Methyl Oleate Research Articles

Anti-obesity and antihyperlipidemic effects of Phaleria macrocarpa fruit liquid CO2 extract: In vitro, in silico and in vivo approaches

ObjectivePhaleria macrocarpa fruit has been reported to be effectively used in Malaysia and neighboring countries to prevent obesity. Despite its anti-obesity potential, no research has ever predicted the compound-lipase, compound-HMG-CoA reductase interactions and in vivo investigations to further confirm its anti-obesity properties. Thus, the purpose of this study was to assess the anti-obesity and antihyperlipidemic effects of P. macrocarpa by in vitro, computational (in silico), and in vivo assays. MethodInitially, fruit was extracted through liquid CO2 and heating under reflux extraction methods to obtain liquid CO2 extracts (LCE-1 and LCE-2) and heating under reflux extract (HRE), respectively. Subsequently, all three extracts were assessed for antioxidant potentials through in vitro bioassays and FTIR analysis to identify different types of functional groups present in the existing bioactive compounds. Successively, the most active fraction (LCE-2) was subjected to GCMS analysis for the identification of lipid lowering and lipase inhibitors through molecular docking approach. Finally, anti-obesity and lipid lowering effects were further confirmed through an in vivo assay using mice. ResultLCE-2 exhibited higher DPPH (IC50 = 0.172 mg/mL) and FRAP (78.98 AAEmg/g) antioxidant activities and showed more potent peaks in FTIR chromatograms than LCE-1 and HRE. Among the identified tentative bioactive compounds viz. methyl palmitate, palmitic acid, ethyl palmitate, methyl oleate, oleic acid, cis-vaccenic acid, 3-deoxyestradiol and phenol, 2,2′-methylenebis[6-(1,1-dimethylethyl)-4-methyl- were found as an anti-obesity and lipid lowering compounds whose protein–ligand interaction was confirmed by binding affinity, amino acid residues and bonding interactions. Similarly, anti-obesity and lipid lowering findings were also found in a mice model after 6 weeks treatment at a dose of 250 mg/kg b.w. ConclusionBased on the aforementioned in vitro, in silico and in vivo findings, it is concluded that the LCE-2 possesses lipase and HMG-CoA reductase inhibitors that can assist to develop this plant’s extract as an alternative safe lipid lowering herbal medicine in future.

A Short and Facile [2 + 2] Photocycloaddition Protocol Toward Construction of a Levuglandin Skeleton

The γ-ketoaldehyde functionality of levuglandins (LGs) has a great propensity for various diseases such as Alzheimer's, atherosclerosis, and renal diseases. The synthesis of LGs constitutes a challenge for synthetic organic chemists due to their complex structures and low abundance in nature which has prompted us to develop its quick synthesis. This study aimed to explore a novel route for the construction of a levuglandin skeleton. We envisaged that the photocycloaddition of an appropriate alkene with equivalent propyne would give the cyclobutene adduct. The oxidative cleavage of the photocycloadduct can lead to the formation of the keto-aldehyde functionality. In this study, the readily available isopropenyl acetate (5) and methyl oleate (6) were used as starting materials to synthesize the target compound 13. The key step involves photocycloaddition of compounds 5 and 6, a regio-controlled elimination of the hydroxy group of compound 10, forming a cyclobutene derivative, as well as an oxidative cleavage of the cyclobutene derivative gives the framework of levuglandin. The intriguing chemistry of elimination resulting in the inseparable mixture of regioisomeric cyclobutenes has also been discussed. The route was simple and economical and helped for the creation of γ-ketoaldehyde functionality which is vital for the activity of levuglandins and can be extended for the construction of prostanoid skeleton through aldol condensation of the γ-ketoaldehydes.

Preparation of sustainable mineral oil-free offset printing ink with vegetable oil esters.

