Ethyl Ester Research Articles

Studies on the Thermal Decomposition Course of Nitrogen-Rich Heterocyclic Esters as Potential Drug Candidates and Evaluation of Their Thermal Stability and Properties.

Drug candidates must undergo thermal evaluation as early as possible in the preclinical phase of drug development because undesirable changes in their structure and physicochemical properties may result in decreased pharmacological activity or enhanced toxicity. Hence, the detailed evaluation of nitrogen-rich heterocyclic esters as potential drug candidates, i.e., imidazolidinoannelated triazinylformic acid ethyl esters 1-3 (where R1 = 4-CH3 or 4-OCH3 or 4-Cl, and R2 = -COOC2H5) and imidazolidinoannelated triazinylacetic acid methyl esters 4-6 (where R1 = 4-CH3 or 4-OCH3 or 4-Cl, and R2 = -CH2COOCH3)-in terms of their melting points, melting enthalpy values, thermal stabilities, pyrolysis, and oxidative decomposition course-has been carried out, using the simultaneous thermal analysis methods (TG/DTG/DSC) coupled with spectroscopic techniques (FTIR and QMS). It was found that the melting process (documented as one sharp peak related to the solid-liquid phase transition) of the investigated esters proceeded without their thermal decomposition. It was confirmed that the melting points of the tested compounds increased in relation to R1 and R2 as follows: 2 (R1 = 4-OCH3; R2 = -COOC2H5) < 6 (R1 = 4-Cl; R2 = -CH2COOCH3) < 5 (R1 = 4-OCH3; R2 = -CH2COOCH3) < 3 (R1 = 4-Cl; R2 = -COOC2H5) < 1 (R1 = 4-CH3; R2 = -COOC2H5) < 4 (R1 = 4-CH3; R2 = -CH2COOCH3). All polynitrogenated heterocyclic esters proved to be thermally stable up to 250 °C in inert and oxidising conditions, although 1-3 were characterised by higher thermal stability compared to 4-6. The results confirmed that both the pyrolysis and the oxidative decomposition of heterocyclic ethyl formates/methyl acetates with para-substitutions at the phenyl moiety proceed according to the radical mechanism. In inert conditions, the pyrolysis process of the studied molecules occurred with the homolytic breaking of the C-C, C-N, and C-O bonds. This led to the emission of alcohol (ethanol in the case of 1-3 or methanol in the case of 4-6), NH3, HCN, HNCO, aldehydes, CO2, CH4, HCl, aromatics, and H2O. In turn, in the presence of air, cleavage of the C-C, C-N, and C-O bonds connected with some oxidation and combustion processes took place. This led to the emission of the corresponding alcohol depending on the analysed class of heterocyclic esters, NH3, HCN, HNCO, aldehydes, N2, NO/NO2, CO, CO2, HCl, aromatics, and H2O. Additionally, after some biological tests, it was proven that all nitrogen-rich heterocyclic esters-as potential drug candidates-are safe for erythrocytes, and some of them are able to protect red blood cells from oxidative stress-induced damage.

Genome analysis of Hanseniaspora vineae CC-P5 and CC-ZZ6 isolate from grapes reveals the biotech potential for winemaking

The genus Hanseniaspora is a non-Saccharomyces yeast frequently isolated from wine-associated environments and has been recognized to play a key role in winemaking. However, most of the research on Hanseniaspora focused on its role in fermentation or its coordination with Saccharomyces cerevisiae, but the genome data of Hanseniaspora is very scarce, which is not conducive to better utilization and development of this yeast. Therefore, in this study, the genome data of two Hanseniaspora vineae strains CC-P5 and CC-ZZ6 with flocculation and antimicrobial abilities were sequenced and bioinformatics analyses were performed. The results showed that the genomes of the two strains have a high degree of homology with an average nucleotide identity of 97.7 %. Both H. vineae CC-P5 and CC-ZZ6 have corresponding genes for adaptability to osmotic stress, sulfur dioxide stress, ethanol toxicity and other stresses, as well as various genes involved in the biosynthesis of ethyl esters, volatile organic acids, aromatic amino acid, benzyl alcohol/benzaldehyde and terpenoid, which are useful for modulating wine flavor and aroma. These results shed light on why H. vineae has the biotechnology to make wine. In addition, the number of publicly available H. vineae genome databases have increased. This has laid the foundation for further research on Hanseniaspora.

