Fatty Acid Carbon Chain Research Articles

Transcriptional activity and variation analysis of genes critical for long-chain fatty acid (C≥16) elongation and desaturation in Pekin ducks

To deepen our understanding of long-chain fatty acid carbon chain elongation and desaturation in ducks, this study systematically analyzed the transcriptional activities of key gene promoters, including ELOVLs, FADSs, and SCDs. Predictive modeling coupled with statistical analysis revealed a prevalence of binding motifs for transcription factors, particularly those associated with Sp1, NF-1, and C/EBPalpha. Moreover, variation analysis of resequencing data from both wild and domestic ducks, specifically mallards and Pekin ducks, informed targeted mutagenesis within the core promoter regions of ELOVL2, ELOVL5, and ELOVL6. Notably, mutations at positions -56 G>C in ELOVL2, -52 T>C in ELOVL5, and -513 T>C in ELOVL6 significantly diminished transcriptional activity. These findings substantially enhance our understanding of the molecular mechanisms regulating the biosynthesis of long-chain fatty acids in ducks and support future genetic selection initiatives aimed at developing Pekin duck breeds with enhanced nutritional value.

Phospholipid biosynthesis regulation for improving pigment production by Monascus in response to ammonium chloride stress.

In the actual industrial production process, the efficient biosynthesis and secretion of Monascus pigments (MPs) tend to take place under abiotic stresses, which often result in an imbalance of cell homeostasis. The present study aimed to thoroughly describe the changes in lipid profiles in Monascus purpureus by absolute quantitative lipidomics and tandem mass tag-based quantitative proteomics. The results showed that ammonium chloride stress (15 g/L) increased MP production while inhibiting ergosterol biosynthesis, leading to an imbalance in membrane lipid homeostasis in Monascus. In response to the imbalance of lipid homeostasis, the regulation mechanism of phospholipids in Monascus was implemented, including the inhibition of lysophospholipids production, maintenance of the ratio of PC/PE, and improvement of the biosynthesis of phosphatidylglycerol, phosphatidylserine, and cardiolipin with high saturated and long carbon chain fatty acids through the CDP-DG pathway rather than the Kennedy pathway. The inhibition of lysophospholipid biosynthesis was attributed to the upregulated expression of protein and its gene related to lysophospholipase NTE1, while maintenance of the PC/PE ratio was achieved by the upregulated expression of protein and its gene related to CTP: phosphoethanolamine cytidylyltransferase and phosphatidylethanolamine N-methyltransferase in the Kennedy pathway. These findings provide insights into the regulation mechanism of MP biosynthesis from new perspectives.IMPORTANCEMonascus is important in food microbiology as it produces natural colorants known as Monascus pigments (MPs). The industrial production of MPs has been achieved by liquid fermentation, in which the nitrogen source (especially ammonium chloride) is a key nutritional parameter. Previous studies have investigated the regulatory mechanisms of substance and energy metabolism, as well as the cross-protective mechanisms in Monascus in response to ammonium chloride stress. Our research in this work demonstrated that ammonium chloride stress also caused an imbalance of membrane lipid homeostasis in Monascus due to the inhibition of ergosterol biosynthesis. We found that the regulation mechanism of phospholipids in Monascus was implemented, including inhibition of lysophospholipids production, maintenance of the ratio of PC/PE, and improvement of biosynthesis of phosphatidylglycerol, phosphatidylserine, and cardiolipin with high saturated and long carbon chain fatty acids through the CDP-DG pathway. These findings further refine the regulatory mechanisms of MP production and secretion.

