Acid Ethyl Ester Research Articles

Asymmetric Phase-Transfer Alkylation of Readily Available Aryl Aldehyde Schiff Bases of Amino Acid Ethyl Esters.

Asymmetric phase-transfer alkylation of the N-(arylmethylene)-α-alkylamino acid ethyl esters and N-(arylmethylene)glycine ethyl esters was found to be catalyzed by the (R)- or (S)-Simplified Maruoka Catalyst with high efficiency and excellent enantioselectivity. This approach was successfully applied to the enantioselective formal synthesis of the angiotensin II type 2 receptor (AT2R) antagonists Olodanrigan and LX9211, and the practical aspect is demonstrated by the kilogram-scale synthesis of a key intermediate for the synthesis of LX9211.

Preparation of chitin/hyaluronic acid/collagen hydrogel loaded with mouse adipose-derived stem cells and its effects on wound healing of full-thickness skin defects in rats

Objective: To prepare the chitin/hyaluronic acid/collagen hydrogel loaded with mouse adipose-derived stem cells and to explore its effects on wound healing of full-thickness skin defects in rats. Methods: The research was an experimental research. Chitin nanofibers were prepared by acid hydrolysis and alkaline extraction method, and then mixed with hyaluronic acid and collagen to prepare chitin/hyaluronic acid/collagen hydrogels (hereinafter referred to as hydrogels). Besides, the hydrogels loaded with mouse adipose-derived stem cells were prepared. Thirty male 12-week-old guinea pigs were divided into negative control group, positive control group, and hydrogel group according to the random number table, with 10 guinea pigs in each group. Ethanol, 4-aminobenzoic acid ethyl ester, or the aforementioned prepared hydrogels without cells were topically applied on both sides of back of guinea pigs respectively for induced contact and stimulated contact, and skin edema and erythema formation were observed at 24 and 48 h after stimulated contact. Adipose-derived stem cells from mice were divided into normal control group cultured routinely and hydrogel group cultured with the aforementioned prepared hydrogels without cells. After 3 d of culture, protein expressions of platelet-derived growth factor-D (PDGF-D), insulin-like growth factor-Ⅰ (IGF-Ⅰ), and transforming growth factor β1 (TGF-β1) were detected by Western blotting (n=3). Eight male 8-week-old Sprague-Dawley rats were taken and a circular full-thickness skin defect wound was created on each side of the back. The wounds were divided into blank control group without any treatment and hydrogel group with the aforementioned prepared hydrogels loaded with adipose-derived stem cells applied. Wound healing was observed at 0 (immediately), 2, 4, 8, and 10 d after injury, and the wound healing rate was calculated at 2, 4, 8, and 10 d after injury. Wound tissue samples at 10 d after injury were collected, the new tissue formation was observed by hematoxylin-eosin staining; the concentrations of interleukin-1α (IL-1α), IL-6, IL-4, and IL-10 were detected by enzyme-linked immunosorbent assay method; the expressions of CD16 and CD206 positive cells were observed by immunohistochemical staining and the percentages of positive cells were calculated. The sample numbers in animal experiment were all 8. Results: At 24 h after stimulated contact, no skin edema was observed in the three groups of guinea pigs, and only mild skin erythema was observed in 7 guinea pigs in positive control group. At 48 h after stimulated contact, skin erythema was observed in 8 guinea pigs and skin edema was observed in 4 guinea pigs in positive control group, while no obvious skin erythema or edema was observed in guinea pigs in the other two groups. After 3 d of culture, the protein expression levels of PDGF-D, IGF-I, and TGF-β1 in adipose-derived stem cells in hydrogel group were significantly higher than those in normal control group (with t values of 12.91, 11.83, and 7.92, respectively, P<0.05). From 0 to 10 d after injury, the wound areas in both groups gradually decreased, and the wounds in hydrogel group were almost completely healed at 10 d after injury. At 4, 8, and 10 d after injury, the wound healing rates in hydrogel group were (38±4)%, (54±5)%, and (69±6)%, respectively, which were significantly higher than (21±6)%, (29±7)%, and (31±7)% in blank control group (with t values of 3.82, 3.97, and 4.05, respectively, Pvalues all <0.05). At 10 d after injury, compared with those in blank control group, the epidermis in wound in hydrogel group was more intact, and there were increases in hair follicles, blood vessels, and other skin appendages. At 10 d after injury, the concentrations of IL-1α and IL-6 in wound tissue in hydrogel group were significantly lower than those in blank control group (with tvalues of 8.21 and 7.99, respectively, P<0.05), while the concentrations of IL-4 and IL-10 were significantly higher than those in blank control group (with tvalues of 6.57 and 9.03, respectively, P<0.05). The percentage of CD16 positive cells in wound tissue in hydrogel group was significantly lower than that in blank control group (t=8.02, P<0.05), while the percentage of CD206 positive cells was significantly higher than that in blank control group (t=7.21, P<0.05). Conclusions: The hydrogel loaded with mouse adipose-derived stem cells is non-allergenic, can promote the secretion of growth factors in adipose-derived stem cells, promote the polarization of macrophages to M2 phenotype in wound tissue in rats with full-thickness skin defects, and alleviate inflammatory reaction, thereby promoting wound healing.