Extraction of tannin, colour and aroma compounds in pinot noir wines as affected by clone selection and whole bunch addition

Our previous study revealed stem inclusion fermentation reduced anthocyanin, and increased tannin and aroma compounds responsible for green notes. This study further investigated the effect of clone selection and whole bunch fermentation on Pinot noir wine composition, with focus on tannin composition. Three treatments were conducted using two clones (AM10/5 and UCD5) in 2021 and 2022: 100% destemmed (DS), 30% whole bunch (WB30), and 60% whole bunch (WB60). WB60 increased stem and skin derived tannins but reduced seed derived tannin proportion in wines. Clone selection had an impact on tannin composition and an even greater impact on tannin concentration, colour, and aroma compounds. AM10/5 produced wines with higher tannin, polymeric pigments and darker colour. AM10/5 wines also had higher concentration of phenylethyl alcohol, but lower concentrations of 3-isobutyl-2-methoxypyrazine and ethyl esters, indicating more floral but less fruity and green notes.

GC‒MS Analysis of Bioactive Compounds in Lime Leaf Ethanol Extract (Citrus amblycarpa (Hassk.) Ochse), and Its Potential as a Traditional Medicine Agents

Lime (Citrus amblycarpa (Hassk.) Ochse) has been widely used in traditional medicine. However, only some studies have comprehensively revealed the content of leaves, including their use as candidate medicinal ingredients. This study aimed to analyze the active compounds of lime leaves through GC‒MS analysis and their benefits in traditional medicine. Experimental research with a laboratory approach is used. The implementation of research by analyzing the bioactive content of lime leaf ethanol extract using GC‒MS along with a comprehensive analysis related to its benefits as a traditional medicine agent. Data analysis using the Willey 7 Library database and descriptive analysis. Using GC-MS showed that lime leaf ethanol extract contains 75 compound components dominated by 11 principal components, including citronellol, caryophyllene, hexadecanoic acid, ethyl ester, 1-heptatriacotanol, Phytol, ethyl 9,12,15-oate; methyl glycocholate, 3TMS derivative; 3,7-dimethyloct-6-en-1-yl stearate; ethyl iso-allocate; Rhopin; and tricyclo [20.8.0.0 (7,16)] triacontane, 1(22),7(16)-diepoxy-. Based on the findings of the content evaluation, the compound constituents of lime leaves have the potential to be developed as traditional remedies for both degenerative and infectious diseases. However, further research is needed precisely to identify the therapeutic effects exerted by using compounds on lime leaves.

Functionalized corn stalk carboxymethyl cellulose and mesoporous silica SBA-15 composite hydrogel-immobilized lipase for the resolution of racemic ibuprofen ethyl ester

ABSTRACT The immobilization of enzymes is an important strategy to improve their stability and reusability. However, it often comes with a trade off of reduced biological activity and catalytic efficiency. In this study, a composite hydrogel based on corn stalk carboxymethyl cellulose, acrylic acid, and mesoporous silica SBA-15 was developed as a support for the immobilization of lipase from Pseudomonas S.P. (PSL). The surface morphology and functional properties of the composite hydrogels were investigated by scanning electron microscopy, Fourier transform infrared, X-ray diffraction and simultaneous thermal analyzer, respectively. The composite hydrogel materials had a large number of mesopores and macropores were present in the wall of the hydrogel sheet. The hydrogel had a network structure that reduced the diffusion resistance of the substrate and improved the accessibility of the enzyme. The immobilized PSL exhibited high enantioselectivity (E value: 88.2) and enzyme activity (316.8 µmol/g/min) in the preparation of (S)-ibuprofen by enzymatic hydrolytic resolution of racemic ibuprofen ethyl ester. This prepared novel composite hydrogel is a promising supporting matrix for the immobilization of enzymes.

