Oleic Ester Research Articles

Hydrolysis of Polysorbate 20 and 80 by a Range of Carboxylester Hydrolases.

Degradation of the non-ionic surfactant polysorbate (PS) has been reported to lead to the formation of visible and subvisible particles that affect product quality. Chemical degradation pathways of PS, such as oxidation and acid/base hydrolysis, have been previously studied, but enzymatic degradation of PS remains poorly understood. In this study, enzyme-mediated hydrolysis of the major components in a heterogeneous mixture of PS20 or PS80 was monitored using an evaporative light scattering detection-high-performance liquid chromatography method. Carboxylester hydrolases from a broad range of organisms were tested, including enzymes from Pseudomonas cepacia, Thermomyces lanuginosus, Candida antarctica, rabbit liver, and pig pancreas. Time course experiments suggested that PS hydrolysis was dependent on the order of esters (mono-, di-, or triester), the identity of the hydrophilic head group (sorbitan or isosorbide), the identity of the fatty acid ester tail (C12 vs C18:1), and the identity of the enzyme. Importantly, no PS component was completely resistant to all the carboxylester hydrolases tested here. Our results illustrate a potential fingerprint approach that could be useful in verifying or identifying enzyme-mediated PS degradation in drug substance and provide an improved understanding of the complexity of PS degradation in the presence of enzymes.

Determination of adsorption and kinetic parameters for methyl oleate (biodiesel) esterification reaction catalyzed by Amberlyst 15 resin

In this work, adsorption equilibrium constants, dispersion coefficients, and kinetic parameters were determined for the reversible esterification reaction of oleic acid with methanol, producing methyl oleate (biodiesel) and water. The reaction was carried out at room temperature in the presence of Amberlyst 15 resin, which acts both as an adsorbent and catalyst in an HPLC column, which served as a packed bed reactor. A quasi‐homogenous kinetic model coupled with a linear adsorption isotherm was explored. The elution profiles of the reactant and products were experimentally monitored and then compared with a mathematical model. The adsorption and kinetic parameters were determined by minimizing the error between the experimentally obtained elution curves and the model‐predicted values using the genetic algorithm optimization technique. Further experiments were conducted under varying conditions to establish the validity of the obtained model parameters. It was also found that the system is not affected by internal and external mass transfer resistances. The mathematical model predicted the experimental outcome quite accurately.

Synthesis, characterization and kinetic analysis of chitosan coated magnetic nanobiocatalyst and its application on glucose oleate ester synthesis

In this work, we report the covalent immobilization of lipase enzyme on the surface of chitosan coated magnetic nanoparticles (MNPs) using N-(3-dimethylaminoproyl)-N-ethylcarbodiimide (EDC) and N-hydroxysuccinimide (NHS) as coupling agents. Surface functional groups of chitosan coated MNPs, lipase enzyme, and immobilized lipase enzyme were characterized by Fourier transform infrared spectroscopic (FT-IR) analysis. The structural characteristics of the chitosan coated magnetic nanoparticles were analyzed by X-ray Diffraction (XRD) studies. The statistical methodology with central composite design (CCD) was applied to evaluate the effects of immobilization, including the magnetic nanoparticles, lipase enzyme, pH and immobilization time on the enzyme activity. Based on the statistical analysis, the optimum immobilization conditions of magnetic nanoparticles (40mg), lipase enzyme (40mg), pH (9), and immobilization time (6h), the maximum enzyme activity obtained was 16.94U/mL. The optimum pH and temperature for maximum enzyme activity of immobilized lipase are found to be pH 9 and 40°C respectively. The immobilized lipase exhibited excellent catalytic activity over eight successive cycles and retain 64% original stability. The Michaelis–Menten enzyme kinetic studies of immobilized lipase on chitosan coated MNPs showed maximum activity (Vmax) and Michaelis–Menten constant (Km) of 33.7 (μmol/mLmin) and 0.89mM respectively. The thermal stability of lipase was significantly improved after immobilization. The thermal deactivation rate of immobilized lipase was studied to follow the Arrhenius law with deactivation energy of 73kJ/mol. Glucose ester yield of 80.8% was achieved in this study revealed that immobilized lipase on MNPs have promising application in industrial scale for sugar ester production.