Microscopic molecular insights of different carbon chain fatty acids on shape-stabilized phase change composite

Microscopic molecular insights of different carbon chain fatty acids on shape-stabilized phase change composite

SCD4 deficiency decreases cardiac steatosis and prevents cardiac remodeling in mice fed a high-fat diet

Stearoyl-CoA desaturase (SCD) is a lipogenic enzyme that catalyzes formation of the first double bond in the carbon chain of saturated fatty acids. Four isoforms of SCD have been identified in mice, the most poorly characterized of which is SCD4, which is cardiac-specific. In the present study, we investigated the role of SCD4 in systemic and cardiac metabolism. We used WT and global SCD4 KO mice that were fed standard laboratory chow or a high-fat diet (HFD). SCD4 deficiency reduced body adiposity and decreased hyperinsulinemia and hypercholesterolemia in HFD-fed mice. The loss of SCD4 preserved heart morphology in the HFD condition. Lipid accumulation decreased in the myocardium in SCD4-deficient mice and in HL-1 cardiomyocytes with knocked out Scd4 expression. This was associated with an increase in the rate of lipolysis and, more specifically, adipose triglyceride lipase (ATGL) activity. Possible mechanisms of ATGL activation by SCD4 deficiency include lower protein levels of the ATGL inhibitor G0/G1 switch protein 2 and greater activation by protein kinase A under lipid overload conditions. Moreover, we observed higher intracellular Ca2+ levels in HL-1 cells with silenced Scd4 expression. This may explain the activation of protein kinase A in response to higher Ca2+ levels. Additionally, the loss of SCD4 inhibited mitochondrial enlargement, NADH overactivation, and reactive oxygen species overproduction in the heart in HFD-fed mice. In conclusion, SCD4 deficiency activated lipolysis, resulting in a reduction of cardiac steatosis, prevented the induction of left ventricular hypertrophy, and reduced reactive oxygen species levels in the heart in HFD-fed mice.

Influence of different fatty acids on the wettability, self-cleaning and anti-corrosion behavior of superhydrophobic surfaces obtained with LDH on aluminum

The present study aims to evaluate the influence of different fatty acids on the wettability, self-cleaning, and anti-corrosion properties of aluminum alloy 5052 (AA5052). Superhydrophobic surfaces are developed through acid etching with HCl solution, in-situ growth of zinc layered double hydroxides (ZnAl LDH), and chemical modification with three different fatty acids: lauric (LA), myristic (MA), and stearic (STA). SEM images show the formation of micro-nanometric binary structures of flowers and petals covered by a thin film, which is associated with ZnAl LDH formation and fatty acid deposition through EDS. The contact angle (CA) values indicate the change in the wettability of the surfaces after chemical modification, ranging from CA = 0° to CA > 160°. Visual tests reveal notable disparities in buoyancy and self-cleaning behaviors, liquid adhesion, and the formation of plastrons between the coated and uncoated samples. The results demonstrate the influence of the fatty acid carbon chain size on the CA and corrosion resistance efficiency (IE) in saline environment (NaCl 0.6 mol/l), with the STA sample exhibiting the best performance (CASTA = 164°; IESTA = 99.98 %) followed by MA (CAMA = 162°; IEMA = 99.27 %) and LA (CALA = 160°; IELA = 81.24 %). Future researchs will focus on obtaining self-healing properties and the durability of the coatings will be evaluated using accelerated testing methods.

Prediction of Lubrication Performances of Vegetable Oils by Genetic Functional Approximation Algorithm

Vegetable oils, which are considered potential lubricants, are composed of different types and proportions of fatty acids. Because of their diverse types and varying compositions, they exhibit different lubrication performances. The genetic function approximation algorithm was used to model the quantitative structure–property relationship between fatty acid structure and the wear scar diameter and friction coefficients measured by four-ball friction and wear tests. Based on the models with adjusted R2 greater than 0.9 and fatty acid compositions of vegetable oils, the wear scar diameter and friction coefficients of Xanthoceras sorbifolia bunge oil and Soybean oil as validation oil samples were predicted. The difference between the predicted and experimental values was small, indicating that the models could accurately predict the lubrication performances of vegetable oils. The lubrication performances of 14 kinds of vegetable oils were predicted by GFA-QSPR models, and the primary factors influencing their lubrication properties were studied by cluster analysis. The results show that the content of C18:1 has a positive effect on the lubrication performances of vegetable oils, while the content of C18:3 has a negative effect, and the length of the carbon chain of fatty acids significantly affects their lubrication properties.