Analysis of Fungal Diversity, Physicochemical Properties and Volatile Organic Compounds of Strong-Flavor Daqu from Seven Different Areas.

Strong-flavor Daqu, as a fermentation agent, plays a significant role in shaping the quality of strong-flavor baijius, and fungal species in Daqu are important factors affecting the quality of Daqu. Therefore, we selected strong-flavor Daqu from seven different origins to study the fungal composition and the effects of the fungal composition on the physicochemical properties and volatile organic compounds (VOCs). It was found that the fungal composition influences the physicochemical properties of Daqu. Specifically, there was a positive link between Rhizomucor, Rhizopus, Thermomyces, and liquefying activity and a positive correlation between Aspergillus and fermenting activity. Furthermore, the relationships between esterifying activity and Thermomyces, Rhizomucor, Aspergillus, Pichia, and Saccharomycopsis were found to be positive. The VOCs in Daqu were affected by Aspergillus, Issatchenkia, Pichia, and Thermoascus. Issatchenkia was significantly positively correlated with benzeneethanol as well as Aspergillus and pentadecanoic acid ethyl ester, ethyl myristate. Pichia and Thermoascus were significantly negatively correlated with benzaldehyde and 2-furaldehyde. This study deepens our understanding of the relationship between VOCs, the physicochemical properties with microbial communities, and reference significance for the production of better-quality strong-flavor Daqu.

Dynamic microbial and metabolic changes during Apulian Caciocavallo cheesemaking and ripening produced according to a standardized protocol

The microbiota of a cheese play a critical role in influencing its sensory and physicochemical properties. In this study, traditional Apulian Caciocavallo cheeses coming from 4 different dairies in the same area and produced following standardized procedures were examined, as well as the different bulk milks and natural whey starter (NWS) cultures used. Moreover, considering the cheese wheels as the blocks of Caciocavallo cheeses as whole, these were characterized at different layers (i.e., core, under-rind, and rind) of the block using a multi-omics approach. In addition to physical-chemical characterization, culturomics, quantitative PCR, metagenomics, and metabolomics analysis were carried out after salting and throughout the ripening time (2 mo) to investigate major shifts in the succession of the microbiota and flavor development. Culture-dependent and 16S rRNA metataxonomics results clearly clustered samples based on microbiota biodiversity related to the production dairy plant as a result of the use of different NWS or the intrinsic conditions of each production site. At the beginning of the ripening, cheeses were dominated by Lactobacillus, and in 2 dairies (Art and SdC), Streptococcus genera were associated with the NWS. The analysis allowed us to show that although the diversity of identified genera did not change significantly between the rind, under-rind, and core fractions of the same samples, there was an evolution in the relative abundance and absolute quantification, modifying and differentiating profiles during ripening. The real-time PCR, also known as quantitative or qPCR, mainly differentiated the temporal adaptation of those species originating from bulk milks and those provided by NWS. The primary starters detected in NWS and cheeses contributed to the high relative concentration of 1-butanol, 2-butanol, 2-heptanol, 2-butanone, acetoin, delta-dodecalactone, hexanoic acid ethyl ester, octanoic acid ethyl ester, and volatile free fatty acids during ripening, whereas cheeses displaying low abundances of Streptococcus and Lactococcus (dairy Del) had a lower total concentration of acetoin compared with Art and SdC. However, the subdominant strains and nonstarter lactic acid bacteria present in cheeses are responsible for the production of secondary metabolites belonging to the chemical classes of ketones, alcohols, and organic acids, reaffirming the importance and relevance of autochthonous strains of each dairy plant although only considering a delimited production area.