Liquid to solid phase transition detection by using a vibrating tube densimeter along with densities up to 137 MPa of beef tallow fatty acid alkyl esters

Phase behavior and thermophysical properties of biodiesel at high pressure and high temperature are limited in the literature. These are useful to develop models and to understand their behavior having in mind the use of biodiesel in engines. Liquid to solid phase transitions, by using a vibrating tube densimeter, along with densities of three beef tallow fatty acid alkyl esters were studied in this work. Measurements of the oscillating period for each biofuel were carried out in a modular array constituted by two vibrating tube densimeters coupled in series and connected to a single loading cell. The oscillating period was converted to density by the forced path mechanical calibration (FPMC) method. Experimental liquid density sets for three beef tallow biodiesel samples based on fatty acid alkyl esters (FAAEs) are reported for the first time for pressures up to 137 MPa. These biofuels, named fatty acid methyl esters (FAMEs), fatty acid ethyl esters (FAEEs) and fatty acid butyl esters (FABEs), were measured in the temperature range of 286–393 K. The detection procedure for the beginning of the high-pressure solidification was focused on the beef tallow FABEs sample based upon its lower cloud point (CPFABEs = 281.15 K) in comparison with the reported property for the other esters (CPFAEEs = 289.15 K, CPFAMEs = 291 K) with the same feedstock; therefore, the conditions for the metastable liquid to solid phase transition associated to the effect of high pressure was detailed for waste beef tallow butyl ester biodiesel by performing step-by-step compressions in the interval of 286.20–298.13 K and with the help of the vibrating tube densimeters. FABEs had the lower density in contrast with FAEEs and FAMEs, this one being the denser biofuel. Modeling of liquid density data was performed by the perturbed-chain statistical associating fluid theory (PC-SAFT) Equation of State and the Tammann-Tait equation with maximum absolute average deviations of 0.15 % and 0.05 %, respectively. Both models were applied for correlating the thermodynamic derived properties of the fluid phase: isobaric thermal expansivity and isothermal compressibility.

Integrated process for a new sequential valorization of corn ethanol production by-products: Production of fermented solid with lipase activity, ethyl esters, and animal feed

The use of co-products from corn ethanol production such as distillers’ dried grains with solubles (DDGS) and distillers’ corn oil (DCO) to produce a crude extract with lipolytic activity and fatty acid ethyl esters was studied in an integrated process. The dry fermented solid (DFS) with lipase activity was produced from the fermentation of the filamentous fungus Rhizomucor miehei in DDGS in tray-type reactors and column systems. The DFS was used to catalyze esterification reactions between oleic acid and ethanol, with conversions of 72% and 80% (within 4 h) for the biocatalyst produced in tray-type and fixed bed systems, respectively. The biocatalyst also converted glycerides from DCO into FAEE, with an ester yield higher than 70% after three consecutive reactions. By introducing 2 wt% of a commercial preparation (Novozym 435) in the system with the DFS, ester contents of 81% were obtained and, the yield was higher than 95% after three consecutive reactions. The biocatalyst could be reused 6 consecutive times in the esterification reactions, after washing with ethanol and 5 times after washing with hexane. In DCO transesterification reactions, reuse was less efficient with a loss of activity after the second reuse. Bromatological analysis showed that the fermented material maintained the main properties of the in natura DDGS, with a reduction in the oil and grease and an increase in protein content. The chemical composition was maintained after its use in the corn oil ethanolysis (used DFS). These findings show the potential for developing novel pathways to diversify the use and enhance the value of co-products derived from the large-scale corn ethanol industry, in a biorefinery concept.

