MyMedR

Fulltext Detoxification of toxic phorbol esters from Malaysian Jatropha curcas Linn. kernel by Trichoderma spp. and endophytic fungi

Najjar A, Abdullah N, Saad WZ, Ahmad S, Oskoueian E, Abas F, et al.

Int J Mol Sci, 2014;15(2):2274-88.

PMID: 24504029 DOI: 10.3390/ijms15022274

The presence of phorbol esters (PEs) with toxic properties limits the use of Jatropha curcas kernel in the animal feed industry. Therefore, suitable methods to detoxify PEs have to be developed to render the material safe as a feed ingredient. In the present study, the biological treatment of the extracted PEs-rich fraction with non-pathogenic fungi (Trichoderma harzianum JQ350879.1, T. harzianum JQ517493.1, Paecilomyces sinensis JQ350881.1, Cladosporium cladosporioides JQ517491.1, Fusarium chlamydosporum JQ350882.1, F. chlamydosporum JQ517492.1 and F. chlamydosporum JQ350880.1) was conducted by fermentation in broth cultures. The PEs were detected by liquid chromatography-diode array detector-electrospray ionization mass spectrometry (LC-DAD-ESIMS) and quantitatively monitored by HPLC using phorbol-12-myristate 13-acetate as the standard. At day 30 of incubation, two T. harzianum spp., P. sinensis and C. cladosporioides significantly (p < 0.05) removed PEs with percentage losses of 96.9%-99.7%, while F. chlamydosporum strains showed percentage losses of 88.9%-92.2%. All fungal strains could utilize the PEs-rich fraction for growth. In the cytotoxicity assay, cell viabilities of Chang liver and NIH 3T3 fibroblast cell lines were less than 1% with the untreated PEs-rich fraction, but 84.3%-96.5% with the fungal treated PEs-rich fraction. There was no inhibition on cell viability for normal fungal growth supernatants. To conclude, Trichoderma spp., Paecilomyces sp. and Cladosporium sp. are potential microbes for the detoxification of PEs.

Matched MeSH terms: Phorbol Esters/toxicity; Phorbol Esters/chemistry*

Optimization of enzymatic synthesis of palm-based kojic acid ester using response surface methodology

Ashari SE, Mohamad R, Ariff A, Basri M, Salleh AB

J Oleo Sci, 2009;58(10):503-10.

PMID: 19745577

Kojic acid monooleate is a fatty acid derivative of kojic acid which can be widely used as a skin whitening agent in a cosmetic applications. In avoiding any possible harmful effects from chemically synthesized product, the enzymatic synthesis appears to be the best way to satisfy the consumer demand nowadays. The ability of immobilized lipase from Rhizomucor meihei (lipozyme RMIM) to catalyze the direct esterification of kojic acid and oleic acid was investigated. Response Surface Methodology (RSM) and 5-level-4-factor central composite rotatable were employed to evaluate the effects of synthesis parameters such as enzyme amount (0.1-0.4 g), temperature (30-60 degrees C), substrate molar ratio (1-4 mmol, kojic acid:oleic acid) and reaction time (24-48 h) on percentage molar conversion to kojic acid monooleate. Analysis of the product using TLC, GC and FTIR showed the presence of kojic acid monooleate. The optimal conditions for the enzymatic reaction were obtained after analysis with backward elimination using 0.17 g of enzyme and 4 mmol of substrate at 52.50 degrees C for 42 h. Under these conditions the esterification percentage was 37.21%. The results demonstrated that response surface methodology can be applied effectively to optimize the lipase-catalysed synthesis of kojic acid monooleate. The optimum conditions can be used to scale up the process.

Matched MeSH terms: Esters/metabolism*; Esters/chemistry

Fulltext Monitoring of heat-induced carcinogenic compounds (3-monochloropropane-1,2-diol esters and glycidyl esters) in fries

Wong YH, Goh KM, Nyam KL, Cheong LZ, Wang Y, Nehdi IA, et al.

Sci Rep, 2020 09 15;10(1):15110.