A Study of the Micellar Formation of N-Alkyl Betaine Ethyl Ester Chlorides Based on the Physicochemical Properties of Their Aqueous Solutions.

In this study, a series of four surface-active compounds-N-alkyl betaine ethyl ester chlorides, CnBetC2Cl-were synthesized and characterized in aqueous solutions. As with other alkyl betaines, these amphiphiles can be practically used, for example, as co-surfactants and/or solubility enhancers acting according to hydrotropic or micellar mechanisms, depending on the alkyl chain length in the amine. We focused on the representatives of the medium alkyl chain length (C6-C12) to find the dependence between the alkyl chain length in N-alkyl betaine ethyl ester chlorides and the surface, volumetric, acoustic, and viscometric properties of their solutions. Ethyl esters, the derivatives of amino acids, were chosen to increase functionality and take advantage of possible hydrolysis in solutions at higher pH, which is also a key parameter in biodegradability. The micellization parameters were calculated based on the physicochemical characteristics. We focused our interest on the ester with a dodecyl substituent since we can compare and discuss its properties with some other C12 representatives that are available in literature. Surprisingly, its micellization characteristic is almost temperature-independent in the investigated temperature range, t = (15-45) °C. Particularly interesting are the results of dynamic light scattering (DLS), which show that the changes in physicochemical parameters of the C12 homolog around the CMC are caused by the two types of micelles of different sizes present in solutions.

Industrial importance seed kernel of Buchanania lanzan in contributing antioxidant, antidiabetic, and anticholinesterase activities

This study aimed to evaluate the antioxidant, antidiabetic, and anticholinesterase activities of Buchanania lanzan Spreng seeds. The therapeutic significance of phytochemicals, minerals, and nutrition were quantified. Hydroalcohol-extract (HABL) possessed the highest phenol contents demonstrated superior inhibitory potential against oxidants in DPPH, CAP-e, and imparted total antioxidant capacity in ORAC test. HABL exhibited mixed-competitive inhibition against α-amylase and α-glucosidase. HABL exhibited mixed-competitive and competitive inhibition against acetyl-, and butyryl-cholinesterase. Seeds were a rich source of minerals, amino acids, protein, carbohydrates, volatile oil, and energy content. Reported Vit B3 and B6 in seeds were responsible for brain function, and neurotransmitter-synthesis. HPLC quantified phenols (gallic acid, chlorogenic acid, caffeic acid, rutin, and quercetin), and GC-MS identified (Catechol, 2-Hydroxy-5-methylbenzaldehyde, Hexadecanoic acid, methyl ester, n-Hexadecanoic acid, Hexadecanoic acid, ethyl ester, 8-Octadecenoic acid, methyl ester, 9,12-Octadecadienoic acid, ethyl ester, (E)-9-Octadecenoic acid ethyl ester, Heptadecanoic acid, 15- methyl-, ethyl ester, Hexadecanoic acid, 2-hydroxy-1-(hydroxymethyl)ethyl ester, 9-Octadecenoic acid (Z)-, 2-hydroxy-1-(hydroxymethyl)ethyl, and β-Sitosterol) in HABL exhibited antioxidant, antidiabetic, and anticholinesterase activities. B. lanzan seeds are given adequate attention for making medicines and dietary supplements in the pharmaceutical and nutraceutical industries.