Synthesis, crystal structure investigation, and theoretical approaches to discover potential 6-bromo-3-cyanocoumarin as a potent inhibitor MetAP (methionine aminopeptidase) 2

It has been ascertained that trifluoroacetic acid accelerates the Knoevenagel condensation reaction of 5-bromosalicylaldehyde and ethyl ester of cyanoacetic acid. As a result, the 6-bromo-3-cyanocoumarin compound has been synthesized and the structure was eventually confirmed by X-ray analysis. Based on the structure-activity relationship and literature survey we found this compound has a potent inhibitor for MetAP (methionine aminopeptidase) and further we have studied molecular docking to understand the binding interactions and also performed ADME/T studies for this compound. The surface reactivity and intermolecular interactions of the studied compound were investigated by Hirshfeld surface analysis. Energy framework analysis shows the interaction between pair of fragments with neighbor molecules. Furthermore, the DFT study is performed to investigate structural reactivity and stability at B3LY/6-311+G(d,p) functional. The decreased HOMO-LUMO gap (3.97 eV) indicates its higher reactivity and soft nature. Molecular electrostatic potential (MESP) analysis and NBO charges indicate the structure's reactive site and charge transfer. Excited analysis by using the TD-DFT was performed to get excitation energy (ΔE), absorbance, and oscillator strength (fo) of crucial transition. Theoretically predicted values of polarizability (αo) and hyperpolarizability (βo) suggest their excellent optical and Nnar (NLO) properties.

Enzymatic Synthesis of Arachidonic Acid-Rich Phosphatidylcholine from Arachidonic Acid Ethyl Esters

Arachidonic acid (ARA) is an essential fatty acid with numerous biological activities that benefits human health. However, ARA-rich phosphatidylcholine (PtdCho), which has a higher bioavailability than ARA-rich triacylglycerols, is scarce in the natural source. In this study, we developed an enzymatic modification approach for the synthesis of ARA-rich PtdCho from ARA-rich ethyl esters (EE). The maximum incorporation of ARA into PtdCho (24.02%) was achieved from the optimized conditions, including ARA-rich EE/PtdCho mass ratio of 2:1, hexane, lipase Novozym 435 as a biocatalyst (15% of enzyme load) and reaction time of 24 h. The 31P nuclear magnetic resonance (NMR) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) results revealed that the PtdCho content decreased to 17.53% and the ARA-containing PtdCho species was primarily identified as PtdCho (18:2/20:4). Taken together, this investigation offers a new reference for the efficient production of ARA-rich PtdCho via enzymatic modification and paves a theoretical groundwork of industrial production practice.

Thiol-ene-based degradable 3D printed network from bio resource derived monomers ethyl-lactate and isosorbide

A polymeric ene-based thiol-ene network is reported that was demonstrated for light-based 3D printing. Allyl poly (acrylate ethyl lactate) (PAEL) was synthesized starting from ethyl lactate in an efficient and scalable manner. Ethyl lactate is a biobased material obtained naturally or chemically in high yields in the form of ethyl ester of lactic acid. Isosorbide, which is also a bio based resource was converted into thiol derivative and was used along with Pentaerythritol tetrakis(3-mercaptopropionate) (PETMP) as multifunctional thiol. The polymeric nature of the ene (i.e. PAEL) imparted exceptionally high mechanical properties like Young's modulus of 1.75 GPa as well as high thermal stability with a decomposition temperature (Td,10%) exceeding 350 °C for all the networks studied. The properties could also be customized by fine tuning the type and stoichiometric ratio of the thiol crosslinked employed. For instance, the Young's modulus range from 1.75 GPa to 1.03 GPa and glass transition temperature range from 44 °C to 54 °C could be achieved. DLP 3D printing was used to demonstrate the printability of the resins with high resolution and structural fidelity. The study also highlights the base-mediated rapid hydrolytic degradation efficiency of the 3D printed parts, demonstrating the applicability of these novel polymeric ene based thiol-ene for sustainable and eco-friendly 3D printable formulations.

The effects of different rootstocks on aroma components, activities and genes expression of aroma-related enzymes in oriental melon fruit.