PMID: 32934328 DOI: 10.1038/s41598-020-72118-z

3-Monochloropropane-1,2-diol (3-MCPD) esters and glycidyl esters (GE) are heat-induced contaminants which form during oil refining process, particularly at the high temperature deodorization stage. It is worth to investigate the content of 3-MCPD and GE in fries which also involved high temperature. The content of 3-MCPD esters and GE were monitored in fries. The factors that been chosen were temperature and duration of frying, and different concentration of salt (NaCl). The results in our study showed that the effect was in the order of concentration of sodium chloride

Matched MeSH terms: Esters/analysis*; Esters/chemistry

Chemical synthesis and characterization of palm oil-based difatty acyl thiourea

Hoidy WH, Ahmad MB, Al-Mulla EA, Yunus WZ, Ibrahim Na

J Oleo Sci, 2010;59(5):229-33.

PMID: 20431238

Difatty acyl thiourea (DFAT), which has biological activities as antibiotics and antifungal, has been synthesized from palm oil and thiourea using sodium ethoxide as catalyst. Ethyl fatty ester (EFE) and glycerol were produced as by-products. The synthesis was carried out by reflux palm oil with thiourea in ethanol. In this process, palm oil converted to about 81% pure DFAT after 11 hour and molar ratio of thiourea to palm oil was 6.0: 1 at 78 degrees C. Elemental analysis, Fourier transform iInfrared (FTIR) spectroscopy and (1)H nuclear magnetic resonance (NMR) technique were used to characterize both DFAT and EFE.

Matched MeSH terms: Esters/chemical synthesis*; Esters/chemistry

Fulltext Dehalogenases: From Improved Performance to Potential Microbial Dehalogenation Applications

Ang TF, Maiangwa J, Salleh AB, Normi YM, Leow TC

Molecules, 2018 05 07;23(5).

PMID: 29735886 DOI: 10.3390/molecules23051100

The variety of halogenated substances and their derivatives widely used as pesticides, herbicides and other industrial products is of great concern due to the hazardous nature of these compounds owing to their toxicity, and persistent environmental pollution. Therefore, from the viewpoint of environmental technology, the need for environmentally relevant enzymes involved in biodegradation of these pollutants has received a great boost. One result of this great deal of attention has been the identification of environmentally relevant bacteria that produce hydrolytic dehalogenases—key enzymes which are considered cost-effective and eco-friendly in the removal and detoxification of these pollutants. These group of enzymes catalyzing the cleavage of the carbon-halogen bond of organohalogen compounds have potential applications in the chemical industry and bioremediation. The dehalogenases make use of fundamentally different strategies with a common mechanism to cleave carbon-halogen bonds whereby, an active-site carboxylate group attacks the substrate C atom bound to the halogen atom to form an ester intermediate and a halide ion with subsequent hydrolysis of the intermediate. Structurally, these dehalogenases have been characterized and shown to use substitution mechanisms that proceed via a covalent aspartyl intermediate. More so, the widest dehalogenation spectrum of electron acceptors tested with bacterial strains which could dehalogenate recalcitrant organohalides has further proven the versatility of bacterial dehalogenators to be considered when determining the fate of halogenated organics at contaminated sites. In this review, the general features of most widely studied bacterial dehalogenases, their structural properties, basis of the degradation of organohalides and their derivatives and how they have been improved for various applications is discussed.

Matched MeSH terms: Esters/metabolism; Esters/chemistry

Fulltext Optimisation and Characterisation of Lipase-Catalysed Synthesis of a Kojic Monooleate Ester in a Solvent-Free System by Response Surface Methodology

Jumbri K, Al-Haniff Rozy MF, Ashari SE, Mohamad R, Basri M, Fard Masoumi HR

PLoS One, 2015;10(12):e0144664.