Evaluation of mesoporous silica particles as a support for lipase immobilization in biodiesel production: Enhanced ethyl ester synthesis from algal oil

The utilization of novel materials in the biofuel production domain has been regarded as a significant advancement in catalyst development. Incorporating lipases in biodiesel manufacturing is often viewed as a cost-restrictive phase since the expenses associated with recovering these catalysts can render market expectations unfeasible. Within this investigation, mesoporous silica (MPS) particles were assessed as a supporting medium for immobilizing commercial lipase, subsequent to their utilization in ethyl ester synthesis. Initially, the production of mesoporous silica was achieved through the co-precipitation technique at a consistent pH and was subsequently chosen as an immobilization support for the enzyme. The characterization of the biocatalyst support materials produced was performed using various analytical methods including X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and BET analysis. The Novozym 435 lipase was then immobilized within the matrices, followed by the transesterification process of algal oil derived from Nannochloropsis. The resulting biodiesel samples demonstrated compliance with commercial standards, exhibiting an ester conversion rate exceeding 94.8 %. Additionally, properties such as density (0.93 g cm−3) and viscosity (5.01 mm2 s−1) satisfied the specifications mandated by ASTM for biofuel application. Experimental planning techniques showed that increasing lipase loading and using temperatures between 38 and 48 °C resulted in higher conversion rates of ethyl esters. This confirms the effectiveness of the enzymatic catalyst in generating primary fatty acid esters, even with residual lipid feedstocks.

9-chloro-5,9-dienoic and other fatty acids from marine sponge &lt;i&gt;Penares&lt;/i&gt; sp.

The fatty acids and their ethyl esters from an extract of a sponge Penares sp. (South China Sea) were fractionated by high-performance liquid chromatography and analyzed by gas chromatography-mass spectrometry using pyrrolidine, 4,4-dimethyloxazoline, dimethyl disulfide, and hydrogenated derivatives. In some cases, 1Н and 13С NMR spectroscopy was applied for the structural analysis of fatty acids. 71 С12–С28 acids, including 12 new compounds, were found. The new compounds were shown to be (5Z,9Z)-9-chloro-24-methy-5,9-pentacosadienoic, (5Z,9Z)-9-chloro-25-methyl-5,9-hexacosadienoic, (5Z,9Z)-9-chloro-24-methyl-5,9-hexacosadienoic, (5Z,9Z)-9-chloro-25-methyl-5,9-heptacosadienoic, 6-chloro-20-methyl-4-heneicosenoic, 6-chloro-19-methyl-4-heneicosenoic, 6-chloro-20-methyl-4-docosenoic, cis-17,18-methylene-tetracosanoic, 16,21-dimethyldocosanoic, 18,23-dimethyltetracosanoic, 16,18,22-trimethyltricosanoic, and 18,20,24-trimethylpentacosanoic acids. It was shown that the characteristic features of the fatty acid mixture were a high level of constituents with monomethylated chains (over 50%) and the nearly total substitution of common demospongic acids for their chloro-derivatives, previously unknown (5Z,9Z)-9-chloro-5,9-dienoic acids. The presence of analogous structural fragments in the fatty acids from Penares sp. and in some biologically active secondary metabolites from Penares sponges was discussed. The results of this work may be used for the structural, comparative and biosynthetic studies of marine lipids.

Synthesis of pH/redox-double-responsive ferrocene-containing diblock copolymers and their application in controlled release

A novel pH/redox-double-responsive ferrocene-containing diblock copolymer of poly(ethylene glycol)-block-poly[2-(2-((2-ferrocenyl ethyl ester) (methyl) amino) ethoxy) ethyl methacrylate] [mPEG113-b-P(Fe–N-EOMA)] was synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization. mPEG113-b-P(Fe–N-EOMA) is amphiphilic with PEG as hydrophilic block and the part containing ferrocene as hydrophobic block. For comparison, three other diblock copolymers were prepared by changing the molecular weight of the hydrophilic block and the microstructure of the hydrophobic block. The diblock copolymers have a critical pH in solution and increases with the increase of the hydrophilicity of the copolymers. The redox-response was confirmed by the shift of characteristic peak of ferrocene in the UV/vis absorption spectrum after adding FeCl3/VC. The self-assembly behavior of these diblock copolymers in solution were then investigated. It shows that they have low critical micelle concentration (cmc), and the cmc decreases as the hydrophobicity of copolymers increases. Their morphology is varied, including sphere, lamella, aggregated sphere, and can be reversible changed by the stimulation of pH and redox. Finally, mPEG113-b-P(Fe–N-EOMA) was applied to the release of Nile Red (NR), which showed a good release efficiency. The prepared diblock copolymers have sensitive and reversible response properties, which provided ideas for the design of multistimuli-responsive polymers, and have good application prospects in drug-release.