Mineral oils are used in substantial quantities for the production of varnishes and inks due to their abundance and versatility. However, as part of the production process, some of mineral oil components are separated as waste material, whereupon they can mix with air, water, or soil and become potentially harmful to the environment. Almost all these waste materials are volatile organic compounds (VOCs), chemicals that can easily evaporate at room temperature and have toxic effect. Therefore, a novel green, mineral oil-free offset printing ink was produced using vegetable oil esters as bio-renewable raw materials. Accompanying varnishes were prepared with linseed oil, methyl oleate, octyl stearate, and four types of resin (A, B, C, and D). The application of these varnishes to magenta color offset ink was subsequently studied to screen out the best combination of resin and ester in terms of setting time. Meanwhile, dyeing force tests were conducted to evaluate the ink's printability, while rheological analysis was done via viscosity and flowability tests. The setting time of the magenta color offset ink made by varnish A was observed to be considerably shorter than that of the ink samples prepared using varnishes B, C, and D. Furthermore, varnish A proved to be a good alternative varnish for the production of yellow, cyan, and black color offset printing inks. Samples of these inks were printed on coated paper, and their printability was contrasted against that of vegetable oil-based (pure vegetable oil), mineral oil-based, and other mineral oil-free offset printing inks. Results determined that the varnishes produced with linseed oil, methyl oleate, and octyl stearate can replace mineral oil-based varnishes for the production of offset printing ink.

Solvent-Free Aerobic Oxidative Cleavage of Methyl Oleate to Biobased Aldehydes over Mechanochemically Synthesized Supported AgAu Nanoparticles.

The performance of mechanochemically synthesized supported bimetallic AgAu nanoalloy catalysts was evaluated in the oxidative cleavage of methyl oleate, a commonly available unsaturated bio-derived raw material. An extensive screening of supports (SiO2 , C, ZrO2 , Al2 O3 ), metallic ratios (Ag : Au), reaction times, temperatures, and use of solvents was carried out. The performance was optimized towards productivity and selectivity for the primary cleavage products (aldehydes and oxoesters). The optimal conditions were achieved in the absence of solvent, using Ag8 Au92 /SiO2 as catalyst, at 80 °C, reaction time of 1 h, substrate to catalyst=555 and 10 bar of molecular oxygen. A strong support effect was observed: the selectivity to aldehydes was best with silica as support, and to esters was best using zirconia. This shows not only that mechanochemical preparation of bimetallic catalysts is a powerful tool to generate useful catalyst compositions, but also that a safe, green, solventless synthesis of bio-derived products can be achieved by aerobic oxidative cleavage.

Biosynthesis, characterization, and cytotoxic activities of zinc nanoparticles (ZnNPs) using Euphorbia retusa extract

Biosynthesis zinc oxide nanoparticles (ZnO-NPs) were produced from aqueous extracts of Euphorbia retusa, and their volatile components and antioxidant and cytotoxic characteristics were examined. Various methods, including UV–visible, TEM, and zeta potential spectroscopy, were used to characterize the ZnO-NPs. The GC/MS spectrum analysis was used to determine the plant extract's volatile components as well as the metal nanoparticles from this plant's antioxidant and cytotoxic characteristics. The results of GC–MS analysis demonstrated that twenty components were recorded on the identified scale; the most prevalent molecule, accounting for 29.25% of the overall composition, is methyl oleate. Hydrocarbons (13.84%), fatty acids, and esters of fatty acids (78.72%) are classified as the primary class. By using the DPPH test, the scavenging activity of metal nanoparticles and E. retusa extract was estimated. In comparison to the effects of plant extract, the results for the metal nanoparticle solutions showed diminished effectiveness. The MTT test was used to compare the cytotoxic potential of the solutions with metal nanoparticles and the plant extract on both tumor cell lines and healthy cell lines. ZnO-NPs from E. retusa inhibited microbial growth better than the plant extract, making them interesting biomedical and environmental options.

