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Improvement of Physicochemical Characteristics of Monoepoxide Linoleic Acid Ring Opening for Biolubricant Base Oil
Jumat Salimon,Nadia Salih,Bashar Mudhaffar Abdullah
Journal of Biomedicine and Biotechnology , 2011, DOI: 10.1155/2011/196565
Abstract: For environmental reasons, a new class of environmentally acceptable and renewable biolubricant based on vegetable oils is available. In this study, oxirane ring opening reaction of monoepoxide linoleic acid (MEOA) was done by nucleophilic addition of oleic acid (OA) with using p-toluene sulfonic acid (PTSA) as a catalyst for synthesis of 9(12)-hydroxy-10(13)-oleoxy-12(9)-octadecanoic acid (HYOOA) and the physicochemical properties of the resulted HYOOA are reported to be used as biolubricant base oils. Optimum conditions of the experiment using D-optimal design to obtain high yield% of HYOOA and lowest OOC% were predicted at OA/MEOA ratio of 0.30 : 1 (w/w), PTSA/MEOA ratio of 0.50 : 1 (w/w), reaction temperature at 110°C, and reaction time at 4.5 h. The results showed that an increase in the chain length of the midchain ester resulted in the decrease of pour point (PP) ?51°C, increase of viscosity index (VI) up to 153, and improvement in oxidative stability (OT) to 180.94°C.
Diesters Biolubricant Base Oil: Synthesis, Optimization, Characterization, and Physicochemical Characteristics  [PDF]
Jumat Salimon,Nadia Salih,Bashar Mudhaffar Abdullah
International Journal of Chemical Engineering , 2012, DOI: 10.1155/2012/896598
Abstract: Diesters biolubricant base oil, oleyl 9(12)-hydroxy-10(13)-oleioxy-12(9)-octadecanoate (OLHYOOD) was synthesized based on the esterification reaction of 9,12-hydroxy-10,13-oleioxy-12-octadecanoic acid (HYOOA) with oleyl alcohol (OL) and catalyzed by sulfuric acid (SA). Optimum conditions of the experiment to obtain high yield % of OLHYOOD were predicted at ratio of OL/HYOOA of 2?:?1?mol/mol, ratio of SA/HYOOA of 0.7?:?1?mol/mol, reaction temperature 110°C, and 7?h of reaction time. At this condition, the yield of OLHYOOD was 88.7%. Disappearance of carboxylic acid (C=O) peak has been observed by FTIR with appearance of ester (C=O) peak at 1738?cm?1. 13C, and 1H?NMR spectra analyses confirmed the result of OLHYOOD with the appearance of carbon-ester (C=O) chemical shift at 173.93?ppm and at 4.05?ppm for 13C and 1H?NMR, respectively. The physicochemical characteristics of the OLHYOOD were also determined, which showed improved low temperature properties (PP) ?62°C, viscosity index (VI) at 192 and also increased oxidative stability (OT) up to 215.24°C. 1. Introduction Oleochemicals that are derived from natural fats and oils are referred to as natural oleochemicals [1]. Industrially, most fatty acids are obtained from animal or vegetable sources. It is possible to produce several industrial products from fatty acids (saturated and unsaturated). Fatty acid products have different utilization as resins, plastics, perfumes, coatings, flavors, cosmetics, solvents, soaps, medicinals, biofuels, and biolubricants [2]. Synthetic biolubricant based on renewable resources are important in developing environmentally acceptable lubricating oils [3]. Currently, lubricant-based petroleum worldwide end up in the environment via total loss applications, spills, or major accidents. A fact remains that about 3 million tones are lost in the European environment every year originating from loss and high-risk lubricants mostly based on mineral oil. Emissions of mineral oil may appear to be negligible importance compared to an accident involving an oil tanker spill [4]. And also, the emissions of mineral oil arising from lubricant applications in water make lubricants contribution to the pollution of water much more significant [5]. In the last decade, a lot of interest was developed to use environmental friendly biolubricant fluids [6]. The use of environmentally acceptable vegetable-oil-based product as biolubricants has many advantages. They are nontoxic, biodegradable, derived from renewable resource and have a reasonable cost when compared to other synthetic fluids [7].