Production of a biodiesel additive in a stirred basket reactor using immobilized lipase: Kinetic and mass transfer analysis

−A laboratory-scale stirred basket reactor (SBR) was constructed to study the synthesis of an n-butyl oleate ester using Novozym 435. An ester yield of approximately 98% was obtained after 6 h using an equimolar substrate ratio, 3.5 g of enzyme, a reaction temperature of 40 °C, and an impeller speed of 200 rpm. The kinetic data were modeled as a ping-pong bi-bi mechanism using a non-linear regression technique. Statistical analysis of the results showed that a model that incorporated the inhibitory effect of n-butanol yielded the best fit with the following parameters: Vmax=24.8mmol L−1 min−1, Km, oleic acid=190.8mM, Km, n-butanol=544.7 mM, and Ki, n-butanol=158.3mM. Mass transfer effects on the enzyme kinetics were also studied, and the absence of internal and external diffusion limitations on the reaction in the SBR was confirmed by considering calculated values of the Thiele modulus and the Damkohler number. Novozym 435 exhibited satisfactory performance in repeated-batch experiments using SBR.

Enzymatic Synthesis of Bio-Surfactant Fructose Oleic Ester Using Immobilized Lipase on Modified Hydrophobic Matrix in Fluidized Bed Reactor

Abstract Enzymatic synthesis of fructose oleic ester (FOE) in stirred tank reactor using the immobilized lipase may cause a physical damage of support matrix, which causes a leaching of lipase from matrix. The objective of this research was to evaluate the best condition of FOE synthesis in fluidized bed reactor (FBR) using the immobilized lipase on modified hydrophobic matrix. Surface of Amberlite IRA 96 was modified with 2-phenylpropionaldehyde to obtain hydrophobic surface. Candida rugosa lipase was immobilized on the modified matrix. Subsequently, it was used for FOE synthesis in FBR system. Factors, such as reaction time, substrate flow rate, amount of water adsorbent, and substrate molar ratio were evaluated based on the conversion of oleic acid into FOE. Results from FTIR analysis showed that modified matrix had a peak at a specific wavelength ∼1674 cm -1 . It indicated that a group of imine (-C=N-) occurred after surface modification. The highest adsorption of lipase was obtained after adsorption for 45 min (13.28±0.57 mg lipase/g matrix), which was equivalent to 52.95±1.67%. The lipase activity was 73.66±5.35 U/g matrix. The best FOE synthesis condition was obtained at flow rate of 0.4 mL/min, molecular sieve of 12%, substrate molar ratio (fructose: oleic acid) 1:4 for 48 h. FOE was confirmed by TLC and FT-IR analysis, which they had Rf 0.72 and specific wave number of ∼1712 cm -1 , respectively. FOE had emulsion capacity, emulsion stability, droplet size, and HLB value of 92.83±0.46%; 85.65±0.92%; 7.86±0.93 μm; 11-16, respectively. Emulsion type of FOE was oil in water emulsion.

Synthesis of Biodegradable Plastic Films from Oil Palm Empty Fruit Bunch Cellulose

Cellulose from Oil Palm Empty Fruit Bunch (OPEFB) has a possibility to be converted into biodegradable plastic cellulose ester due to its huge availability. Cellulose ester has thermoplastic properties and is widely used in many polymer applications. This paper describes about esterification OPEFB cellulose with long chain fatty acid chloride in homogeneous system. Some different molar ratios of anhydroglucose unit (AGU) to fatty acid chloride were applied to observe cellulose ester with regards to weight increase percentage (%WIP), recovery yield (%RY) and degree of substitution (DS). Others characteristics were also determined, such as solubility and tensile strength of film casting (MPa). Cellulose palmitate, cellulose laurate and cellulose oleate were successfully produced from OPEFB cellulose. The study found that there is a correlation between type and molar ratio of fatty acid chloride. In an identical reaction condition, a longer fatty acid chlorides and a higher ratio molar AGU to fatty acid chloride produce cellulose ester with high WPI except cellulose oleate ester.