New N-Terminal Fatty-Acid-Modified Melittin Analogs with Potent Biological Activity.

Melittin, a natural antimicrobial peptide, has broad-spectrum antimicrobial activity. This has resulted in it gaining increasing attention as a potential antibiotic alternative; however, its practical use has been limited by its weak antimicrobial activity, high hemolytic activity, and low proteolytic stability. In this study, N-terminal fatty acid conjugation was used to develop new melittin-derived lipopeptides (MDLs) to improve the characteristics of melittin. Our results showed that compared with native melittin, the antimicrobial activity of MDLs was increased by 2 to 16 times, and the stability of these MDLs against trypsin and pepsin degradation was increased by 50 to 80%. However, the hemolytic activity of the MDLs decreased when the length of the carbon chain of fatty acids exceeded 10. Among the MDLs, the newly designed analog Mel-C8 showed optimal antimicrobial activity and protease stability. The antimicrobial mechanism studied revealed that the MDLs showed a rapid bactericidal effect by interacting with lipopolysaccharide (LPS) or lipoteichoic acid (LTA) and penetrating the bacterial cell membrane. In conclusion, we designed and synthesized a new class of MDLs with potent antimicrobial activity, high proteolytic stability, and low hemolytic activity through N-terminal fatty acid conjugation.

A stable and visualized fatty acid-based phase transition material constructed by solid-phase molecular self-assembly for thermal management.

Fatty acids are excellent thermal management materials for thermal storage, release and preventing thermal runaway. However, the leakage of fatty acids leads to instability and prevents their application in thermal management. Herein, a stable and visualized fatty acid-based phase transition material P-S/PA was constructed through solid-state molecular self-assembly strategy from polydiallyldimethylammonium chloride (PDDA), sodium dodecyl benzene sulfonate (SDBS) and palmitic acid (PA). The electrostatic interaction between PDDA and SDBS and hydrophobic interaction between PA and SDBS can prevent PA leakage during phase transition, achieving stability. After 1000 cycles, the changes in the phase transition enthalpy (ΔH M, ΔH C) were less than 1%. The structural similarity also made P-S/PA phase transition visible, and the transmittance changed significantly from 0% to 68% during phase transition. In addition, P-S/PA can be remolded by hot-pressing without performance changes, showing temperature adjustability on varying the fatty acid carbon chain length. Thus, the stable and visualized P-S/PA fatty acid-based phase transition material constructed by solid-phase molecular self-assembly has promising application in thermal management.

Potential of algal oil production from secondary treated sewage: a study using Chlorella vulgaris and synthetic wastewater

ABSTRACT To assess the potential of using the secondary treated wastewater for the production of algal biofuel, batch experiments were carried out in photobioreactors using indigenous Chlorella vulgaris isolated from the natural freshwater body. Secondary treated wastewater with partial nitrification was simulated using various proportions of NO3-N and NH4-N while keeping the total nitrogen the same. Experiments with similar concentrations of nitrate without the NH4-N were used for comparison. In the presence of only NO3-N in the concentration range of 9–37 mg/L, the growth and fatty acid methyl ester (FAME) production was similar to the literature reports. When NH4-N was present along with NO3-N, the biomass growth was adversely affected, indicating an impact on the metabolic activity. For the same initial concentrations of nitrate in the culture, the maximum biomass concentration was reduced by 50–60% in the presence of NH4-N. The FAME profile changed significantly and a new FAME was identified, suggesting an impact on the lipid synthesis pathway. Comparison and analysis with the help of existing literature indicated that the adverse effect due to NH4-N was a function of pH. The growth, biomass yield, and FAME production were unaffected by a wide range of phosphorus concentrations. Maximum fatty acid methyl ester (FAME) suitable for biodiesel production (fatty acid carbon chain length C16 to C18) was 381.01 mg/L (224.58 mg/g of dry biomass), produced at NO3-N concentration of 18.5 mg/L and initial nitrogen loading per unit biomass of 0.37 g NO3-N/g of dry biomass.

