxidant, but this has not been tested in animal models. In this study, we used C. elegans mutants to test the hypothesis that the vinyl ether bond in plasmalogens acts as an antioxidant to protect against germ cell ferroptosis as well as to protect from whole-body tert-butyl hydroperoxide (TBHP)-induced oxidative stress. We found no role for plasmalogens in either process. Instead, we demonstrate that ether lipid-deficiency disrupts lipid homeostasis in C. elegans, leading to altered ratios of saturated and monounsaturated fatty acid (MUFA) content in cellular membranes. We demonstrate that ferroptosis sensitivity in both wild type and ether-lipid deficient mutants can be rescued in several ways that change the relative abundance of saturated fats, MUFAs and specific polyunsaturated fatty acids (PUFAs). Specifically, we reduced ferroptosis sensitivity by (1) using mutant strains unable to synthesize DGLA, (2) using a strain carrying a gain-of-function mutation in the transcriptional mediator MDT-15, or (3) by dietary supplementation of MUFAs. Furthermore, our studies reveal important differences in how dietary lipids influence germ cell ferroptosis versus whole-body peroxide-induced oxidative stress. These studies highlight a potentially beneficial role for endogenous and dietary MUFAs in the prevention of ferroptosis. Author summary: Ferroptosis is a regulated form of cell death driven by excess production of lipid peroxides. Understanding ferroptosis is important because this type of cell death is associated with disease states such as neurodegeneration and various renal, liver, and lung diseases. In addition, with more knowledge of regulatory mechanisms, induction of ferroptosis could be harnessed to control tumor growth. To examine specific lipid contributions to ferroptosis sensitivity, we used mutant strains of the small roundworm Caenorhabditis elegans exhibiting a range of altered lipid compositions to examine how cellular and dietary lipids influence ferroptosis and oxidative stress sensitivity. We found that the accumulation of lipid peroxides correlates with cell death but that plasmalogens, a subset of ether lipids that are proposed to act as cellular antioxidants, do not protect from ferroptosis or oxidative stress. Instead, ether lipid biosynthesis contributes to lipid homeostasis in membranes. In their absence, membrane saturated fatty acids are increased, while membrane monounsaturated fatty acids (MUFAs) are less abundant. Restoring membrane MUFAs reduces lipid peroxides and contributes to cellular resistance to ferroptotic cell death. These studies suggest that dietary MUFAs could prevent ferroptosis in disease. [ABSTRACT FROM AUTHOR]

SMALL molecules, HYDROGELS, PROPYLENE oxide, SCIATIC nerve, NERVE block, POLYMERSOMES, and GLYCERYL ethers

Efficient encapsulation and sustained release of small hydrophilic molecules from traditional hydrogel systems are challenging due to the large mesh size of 3D networks and high water content. Furthermore, the encapsulated molecules are prone to early release from the hydrogel prior to use, resulting in a short shelf life of the formulation. Here, a hydration‐induced void‐containing hydrogel (HVH) based on hyperbranched polyglycerol‐poly(propylene oxide)‐hyperbranched polyglycerol (HPG‐PPG‐HPG) as a robust and efficient delivery system is presented for small hydrophilic molecules. Specifically, after the HPG‐PPG‐HPG is incubated overnight at 4 °C in the drug solution, it is hydrated into a hydrogel containing micron‐sized voids, which can encapsulate hydrophilic drugs and achieve 100% drug encapsulation efficiency. In addition, the voids are surrounded by a densely packed polymer matrix, which restricts drug transport to achieve sustained drug release. The hydrogel/drug formulation can be stored for several months without changing the drug encapsulation and release properties. HVH hydrogels are injectable due to shear thinning properties. In rats, a single injection of the HPG‐PPG‐HPG hydrogel containing 8 µg of tetrodotoxin (TTX) produces sciatic nerve block lasting up to 10 h without any TTX‐related systemic toxicity nor local toxicity to nerves and muscles. [ABSTRACT FROM AUTHOR]

FATTY acids, GLYCERYL ethers, ESSENTIAL fatty acids, EDIBLE fats & oils, OLEIC acid, HEART, FATTY liver, and ADRENOLEUKODYSTROPHY