Constructing 2D channel catalysts with accessible open transport channels for boosting epoxidation of methyl oleate

For the epoxidation of methyl oleate (MO), slow chemical reaction rate resulted from poor mass transfer remains a tough problem. Herein, we demonstrate a series of efficient 2D channel catalysts with accessible open transport channels, which provides an idea strategy for boosting epoxidation of MO and shortening its reaction time. 2D channel catalysts (2D-CSx-NH2-HPA) are fabricated by immobilizing heteropoly acid (HPA) on aminopropyl-functionalized 2D channel silica (2D-CSx-NH2), in which HPA is highly dispersed. These catalysts are applied to the epoxidation of MO, and the results show that the epoxidation performance of 2D channel catalysts for MO is related to its particle size and HPA types. As expected, the 2D-CS3.5-NH2-HPW with a length of 300 nm and an equatorial diameter of 150 nm exhibits outstanding catalytic activity (XMO = 91.68%) and epoxide selectivity (SEMO = 90.03%) with only 4 hours, which is much faster than that of majority of epoxidation catalysts reported so far. The excellent catalytic activity of 2D channel catalyst benefits from the appropriate pore width and particle size, which play an important role in exchanging substrates and dispersing active components. This study uses 2D channel catalyst to effectively shorten the reaction time of MO epoxidation, which paves a new avenue to develop other 2D channel materials for novel catalytic applications.

Preparation and Effect of Methyl-Oleate-Based Polyol on the Properties of Rigid Polyurethane Foams as Potential Thermal Insulation Material.

Recently, most of the commercial polyols used in the production of rigid polyurethane foams (RPUFs) have been derived from petrochemicals. Therefore, the introduction of modified palm oil derivatives-based polyol as a renewable material into the formulation of RPUFs is the focus of this study. A palm oil derivative-namely, methyl oleate (MO)-was successfully modified through three steps of reactions: epoxidation reaction, ring-opened with glycerol, followed by amidation reaction to produce a bio-based polyol named alkanolamide polyol. Physicochemical properties of the alkanolamide polyol were analyzed. The hydroxyl value of alkanolamide polyol was 313 mg KOH/g, which is suitable for producing RPUFs. Therefore, RPUFs were produced by replacing petrochemical polyol with alkanolamide polyol. The effects of alkanolamide polyol on the physical, mechanical and thermal properties were evaluated. The results showed that the apparent density and compressive strength increased, and cell size decreased, upon introducing alkanolamide polyol. All the RPUFs exhibited low water absorption and excellent dimensional stability. The RPUFs made with increased amounts of alkanolamide polyol showed higher thermal conductivity. Nevertheless, the thermal conductivities of RPUFs made with alkanolamide polyol are still within the range for thermal insulating materials (<0.1 W/m.K). The thermal stability of RPUFs was improved with the addition of alkanolamide polyol into the system. Thus, the RPUFs made from alkanolamide polyol are potential candidates to be used as insulation for refrigerators or freezers.

Biocharacterization Study on Fermented Liquid Organic Manure (Kunapajala) Using Analytical Technique: Gas Chromatography – Mass Spectrometry (GC-MS)

“Vrikshayurveda”, an ancient literature collection of plant life science depicted importance of kunapajala, a fermented liquid organic manure sourced from animal origin. It is an excellent organic fertilizer influencing a wide range of crops with enhanced growth and development. During later days, “kunapajala” with vegetarian ingredients, without nutrient compromise was developed and standardized. It includes ingredients viz., soybean meal, paneer, tofu, rice husk, black gram, groundnut oilcake, cow dung, urine, honey, ghee and milk. The fermented formulation has essential nutrients, amino acids, keratins etc. which applied on plants, naturally flourished with excellent growth, flowering and fruiting. In this study, the fermented liquid organic manure kunapajala at 20th, 40th and 60th day of fermentation period was analysed for its bioactive compounds using the analytical technique Gas Chromatography – Mass Spectrometry (GC-MS). Extract was prepared using organic solvents diethyl ether and methanol. The mass spectra of compounds matched with Wiley's standard mass spectrum database and National Institute of Standards and Technology's (NIST) libraries. This study unfolded the presence of various compounds like Hexanoic acid, Phenol-TMS, Methyl oleate, Octadecanoic acid, Methyl palmitate, Myristic acid-TMS, Tetradecanoic acid, Caproic acid, Methyl myristoleate; (Z)-tetradec-9-enoic acid, 2-Aminooctanoic acid-TMS; 2-aminooctanoic acid, Butylated Hydroxytoluene, Juniperic acid-2TMS, Stearic acid-TMS, Linoleic acid-TMS etc. These phytochemicals have antimicrobial, antifungal, antibacterial, physiological and metabolic responses, antioxidant, Insecticidal irritant and nematicidal activities which effectively influence organic crop production. The result indicated the vital role of kunapajala as an effective source of liquid formulation through its phytochemical importance.