Grafting is widely applied in the cultivation of melon. In this study, 'Qinmi No.1' (Cucumis melo L.(QG)) and 'Ribenxuesong' (Cucurbita maxima Duch. (RG)) were used as rootstocks for 'Qingxin Yangjiaocui' (Cucumis melo L.). The results showed that grafting with muskmelon rootstocks had no significant effect on fruit aroma, but grafting with pumpkin rootstocks significantly reduced the odor intensity and odor preference scores of melon fruits. Compared with the fruits from self-grafted plants (SG), four new aromatic volatiles with a sweet smell were detected, the alcohol dehydrogenase (ADH) activity was significantly decreased at 30 DAP, but unaffected at 42 DAP in QG fruits. There was no difference for alcohol acetyltransferase (AAT) activity between QG and SG fruits. The expression level of CmADH2 was significantly higher at 30 DAP and 42 DAP, but CmAAT2 was significantly lower at 42 DAP in QG fruits compared with SG fruits. In RG fruits, the main aroma compounds including butanoic acid ethyl ester, 2-methyl-2-butene-1-al, and 2-methylheptan-1-al were absent, while the volatile compounds with unpleasant odor characteristics including trans, cis-2,6-nonadien-1-ol, (E,E)-2,4-heptadienal, octanoic acid, and styrene were detected. Compared with SG fruits, 1-nonanol and 1-heptanol with green odor characteristics were significantly increased, but eucalyptol and farnesene with fruity aroma characteristics were significantly decreased in RG fruits. The ADH activity of RG fruits was significantly lower than that of SG fruits at 30 DAP and the AAT activity was significantly lower than that of SG fruits at 42 DAP. In addition, the expression levels of CmADH and CmAAT homologs in RG fruits were significantly lower than those in SG or QG fruits. These results show that grafting with pumpkin rootstocks affected the main aroma components, reduced ADH and AAT activities, and down-regulated the expression levels of CmADHs and CmAATs in the melon fruits. This study reveals the mechanism of different rootstocks on melon fruit aroma quality, and lays a theoretical foundation for the selection of rootstocks in melon production. Future studies using overexpression or CRISPR/CAS system to obtain stable transgenic lines of genes encoding key aromatic volatiles, would be promising to effectively improve the flavor quality of melon.

Characterization and Antioxidant Activities of Different Solvent Extracts of Philippine Stingless Bee (Tetragonula biroi Friese) Pollen Samples

Bee pollen is among the bee products that are considered functional food due to its components exhibiting various biological activities. This study aimed to characterize the volatile compounds present in stingless bee pollen extracted by different solvents using gas chromatography–mass spectrometry (GC-MS). Antioxidant activities and total phenolic content of bee pollen solvent extracts were also determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and Folin-Ciocalteu assays, respectively. Fatty acids and esters were detected in ethanolic and methanolic extracts – namely, n-hexadecanoic acid, hexadecanoic acid ethyl ester, and 9,12,15-octadecatienal acid ethyl ester (Z,Z,Z). Long-chain hydrocarbons – namely, heptacosane and pentacosane – were detected in dicholoromethane, chloroform, and hexane extracts. Total phenolic content was in the range of 20.43 ± 2.78 to 371.66 ± 11.26 mg GAE/g, with ethanolic and methanolic extracts having the highest amounts detected. Antioxidant activities IC50 values ranged from 5.69 ± 0.74 to 153.90 ± 13.43 mg/mL, with ethanol and methanol exhibiting the highest activities. Hence, bee pollen is a potential source of antioxidant and phenolic compounds.

Comparison of the Catabolic Rates of Linoleic and Oleic Acid Hydroperoxides Using 13CO2 Expired from Mice.