Neurodegenerative diseases (ND) are characterised by loss of neurons in the brain and spinal cord. For the normal functioning of the brain, divers group of fatty acids in the form of glycerophospholipids, glycerol ether lipids, cerebrosides, sulfatides, and gangliosides are essential. They are present abundantly in the nervous system and are actively involved in both the development and maintenance of the nervous system. A dietary deficiency of essential fatty acid during development results in hypomyelination state which affects various neuronal functions. Several studies suggested that age remains the primary risk factor for almost all neurodegenerative disorders. The potential contribution of these fatty acids in the progression of neurodegenerative disorders is indispensable. Erucic acid an omega 9 fatty acid, which is obtained from edible oils has proven to cause myocardial lipidosis, heart lesions and hepatic steatosis in animals therefore, its content in edible oils is restricted to certain levels by regulatory agencies. However, erucic acid in the form of a mixture with oleic acid is often used as a dietary treatment for the management of adrenoleukodystrophy without any cardiotoxicity. Our literature search revealed that, erucic acid reported to enhance cognitive function, interact with peroxisome proliferator activated receptors (PPARs), inhibit elastase and thrombin. In this review first we have attempted to describe the relationship between fatty acids and neurodegeneration followed by a description on the pharmacology of erucic acid. The overall purpose of this review is to analyse toxic and beneficial neuropharmacological effects of erucic acid. [ABSTRACT FROM AUTHOR]

PLANT clones, GAS chromatography/Mass spectrometry (GC-MS), SALICYLIC acid, ESSENTIAL oils, ACID derivatives, ORGANIC acids, and GLYCERYL ethers

Since time immemorial, genus Salix has been well known for its ethnobotanical uses for the treatment of various health ailments. Willow bark and leaf extracts contain a heterogeneous mixture of different chemical entities. Rapid extract screening techniques are frequently required to generate the phytochemical profile of bioactive compounds in plant parts. Metabolic profiles are generally genetically determined in plants. However, their quantification may exhibit variations under different environmental conditions. In order to estimate the magnitude of variability in the level of chemical composition among different hybrid clones of Salix (UHFS 08, UHFS 34, UHFS 39, and UHFS 40), phytochemical profiling of bark and leaves was performed with Gas chromatography/mass spectrometry (GC-MS) analysis. Putative identification extrapolated the presence of various secondary metabolites, volatile oils, acid esters, organic acids, and other compounds that mark these clones as pharmaceutically important. All extracts of studied Salix clones contained phytochemical important compounds such as 9,12,15-octadecatrienoic acid, 2,3-bis[(trimethylsilyl)oxy]propyl ester, ergosta-5,22-dien-3-ol, acetate, (3a-22E)-1-monolinoleoyl glycerol trimethylsilyl ether and ethyl iso-allocholate. Salicylic acid derivatives from the willow shoots are of great interest due to their pharmacological activity, which has been identified in UHFS 08 and UHFS 39 methanolic bark extracts. [ABSTRACT FROM AUTHOR]

HYDROGELS, ACTUATORS, REFRACTIVE index, VISIBLE spectra, GLYCERIN, WATER use, and GLYCERYL ethers

Hydrogels are characterized by high water content and are typically used in water environments. However, when used in air environments, hydrogels face limitations due to instability caused by water loss. This study reports the development of PAM/glycerol hydrogels with improved stability. By using water–glycerol bi‐solvents to lock in water internally, a closed environment was established to reduce water exchange with the outside world. The hydrogel was made by forming a single PAM crosslinking network using UV crosslinked acrylamide (AM) monomer. The weight of the hydrogel varied by no more than 2% within 6 days, and the visible light transmittance was higher than 90%. In addition, the hydrogel had adjustable refractive index and mechanical properties. The hydrogels with stable performance could be used to fabricate optical lens with practical function in air environment. Meanwhile, the gels also have certain advantages in making a fluid‐driven hydrogel actuator with stable performance. [ABSTRACT FROM AUTHOR]

BODY centered cubic structure, OXYGEN reduction, DENSITY functional theory, FACE centered cubic structure, ALCOHOL oxidation, HYDROGEN evolution reactions, and GLYCERYL ethers