PMID: 26657030 DOI: 10.1371/journal.pone.0144664

Kojic acid is widely used to inhibit the browning effect of tyrosinase in cosmetic and food industries. In this work, synthesis of kojic monooleate ester (KMO) was carried out using lipase-catalysed esterification of kojic acid and oleic acid in a solvent-free system. Response Surface Methodology (RSM) based on central composite rotatable design (CCRD) was used to optimise the main important reaction variables, such as enzyme amount, reaction temperature, substrate molar ratio, and reaction time along with immobilised lipase from Candida Antarctica (Novozym 435) as a biocatalyst. The RSM data indicated that the reaction temperature was less significant in comparison to other factors for the production of a KMO ester. By using this statistical analysis, a quadratic model was developed in order to correlate the preparation variable to the response (reaction yield). The optimum conditions for the enzymatic synthesis of KMO were as follows: an enzyme amount of 2.0 wt%, reaction temperature of 83.69°C, substrate molar ratio of 1:2.37 (mmole kojic acid:oleic acid) and a reaction time of 300.0 min. Under these conditions, the actual yield percentage obtained was 42.09%, which is comparably well with the maximum predicted value of 44.46%. Under the optimal conditions, Novozym 435 could be reused for 5 cycles for KMO production percentage yield of at least 40%. The results demonstrated that statistical analysis using RSM can be used efficiently to optimise the production of a KMO ester. Moreover, the optimum conditions obtained can be applied to scale-up the process and minimise the cost.

Matched MeSH terms: Esters

Synergistic effect of optimizing light-emitting diode illumination quality and intensity to manipulate composition of fatty acid methyl esters from Nannochloropsis sp

Teo CL, Idris A, Zain NAM, Taisir M

Bioresour Technol, 2014 Dec;173:284-290.

PMID: 25310864 DOI: 10.1016/j.biortech.2014.09.110

In the study, the relationship between the quality and intensity of LED illumination with FAMEs produced were investigated. Nannochloropsis sp. was cultivated for 14 days under different intensities of 100, 150 and 200 μmol photons m(-2) s(-1) of red, blue and mixed red blue LED. The findings revealed that suitable combination of LED wavelengths and intensity; (red LED: 150, blue: 100 and mixed red blue: 200 μmol photons m(-2) s(-1)) produced maximum biomass growth and lipid content. It was observed that the quality and intensity of LED significantly influenced the composition of FAMEs. FAMEs produced under blue LED has high degree of unsaturation (DU) and low cetane number while those under red LED has low DU but higher CN. The combination of red blue LED has produced FAMEs with high ignition and lubricating property and also good oxidation stability indicated by the DU and CN values which lies midway between the red and blue.

Matched MeSH terms: Esters

Fulltext Chirogenesis and Pfeiffer Effect in Optically Inactive EuIII and TbIII Tris(β-diketonate) Upon Intermolecular Chirality Transfer From Poly- and Monosaccharide Alkyl Esters and α-Pinene: Emerging Circularly Polarized Luminescence (CPL) and Circular Dichroism (CD)

Fujiki M, Wang L, Ogata N, Asanoma F, Okubo A, Okazaki S, et al.

Front Chem, 2020;8:685.

PMID: 32903703 DOI: 10.3389/fchem.2020.00685

We report emerging circularly polarized luminescence (CPL) at 4f-4f transitions when lanthanide (EuIII and TbIII) tris(β-diketonate) embedded to cellulose triacetate (CTA), cellulose acetate butyrate (CABu), D-/L-glucose pentamethyl esters ( D-/ L-Glu), and D-/L-arabinose tetramethyl esters ( D-/ L-Ara) are in film states. Herein, 6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionate (fod) and 2,2,6,6-tetramethyl-3,5-heptanedione (dpm) were chosen as the β-diketonates. The glum value of Eu(fod)3 in CABu are +0.0671 at 593 nm (5

D

0

→

7

F1) and -0.0059 at 613 nm (5

D

0

→

7

F2), respectively, while those in CTA are +0.0463 and -0.0040 at these transitions, respectively. The glum value of Tb(fod)3 in CABu are -0.0029 at 490 nm (5