Roles of Fatty Acid Chain Length and Enzyme-Oriented Drug Controlled Release from pH-Triggering Self-Assembled Fatty Acid Conjugated Quetiapine Nanosuspensions.

Quetiapine (QTP) is a first-line antipsychotic drug, but its therapeutic druggability and patient adherence were limited due to high oral dose strength, low bioavailability and physicochemical/biopharmaceutical issues. To investigate the roles of fatty acid chain length and enzyme-oriented QTP controlled release from pH-triggering self-assembled fatty acid conjugated QTP nanosuspensions (NSPs). QTP was conjugated with different chain length fatty acids (C10-decanoic acid, C14-myristic acid, C18-stearic acid) to obtain QTP-fatty acid conjugates (QFCs: QD, QM, QS) by exploiting 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/4-dimethylaminopyridine (EDC/DMAP) conjugation chemistry. Then, the solubility, partitioning coefficient (log P), cell viability and cleavage kinetics of QFCs were evaluated. The pH-triggering self-assembled behaviors of QFCs to form QTP-fatty acid NSPs (QDN, QMN, QSN) by varying pH, QFC concentration and proton-to-QTP ratios were characterized. The morphological images, critical micelle concentration (CMC), physicochemical properties and enzyme-oriented QTP controlled release of NSPs were examined. Three QFCs were synthesized with different chain length fatty acids from QTP after desalting fumarate from QTP fumarate. The pH, QFC concentration and proton-to-quetiapine molar ratio could influence physicochemical properties and nanonization behaviors of QFCs. All three QFCs showed no effect on the viability of myoblast cells. The pH-triggering self-assembly of amphiphilic QFCs to form nanoparticles (NPs) occurred as the amine moiety of QTP was readily ionized in a strongly acidic environment (pH 1.2). Interestingly, the longer the fatty acid chain length, the lower water solubility, the higher log P (lipophilicity) and the smaller NP particle size were observed. The conversion rate of QFCs to liberate QTP by esterase in human plasma and liver S9 fractions was also inversely proportional to the fatty acid carbon chain length. Interestingly, the freeze-dried QMN showed the esterase-oriented controlled release of QTP over one month, unlike the initial burst release of QDN or the slowly delayed release pattern of QSN. A new pH-triggering self-assembled nanonization platform was developed using different chain length fatty acid conjugated QTP in low pH environment. By varying fatty acid chain length, the enzyme-oriented QTP controlled release dosage form was challenged to enhance the therapeutic effectiveness of QTP.

Application of the Compound-Specific Stable Isotopes (CSSI) Technique to Evaluate the Contributions of Sediment Sources in the Panama Canal Watershed

Sedimentation processes have negative socioeconomic and environmental consequences. The Compound-Specific Stable Isotopes (CSSI) technique allows for the evaluation of sediment inputs associated with different land use changes in a study region. In the present work, this technique was used in the Alhajuela Lake sub-basin, within the Panama Canal Watershed. The role of the main soil contributors to the landscape (land uses, river, runoff, slope) relevant to the sediment load within the sub-basin of Alhajuela Lake was evaluated, and the relevant indicators in the landscape were selected in order to obtain the best representative sample. The contribution levels of three (3) representative land uses (Forest, Pasture and Sediment) in the study area were evaluated for the sediments present in sixteen (16) selected mixing points. The samples collected were subjected to the standard laboratory process to obtain the carbon chain isotopic values present in the fatty acids. The results of the determinations of the carbon chain fatty acid isotope ratios were evaluated using a Bayesian mixing model that takes into account the uncertainty present in the identified source values. According to the results obtained, the source identified as Sediment has a prominent contribution in most of the mixing points. The contributions of Forest land use are important in the mixing points located north of the study area. The contributions associated with Pasture land use are relevant in the points located in the proximity of this land use. The results suggest that landslides caused by high rainfalls events (Forest and Pasture sources) cause strong sedimentation to the north of Alhajuela Lake. At the same time, a high distribution of soils deposition is observed in the area surrounding Alhajuela Lake due to the strong presence of soils with Sediment source in these places. The results obtained are consistent with observations and measurements of the sediments accumulated in Alhajuela Lake between the years 2008 and 2012.