The Influence of Prefermentation Skin Contact, Stabulation, and Skin Fermentation on the Aromatic Behaviour and Phenolic Compounds of Important Austrian White Wine Cultivars

Many varietal aromas of wine are located in the berry skin. In the present study, we evaluated four important Austrian grape varieties: Grüner Veltliner, Sauvignon Blanc, Traminer, and Pinot Blanc. We assessed whether prefermentation skin contact, fermentation with the skin (only for Grüner Veltliner), and stabulation (lees stirring; only for Sauvignon Blanc, Traminer, and Pinot Blanc) could enhance the varietal aromas of the different grape cultivars. The aim was to intensify the varietal aromas without extracting the undesirable phenols. We performed a detailed analytical characterisation of approximately 100 volatile and phenolic compounds as well as a sensory characterisation. Although mash fermentation significantly increased the spicy aromas of Grüner Veltliner, which are affected by climate change (especially the sesquiterpene rotundone), it markedly decreased the fruitiness and increased the bitterness; therefore, it cannot be recommended for this cultivar. For Sauvignon Blanc, stabulation is a possible option; the varietal aromas (thiols and methoxypyrazines) were increased in the final wines of these variants. For Pinot Blanc and Traminer, prefermentation skin contact yielded the best results: for Traminer, it produced the highest content of monoterpenes (especially z-rose oxide), and for Pinot Blanc, it produced the highest content of ethyl esters. To summarise, stabulation will not completely replace classic skin contact, and mash fermentation is certainly not an alternative for the production of standard Grüner Veltliner wine. However, additional investigations are necessary with regard to other grape varieties, terroirs, and vintages before we can make final recommendations.

Gas chromatography-mass spectrometry characterization of the aroma of Ossetian cheeses

The aim of the study was the qualitative and quantitative determination of volatile aroma compounds and their formation pathways in brine Ossetian cheeses. Volatile components of cheeses were isolated by steam distillation and extraction with dichloromethane, with their subsequent determination and quantification by gas chromatography-mass spectrometry. The results of the analysis are presented according to the structural classes of the main chemical components and the corresponding microbial metabolic processes. Four processes were found to be the main contributors to flavor formation: lipolysis, proteolysis, glycolysis, and a number of oxidative enzymatic transformations. Lipolysis of the fatty fraction of cheeses is a source of formation of volatile carboxylic acids and their esters. Proteolysis of the casein fraction yields branched alcohols, aldehydes, and a number of aromatic and heteroaromatic compounds. Glycolysis of the carbohydrate fraction is a source of ethanol formation, which is the main cause of the dominance of ethyl esters in the ester fraction. Redox enzymatic transformations mainly determine the biosynthesis of unbranched aldehydes, ketones and lactones. A clear distinction between retail and homemade cheeses was observed, due to the different technological approaches to the cheese preparation. The structuralchemical and quantitative evolution of the volatile composition of the studied cheese samples during ripening is tentatively shown. From the authors’ point of view, the aromatic composition of the Tib cheese sort is the most consistent with the Ossetian cheese standard. This study represents the first gas chromatographic study of Ossetian cheeses and aims to create objective criteria for controlling technological processes and product quality during production and storage in the food industry.