D

4

→

7

F6), +0.0078 at 540 nm (5

D

4

→

7

F5), and -0.0018 at 552 nm (5

D

4

→

7

F5), respectively, while those in CTA are -0.0053, +0.0037, and -0.0059 at these transitions, respectively. D-/ L-Glu and D-/ L-Ara induced weaker glum values at 4f-4f transitions of Eu(fod)3, Tb(fod)3, and Tb(dpm)3. For comparison, Tb(dpm)3 in α-pinene showed clear CPL characteristics, though Eu(dpm)3 did not. A surplus charge neutralization hypothesis was applied to the origin of attractive intermolecular interactions between the ligands and saccharides. This idea was supported from the concomitant opposite tendency in upfield 19F-NMR and downfield 1H-NMR chemical shifts of Eu(fod)3 and the opposite Mulliken charges between F-C bonds (fod) and H-C bonds (CTA and D-/ L-Glu). An analysis of CPL excitation (CPLE) and CPL spectra suggests that (+)- and (-)-sign CPL signals of EuIII and TbIII at different 4f-4f transitions in the visible region are the same with the (+)-and (-)-sign exhibited by CPLE bands at high energy levels of EuIII and TbIII in the near-UV region.

Matched MeSH terms: Esters

Fulltext An acceleration of microwave-assisted transesterification of palm oil-based methyl ester into trimethylolpropane ester

Aziz NAM, Yunus R, Hamid HA, Ghassan AAK, Omar R, Rashid U, et al.

Sci Rep, 2020 11 12;10(1):19652.

PMID: 33184363 DOI: 10.1038/s41598-020-76775-y

Microwave-assisted synthesis is known to accelerate the transesterification process and address the issues associated with the conventional thermal process, such as the processing time and the energy input requirement. Herein, the effect of microwave irradiation on the transesterification of palm oil methyl ester (PME) with trimethylolpropane (TMP) was evaluated. The reaction system was investigated through five process parameters, which were reaction temperature, catalyst, time, molar ratio of TMP to PME and vacuum pressure. The yield of TMP triester at 66.9 wt.% and undesirable fatty soap at 17.4% were obtained at 130 °C, 10 mbar, sodium methoxide solution at 0.6 wt.%, 10 min reaction time and molar ratio of TMP to PME at 1:4. The transesterification of palm oil-based methyl ester to trimethylolpropane ester was 3.1 folds faster in the presence of microwave irradiation. The total energy requirement was markedly reduced as compared to the conventional heating method. The findings indicate that microwave-assisted transesterification could probably be an answer to the quest for a cheaper biodegradable biolubricant.

Matched MeSH terms: Esters

Fulltext A Review on Citric Acid as Green Modifying Agent and Binder for Wood

Lee SH, Md Tahir P, Lum WC, Tan LP, Bawon P, Park BD, et al.

Polymers (Basel), 2020 Jul 29;12(8).

PMID: 32751175 DOI: 10.3390/polym12081692

Citric acid (CA) can be found naturally in fruits and vegetables, particularly citrus fruit. CA is widely used in many fields but its usage as a green modifying agent and binder for wood is barely addressed. Esterification is one of the most common chemical reactions applied in wood modification. CA contains three carboxyl groups, making it possible to attain at least two esterification reactions that are required for crosslinking when reacting with the hydroxyl groups of the cell wall polymers. In addition, the reaction could form ester linkages to bring adhesivity and good bonding characteristics, and therefore CA could be used as wood binder too. This paper presents a review concerning the usage of CA as a wood modifying agent and binder. For wood modification, the reaction mechanism between wood and CA and the pros and cons of using CA are discussed. CA and its combination with various reactants and their respective optimum parameters are also compiled in this paper. As for the major wood bonding component, the bonding mechanism and types of wood composites bonded with CA are presented. The best working conditions for the CA in the fabrication of wood-based panels are discussed. In addition, the environmental impacts and future outlook of CA-treated wood and bonded composite are also considered.