High-entropy materials, for both complexity in structure and superiority in performance, have been widely confirmed to be one possible kind of advanced electrocatalyst. Significant efforts have been dedicated to modeling the atomic-level details of high-entropy catalysts to improve the viability for bottom-up design of advanced electrocatalysts. In this review, first, we survey developments in various modeling methods that are based on density functional theory. We review progress in density functional theory simulations for emulating different high-entropy electrocatalysts. Then, we review the advancements in simulations of high-entropy materials for electrocatalytic applications. Finally, we present prospects in this field. Abbreviations: HEMs: high-entropy materials; CCMs: compositionally complex materials; DFT: density functional theory; LDA: local density approximation; GGA: generalized gradient approximation; VASP: Vienna Ab initio simulation package; ECP: effective core potential; PAW: projector-augmented wave potential; VCA: virtual crystal approximation; CPA: coherent potential approximation; SQS: special quasi-random structures; SSOS: small set of ordered structures; SLAE: similar local atomic environment; HEAs: high-entropy alloys; FCC: face-centered cubic; BCC: body-centered cubic; HCP: hexagonal close-packed; ORR: oxygen reduction reaction; OER: oxide evolution reaction; HER: hydrogen evolution reaction; RDS: rate-limiting step; AEM: adsorbate evolution mechanism; LOM: lattice oxygen oxidation mechanism; HEOs: high-entropy oxides; OVs: oxygen vacancies; PDOS: projected densities of states; ADR: ammonia decomposition reaction; NRR: nitrogen reduction reaction; CO2RR: CO2 reduction reaction; TMDC: transition metal dichalcogenide; TM: transition metal; AOR: alcohol oxidation reaction; GOR: glycerol oxidation reaction; UOR: urea oxidation reaction; HEI: high-entropy intermetallic. This paper reviews recent developments in the field of atomistic simulations of high-entropy electrocatalysts, one of emerging state-of-the-art catalytic materials. [ABSTRACT FROM AUTHOR]

MICROEMULSIONS, SMALL-angle neutron scattering, LIGHT scattering, NEUTRON scattering, SOLUBILIZATION, GLYCERYL ethers, and GLYCERIN

Microemulsions are thermodynamically stable mixtures of water and oil. For many applications, such as in cosmetics, it is important that the components are biocompatible. For the formulation of a new biocompatible microemulsion based on Tween 20 (Tw20) surfactant, the glycerol ether 2-ethylhexylglycerin (EHG) is employed as an alternative to commonly used short- to medium chain alcohols as cosurfactant. Tw20 itself is not capable of any significant solubilization but the addition of EHG allows to enhance the solubilization capacity for the polar oil isopropyl palmitate (IPP) largely. At a Tw20 to EHG molar ratio of 1:12, i.e., very large excess of cosurfactant, the solubilization capacity is increased by nearly three orders of magnitude compared to a pure Tw20 solution. The resulting oil-in-water (O/W) microemulsion is studied using static and dynamic light scattering (SLS/DLS) and small-angle neutron scattering (SANS). The SANS spectra are analyzed with a core–shell ellipsoid model, which indicates formation of oblate droplets at higher EHG content. Dynamic light scattering experiments confirm the presence of microemulsion droplets with hydrodynamic radii increasing from 3.8 to 19.8 nm upon addition of cosurfactant. In summary, this study shows that EHG is a cosurfactant that enhances the solubilization properties of a biocompatible surfactant largely and thereby renders it very useful for formulations. [ABSTRACT FROM AUTHOR]

GLYCERYL ethers, ETHER lipids, HYDROGEN isotopes, KINETIC isotope effects, MICROBIAL lipids, MEMBRANE lipids, and LIPIDS