Unsaturated fatty acids, such as oleic and linoleic acids, are easily oxidized by exposure to temperature and light in the presence of air to form unsaturated fatty acid hydroperoxides as primary oxidation products. However, the catabolic rates of unsaturated fatty acid hydroperoxides in the human body remain unknown. In this study, ethyl esters of 13C-labeled linoleic acid (*C18:2-EE) and oleic acid (*C18:1-EE) and their hydroperoxides (*C18:2-EE-OOH and *C18:1-EE-OOH, respectively) prepared by the photo-oxidation of *C18:2-EE and *C18:1-EE, respectively, were administered to mice and their catabolic rates were determined by measuring the expired 13CO2 levels. *C18:2-EE-OOH and *C18:1-EE-OOH were β-oxidized faster than *C18:2-EE and *C18:1-EE, respectively. Notably, rapid β-oxidation of *C18:2-EE-OOH and *C18:1-EE-OOH was similar to that of medium-chain fatty acids, such as octanoic acid. Then, degradation products of C18:2-EE-OOH and C18:1-EE-OOH were analyzed under gastric conditions by gas chromatography/mass spectrometry. Major decomposition products of C18:2-EE-OOH and C18:1-EE-OOH were medium-chain compounds, such as octanoic acid ethyl ester, 9-oxo-nonanoic acid ethyl ester, and 10-oxo-8-decenoic acid ethyl esters, indicating that C18:2-EE-OOH and C18:1-EE-OOH isomers formed during photo-oxidation were decomposed under acidic conditions. These findings support previous reports that dietary lipid hydroperoxides are not absorbed into the intestine as lipid hydroperoxides but as degradation products. This is the first study to suggest that dietary lipid hydroperoxides decompose during gastric digestion to form medium-chain compounds that are directly absorbed into the liver via the portal vein and rapidly catabolized via β-oxidation.

Binding modes of the metabolites docosahexaenoic acid, eicosapentaenoic acid, and eicosapentaenoic acid ethyl ester from Caulerpa racemosa as COX-2 inhibitors revealed via metabolomics and molecular dynamics

A total of 116 metabolites of Caulerpa racemosa were identified. However, only three (DHA, EPA, and EPAS) were found to have high anti-inflammatory potential, with Pa scores ranging from 0.764 to 0,827. The inhibition constant (Ki) and binding energy interactions with COX-2 revealed by DHA (−8.83 kcal/mol: 0.338 μM), EPA (−8.35 kcal/mol: 0.763 μM), EPAS (−8.05 kcal/mol: 1.25 μM). They were used to bind to the fundamental residues of COX-2 (TYR 348, VAL 349, LEU 384, TYR 385, and TRP 387). The result of molecular dynamics showed that DHA, EPA, and EPAS had high stability while interacting with COX-2 in 310 K. The stabilities were 1.8 Å for DHA from 60 Ns to 200 Ns, 2.0 Å for EPA from 75 Ns to 200 Ns, and 2.2 Å for EPAS from 100 Ns to 200 Ns. Additionally, the potential energy of DHA (−1.069.250 eV) was higher compared with that of EPA (−1.069.247 eV) and EPAS (−1.069.220 eV). This data shows that DHA, EPA, and EPAS could stably inhibit COX-2 by blocking the transcriptional regulation of COX-2 via TYR348, VAL349, LEU384, TYR385, and TRP387.

Comparative characteristics of different methods for electrophoretic determination of mono- and disaccarides using derivatization

The following variants of electrophoretic determination of sugars with prior derivatization are considered in the article: reductive amination using p-aminobenzoic acid ethyl ester (ABEE) and condensation with 1-phenyl-3-methyl-5-pyrazolone (PMP). Derivatization products were separated using capillary electrophoresis in both zone and micellar modes, and comparative estimate characteristics were obtained. The best efficiency (ca. 650 thousand theoretical plates), selectivity (2.1–2.4), and LOD (0.8–2.9 μg/mL) was observed for the separation of reductive amination products using micellar electrokinetic chromatography (MEKC). Optimization of derivatization conditions was performed for the reductive amination using the central composite experiment design. Additionally, LOD was lowered by the sample intracapillary concentration in sweeping mode, and sample enhancement factors (SEF) of 13–19 were achieved. A proof-of-concept possibility of the intracapillary reductive amination ensuring electrophoretic mobility of the derivatization reagent using detergent micelles as carrying agents was demonstrated. Both derivatization methods were applied for the analysis of baby food.