Matched MeSH terms: Esters

α-Sulfo alkyl ester surfactants: Impact of changing the alkyl chain length on the adsorption, mixing properties and response to electrolytes of the tetradecanoate

Wang Z, Li P, Ma K, Chen Y, Yan Z, Penfold J, et al.

J Colloid Interface Sci, 2021 Mar 15;586:876-890.

PMID: 33309145 DOI: 10.1016/j.jcis.2020.10.122

HYPOTHESIS: The α-sulfo alkyl ester, AES, surfactants are a class of anionic surfactants which have potential for improved sustainable performance in a range of applications, and an important feature is their enhanced tolerance to precipitation in the presence of multivalent counterions. It is proposed that their adsorption properties can be adjusted substantially by changing the length of the shorter alkyl chain, that of the alkanol group in the ester.

EXPERIMENTS: Surface tension and neutron reflectivity have been used to investigate the variation in the adsorption properties with the shorter alkyl chain length (methyl, ethyl and propyl), the impact of NaCl on the adsorption, the tendency to form surface multilayer structures in the presence of AlCl3, and the effects of mixing the methyl ester sulfonate with the ethyl and propyl ester sulfonates on the adsorption.

FINDINGS: The variations in the critical micelle concentration, CMC, the adsorption isotherms, the saturation adsorption values, and the impact of NaCl illustrate the subtle influence of varying the shorter alkyl chain length of the surfactant. The non-ideal mixing of pairs of AES surfactants with different alkanol group lengths of the ester show that the extent of the non-ideality changes as the difference in the alkanol length increases. The surface multilayer formation observed in the presence of AlCl3 varies in a complex manner with the length of the short chain and for mixtures of surfactants with different chains lengths.

Matched MeSH terms: Esters

Globrauneine A-F: six new triterpenoid esters from the leaves of Globimetula braunii

Muhammad KJ, Jamil S, Basar N, Sarker SD, Mohammed MG

Nat Prod Res, 2020 Oct;34(19):2746-2753.

PMID: 30931627 DOI: 10.1080/14786419.2019.1586693

Phytochemical study was conducted on the leaves of Globimetula braunii which is a hemi parasitic plant belonging to the family Loranthaceae. Extraction was carried out using cold extraction method with increasing polarity of solvents i.e n-hexane, CH2Cl2 and MeOH. The components were separated by chromatographic technique and the structures of the compounds were elucidated by extensive spectroscopic analyses including MS, FTIR, 1D and 2D NMR, HRMS and chemical methods. Six new pentacyclic triterpenoid esters named as globrauneine A (1), globrauneine B (2), globrauneine C (3), globrauneine D (4), globrauneine E (5), and globrauneine F (6), together with six known compounds (7 - 12) were successfully isolated from the leaves of G. braunii growing on Piliostigma thonningii. These results depict a substantial support to the chemotaxonomy of the genus Globimetula.

Matched MeSH terms: Esters

Fulltext Contact angle and surface free energy of PVC and Eudragit RS 100 in binary mixture study

Mohd Cairul Iqbal Mohd Amin, Fell, J.T.

Jurnal Sains Kesihatan Malaysia, 2006;4(1):1-8.

MyJurnal

Polyvinyl chloride (PVC) and ammonio methacrylate copolymer (Eudragit RS 100) were used as models in binary mixture tablets of direct compression study. Eudragit RS 100 is a copolymer synthesized from acrylic and methacrylic acid esters with a low content of quaternary ammonium groups. Combination of PVC and Eudragit RS 100 of different polarities and knowing the surface free energy values allow the possibility of predicting the tensile strength of the tablets. Specimens of 500 mg in the form of thin plates (25 mm x 12.5 mm), were made by compressing each powder at 20 000 MP a compression pressure using a special punch and die set. A Howden Universal Testing Machine was used to compress the powder. Contact angle measurements of the samples were carried out using a Wilhelmy balance, ran by a Cahn Dynamic Contact Angle Machine while different test liquids media such as water, glycerol, formamide and PEG 200 were used in the study. The surface free energy values of the solid materials were calculated using Wu's equation. The results showed large differences between the advancing and receding contact angle values for both materials when tested with glycerol: PVC (0) and PVC (0,) were 93.2 and 65.24 while Eudragit RS 100 (0) and Eudragit RS 100 (0) were 94.56 and 68.18 respectively. The surface free energy values for PVC using PEG 200-glycerol liquid pair were Is: 38.01, ysci: 33.42, ysP: 4.59 and for Eudragit RS 100 using formamide-glycerol liquid pair were ys: 75.03, yd: 51.66, ysP : 23.37, respectively. The results showed harder solid material like Eudragit RS 100 had higher surface free energy compared to elastic material like PVC.