A combined approach of lauroyl arginine ethyl ester hydrochloride and kojic acid in mitigating fresh-cut potato deterioration

The combinational effects of kojic acid and lauroyl arginine ethyl ester hydrochloride (ELAH) on fresh-cut potatoes were investigated. Kojic acid of 0.6% (w/w) effectively inhibited the browning of fresh-cut potatoes and displayed antimicrobial capacity. The color difference value of samples was decreased from 175 to 26 by kojic acid. In contrast, ELAH could not effectively bind with the active sites of tyrosinase and catechol oxidase at molecular level. Although 0.5% (w/w) of ELAH prominently inhibited the microbial growth, it promoted the browning of samples. However, combining kojic acid and ELAH effectively inhibited the browning of samples and microbial growth during the storage and the color difference value of samples was decreased to 52. This amount of kojic acid inhibited enzyme activities toward phenolic compounds. The results indicated that combination of kojic acid and ELAH could provide a potential strategy to extend the shelf life of fresh-cut products.

The Physicochemical Basis for the Production of Rapeseed Oil Fatty Acid Esters in a Plug Flow Reactor

This article describes the results of a comprehensive comparative study of the production of fatty acid ethyl esters (FAEEs) for use as biodiesel in perfect mixing reactors (PMRs) and plug flow reactors (PFRs). The products obtained on a laboratory scale at all stages of the separation and purification of the FAEE phase were analyzed using the FTIR, XRF and GC-MS methods. We compared distillation methods for the separation of stoichiometrically excessive ethanol from the reaction mixture. Neutralization methods with H2SO4 solution and carbonation with CO2 were applied for FAEE phase purification from the catalyst. Emulsions formed during the water flushing stage were analyzed via the optical microscopy method. The optimal conditions of stirring speed and temperature were selected to maintain a high level of FAEE–water phase contact area with minimum phase separation time. The efficiency of the carbonation method for catalyst neutralization in the FAEE phase has been proven, allowing us to consider this method as an alternative to the traditional acid neutralization method. According to the results of experimental studies, we have developed a new high-performance technological scheme for the production of fatty acid esters in PFRs. The synthesis of FAEEs in a stoichiometric excess of ethanol of about 1:50 allowed us to increase the reaction rate and productivity of the synthesis unit after the transition from a PMR to a PFR. The yield of the product amounted to 86.7%. The purified FAEE fraction complied with most EN14214 specifications.

Effects of triglyceride and ethyl ester forms of EPA on hepatic lipid metabolism in mice with non-alcoholic fatty liver disease

In this study, the beneficial effects of EPA in ethyl esters (EE) and triacylglycerides (TAG) forms on high fat diet (HFD)-induced non-alcoholic fatty liver disease (NAFLD) were studied and compared. Results indicated that both EPA-TAG and EPA-EE can alleviate pathological features of NAFLD, such as hepatic lipid accumulation and lobular inflammation, with a more pronounced protective effects observed in EPA-TAG treated mice. The integrated hepatic transcriptomic, metabolic and gut microbiota profiles suggest that EPA-TAG and EPA-EE improved hepatic steatosis by suppression of food intake and lipogenesis, promotion of lipid and phospholipid PUFA remodeling, ketogenesis and fatty acids oxidation, possibly via activating the AMPK/adipocytokine signaling pathway. The protective effect of EPA was also associated with the regulation of intestinal flora structure. In general, EPA-TAG was found to be more effective than EPA-EE in preventing HFD-induced NAFLD by reducing appetite, improving hepatic lipid metabolism, increasing energy expenditure, and enhancing gut-liver cross-talk.