Using Gibbs Energy Additivity Methods for QSPR to Model the Density of Fatty Acid Ethyl Esters and Biodiesels

Liquid fuel density is an essential physical parameter in the design and application processes. This paper employed the Gibbs free energy technique with quantitative structure‐property relationship (QSPR) for determining the density of pure fatty acid ethyl ester (FAEE) and ethyl ester biodiesel at temperature 283.15–363.15 K. The density (ρ) of biodiesel can be estimated from (1) the number of carbon atoms of fatty acids (z) and the number of double bonds (nd): ln ρ = −0.4466–0.0009z + 88.28/T + 0.2092z/T + 0.01734nd–1.578nd/T or (2) the saponification number (SN) and iodine value (IV): ln ρ = −0.4436–3.60/SN + 87.594/T + 836.8/(T × SN) + 0.0380 IV/SN – 3.4222 IV/(T × SN), where T is the absolute temperature. The predicted densities at different temperatures for pure FAEEs and ethyl ester biodiesel have average absolute deviations (AAD) of 0.100% and 0.200%, respectively.

Regulating and controlling the stepwise ESDPT channel of BP(OH)2DCEt2 using the strategy of solvent polarity and external electric field.

Excited state double proton transfer (ESDPT) has attracted great scientific interest because of its excellent luminescent properties. However, the complex process of ESDPT has plagued theoretical and experimental scientists for a long time and has become a hot issue. In this work, the ESDPT process of 2,2'-bipyridine-3,3'-diol-5,5'-dicarboxylic acid ethyl ester (BP(OH)2DCEt2) is systematically studied and the regulation of the ESDPT process is further realized. The potential energy curves indicate that BP(OH)2DCEt2 shows the characteristics of stepwise ESDPT in different polar solvents. The increase in solvent polarity will be beneficial to the stepwise ESDPT reaction. Regrettably, it is not possible to distinguish the specific stepwise transfer path of the BP(OH)2DCEt2 molecule due to the symmetry of the potential energy surface along the diagonal. On this basis, we proposed a method to control and regulate the stepwise ESDPT path using an external electric field. The results show that the increase of external electric field intensity is favorable to stepwise ESDPT. It is interesting to note that applying an external electric field in a specific direction will effectively distinguish stepwise ESDPT reaction paths. Therefore, this work not only helps to understand the mechanism of ESDPT, but also contributes to regulation and design of new luminescent materials with excellent luminescent properties.

Effect of six month's treatment with omega-3 acid ethyl esters on long-term outcomes after acute myocardial infarction: The OMEGA-REMODEL randomized clinical trial

BackgroundOmega-3 polyunsaturated fatty acids (O3-FA) have been shown to reduce inflammation and adverse cardiac remodeling after acute myocardial infarction (AMI). However, the impact of O3-FA on long-term clinical outcomes remains uncertain. AimsTo investigate the impact of O3-FA on adverse cardiac events in long-term follow up post AMI in a pilot-study. MethodsConsecutive patients with AMI were randomized 1:1 to receive 6 months of O3-FA (4 g/daily) or placebo in the prospective, multicenter OMEGA-REMODEL trial. Primary endpoint was a composite of major adverse cardiovascular events (MACE) encompassing all-cause death, heart failure hospitalizations, recurrent acute coronary syndrome, and late coronary artery bypass graft (CABG). ResultsA total of 358 patients (62.8% male; 48.1 ± 16.1 years) were followed for a median of 6.6 (IQR: 5.0–9.1) years. Among those receiving O3-FA (n = 180), MACE occurred in 65 (36.1%) compared to 62 (34.8%) of 178 assigned to placebo. By intention-to-treat analysis, O3-FA treatment assignment did not reduce MACE (HR = 1.014; 95%CI = 0.716–1.436; p = 0.938), or its individual components. However, patients with a positive response to O3-FA treatment (n = 43), defined as an increase in the red blood cell omega-3 index (O3I) ≥5% after 6 months of treatment, had lower annualized MACE rates compared to those without (2.9% (95%CI = 1.2–5.1) vs 7.1% (95%CI = 5.7–8.9); p = 0.001). This treatment benefit persisted after adjustment for baseline characteristics (HRadjusted = 0.460; 95%CI = 0.218–0.970; p = 0.041). ConclusionIn long-term follow-up of the OMEGA-REMODEL randomized trial, O3-FA did not reduce MACE after AMI by intention to treat principle, however, patients who achieved a ≥ 5% increase of O3I subsequent to treatment had favorable outcomes.

Efficient Enzymatic Enrichment of High-purity Nervonic Acid from Malania oleifera Seed Oil.