Matched MeSH terms: Esters

Fulltext Thermomyces lanuginosus lipase-catalyzed synthesis of natural flavor esters in a continuous flow microreactor

Gumel AM, Annuar MSM

3 Biotech, 2016 Jun;6(1):24.

PMID: 28330099 DOI: 10.1007/s13205-015-0355-9

Enzymatic catalysis is considered to be among the most environmental friendly processes for the synthesis of fine chemicals. In this study, lipase from Thermomyces lanuginosus (Lecitase Ultra™) was used to catalyze the synthesis of flavor esters, i.e., methyl butanoate and methyl benzoate by esterification of the acids with methanol in a microfluidic system. Maximum reaction rates of 195 and 115 mM min(-1) corresponding to catalytic efficiencies (k cat/K M) of 0.30 and 0.24 min(-1) mM(-1) as well as yield conversion of 54 and 41 % were observed in methyl butanoate and methyl benzoate synthesis, respectively. Catalytic turnover (k cat) was higher for methyl butanoate synthesis. Rate of synthesis and yield decreased with increasing flow rates. For both esters, increase in microfluidic flow rate resulted in increased advective transport over molecular diffusion and reaction rate, thus lower conversion. In microfluidic synthesis using T. lanuginosus lipase, the following reaction conditions were 40 °C, flow rate 0.1 mL min(-1), and 123 U g(-1) enzyme loading found to be the optimum operating limits. The work demonstrated the application of enzyme(s) in a microreactor system for the synthesis of industrially important esters.

Matched MeSH terms: Esters

Deoxygenation of pyrolysis vapour derived from durian shell using catalysts prepared from industrial wastes rich in Ca, Fe, Si and Al

Tan YL, Hameed BH, Abdullah AZ

Sci Total Environ, 2020 Feb 10;703:134902.

PMID: 31753498 DOI: 10.1016/j.scitotenv.2019.134902

Catalysts prepared from industrial wastes rich in Fe, Ca, Si, and Al were used in catalytic upgrading of pyrolysis vapour derived from durian shell and their effect on product yield and properties were compared. With same silica-to-alumina ratio, catalyst prepared from oil palm ash (AS-OPA) with lower Fe and Ca contents gave higher liquid yield (8.32 wt%) with alcohols (28.90%), hydrocarbons (46.00%), and nitrogen-containing compounds (21.46%) while catalyst prepared from electric arc furnace slag (AS-EAF) with higher Fe and Ca contents produced lower liquid yield (50.21 wt%) with high amount of esters (25.80%) and hydrocarbons (72.82%). The presence of AS-OPA and AS-EAF catalysts enhanced deoxygenation degree of bio-oil to 81.13% and 85.49%, respectively. The catalytic performance of AS-EAF at different temperatures (400-600 °C) and AS-EAF/durian shell ratios (1:30, 2:30, 3:30) was investigated. Increasing catalytic temperature enhanced production of bio-oil, reduced oxygenates and enhanced formation of esters. The liquid yield and yield of esters decreased with increasing catalyst loading. Hydrocarbons (mainly neopentane) were the major chemical compounds found in bio-oil produced over AS-EAF. Besides that, AS-EAF showed good deoxygenation performance with highest selectivity of hydrocarbons at 500 °C and AS-EAF/durian shell ratio of 2:30. Catalytic fast pyrolysis of durian shell using waste-derived catalysts is an effective waste management strategy as the bio-oil produced can be a potential alternative source of energy or chemical feedstocks.