Exploring Metschnikowia pulcherrima as a Co-Fermenter with Saccharomyces cerevisiae: Influence on Wine Aroma during Fermentation and Ageing

Non-Saccharomyces yeasts, particularly Metschnikowia pulcherrima, are considered alternatives to SO2 in winemaking, combating specific microorganisms. The sensory profile of the wine is contingent upon the type of yeast, the fermentation conditions, and the concentration and mode of application with Saccharomyces cerevisiae strains (whether pure or used in mixed/sequential co-fermentation). This study assessed the aroma in red wines produced with S. cerevisiae (Sc) and M. pulcherrima (Mp, non-Sc), incorporating variations in the method of addition and the inclusion or exclusion of SO2. The enological parameters of the wines were slightly affected. Volatile compounds were analysed in the wines through gas chromatography–mass spectrometry (GC-MS) at three moments: at the end of malolactic fermentation (MLF) and after 6 and 9 months of bottle ageing. Sequential fermentation of Sc and Mp reduced the concentration of most identified alcohols and acids, which is favourable, as these compounds can yield undesirable aromas at high concentrations. Regardless of the yeast mixture and Mp dose, a majority of the acetate esters and ethyl esters were quantified at concentrations above their perception thresholds, thus enhancing the sensory quality of the wines. Sensory analysis of wines showed generally positive evaluations. Using non-Saccharomyces as an alternative to SO2 improves the aromatic profile of wines.

Discrimination between the Triglyceride Form and the Ethyl Ester Form of Fish Oil Using Chromatography-Mass Spectrometry.

Although the triglyceride form is the natural form of fish oil found in fish, the ethyl ester form of fish oil, which is used during processing to save costs, is also present on the market. In this study, fatty acids and lipids were determined using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-linear ion trap mass spectrometry (LC-LIT/MS), respectively, according to developed methods. The identification of fatty acids was based on the mass spectral characteristics and equivalent chain lengths. However, the fatty acid contents of both forms of fish oils are quite similar. The application of the LC-LIT/MS method for the structural characterization of triacylglycerols (TAGs) and the mechanism of LIT/MS fragmentation are also discussed. Neutral losses of CH2=CH2 (m/z 28) and CH3CH2OH (m/z 46), which are LIT/MS characteristics of ethyl ester from fish oil, were found for the first time. The triglyceride form of fish oils was easily and accurately identified using fingerprint chromatography. In conclusion, lipid analysis combined with LC-LIT/MS showed an improved capability to distinguish between types of fish oil.

Lipophilic analogues of D-cysteine prevent and reverse physical dependence to fentanyl in male rats.

We examined whether co-injections of the cell-permeant D-cysteine analogues, D-cysteine ethyl ester (D-CYSee) and D-cysteine ethyl amide (D-CYSea), prevent acquisition of physical dependence induced by twice-daily injections of fentanyl, and reverse acquired dependence to these injections in freely-moving male Sprague Dawley rats. Injection of the opioid receptor antagonist, naloxone HCl (NLX, 1.5mg/kg, IV), elicited a series of withdrawal phenomena that included cardiorespiratory and behavioral responses, and falls in body weight and body temperature, in rats that received 5 or 10 injections of fentanyl (125μg/kg, IV), and the same number of vehicle co-injections. Regarding the development of physical dependence, the NLX-precipitated withdrawal phenomena were markedly reduced in fentanyl-injected rats that had received co-injections of D-CYSee (250μmol/kg, IV) or D-CYSea (100μmol/kg, IV), but not D-cysteine (250μmol/kg, IV). Regarding reversal of established dependence to fentanyl, the NLX-precipitated withdrawal phenomena in rats that had received 10 injections of fentanyl (125μg/kg, IV) was markedly reduced in rats that received co-injections of D-CYSee (250μmol/kg, IV) or D-CYSea (100μmol/kg, IV), but not D-cysteine (250μmol/kg, IV), starting with injection 6 of fentanyl. This study provides evidence that co-injections of D-CYSee and D-CYSea prevent the acquisition of physical dependence, and reverse acquired dependence to fentanyl in male rats. The lack of effect of D-cysteine suggests that the enhanced cell-penetrability of D-CYSee and D-CYSea into cells, particularly within the brain, is key to their ability to interact with intracellular signaling events involved in acquisition to physical dependence to fentanyl.