Extension of Biodiesel Aging Mechanism-the Role and Influence of Methyl Oleate and the Contribution of Alcohols Through the Use of Solketal.

The energy crisis and dependence on fossil fuels forces societies to develop alternative pathways to secure energy supplies. Therefore, non-fossil fuels such as biofuels and e-fuels can help counteract the resulting demand for existing combustion engines. However, biofuels, like biodiesel, have disadvantages in terms of oxidation stability. In general, aging of biodiesel is a complex mechanism due to interaction of various components. In order to develop an ideal fuel, the mechanism must be understood in full detail. In this work, an attempt is made to simplify the system by using methyl oleate as a biodiesel model component. In addition, other fuel components of interest such as alcohols and their respective acids help to clarify the aging mechanism. This work used isopropylidene glycerol (solketal) as the main alcohol, 1-octanol and octanoic acid. A holistic biodiesel aging scheme was developed by using generated data and evaluating the role of acids. They epoxidize unsaturated fatty acid via Prileschajev reactions. In addition, the role of epoxides in oligomerization reactions is confirmed. Moreover, the alcohols show that the suppression of oligomerization can be achieved by the reaction with methyl oleate. The alcohol-dependent aging products were determined by quadrupole time-of-flight (Q-TOF) mass spectrometry.

Microwave-assisted biodiesel production using –SO3H functionalized heterogeneous catalyst derived from a lignin-rich biomass

The synthesis of biodiesel from renewable resources has immense potential as a sustainable and cost-effective energy alternative. In this work, a reusable –SO3H functionalized heterogeneous catalyst that has a total acid density of 2.06 mmol/g was prepared from walnut (Juglans regia) shell powder by low-temperature hydrothermal carbonization (WNS-SO3H). Walnut shell (WNS) contains more lignin (50.3%), which shows great resistance toward moisture. The prepared catalyst was employed for the effective conversion of oleic acid to methyl oleate by a microwave-assisted esterification reaction. The EDS analysis revealed the significant presence of sulfur (4.76 wt%), oxygen (51.24 wt%), and carbon (44 wt%) content. The results of the XPS analysis confirm the bonding of C–S, C–C, C=C, C–O, and C=O. Meanwhile, the presence of –SO3H (the responsible factor for the esterification of oleic acid) was confirmed by FTIR analysis. Under the optimized conditions (9 wt% catalyst loading, 1:16 oleic acid to methanol molar ratio, 60 min reaction time, and 85 °C temperature), the conversion of oleic acid to biodiesel was found to be 99.01 ± 0.3%. The obtained methyl oleate was characterized by employing 13C and 1H nuclear magnetic spectroscopy. The conversion yield and chemical composition of methyl oleate were confirmed by gas chromatography analysis. In conclusion, it can be a sustainable catalyst because the catalyst preparation controls the agro-waste, a great conversion is achieved due to the high lignin content, and the catalyst was reusable for five effective reaction cycles.

Kinetics of the Catalytic Oxidation of Methyl Oleate

Kinetics of the Catalytic Oxidation of Methyl Oleate

Investigation of the enhancement for Echinocandin B fermentation with methyl oleate from transcription level

Echinocandin B (ECB) is the key precursor compound of the antifungal drug Anidulafungin. The effects of the five precursor amino acids on ECB biosynthesis were firstly investigated. It showed that although L-threonine was a main compound of the hexapeptide scaffold of ECB, exogenous addition of L-threonine had no significant effect on the increase of ECB fermentation titer. Meanwhile, the ECB fermentation titer with methyl oleate showed two times higher than that of the other carbon sources. Transcription level analysis of the key genes for ECB biosynthesis indicated that the gene an655543 related to L-threonine biosynthesis showed higher value during the fermentation process, therefore, the exogenous addition of L-threonine had no obvious affection. Furthermore, it indicated that the transcription level of gene ecdA might be the main restriction factor for the ECB biosynthesis. The study provided the research foundation for the modification of the ECB producing strains in the following work.