One-Pot Chemoenzymatic Multicomponent Synthesis of Thiazole Derivatives  [PDF]
Hui Zheng,Yi-Jia Mei,Kui Du,Xian-Ting Cao,Peng-Fei Zhang
Molecules , 2013, DOI: 10.3390/molecules181113425
Abstract: A novel chemoenzymatic one-pot multicomponent synthesis of thiazole derivatives was developed. A series of thiazole derivatives were synthesized with high yields up to 94% under mild enzyme-catalyzed conditions. The blank and control experiments reveal that trypsin from porcine pancreas (PPT) displayed great catalytic activity to promote this reaction and showed a wide tolerance range towards different substrate amines. This trypsin-catalyzed multicomponent conversion method provides a novel strategy to synthesize thiazole derivatives and expands the application of enzymes in organic synthesis.
Oleins as a source of estolides for biolubricant applications
García-Zapateiro, L. A.,Delgado, M. A.,Franco, J. M.,Valencia, C.
Grasas y Aceites , 2010, DOI: 10.3989/gya.075209
Abstract: This study deals with the synthesis of estolides from high-oleic sunflower oil oleins, and its potential use as viscosity modifiers for biolubricant applications. Synthesis reactions were monitored for 24 h. Estolide molecular weight increased continuously with reaction time. Dynamic viscosities and densities of the different estolides were measured in a temperature range comprised between 10 and 120 °C. Maximum viscosities and estolide molecular weight were obtained after 12 h of reaction. However, the largest viscosity increments were observed within the first 3 hours of processing, due to a dramatic increase in the molecular weight of the estolides. En este estudio se presenta la síntesis de estólidos a partir de oleinas de girasol alto-oleico y su utilización potencial como modificadores de la viscosidad en aplicaciones como biolubricantes. La reacción de síntesis se controló durante 24h. El peso molecular de los estólidos se incrementa durante todo el periodo de reacción. Las viscosidades dinámicas y densidades de los diferentes estólidos se midieron en un rango de temperatura entre 10 y 120 °C. El máximo de viscosidad y de peso molecular se alcanza al cabo de 12 horas de reacción, sin embargo, el incremento mayor de viscosidad se produce durante las 3 primeras horas de tratamiento debido al importante aumento del peso molecular del estólido.
Structural Characterisation by ESI-MS of Feruloylated Arabino-oligosaccharides Synthesised by Chemoenzymatic Esterification  [PDF]
Christina Vafiadi,Evangelos Topakas,Edwin J Bakx,Henk A Schols,Paul Christakopoulos
Molecules , 2007, DOI: 10.3390/12071367
Abstract: The chemoenzymatic synthesis of feruloylated arabino-oligosaccharides has been achieved, using a feruloyl esterase type C from Sporotrichum thermophile (StFaeC).The structure of the feruloylated products was confirmed by ESI-MSn.
Chemoenzymatic synthesis of organoselenium(IV) compounds and their evaluation as cysteine protease inhibitors
Piovan, Leandro;Alves, Márcio F. M;Juliano, Luiz;Br?mme, Dieter;Cunha, Rodrigo L. O. R;Andrade, Leandro H;
Journal of the Brazilian Chemical Society , 2010, DOI: 10.1590/S0103-50532010001100012
Abstract: a series of organoselenium dihalides (organoselenanes) was synthesized from organoselenides using a chemoenzymatic approach. the organoselenanes have variations in their stereochemistry and in the halogen atom bonded to the selenium atom. because of the unique selenium-thiol chemistry displayed by several organoselenium compounds, the organoselenanes were evaluated as new potential inhibitors of cysteine proteases (cathepsins s and v). by the analysis of the second-order rate constants of the inhibition of cathepsin s and v, it was possible to conclude that organoselenanes inhibited the cathepsin s faster than cathepsin v. it was observed higher inhibitory potencies for the dibromo organoselenanes derivatives than the dichloro analogues. in addition, the present data suggest the use of hypervalent selenium compounds as novel motifs for cysteine proteases inhibitors.