Nervonic acid (NA) is a monounsaturated fatty acid vital for brain health and is of emerging importance in various industrial applications, including therapeutics, food, and cosmetics. Given the growing demands of the food and pharmaceutical industries, there's a pressing need for high-purity NA. Previously, NA constituents in plant seed oils were chemically transformed into nervonic acid ethyl ester (NAEE) to facilitate extraction from seed oils. In this study, we present an enzymatic approach to convert NA constituents in Malania oleifera seed oil to NAEE. Combined with the utilization of the semi-preparative chromatography, we achieved a remarkable purity of 97.52% NAEE. Compared to conventional chemical preparations characterized by multiple steps, prolonged processing times, and low yields and purities, our enzymatic method stands out as a more efficient and advantageous alternative. On top of that, this innovative approach is environmentally friendly and circumvents health and safety issues associated with chemical processes.

Preparation of High-Purity Docosahexaenoic Acid Ethyl Ester from Algal Oil through Enzymatic Ethanolysis.

Docosahexaenoic acid plays a crucial role in infant brain function, and the market demand of high-purity docosahexaenoic acid is continuously increasing. The availability of docosahexaenoic acid in natural fish oil is limited, prompting the exploration of alternative sources like microalgae. For algal oil, enzymatic ethanolysis is preferred to chemical methods because the former is milder and can avoid docosahexaenoic acid oxidation. However, enzymatic methods have generally low yield due to the poor substrate-specificity of lipase to long-chain polyunsaturated fatty acids, affecting the yield and purity of docosahexaenoic acid. Therefore, we developed an efficient process to produce high-purity docosahexaenoic acid ethyl ester from algal oil, by screening lipases, optimizing enzymatic ethanolysis and applying molecular distillation. Lipase UM1 was the best lipase to produce ethyl ester from algal oil with the highest ethyl ester yield (95.41%). Meanwhile, it was a catalyst for the reaction of long-chain polyunsaturated fatty acids with ethanol. The fatty acid docosahexaenoic acid conversion rates exceeded 90%. After molecular distillation, a final product containing 96.52% ethyl ester was obtained with a docosahexaenoic acid content up to 80.11%. Our findings provide an highly effective enzymatic method for the production of high-purity docosahexaenoic acid ethyl esters, with potential commercial applications.

Isolation and Structural Elucidation of Antimicrobial Molecules from Crinum ornatum (Aiton) Rhizome of Dutsin-Ma

Crinum ornatum is a well-known traditional herb used used traditionally to treat various diseases including wounds, sores, vomiting, ear-aches, urinary tract infection, coughs and cold, renal and hepatic conditions, sexually transmitted diseases and backaches. The rhizomes of C. ornatum were collected, identified, air-dried and pulverized and subjected to cold extraction using hexane, dichloromethane (DCM), ethyl acetate (EtOAc) and methanol (MeOH) respectively. Antimicrobial activity of the extracts was determined using standard antimicrobial tests with Staphylococcus aureus, Salmonella typhi, Baccilus subtilis and Pseudomonas aeruginosa as test microorganisms. The most active extract was thereafter subjected to Gas chromatography Mass Spectrometry (GCMS) analysis, the Structural elucidation of the isolated molecule was performed using advanced spectroscopic techniques, including nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR), Results of the antimicrobial activity test of the extracts showed appreciable antimicrobial activity against Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Salmonella typhi (with MIC value ranging from 200 mg/ml to 25 mg/ml). The results demonstrated significant inhibitory effects, highlighting the potential of the compound as an antimicrobial agent. GCMS analysis identified 45 compounds in the most active (DCM) extract. Out of these, eight (8) compounds were most abundant (revealed &gt;5% peak areas on GC chromatogram). These are: n-hexanedecanoic acid, hexadecanoic acid ethyl ester, 9,12-octadecadienoic acid (Z,Z),oleic acid, linoleic acid ethyl ester, ethyl oleate, squalene and tetrapentacontane. Antibacterial activity exhibited by the plant could be ascribed to the presence of the major phytocompounds in the plant and this provides scientific proof of some of ethnomedicinal uses of Crinum ornatum rhizome.