Matched MeSH terms: Esters

Preparation of palm oil methyl esters for alkenyl succinic anhydride production

Nur Azreena Idris, Loh SK, Choo YM, Boey PL

Sains Malaysiana, 2010;39.

The fractions of fatty acid methyl esters (FAME) i.e. crude palm oil methyl esters (CPOME), RBD palm olein methyl esters (RBD Palm Olein ME) and used frying oil methyl esters (UFOME) rich in unsaturated fatty esters were used to prepare alkenyl succinic anhydrides (ASA). The fractions were obtained via fractional distillation that separated the unsaturated fatty esters from the saturated fatty esters. The fractions with the highest content of unsaturated fatty esters were reacted with maleic anhydride (MA) for 8 hours at 240oC with the MA/FAME ratio of 1.5. The reaction was conducted without catalyst and solvent. The crude alkenyl succinic anhydride (ASA) obtained was purified by column chromatography. The purified compound was characterised by FTIR.

Matched MeSH terms: Esters

Biodiesel from Thevetia Peruviana seed oil with Dimethyl carbonate using as an active catalyst potassium-methoxide

Panchal BM, Deshmukh SA, Sharma MR

Sains Malaysiana, 2016;45:1461-1468.

The transesterification of Thevetia peruviana seed oil with dimethyl carbonate (DMC) for preparing biodiesel has been studied using as an active catalyst potassium-methoxide (KOCH3). The effects of reaction conditions: Molar ratio of dimethyl carbonate to Thevetia peruviana seed oil, catalyst concentration, reaction time and agitation speed on dimethyl esters (DMC-Tp-BioDs) yield were investigated. The highest DMC-Tp-BioDs yield could reach 97.1% at refluxing temperature for 90 min with molar ratio of DMC-to-oil 5:1 and 2.0% w/w KOCH3 (based on oil weight). The fuel properties of the produced DMC-Tp-BioDs were compared with the ASTM D6751-02 biodiesel standard.

Matched MeSH terms: Esters

Biodiesel production from fish (cyprinus carpio) waste and evaluation of engine performance

Mohammed Saifuddin, Amru N. Boyce

Sains Malaysiana, 2017;46:1771-1778.

As fossil energy resources are depleting quick and energy security is playing a vital role in the world economy. Quest for alternative energy sources have turned researches investigation in waste foods for next generation fuel. Biodiesel is usually considered to be environmentally friendly as it reduces greenhouse gas emission. Fish wastes rich in fatty acids and can be used as the raw material to produce biodiesel through transesterification reaction. The results showed that the seven peaks are fatty acid methyl esters, indicating all the triglycerides were successfully methylated to methyl esters. Fish based biodiesel provided a significant reduction in carbon monoxide (CO) and hydrocarbon (HC) emissions under engine loads of 15 (Nm) and required no engine modification. The viscosity of the produced biodiesel was within the range of international standards (ASTM). The biodiesel was found to contain a low base number and exhibited a lower specific fuel consumption compared to the conventional diesel. It can be concluded that biodiesel derived from waste fish oil can be considered as a potential source of commercial biodiesel.

Matched MeSH terms: Esters

Palm-Based Neopentyl Glycol Diester: A Potential Green Insulating Oil

Raof NA, Yunus R, Rashid U, Azis N, Yaakub Z

Protein Pept Lett, 2018;25(2):171-179.

PMID: 29359647 DOI: 10.2174/0929866525666180122095056

BACKGROUND: The transesterification of high oleic palm oil methyl ester (HOPME) with neopentyl glycol (NPG) has been investigated. The present study revealed the application of low-pressure technology as a new synthesis method to produce NPG diesters. Single variable optimization and response surface methodology (RSM) were implemented to optimize the experimental conditions to achieve the maximum composition (wt%) of NPG diesters.