Extracellular proteolytic enzyme-mediated amino exposure and β-oxidation drive the raspberry aroma and creamy flavor formation.

The fermentation-driving ability of Daqu has been widely reported, while the potential influence of substances in Daqu on Baijiu flavor formation has attracted increasing interest. Pseudo-targeted metabolomics integrated proteomics combined with sensory evaluation strategy was applied to investigate the correlation between flavor characteristics and metabolic profiling of Daqu, and the mechanism of flavor formation was also elucidated. The 4-hydroxy-2,5-dimethylfuran-3-one (3.5mgkg-1) and 2,3-dihydro-1h-inden-5-ol (894.3μgkg-1) were identified as the unique substances in qingcha qu, which were vital for raspberry flavor formation and associated with the up-regulation of amino acid metabolism. The dec-9-enoic acid (37.4mgkg-1) was screened out as the substance related to the formation of cream flavor in hongxin qu produced through the shortening of fatty acid carbon chains and unsaturated modification of long chain fatty and acceleration of carbon metabolism in hongxin qu mediated by filamentous Aspergillus spp. was related to the smoky aroma enhancement.

Enrichment of high‐purity nervonic acid ethyl ester from Acer truncatumBunge seed oil by combination method of urea inclusion and molecular distillation

AbstractAcer truncatum Bunge is a type of maple that is unique to China. Its fruit setting rate and seed oil content are both high. The oil is mainly composed of C16–C24 fatty acids and contains 5%–7% nervonic acid (NA). NA and its derivatives can delay ageing and prevent and treat disorders such as senile dementia and Alzheimer's disease. The content of NA ethyl ester prepared by the seed oil of A. truncatum Bunge is 5.84%. We report a new process for the enrichment of NA ethyl ester by urea inclusion (UI) and molecular distillation (MD), with the aim of obtaining highly pure NA ethyl ester. First, based on the difference in fatty acid ethyl ester saturation and carbon chain length, unwanted compounds such as oleic acid ethyl ester, linoleic acid ethyl ester, and sterol were removed by one‐stage UI, the content of NA ethyl ester was increased to 18.69%. The oil in the UI compound was used as a feed, and differences in the mean molecular free paths between the components were exploited to separate the C16–C20 fatty acid ethyl esters (FAEEs) by two‐stage MD. The total content of C16–C20 FAEEs decreased to 3.69% and the purity of NA ethyl ester increased to 47.47%. A new purification process of UI‐MD‐UI was established and NA ethyl ester could be purified to 91.8%. The combination of MD and UI has an important reference value for the industrialization of producing high‐purity NA ethyl ester.

Characterization of Oil Body and Starch Granule Dynamics in Developing Seeds of Brassica napus.

Brassica napus is the most important oilseed crop in the world, and the lipid was stored in the oil body (OB) in the form of triacylglycerol. At present, most of studies on the relationship between oil body morphology and seed oil content in B. napus was focused on mature seeds. In the present study, the OBs in different developing seeds of B. napus with relatively high oil content (HOC) of about 50% and low oil content (LOC) of about 39% were analyzed. It was revealed that the size of OBs was first increased and then decreased in both materials. And in late seed developmental stages, the average OB size of rapeseed with HOC was higher than that of LOC, while it was reversed in the early seed developmental stages. No significant difference was observed on starch granule (SG) size in HOC and LOC rapeseed. Further results indicated that the expression of genes that involved in malonyl-CoA metabolism, fatty acid carbon chain extension, lipid metabolism, and starch synthesis in the rapeseed with HOC was higher than that of rapeseed with LOC. These results give some new insight for understanding the dynamics of OBs and SGs in embryos of B. napus.