IDENTIFIKASI SENYAWA AKTIF EKSTRAK DAUN JARAK KEPYAR (Ricinus communis) DENGAN ANALISIS FITOKIMIA DAN GC-MS SEBAGAI KANDIDAT SENYAWA OBAT

As a tropical country with biodiversity, Indonesia is rich with flora especially those with potential as medicinal plants such as Jarak Kepyar (Ricinus communis). Leaves of jarak kepyar (Ricinus communis) are used as a medicine for wounds, rash, abscess, and fever. Therefore, the purpose of this study was to determine the active compound in ethanol and n-hexane extract of jarak kepyar (Ricinus communis) leaves using phytochemical analysis and GC-MS. The research method used is the experimental method in the laboratory. The steps of the research were extraction of jarak kepyar (Ricinus communis) leaves using 96% ethanol and n-hexane with the maceration method. Furthermore, jarak kepyar (Ricinus communis) leaves extract was analyzed qualitative and quantitatively by phytochemical screening and GC-MS analysis. The results of the phytochemical screening showed that the chemical compounds contained in the ethanol extract of jarak kepyar (Ricinus communis) leaves were flavonoids, alkaloids, terpenoids, tannins and phenolics. While the chemical compounds contained in the n-hexane extract of jarak kepyar (Ricinus communis) leaves are alkaloids. GC-MS analysis of the ethanol and n-hexane extracts of jarak kepyar (Ricinus communis) leaves showed that several compounds that are found in the extract of jarak kepyar (Ricinus communis) leaves such as 2-ethoxycarbonyl-5-oxo-pyrolidine, delta-octalactone, trimethyl ester or trimethyl citrate, quinic acid, 2,3- Dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one and methyl oleate have potential as medicinal compounds.

Enhancing Flotation Performance of Low-Rank Coal Using Environment-Friendly Vegetable Oil

Flotation is widely used for low-rank coal upgrading, although it is always inefficient due to its rough surface morphology and rich oxygen-containing functional groups. In this study, the environment-friendly vegetable oil 1030# was used to enhance the flotation performance of low-rank coal. The mechanism of 1030# enhancing the flotation of low-rank coal was revealed through surface property analysis of coal particles and bubble–particle adhesion tests. The flotation results showed that the flotation yield of low-rank coal increased with the increase in the collector dosage, and the flotation yield of 1030# as a collector is obviously higher than that of diesel. Scanning electron microscopy (SEM) and chromatography–mass spectrometry (GC-MS) were used to analyze the surface morphology of coal particles and components of the reagent. The SEM results showed that the surface of low-rank coal is loose and contains a large number of pores and cracks, which is not conducive to the spreading of chemicals on the coal surface and the mineralization of bubbles and particles. GC-MS results showed that 1030# mainly contained methyl oleate with more unsaturated double bonds than diesel. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) were used to analyze the surface functional groups of the low-rank coal before and after reagent treatment. The results of FTIR and XPS showed that the coal surface of low-rank coal before reagent treatment contained a large number of oxygen-containing functional groups with poor surface hydrophobicity, while the surface of low-rank coal after reagent treatment had reduced oxygen-containing functional groups and increased hydrophobicity. The contact angle of the low-rank coal surface also showed the same variation trend as the FTIR and XPS results. The adhesion force between the bubble and coal surface in different collector solutions was measured. The maximum adhesion between the bubble and coal surface increased with the increase in the collector, and the maximum adhesion force with 1030# treatment was higher than that of diesel. This indicated that 1030# with a large number of polar components is more easily spread on the surface of low-rank coal, thus improving the hydrophobicity of low-rank coal.