The stable hydrogen isotope composition of persistent biomolecules is used as a palaeohydrological proxy. While much previous work has focused on plant leaf wax-derived n -alkanes, the potential of prokaryotic lipid biomarkers as carriers of H isotope signatures remains underexplored, particularly in the Archaea. Here we investigated H isotope distributions in the membrane lipids of the ammonia-oxidizing chemoautotroph Nitrosopumilus maritimus strain SCM1. Hydrogen isotope ratios were measured on the cleaved biphytane chains of tetraether membrane lipids extracted from steady-state continuous cultures cultivated at slow, medium, and fast growth rates. In contrast to recent work on bacterial fatty acids, where the direction and magnitude of isotopic fractionation varies widely (ca. 600‰ range) as a function of central C and energy metabolism, archaeal biphytane data in the present work are relatively invariant. The weighted average 2H/1H fractionation values relative to growth water (2 ε L/W) ranged from –272 to –260‰, despite a three-fold difference in doubling times (30.8–92.5 hr), yielding an average growth-rate effect <0.2‰ hr−1. These 2 ε L/W values are more negative than most heterotrophic microbial lipid H isotope measurements in the literature, and are on par with those from other autotrophic archaea, as well as with phytol from photoautotrophic algae. N. maritimus values of 2ε L/W also varied systematically with the number of internal rings (cyclopentyl + cyclohexyl), increasing for each additional ring by 6.4 ± 2.7‰. Using an isotope flux-balance model in tandem with a comprehensive analysis of the sources of H in archaeal lipid biosynthesis, we use this observation to estimate the kinetic isotope effects (KIEs) of H incorporation from water; from reducing cofactors such as flavins and NADPH, and for the transhydrogenation reaction(s) that convert the electron-donor derived NADH into these cofactors. Consistent with prior studies on bacteria and plants, our results indicate the KIEs of reducing cofactors in archaea are highly fractionating, while those involving exchange of water protons are less so. When combined with the observation of minimal growth-rate sensitivity, our results suggest biphytanes of autotrophic 3HP/4HB utilizing Nitrososphaerota (a.k.a. Thaumarchaeota) may be offset from their growth waters by a nearly constant 2ε L/W value. Together with the ring effect, this implies that all biphytanes originating from a common source should have a predictable ordering of their isotope ratios with respect to biphytane ring number, allowing precise reconstruction of the original δ2H value of the environmental water. Collectively, these patterns indicate archaeal biphytanes have potential as paleo-hydrological proxies, either as a complement or an alternative to leaf wax n -alkanes. [ABSTRACT FROM AUTHOR]

BORON, BORON trifluoride, SUBSTITUTION reactions, ADDITION reactions, FUNCTIONAL groups, PYRAZOLYL compounds, and GLYCERYL ethers

When tetraketone, in which two dibenzoylmethanate groups are connected by a disulfide bridge through central (α) carbon atoms, was treated with a mixture of boron trifluoride ether and tributyl borate, a binuclear complex containing bordibenzoylmethanate fragments was obtained. Like aromatic disulfides, this compound is cleaved by the action of sulfuryl chloride and bromine to form sulfenyl chloride or sulfenyl bromide derivatives. These compounds enter into substitution and addition reactions common for sulfenyl halides, making it possible to obtain bordibenzoylmethanate complexes containing various functional groups linked to the chelate cycle through the central carbon atom. Based on studying the UV spectra of the obtained compounds, an assumption was made about the nature of the interaction of α and β substituents with the chelate ring. [ABSTRACT FROM AUTHOR]

LUCIFERASES, MOLECULAR size, CHEMICAL properties, MOLECULAR spectroscopy, PHOTOBACTERIUM, MOLECULAR dynamics, DEXTRAN, and GLYCERYL ethers

Simple Summary: Traditionally, enzymes have been studied in standardized buffers, but in real life, inside cells, they have to function under conditions far from "ideal". The intracellular milieu is crowded by numerous molecules with various physical and chemical properties. What consequences does it have for enzymatic reactions? How do enzymes deal with disturbing neighbors? To examine this issue, we studied the mechanisms of influence of seven model substances with different molecular sizes on the reaction catalyzed by bacterial luciferase. This reaction passes through several stages and ends with light emission. We analyzed the responses rate in different stages to the addition of alcohols, saccharides, and biopolymers and found the counteraction of two effects. On the one hand, increased viscosity slows down many of the stages, both associative and dissociative. On the other hand, it is accompanied by an increase in the catalytic constant of luciferase, which compensates for kinetic disadvantages. We assumed that both effects could be caused by the same property of the added substances—their ability to interact with water. Our findings serve not only to shed light on the organization of the cellular metabolism, but also to improve enzyme-based biotechnologies using the recipes of nature. A complex heterogeneous intracellular environment seems to affect enzymatic catalysis by changing the mobility of biomolecules, their stability, and their conformational states, as well as by facilitating or hindering continuously occurring interactions. The evaluation and description of the influence of the cytoplasmic matrix components on enzymatic activity are problems that remain unsolved. In this work, we aimed to determine the mechanisms of action of two-component media with cosolvents of various molecular sizes on the complex multi-stage bioluminescent reaction catalyzed by bacterial luciferase. Kinetic and structural effects of ethylene glycol, glycerol, sorbitol, glucose, sucrose, dextran, and polyethylene glycol on bacterial luciferase were studied using stopped-flow and fluorescence spectroscopy techniques and molecular dynamics simulations. We have found that diffusion limitations in the presence of cosolvents promote the stabilization of flavin substrate and peroxyflavin intermediate of the reaction, but do not provide any advantages in bioluminescence quantum yield, because substrate binding is slowed down as well. The catalytic constant of bacterial luciferase has been found to be viscosity-independent and correlated with parameters of water–cosolvent interactions (Norrish constant, van der Waals interaction energies). Crowding agents, in contrast to low-molecular-weight cosolvents, had little effect on peroxyflavin intermediate decay and enzyme catalytic constant. We attributed specific kinetic effects to the preferential interaction of the cosolvents with enzyme surface and their penetration into the active site. [ABSTRACT FROM AUTHOR]