Evaluation of NMR predictors for accuracy and ability to reveal trends in 1 H NMR spectra of fatty acids.

Four different nuclear magnetic resonance (NMR) predictors have been evaluated for their ability to predict 600-MHz 1 H spectra of free fatty acids and fatty acid methyl esters of 20 common fatty acids. The predictors were evaluated on two main criteria: (1) their accuracy in direct prediction of the spectra (absolute accuracy) and (2) the ability to reveal trends or predict the change that occurs in the spectra as a result of a change in the fatty acid carbon chain, or by esterification of the free fatty acids to methyl esters (relative accuracy). The absolute accuracy in chemical shift prediction for fatty acids was good, compared with previous reports on a broader range of compounds. All four predictors had median prediction errors for chemical shifts of the signals in fatty acid methyl esters well below 0.1ppm and as low as 0.015 ppm for one of the predictors. However, all predictors also had outliers with errors far above the upper interquartile range. In general, they also fail to reproduce trends of diagnostic value that were observed in the experimental data or properly predict the result of a minor change in molecular structure. All four predictors depend on experimental data from different origins. This may be a limiting factor for the relative accuracy of the predictors.

The Characteristics of Lipid Biomarkers from the Abyssal and Hadal Sediments of the Yap Trench and the Influence of V-Shape Topography

Lipid biomarkers from deep-sea sediments have been observed in several studies, but little is known about their occurrence in trench system sediments. Here, we determined the concentrations of lipid biomarkers (fatty acids and neutral lipids) in sediments from the north Yap Trench. Our results showed that short-chain (C12–20) saturated fatty acids (SFAs) contributed more than (C12:1–23:1) monounsaturated fatty acids (MUFAs), and (C16:3–24:4) polyunsaturated fatty acids (PUFAs). Most fatty acids (FAs) suggest that bacteria and algae were the main contributors to marine organic matter. In contrast, terrestrial organic matter (OM) was a minor contributor to long carbon chain fatty acids greater than C20. On the other side, the observed neutral lipids such as alkanes (C14–C27), alkanols (C12–C20), alkenes (C17:1–C26:1), phytol and sterol (C27–29) indicate that phytoplankton and bacteria were the main contributors of organic materials in the sediments, and the carbon chain of neutral lipids C20–29 offering the sources of terrestrial organic matter. The extremely depleted δ13C values of fatty acids give the sources of organic carbon in the sediments from bacteria, algae, and methane-related microbes. This study is important for understanding the biogeochemical activities in deep-sea environments, particularly in the abyss and hadal zones. It will be helpful to understand the sources, transfer, and deposition of organic matter in marine trenches.

Olive- and Coconut-Oil-Enriched Diets Decreased Secondary Bile Acids and Regulated Metabolic and Transcriptomic Markers of Brain Injury in the Frontal Cortexes of NAFLD Pigs.

The objective of this study was to investigate the effect of dietary fatty acid (FA) saturation and carbon chain length on brain bile acid (BA) metabolism and neuronal number in a pig model of pediatric NAFLD. Thirty 20-day-old Iberian pigs, pair-housed in pens, were randomly assigned to receive one of three hypercaloric diets for 10 weeks: (1) lard-enriched (LAR; n = 5 pens), (2) olive-oil-enriched (OLI, n = 5), and (3) coconut-oil-enriched (COC; n = 5). Pig behavior and activity were analyzed throughout the study. All animals were euthanized on week 10 and frontal cortex (FC) samples were collected for immunohistochemistry, metabolomic, and transcriptomic analyses. Data were analyzed by multivariate and univariate statistics. No differences were observed in relative brain weight, neuronal number, or cognitive functioning between diets. Pig activity and FC levels of neuroprotective secondary BAs and betaine decreased in the COC and OLI groups compared with LAR, and paralleled the severity of NAFLD. In addition, OLI-fed pigs showed downregulation of genes involved in neurotransmission, synaptic transmission, and nervous tissue development. Similarly, COC-fed pigs showed upregulation of neurogenesis and myelin repair genes, which caused the accumulation of medium-chain acylcarnitines in brain tissue. In conclusion, our results indicate that secondary BA levels in the FCs of NAFLD pigs are affected by dietary FA composition and are associated with metabolic and transcriptomic markers of brain injury. Dietary interventions that aim to replace saturated FAs by medium-chain or monounsaturated FAs in high-fat hypercaloric diets may have a negative effect on brain health in NAFLD patients.