Measurement and Modeling of Speed of Sound in Binary Mixtures of Methyl Oleate with n-Hexane or n-Decane Under Pressure

Measurement and Modeling of Speed of Sound in Binary Mixtures of Methyl Oleate with n-Hexane or n-Decane Under Pressure

Utilization of vanillin to prepare sulfated Calix[4]resorcinarene as efficient organocatalyst for biodiesel production based on methylation of palmitic acid and oleic acid

Recently, biodiesel production from palm oils has been thoroughly investigated to substitute crude oil due to its scarcity. However, the biodiesel production process is time-consuming due to its slow kinetics; thus, concentrated sulfuric acid has been used to fasten the reaction process in some industries. Unfortunately, sulfuric acid is a toxic, corrosive, and non-environmentally friendly catalyst. In this study, we prepared sulfated Calix[4]resorcinarene derived from vanillin as an efficient organocatalyst to replace sulfuric acid. The catalytic activity of sulfated Calix[4]resorcinarenes was evaluated through the methylation of palmitic acid and oleic acid as model compounds due to their abundant amounts in palm oil. The Calix[4]resorcinarene and sulfated Calix[4]resorcinarenes have been obtained through a one-pot reaction in 71.8–98.3% yield. Their chemical structures were confirmed by using FTIR, NMR and HRMS spectrometry analyses. The results showed that the sulfated Calix[4]resorcinarene exhibited high catalytic activity for methyl palmitate and methyl oleate productions in 94.8 ± 1.8 and 97.3 ± 2.1% yield, respectively, which was comparable to sulfuric acid (96.3 ± 1.8 and 95.9 ± 2.5%). The optimum condition was achieved by using 0.020 wt equivalent of organocatalyst for 6 h reaction process at 338 K. The methylation of palmitic acid and oleic acid fits well with the first-order kinetic model (R2 = 0.9940–0.9999) with a reaction rate constant of 0.6055 and 1.1403 h-1, respectively. Further investigation reveals that the hydroxyl group of vanillin plays a pivotal role in the organocatalytic activity of sulfated Calix[4]resorcinarene.

Performance, Emission, and Spectroscopic Analysis of Diesel Engine Fuelled with Ternary Biofuel Blends

The demand for sustainable alternative-fuels in the transportation and agriculture domains is essential due to the quick depletion of petroleum supplies and the growing environmental challenges. The ternary-blends (diesel, biodiesel, and Methyl oleate) have the ability to report the existing challenges in this area because they offer significant promise for reducing exhaust emissions and improving engine performance. In the current work, soy methyl ester is blended with methyl oleate and diesel. The emissions and performance of blended biodiesel was conducted in common rail direct injection engine (CRDI). The characterization and physical properties were also evaluated by utilizing various methods like Fourier-Transform Infrared Spectroscopy (FTIR), UV-vis Spectroscopy (UV-vis), and Nuclear Magnetic Resonance. FTIR spectra showed the existence of the strong C=O, indicating the presence of FAME at 1745 cm−1. Again, UV-vis has reported the appearance of conjugated dienes in the oxidized biodiesel. The results indicated all blended samples retained the properties of diesel. The addition of methyl oleate improved brake specific fuel consumption of blended biodiesel almost near to diesel. D50::S80:M20 produced a mean reduction in hydrocarbon 42.64% compared to diesel. The average carbon monoxide emission reduction for D50::S80:M20 was 49.36% as against diesel.