OBJECTIVE: The main objective of this study was to optimize the production of NPG diesters and to characterize the optimized esters with typical chemical, physical and electrical properties to study its potential as insulating oil.

METHODS: The transesterification reaction between HOPME and NPG was conducted in a 1L three-neck flask reactor at specified temperature, pressure, molar ratio and catalyst concentration. For the optimization, four factors have been studied and the diester product was characterized by using gas chromatography (GC) analysis. The synthesized esters were then characterized with typical properties of transformer oil such as flash point, pour point, viscosity and breakdown voltage and were compared with mineral insulating oil and commercial NPG dioleate. For formulation, different samples of NPG diesters with different concentration of pour point depressant were prepared and each sample was tested for its pour point measurement.

RESULTS: The optimum conditions inferred from the analyses were: molar ratio of HOPME to NPG of 2:1.3, temperature = 182°C, pressure = 0.6 mbar and catalyst concentration of 1.2%. The synthesized NPG diesters showed very important improvement in fire safety compared to mineral oil with flash point of 300°C and 155°C, respectively. NPG diesters also exhibit a relatively good viscosity of 21 cSt. The most striking observation to emerge from the data comparison with NPG diester was the breakdown voltage, which was higher than mineral oil and definitely in conformance to the IEC 61099 limit at 67.5 kV. The formulation of synthesized NPD diesters with VISCOPLEX® pour point depressant has successfully increased the pour point of NPG diester from -14°C to -48°C.

CONCLUSION: The reaction time for the transesterification of HOPME with NPG to produce NPG diester was successfully reduced to 1 hour from the 14 hours required in the earlier synthesis method. The main highlight of this study was the excess reactant which is no longer methyl ester but the alcohol (NPG). The optimum reaction conditions for the synthesis were molar ratio of 2:1.13 for NPG:HOPME, 182°C, 0.6 mbar and catalyst concentration of 1.2 wt%. The maximum NPG diester yield of 87 wt% was consistent with the predicted yield of 87.7 wt% obtained from RSM. The synthesized diester exhibited better insulating properties than the commercial products especially with regards to the breakdown voltage, flash point and moisture content.

Matched MeSH terms: Esters

Hazardous waste management (Buxus papillosa) investment for the prosperity of environment and circular economy: Response surface methodology-based simulation

Faiz I, Ahmad M, Ramadan MF, Zia U, Rozina, Bokhari A, et al.

J Environ Manage, 2024 Jan 15;350:119567.

PMID: 38007927 DOI: 10.1016/j.jenvman.2023.119567

Dealing with the current defaults of environmental toxicity, heating, waste management, and economic crises, exploration of novel non-edible, toxic, and waste feedstock for renewable biodiesel synthesis is the need of the hour. The present study is concerned with Buxus papillosa with seeds oil concentration (45% w/w), a promising biodiesel feedstock encountering environmental defaults and waste management; in addition, this research performed simulation based-response surface methodology (RSM) for Buxus papillosa bio-diesel. Synthesis and application of novel Phyto-nanocatalyst bimetallic oxide with Buxus papillosa fruit capsule aqueous extract was advantageous during transesterification. Characterization of sodium/potassium oxide Phyto-nanocatalyst confirmed 23.5 nm nano-size and enhanced catalytic activity. Other characterizing tools are FTIR, DRS, XRD, Zeta potential, SEM, and EDX. Methyl ester formation was authenticated by FTIR, GC-MS, and NMR. A maximum 97% yield was obtained at optimized conditions i.e., methanol ratio to oil (8:1), catalyst amount (0.37 wt%), reaction duration (180 min), and temperature of 80 °C. The reusability of novel sodium/potassium oxide was checked for six reactions. Buxus papillosa fuel properties were within the international restrictions of fuel. The sulphur content of 0.00090% signified the environmental remedial nature of Buxus papillosa methyl esters and it is a highly recommendable species for biodiesel production at large scale due to a t huge number of seeds production and vast distribution.

Matched MeSH terms: Esters

Displaying publications 41 - 60 of 170 in total