SINGLE crystals, X-ray diffraction, GLYCERYL ethers, and CRYSTALS

3-(2-Chloro-5-methylphenoxy)propane-1,2-diol 1 is a possible precursor in the chiral beta blocker Bupranolol synthesis. Both racemic and single-enantiomeric samples of 1 were synthesized and characterized by single crystal XRD. The absolute configuration of an (S)-1 sample was determined by data refinement (the value of the Flack parameter is 0.03(4)). Hydrogen-bonded supramolecular synthons (SMS) were identified for both crystals. In rac-1, as well as in (S)-1 crystals, one of the two main SMS is the homochiral chain C 1 1 (5):21 (⋯O1–C1–C2–O2–H2⋯). The second of the two SMSs changes is the change of chiral environment. For rac-1, this is the heterochiral chain C 3 3 (9) : { 12 / 12 / 21 } ; (⋯O2–C2–C1–O1–H1⋯O′2–H′2⋯O″1–H″1⋯), in which molecules with different configurations alternate. In (S)-1 crystals, this is the homochiral chain C 1 1 (2):11 (⋯O1–H1⋯). The results obtained once again confirm the influence of the chiral environment on the crystallization of scalarly identical molecules. [ABSTRACT FROM AUTHOR]

ASYMMETRIC synthesis, LIPID synthesis, ETHER synthesis, GLYCERYL ethers, ETHER lipids, BLOCK designs, and HYDROXYMETHYL compounds

The asymmetric synthesis of a triene C18 : 3 n‐8 methoxylated ether lipid (MEL) of the 1‐O‐alkyl‐sn‐glycerol type is described by two different routes. The C18 : 3 hydrocarbon chain is attached by an ether linkage to the pro‐S hydroxymethyl group of the glycerol backbone, and constitutes an all‐cis methylene skipped triene framework, along with a methoxyl group in the 2'‐position and R‐configuration at the resulting chiral centre. The initial synthesis was based on the polyacetylene approach involving a semi‐hydrogenation of the resulting triyne. A modified approach based on a combined polyacetylene‐Wittig strategy was also successfully executed and an attempt made to compare and evaluate these strategies. Both syntheses were started from our previously described enantio‐ and diastereomerically pure isopropylidene‐protected glyceryl glycidyl ether, a double‐C3 building block designed as a head group synthon for synthesis of various types of MELs which was shown to suit the Wittig‐based approach very well. [ABSTRACT FROM AUTHOR]

ABSORPTION coefficients, MICROWAVE chemistry, SUBSTITUTION reactions, CORE & periphery (Economic theory), THIOLATES, and GLYCERYL ethers

The synthesis of novel mono‐, di‐, tri‐, tetra‐, and hexafluorinated hexa‐peri‐hexabenzocoronenes (HBCs) and their conversion into their thioether‐substituted analogs is reported. The substitution reaction with the corresponding thiolates was performed microwave‐assisted to significantly reduce the reaction time. With increasing amount of fluorination or thioether‐substituents, a decreasing extinction coefficient can be observed for the HBCs. Successive addition of thioether‐moieties leads to a bathochromic shift of the absorption and emission bands, whereas the nature of the attached thioether does not affect the optoelectronical properties. To further tune the electronic environment of the HBC core, a successive oxidation to the corresponding sulfone as well as the formation of the sulfonium salts were performed. With that, the electron‐donating thioethers were transformed into electron‐withdrawing substituents, resulting in an inversed electron demand in the periphery of the core. The so obtained compounds showed decreased extinction coefficients and a broadening of the absorption and emission bands. [ABSTRACT FROM AUTHOR]