Dietary Plant Sterol Esters Must Be Hydrolyzed to Reduce Intestinal Cholesterol Absorption in Hamsters1–3

Background: Elevated concentrations of LDL cholesterol are associated with the development of atherosclerosis and therefore are considered an important target for intervention to prevent cardiovascular diseases. The inhibition of cholesterol absorption in the small intestine is an attractive approach to lowering plasma cholesterol, one that is addressed by drug therapy as well as dietary supplementation with plant sterols and plant sterol esters (PSEs).Objective: This study was conducted to test the hypothesis that the cholesterol-lowering effects of PSE require hydrolysis to free sterols (FSs).Methods: Male Syrian hamsters were fed atherogenic diets (AIN-93M purified diet containing 0.12% cholesterol and 8% coconut oil) to which one of the following was added: no PSEs or ethers (control), 5% sterol stearate esters, 5% sterol palmitate esters (PEs), 5% sterol oleate esters (OEs), 5% sterol stearate ethers (STs; to mimic nonhydrolyzable PSE), or 3% FSs plus 2% sunflower oil. The treatments effectively created a spectrum of PSE hydrolysis across which cholesterol metabolism could be compared. Metabolic measurements included cholesterol absorption, plasma and liver lipid concentration, and fecal neutral sterol and bile acid excretion.Results: The STs and the PEs and SEs were poorly hydrolyzed (1.69–4.12%). In contrast, OEs were 88.3% hydrolyzed. The percent hydrolysis was negatively correlated with cholesterol absorption (r = −0.85; P < 0.0001) and positively correlated with fecal cholesterol excretion (r = 0.92; P < 0.0001), suggesting that PSE hydrolysis plays a central role in the cholesterol-lowering properties of PSE.Conclusions: Our data on hamsters suggest that PSE hydrolysis and the presence of FSs is necessary to induce an optimum cholesterol-lowering effect and that poorly hydrolyzed PSEs may lower cholesterol through an alternative mechanism than that of competition with cholesterol for micelle incorporation.

Synthetic zeolite utilised for synthesis of Oleate ester

Synthetic zeolite was successfully prepared by hydrothermal treatment. Structural morphologies, compositions, surface area and acidic strength were analysed by Powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), BET surface area and temperature programme desorption (TPD). This zeolite utilized for the synthesis of Oleate ester as biodiesel from oleic acid. The features of this procedure are mild reaction conditions, good yield, the operational simplicity at ambient temperature and it can be easily industrialized.

Ester Hydrolysis of Polysorbate 80 in mAb Drug Product: Evidence in Support of the Hypothesized Risk After the Observation of Visible Particulate in mAb Formulations

An observation of visible particulate matter was made during formulation development of a mAb and investigations initiated to understand the colloidal instability of the formulation. It was observed that there was a loss of polysorbate in the IgG formulation and concurrent hydrolysis of polysorbate 80 (PS80) into fatty acid, polyethylene glycol (PEG), and pegylated sorbitan in the presence of mAb A. This observation was confirmed with two other mAb development programs (mAb B and mAb C) that used PS80 and formed particulate, but was absent in any placebo sample tested. Comparative analysis to acid, base and esterase hydrolysis, and exposure to the oxidation reagents Iron(II) and tert-Butyl hydroperoxide demonstrates that the observed reaction is reproduced by a biologic (enzymatic) mechanism. Monooleates of PS80, including the sorbitan and PEG oleates, are hydrolyzed first, showing a slower reaction with higher-order oleates. This leads to a change in the composition of the formulation over time where PS85 becomes the predominant component of the original surfactant remaining in solution. Data suggest that there is a lipid-specific mechanism rather than a general biologic hydrolysis mechanism that hydrolyzes oleate esters of PS80 increasing the risk that colloidal IgG particles will form in mAb drug product.

Scale up synthesis of ART207, a paclitaxel-based lipophilic prodrug for tumor selective delivery via pseudo-LDL nanoparticles

The ultimate goal of an anticancer regime is to eliminate tumor cells without harming healthy cells. However, currently used chemotherapeutic drugs are not selective and hence attack both healthy and tumor cells which results in very serious side effects. Targeted delivery of anticancer drugs to tumors utilizing nanoparticles has been the focus of the scientific community as well as pharmaceutical companies with the hope of selectively delivering the drug to the cancer cell and increasing the efficacy of the drug while reducing systemic toxicity. Arbor Therapeutics has developed a targeted delivery approach based on the synthesis of acid-labile lipophilic prodrugs of approved clinical anticancer drugs and their formulation into pseudo-LDL nanoparticles for selective tumor delivery via over expressed LDL receptors. A paclitaxel-based lipophilic prodrug, ART207, has been synthesized starting from methyl oleate ester. Challenges of the scale-up process and the separation of ART206 stereoisomers will be discussed in detail. ART207 has shown cytotoxicity to several paclitaxel sensitive cell lines including prostate, breast and ovarian.