Partial dealcoholization of a Malbec wine through pervaporation with a PDMS membrane: Effect of operation temperature on process economics, volatile aroma composition and sensory properties

In the present work, partial dealcoholization of a Malbec red wine with 14.8% v/v alcohol by pervaporation through a PDMS membrane (polydimethylsiloxane) was addressed. The influence of the process temperature on the economy of the process, the composition of volatile aroma compounds and wine sensory characteristics was deeply analyzed.To do so, partial dealcoholization experiments at lab scale were run with the pervaporation setup operated at a permeate pressure of 0.013 bar and at three different temperatures; i.e. 35, 40 and 45 °C. Two types of runs were carried out: (i) simple runs to build a conceptual model of the process and (ii) repetitions to accumulate an adequate volume of partially dealcoholized wine (10.5%v/v) to allow the sensory analysis of the following Malbec wines: the initial wine, the partially dealcoholized wines and the blends in a 70/30 ratio (13.5% v/v)).From the conceptual modeling stage the required value of the fractional pervaporation advance ηreq of 0.09 was obtained, as well as the average values of permeate overall fluxes at 35, 40 and 45 °C; i.e., 1.02, 1.38 and 1.82 kg m−2 h−1, respectively. For all variants, a permeate product with an alcohol content of 54% v/v was estimated. Experimental values agreed reasonably well with those obtained from the model simulation.The conceptual modeling of the process enabled the scaling-up of the process and the subsequent economic analysis. The best figures corresponded to the design with heat integration at 45 °C when earnings estimated from the sale of the ethanol-rich permeate to the local market was taken into account.Fresh Malbec, partially dealcoholized wines at the selected temperatures, and their corresponding blends were chemical and sensory characterized. Dealcoholized wines showed differences concerning the operating temperature on the volatile and total acidity, fructose, anthocyanins, tannins, total polymers, and CIELAB parameters, except lightness. The total and volatile acidity were affected by the temperature and showed an increase in dealcoholized and blended wines with the respective decrease of the pH. Dealcoholization favored the presence of large polymeric pigments (0.6 in initial wines and an average of 0.96 in blends), which are associated positively with color stability.Volatiles were also affected by the operating temperature, decreasing the concentration of all chemical groups in these wines. A total of thirty-two free volatile organic compounds (VOCs) including higher alcohols (HA), medium chain fatty acid ethyl esters (MCFAEE), higher alcohol acetates (HAA), medium chain fatty acids (MCFA), norisoprenoids (NI) and terpenoids (TP) were identified and quantified.Finally, sensory evaluation demonstrated that partially dealcoholized wines could not be differentiated by the operation temperature. The fullness, astringency, pungency, floral notes, bitterness, color intensity, and sweetness were significant variables that allowed differentiate between initial, partially dealcoholized, and blend wines. Despite the loss of volatile compounds, blended wines showed higher intensity of floral attributes, and in mouth were lesser astringent, bitter, and pungent than the fresh wine.From an overall perspective, pervaporation of fresh wine with a PDMS membrane at 45 °C and the adoption of a dilution ratio of 70/30 for initial wine to partially dealcoholized wine result in a promising strategy to reduce the alcohol content without affecting the sensory quality of the final red wine.

The Effects of Nine Compounds on Aldehyde-Oxidase-Related Genes in Bactrocera dorsalis (Hendel).

Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) (B. dorsalis) is an important agricultural, major invasive, and quarantine pest that can cause significant damage to the economic value of the fruit and vegetable industry. Male bait is one of the most effective methods of surveying, monitoring, and controlling B. dorsalis. In our study, we constructed cDNA libraries using total RNA extracted independently from the antennae, mouthparts, and thoracic legs of male and female adults and the ovipositors of female adults and screened out four aldehyde-oxidase-related genes (AOX-related), C58800, C66700, C67485, and C67698. Molecular docking predictions showed that eight compounds, including 3,4-dimethoxycinnamyl alcohol, 3,4-dimethoxy-cinnamaldehyde, deet, ethyl N-acetyl-N-butyl-β-alaninate, n-butyl butyrate, n-butyl butyrate, ethyl butyrate, methyl eugenol, and ethyl acetate, could combine with proteins encoded by the four B. dorsalis AOX-related genes. Furthermore, QPCR was performed to confirm that four compounds, including 3,4-dimethoxy cinnamic aldehyde, butyl levulinic acid ethyl ester (mosquito repellent), butyl butyrate, and methyl eugenol, induced significant changes in the AOX-related genes of B. dorsalis. These results provide useful information and guidance for the batch screening of potentially useful compounds and the search for effective attractants of B. dorsalis.