Synthesis of novel ternary NiO–CdO-Nd2O3 nanocomposite for biodiesel production

Novel tri-phase NiO–CdO-Nd2O3 nanocomposite was prepared by coprecipitation method and its catalytic activity in transesterification reaction was studied. The synthesized nanocomposite was characterized by using FTIR, XRD, SEM and EDX to explore the functional, structural morphological and compositional properties respectively. In FTIR studies the vibrational bands for NiO, CdO and Nd2O3 have been observed. The XRD pattern of nanocomposite revealed its crystalline nature and average particle size was calculated as 28nm. The SEM studies of nanocomposite revealed that the shape of nanocomposite is semi-circle and oval shaped. EDX analysis represented elemental composition of ternary composite. The newly prepared catalyst was used as heterogeneous catalyst in transesterification of triglycerides from mustard oil into fatty acid methyl esters as biodiesel fuel. The oval shaped nanoparticles showed good catalytic activity in biodiesel synthesis. The obtained biodiesel was thoroughly characterized using FTIR and 1H NMR spectroscopic techniques. FT-IR analysis was also used to find out percentage yield using absorption spectra of different oil & methanol molar ratio. The FAMEs composition of obtained biodiesel was determined by GC-MS analysis which showed presence of methyl palmitoleate (C16:1), methyl linoleate (C18:2), methyl oleate (C18:1), metyl erucate (C22:1) and methyl behenate (C22:0) at various retention time. The quality of fuel parameters such as density, viscosity, cloud, pour and flash points were determined using ASTM methods and found within limits. The effect of several parameters on yield of biodiesel such as oil to methanol ratio (1:6, 1:9, 1:12, 1:15 and 1:18) catalyst amount (0.1, 0.5 and 0.9g) time of reaction (1.5, 2.5, 5.0 and 7.5h) and effect of temperature (60–80 °C with interval of 5 °C) were studied in detail and optimized. The 80% yield of biodiesel was achieved at optimum conditions of 1:15 oil:methanol ratio, 0.5 g catalyst concentration, 5 h reaction time and 80 °C temperature. The reusability of catalyst was tested by using three times and the results were good with minor loss of catalytic activity.

Thermal oxidation of model molecules to reveal vegetable oil polymerization studied by NMR spectroscopy and self‐diffusion

AbstractOxidative polymerization of plant oils and lipids is poorly understood yet widely encountered. Oils and fats are renewable resources providing biofuels and polymers. Oil oxidation is accelerated at high temperatures, typically above 110°C, where triacylglycerides are converted into toxic compounds and viscous deleterious polymers. Polymerization of mono‐unsaturated oil (210°C, 3 h, open to air) was investigated by comparing four similar sized molecules with different functional groups: oleic acid, methyl oleate, trans‐7‐tetradecene, and stearic acid. Non‐volatile products identified by NMR spectroscopy are minor ketones for saturated fatty acid (stearic acid), epoxides for acyl chains without acid groups (methyl oleate, tetradecane) and copious oligomerization, through ester cross‐links, for acyl chains with acid, and olefinic groups (oleic acid). Long range CH coupling clearly shows ester (not ether) cross‐links, contradicting long‐held beliefs. Chain fragmentation also occurs for heated oleic acid as revealed by formation of a species with a methylene group bonded to oxygen of an ester, CH2OC(O). Large size (slow diffusion) of the first oligomer (trimer) formed from oleic acid, used to represent hydrolyzed vegetable oil, was evidenced by DOSY (diffusion‐ordered spectroscopy). Combined NMR results show oligomers found in heated oleic acid are fatty acid estolides. Model oil reactions demonstrate why olefin and carboxylic acid groups are required for polymerization.

Purification and characterization of a psychrophilic lipase from Serratia marcescens VT 1 and its application in methyl ester synthesis

Lipase from Serratia marcescens VT 1 with a molecular weight of 62 kDa was purified by 9.42 fold with 16.89 % recovery by DEAE Cellulose and Sephadex G-75 columns. The characterization studies showed the optimum temperature and pH were 30 °C and 7, with good stability from 10 to 30 °C and pH 7. The lipase displayed good stability in the presence of metal ions Ca2+ and Na+, surfactants Gum arabic and Triton X-100, inhibitor EDTA, and organic solvents hexane and methanol. The serine inhibitor PMSF reduced lipase activity by 66 %. Vmax and Km kinetic parameters were 35.21 μmol/ml/min and 0.823 mM with p-nitrophenyl palmitate as substrate. The induction of methyl palmitate, methyl stearate, methyl oleate, and methyl linoleate from palm oil was confirmed by fatty acid methyl ester (FAME) analysis. The present study showed that the Serratia marcescens VT 1 lipase is a psychrophilic, neutral, and serine lipase efficacious of methyl esters genesis.