Physical and monolayer film properties of potential fatty ester biolubricants

The desire to replace petroleum‐based lubricants with alternatives that are environmentally friendly and made from sustainable sources has encouraged the development of biolubricants based on vegetable oils. To be good lubricants, the materials should have low melting points, appropriate viscosity and oxidative stability. In this paper, we report the melting point and viscosity of oleate esters of ethylene glycol, 1,2‐propanediol, 2,3‐butanediol, and pentaerythritol as well as the decanoate esters of 2,3‐butanediol and the 12‐methyltetradecanoate esters of 1,2‐propanediol. Polyol esters that have a free hydroxy group had lower melting points than the completely esterified polyols, but the completely esterified polyol esters exhibited less change in viscosity with temperature than those having a free hydroxy group. 2, 3‐Butanediol monooleate, which melted at −48.6°C shows promise as a biolubricant, but its viscosity index was estimated to be 100. Pentaerythritol oleate esters, with melting points below −10°C and viscosity indices in the range of 170–197, may be suitable candidates as biolubricants. The behavior of esters spread as a monomolecular film at air/water interface may provide insight into the way they behave when spread on metal or polar surfaces, so the pressure‐area isotherms of 2,3‐butanediol monoleate and selected esters are also reported.Practical applications: The structure and function relationships demonstrated can be used to synthesize biolubricants with desirable physical and performance properties.This figure shows the melting and viscosity properties of various types of synthesized biolubricants. Abbreviations: BDMO, 2,3‐butanediol monooleate; BDM10, 2,3‐butanediol monodecanoate; PGMO, 1,2‐propanediol monooleate; PET, pentaerythritol; R‐Ac, a group of acetylated ricinoleates; BuR, butyl ricinoleate; IsR, isopropyl ricinoleate; BuO, butyl oleate; IsO, isopropyl oleate; MeR‐11u, methyl 12‐undec‐10‐enylricinoleate.

Analysis of sitosteryl oleate esters in phytosterols esters enriched foods by HPLC–ESI-MS2

Phytosteryl esters (PE)-enriched spreads are marketed for eating and cooking purposes. Temperature and also light exposure are the major factors leading to the formation of PE oxides in food matrix. In this study a high-speed HPLC–MS2 method was developed to analyze the major PE present in PE-enriched spreads: sitosteryl oleate (SO) and its oxidation products, by using synthesized compounds as standards. This analytical method was used to quantify seven SO oxides formed in PE-enriched spreads after heating at different temperatures for varying time periods and after prolonged exposure to sunlight. Quantification of remaining native SO was also performed after these different treatments. It was found that under specific heating conditions the decrease of the SO amount was much more important compared to the formation of SO oxides showing that many other products are formed. In contrast to heating, sunlight radiation did not result in the degradation of SO and very few oxides were formed.

KAJIAN AWAL PENGARUH WAKTU REAKSI DAN RASIO MOLAR ASAM OLEAT DENGAN BUTANOL TERHADAP SIFAT FISIKO KIMIA PLASTISIZER BUTIL OLEAT