DRUG resistance in bacteria, NOSOCOMIAL infections, BLOOD proteins, GLYCERYL ethers, and CHEMICAL stability

Biofouling on medical device surfaces, which is initiated by protein adsorption and adhesion of microbes especially the antibiotic-resistant bacteria, attracts global attention for centuries due to its enduring challenges in healthcare. Here, the antifouling effect of hydrophilic poly(glycerol glycidyl ether) (polyGGE) film is explored in comparison to hemocompatible and protein-resistant control polymers. The chemical and thermomechanical stability of polyGGE in hydrated conditions at body temperature was achieved via adjusting UV curing and KOH quenching time. The polyGGE surface is inert to the plasma protein adsorption and interfered the metabolism conditions, biofilm formation and growth of both Gram negative (Gram–) and antibiotic-resistant Gram positive (Gram+) bacteria. These results indicate the potential application of polyGGE for combating the risk of hospital-acquired infections and preventing drug-resistant superbug spreading. [ABSTRACT FROM AUTHOR]

ETHYLENE oxide, MICROBIAL contamination, BIOMACROMOLECULES, SULFATION, GLYCERYL ethers, and POLYMER films

Sulfated biomolecules are known to influence numerous biological processes in all living organisms. Particularly, they contribute to prevent and inhibit the hypercoagulation condition. The failure of polymeric implants and blood contacting devices is often related to hypercoagulation and microbial contamination. Here, bioactive sulfated biomacromolecules are mimicked by sulfation of poly(glycerol glycidyl ether) (polyGGE) films. Autoclaving, gamma-ray irradiation and ethylene oxide (EtO) gas sterilization techniques were applied to functionalized materials. The sulfate group density and hydrophilicity of sulfated polymers were decreased while chain mobility and thermal degradation were enhanced post autoclaving when compared to those after EtO sterilization. These results suggest that a quality control after sterilization is mandatory to ensure the amount and functionality of functionalized groups are retained. [ABSTRACT FROM AUTHOR]

ETHYLCELLULOSE, CENTRAL nervous system, BRAIN anatomy, PRINCIPAL components analysis, GLYCERYL ethers, and CLUSTER analysis (Statistics)

Introduction: The endocannabinoid system consists of different types of receptors, enzymes and endocannabinoids (ECs), which are involved in several physiological processes, but also play important role in the development and progression of central nervous system disorders. Objectives: The purpose of this study was to apply precise and sensitive methodology for monitoring of four ECs, namely anandamide (AEA), 2-arachidonoyl glycerol (2-AG), N-arachidonoyl dopamine (NADA), 2-arachidonyl glyceryl ether (2-AGe) in selected brain regions of female and male rats at different stages of development (young, adult and old). Methods: Biocompatible solid-phase microextraction (SPME) probes were introduced into the intact (non-homogenized) brain structures for isolation of four ECs, and the extracts were subjected to LC–MS/MS analysis. Two chemometric approaches, namely hierarchical cluster analysis (HCA) and Principal Component Analysis (PCA) were applied to provide more information about the levels of 2-AG and AEA in different brain structures. Results: 2-AG and AEA were extracted and could be quantified in each brain region; the level of 2-AG was significantly higher in comparison to the level of AEA. Two highly unstable ECs, NADA and 2-AGe, were captured by SPME probes from intact brain samples for the first time. Conclusion: SPME probes were able to isolate highly unstable endogenous compounds from intact tissue, and provided new tools for precise analysis of the level and distribution of ECs in different brain regions. Monitoring of ECs in brain samples is important not only in physiological conditions, but also may contribute to better understanding of the functioning of the endocannabinoid system in various disorders. [ABSTRACT FROM AUTHOR]

CATIONIC lipids, SMALL interfering RNA, MESSENGER RNA, PROTEIN expression, INJECTIONS, GLYCERYL ethers, GENE transfection, and ETHANOL