Hydrogen-free deoxygenation of industrial vegetable oil waste using Ce, Zr-NiAl catalysts for second-generation biofuels production

High acidic vegetable oil feedstocks and wastes are not suitable for conventional biodiesel production. These wastes could be used to produce cheap hydrocarbon-rich biofuels without affecting food production. In this work, we studied the hydrogen-free fast pyrolysis and deoxygenation of an acidic industrial vegetable oil waste for biofuels and chemicals production, assessing the effect of Ce or Zr on NiAl mixed oxides obtained from layered double hydroxides. Oily waste (OW) was pre-adsorbed on the catalysts using a Catalyst:OW mass ratio of 5:1. Without a catalyst, pyrolysis of OW, containing triglycerides and a high percentage of free fatty acids, produced mainly 1-alkenes, lower carbon chain fatty acids, and fatty acid esters. Catalytic pyrolysis increased hydrocarbons favoring 1-alkenes between propene and 1-heptadecene, as well as alkyl-benzenes. Linear alkylbenzenes are feedstock for the production of biodegradable surfactants. NiAlCe was most selective to polyenes, alkanes and ketones, while NiAl and NiAlZr catalysts were efficient in producing aromatics, alkenes and light hydrocarbons in the GLP and gasoline range (C3-C10). The combination of acidic and metallic properties on high surface area unsupported bulk mixed oxide catalysts can be used to maximize the production of specific-range hydrocarbons for second-generation drop-in biofuels and bio-based surfactant precursors, towards the decarbonization of industry.

PH-Responsive Liquid Marbles Based on Dihydroxystearic Acid.

Herein, we report pH-responsive liquid marbles stabilized by 9,10-dihydroxystearic acid (DHSA). The particle morphology and the pH-responsive behavior of the liquid marbles were investigated. The rolling time during the preparation of liquid marbles has a great influence on the thickness of powder adsorption and the stability of the marbles. Compared with the liquid marbles stabilized by other fatty acids (e.g., stearic acid and docosoic acid), the liquid marbles prepared by DHSA have a much higher mechanical robustness. The increase in the number of hydroxyl groups on the carbon chain of fatty acids improves the mechanical robustness of the liquid marbles. Such liquid marbles immediately disintegrated on the surface of an alkaline solution or after exposure to NH3 gas, which extends their applications in the NH3 sensor and chemical reactions.

Steric hindrance effect on miscibility and properties of palm oil derived pentaerythritol ester lubricants

The miscibility and solubility between refrigerant and lubricant is a prerequisite in any refrigeration system. Polyol is known to have good miscibility with refrigerant and can be synthesized from methyl ester of vegetable oils via transesterification reaction. Pentaerythritol (PE) ester is the best biolubricant in hydrofluorocarbons (HFCs) refrigerant system due to its high viscosity. PE ester was analyzed for its physicochemical properties and was compared with commercial refrigeration polyol ester (POE) RL 68H. The kinematic viscosity and density of PE ester were comparable with commercial POE. The pour point was obtained at −24 °C which is slightly higher than commercial POE. Nevertheless, the PE ester was not completely miscible in refrigerant, HFC R134a. The miscibility with refrigerant decreases as the number of ester functional group increases and the number of fatty acids carbon chain increases because of the neopentyl structure of esters hindered the ester functional group to interact with polar group of HFC refrigerant. An appropriate surfactant is needed to improve the miscibility and solubility of PE ester with HFC refrigerant.