Vol 7 No 2ABSTRACTEsterification reaction is a reaction between fatty acids or carboxylic acids with alcohols toesters. Fatty acid (oleic acid) sourced from palm oil. One alternative to increase the economicvalue of palm oil is oleic acid esterification into oleic butyl known as plasticizers. Plasticizeradditives are compounds added to polymers to improve its flexibility and workabilitas. Thisstudy aims to study the effect of reaction time and molar ratio of the plasticizer synthesis oleicbutyl and identify the plasticizer oleic butyl. In this study, the first step is preparation H-Zeolitecatalyst, then synthesis of plasticizer butyl oleic esterification using natural zeolite catalystswere activated to H-zeolites with variables in the reaction time (6, 9 and 12 hours) and themolar ratio of oleic acid and butanol (1: 6, 1: 9 and 1:12) with the permanent variable stirringspeed of 200 rpm, 108-112 ° C of temperature and the catalyst were 15% oleic acid-based. Fromthe test results obtained 0.862 specific gravity, viscosity of 8.39 mPa and showed that thespecific gravity and viscosity of the resulting plasticizer has commercial plasticizer standardnamely 0.862 to 0.928 and from 8.2 to 9.4. Optimal operating conditions obtained in thisresearch is the molar ratio of 1:12, reaction time 12 hours resulted in a conversion reaction of76.73%.Keywords: Esterifikasi, H-zeolite, Oil, Plasticizer

Comparative aging characteristics between a high oleic natural ester dielectric liquid and mineral oil

This paper presents a comparative evaluation of the aging characteristics between a high oleic natural ester dielectric liquid (HONE) and mineral oil based on an accelerated single-temperature thermal aging experiment at 150°C for a period of 3000 hours. The important physical (e.g., viscosity, moisture content, acidity) and dielectric (e.g., power factor, alternating current (AC) dielectric breakdown) properties of both the oils were measured and analyzed at different aging intervals. As expected, results show differences in aging behaviors between mineral oil and the natural ester liquid. The relative moisture content in HONE had stable and lower values during the aging duration as compared to the case of mineral oil, where the relative moisture content increased with the aging duration. Further, unlike the observations in mineral oil, the power factor (PF) and acidity of HONE increased drastically with increasing aging times. The most relevant observation made from this study was that in spite of this significant increase in the PF and acidity of HONE with aging, its AC dielectric breakdown voltage was quite stable, which is not observed in the case of mineral oil. This indicates that for natural ester liquids, higher values of PF (or dielectric dissipation factor) and/or acidity due to aging may not necessarily give a true picture on the dielectric performance of the ester. It is therefore important to note here that the threshold limits of some of the diagnostic parameters which are already established for mineral oil do not apply for ester liquids.

Lipophilic prodrugs of a triazole-containing colchicine analogue in liposomes: Biological effects on human tumor cells

Colchicine site binders--blockers of tubulin polymerization--are potential antimitotic agents for anticancer therapy. To reduce their systemic toxicity and improve biodistribution, encapsulation in nanosized liposomes may be employed. Liposomes present a convenient means for preparation of injectable formulations of hydrophobic compounds, however colchicine as such is known to leak through the lipid bilayer. In this study, newly synthesized triazole-containing analogues of colchicine and allocolchicine, and their palmitic and oleic esters (lipophilic prodrugs) were tested for anti-proliferative activity and apoptosis-inducing potential. In contrast to colchicine conjugates, whose activities ranged with those of colchicine, allocolchicine derivatives exhibited drastically lower effects and were discarded. Liposomes of about 100 nm in diameter composed of egg phosphatidylcholine--yeast phosphatidylinositol--palmitic or oleic prodrug, 8 : 1: 1, by mol, were prepared by standard extrusion technique and tested in a panel of four human tumor cell lines. Liposome formulations preserved the biological activities of the parent colchicinoid the most towards human epithelial tumor cells. Moreover, liposomal form of the oleoyl bearing colchicinoid inhibited cell proliferation more efficiently than free lipophilic prodrug. Due to substantial loading capacity of the liposomes, the dispersions contain sufficient concentration of the active agent to test wide dose range in experiments on systemic administration to animals.

A Convenient Route For The Alkoxylation Of Biodiesel And Its Influence On Cold Flow Properties

The attachment of alkoxy side chains to biodiesel and the associated effects on its cold flow properties are reported. High oleic methyl ester biodiesel was epoxidized using peroxy formic acid and subsequently alkoxylated using nine different alcohols employing BF3-ethereate complex as catalyst. A low molar excess for alcohols was used at moderately low reaction temperatures (40–50°C). A high conversion for attachment of alkoxy group ranging 84%–93% was achieved with excellent selectivity. Cloud points, pour points, and kinematic viscosities were measured to evaluate the cold flow properties of modified biodiesel. The lowest cloud point –11°C and pour point –14°C were obtained with n-decoxy biodiesel. Elevated kinematic viscosities were observed for all alkoxylated products. The lowest kinematic viscosity (6.26 mm2·s−1) was observed for methoxy biodiesel. Gas chromatography mass spectrometry (GC-MS), proton nuclear magnetic resonance (1H NMR), 13C NMR, and Fourier transform infrared (FT-IR) were used for structural elucidation. The reported alkoxylation route has high conversion rate and is convenient to implement.