Messenger RNA (mRNA)-based therapies are a novel class of therapeutics used in vaccination and protein replacement therapies for monogenic diseases. Previously, we developed a modified ethanol injection (MEI) method for small interfering RNA (siRNA) transfection, in which cationic liposome/siRNA complexes (siRNA lipoplexes) were prepared by mixing a lipid-ethanol solution with a siRNA solution. In this study, we applied the MEI method to prepare mRNA lipoplexes and evaluated the in vitro and in vivo protein expression efficiencies. We selected six cationic lipids and three neutral helper lipids to generate 18 mRNA lipoplexes. These were composed of cationic lipids, neutral helper lipids, and polyethylene glycol-cholesteryl ether (PEG-Chol). Among them, mRNA lipoplexes containing N-hexadecyl-N,N-dimethylhexadecan-1-aminium bromide (DC-1-16) or 11-((1,3-bis(dodecanoyloxy)-2-((dodecanoyloxy)methyl) propan-2-yl) amino)-N,N,N-trimethyl-11-oxoundecan-1-aminium bromide (TC-1-12) with 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) and PEG-Chol exhibited high protein expression in cells. Furthermore, mRNA lipoplexes composed of DC-1-16, DOPE, and PEG-Chol exhibited high protein expression in the lungs and spleen of mice after systemic injection and induced high antigen-specific IgG1 levels upon immunization. These results suggest that the MEI method can potentially increase the efficiency of mRNA transfection, both in vitro and in vivo. [ABSTRACT FROM AUTHOR]

TANNING (Hides & skins), ASPERGILLUS flavus, LEATHER industry, GLYCERYL ethers, and ASPERGILLUS niger

To reduce the contamination of Cr6+ and dyes from tannery wastewater, a chromium-free tanning agent with rich terminal epoxy groups (COS-GTE) was synthesized using oligomeric chitosan (COS) and glycerol triglycidyl ether (GTE). The structural characteristics and application performance of prepared COS–GTE were investigated by FTIR NMR, GPC, SEM, adsorption properties of fatliquor and dyes, and other analysis techniques. The application results indicated that the shrinkage temperature of finished leather tanned with COS–GTE can reach 83.5 °C. Compared with traditional tanning materials (F-90 and TWS), the finished leather had better mechanical properties (tear strength of 47.410 N/mm2) and yellowing resistance. Moreover, the natural skin modified with COS–GTE showed excellent antimicrobial properties against Escherichia coli , Staphylococcus aureus , Aspergillus flavus , and Aspergillus niger. Especially, the finished COS-GTE tanned leather had a high absorption rate of fatliquor (69.27 %) and dyes (X = 93.21 %), which is beneficial for reducing comprehensive wastewater pollution. The research revealed that the COS–GTE not only can be considered a new biomass material to solve the problem of chromium and dye contamination in the leather industry but also endows leathers with a unique antimicrobial function to extend product protection and service time. [ABSTRACT FROM AUTHOR]

INTRACELLULAR pathogens, TOXOPLASMA gondii, LYTIC cycle, ISOTOPIC analysis, CELL division, LIPIDOMICS, and GLYCERYL ethers

Toxoplasma gondii is a prevalent zoonotic pathogen infecting livestock as well as humans. The exceptional ability of this parasite to reproduce in several types of nucleated host cells necessitates a coordinated usage of endogenous and host-derived nutritional resources for membrane biogenesis. Phosphatidylethanolamine is the second most common glycerophospholipid in T. gondii, but how its requirement in the acutely-infectious fast-dividing tachyzoite stage is satisfied remains enigmatic. This work reveals that the parasite deploys de novo synthesis and salvage pathways to meet its demand for ester- and ether-linked PtdEtn. Auxin-mediated depletion of the phosphoethanolamine cytidylyltransferase (ECT) caused a lethal phenotype in tachyzoites due to impaired invasion and cell division, disclosing a vital role of the CDP-ethanolamine pathway during the lytic cycle. In accord, the inner membrane complex appeared disrupted concurrent with a decline in its length, parasite width and major phospholipids. Integrated lipidomics and isotope analyses of the TgECT mutant unveiled the endogenous synthesis of ester-PtdEtn, and salvage of ether-linked lipids from host cells. In brief, this study demonstrates how T. gondii operates various means to produce distinct forms of PtdEtn while featuring the therapeutic relevance of its de novo synthesis. A genetic and lipidomic investigation reveals that depletion of ECT in Toxoplasma gondii disrupts ester-phosphatidylethanolamine (PtdEtn) synthesis and results in parasite death. Notably, T. gondii salvages ether-PtdEtn from its host cells. [ABSTRACT FROM AUTHOR]