Rubber-Like Materials Prepared from Copolymerization of Tannin Fatty Acid Conjugates and Vegetable Oils

Novel bio-based rubber-like materials are prepared from the oxidative copolymerization of tannin oleate esters and vegetable oils. The copolymer materials are prepared as solvent-cast films. Analysis reveals the reactivity and amount of vegetable oil employed has the greatest influence on copolymer crosslinking and mechanical properties. Copolymer film stiffness values range between 6 and 300 MPa and crosslink densities are 661–15 800 mol · m−3. Glass transition temperature (Tg) and Soxhlet insolubles (>80%) are relatively similar when forming copolymers with tung oil. In contrast, both Tg and degree of crosslinking decrease significantly with use of linseed stand oil. Thermogravimetric analysis indicates that the copolymers are thermally stable up to 200 °C.

Stability of Dye Dispersions in the Presence of Some Eco‐Friendly Dispersing Agents

AbstractThe stability of dye dispersions in the presence of ethoxylated sorbitan lauryl and oleyl esters were reported and compared with dye dispersions containing a conventional dispersing agent, i.e. naphthalene sulfonic acid methylene‐bis sodium salt (NSAB). The optimum operating conditions obtained using a central composite design and stability of dye dispersions were evaluated by a turbidimetry method. Results showed that the dose of surfactants and the temperature of operation were important factors in preparing stable dye dispersions. Also, the best conditions for preparing dye dispersions were as follows: dose of surfactant 0.05 g, temperature 25 °C and time 5 min. In addition to, findings indicated that both of the used surfactants had better performance in dispersing the dyes in water. However, ethoxylated sorbitan oleate had better efficiency relative to other used dispersing agents. The performance of both sorbitan esters were compared with NSAB. The results indicated that they can create stable dye dispersions in aqueous media and have approximately the same effectiveness with NSAB. In this series, although oleate ester had a better performance than the laurate, the difference in performance of using dispersing agents was not significant. This finding was confirmed by the results of the particle size analysis of dye dispersions.

High Temperature Tribological Properties of Modified Nano-diamond Additive in Lubricating Oil

The high temperature tribological properties of surface-modified nano-diamond in colza oil were tested with SRV machine, and wear surface morphology was observed by using three dimension profiler. The results show that the modified nano-diamond by dimer ester possesses excellent anti-wear and friction reducing properties as lubricating oil additive. The friction coefficients of the modified nano-diamond by dimer ester are lower than those of nano-daimond and the modified nano-diamond by oleic ester when the temperature is lower than 200 °C, and its friction coefficients are very similar to nano-diamond's when the temperature is higher than 200 °C, but are better than that of the modified nano-diamond by oleic ester. The wear volume of the modified nano-diamond by dimer ester is far-forth lower than that of nano-daimond and the modified nano-diamond by oleic ester after the continuously heating test, and the wear volume decrease 60% than nano-diamond's.

Investigation of &amp;lt;i&amp;gt;β&amp;lt;/i&amp;gt;-Cryptoxanthin Fatty Acid Ester Compositions in Citrus Fruits Cultivated in Japan

In this study, a catalog of β-cryptoxanthin (βCX) and its fatty acid esters (βCXFAs) in citrus fruits were constructed. The peel and pulp of citrus fruits from nine Japanese cultivars and one foreign cultivar were surveyed by supercritical fluid chromatography/triple quadrupole mass spectrometry (SFC/QqQMS). In each citrus sample, the major components were βCX and its laurate ester, myristate ester, palmitate ester, and oleate ester. However, the composition ratio of βCXFA varied with the citrus breed and between the pulp and the peel of the fruit in most cultivars. The SFC/QqQMS system could be used to obtain new information about βCXs and carry out further discussion on the feature and tendency of each citrus variety.