Synthesis and Characterisation of a Biolubricant from Cameroon Palm Kernel Seed Oil Using a Locally Produced Base Catalyst from Plantain Peelings  [PDF]
Michael Bong Alang, Maurice Kor Ndikontar, Yahaya Muhammad Sani, Peter T. Ndifon
Green and Sustainable Chemistry (GSC) , 2018, DOI: 10.4236/gsc.2018.83018
Abstract: Biolubricant was synthesized from Cameroon palm kernel oil (PKO) by double transesterification, producing methyl esters in the first stage which were then transesterified with trimethylolpropane (TMP) to give the PKO biolubricant in the presence of a base catalyst obtained from plantain peelings (municipal waste). The yields from both catalysts were significantly similar (48% for the locally produced and 51% for the conventional) showing that the locally produced catalyst could be valorized. The synthesized biolubricant was characterized by measuring its physical and chemical properties. The specific gravity of 1.2, ASTM color of 1.5, cloud point of 0°C, pour point of -9°C, viscosities at 40°C of 509.80 cSt and at 100°C of 30.80 cSt, viscosity index of 120, flash point greater than 210°C and a fire point greater than 220°C were obtained. This synthesized biolubricant was found to be comparable to commercial T-46 petroleum lubricant sample produced industrially from mineral sources. We have therefore used local materials to produce a biolubricant using a cheap base catalyst produced from municipal waste.
Chemoenzymatic Site-Specific Labeling of Influenza Glycoproteins as a Tool to Observe Virus Budding in Real Time  [PDF]
Maximilian Wei-Lin Popp equal contributor,Roos A. Karssemeijer equal contributor,Hidde L. Ploegh
PLOS Pathogens , 2012, DOI: 10.1371/journal.ppat.1002604
Abstract: The influenza virus uses the hemagglutinin (HA) and neuraminidase (NA) glycoproteins to interact with and infect host cells. While biochemical and microscopic methods allow examination of the early steps in flu infection, the genesis of progeny virions has been more difficult to follow, mainly because of difficulties inherent in fluorescent labeling of flu proteins in a manner compatible with live cell imaging. We here apply sortagging as a chemoenzymatic approach to label genetically modified but infectious flu and track the flu glycoproteins during the course of infection. This method cleanly distinguishes influenza glycoproteins from host glycoproteins and so can be used to assess the behavior of HA or NA biochemically and to observe the flu glycoproteins directly by live cell imaging.
Chemoenzymatic Synthesis and Chemical Recycling of Poly(ester-urethane)s  [PDF]
Hiroto Hayashi,Yoshio Yanagishita,Shuichi Matsumura
International Journal of Molecular Sciences , 2011, DOI: 10.3390/ijms12095490
Abstract: Novel poly(ester-urethane)s were prepared by a synthetic route using a lipase that avoids the use of hazardous diisocyanate. The urethane linkage was formed by the reaction of phenyl carbonate with amino acids and amino alcohols that produced urethane-containing diacids and hydroxy acids, respectively. The urethane diacid underwent polymerization with polyethylene glycol and a,w-alkanediols and also the urethane-containing hydroxy acid monomer was polymerized by the lipase to produce high-molecular-weight poly(ester-urethane)s. The periodic introduction of ester linkages into the polyurethane chain by the lipase-catalyzed polymerization afforded chemically recyclable points. They were readily depolymerized in the presence of lipase into cyclic oligomers, which were readily repolymerized in the presence of the same enzyme. Due to the symmetrical structure of the polymers, poly(ester-urethane)s synthesized in this study showed higher T m, Young’s modulus and tensile strength values.
Synthetic Biolubricant Basestocks from Epoxidized Ricinoleic Acid: Improved Low Temperature Properties  [PDF]
Salimon, J.,Salih, N.,Yousif, E.
Kemija u Industriji , 2011,
Abstract: This paper presents a series of structural modifications of epoxidized ricinoleic acid for biolubricant to improve the cold flow behavior and oxidation stability of vegetable oils through measurement of pour point (PP) and oxidation onset temperature (OT) and signal maximum temperature (SMT) of each synthetic compound. The results showed that butyl 10,12-dihydroxy-9-behenoxystearate with bulky ester behenyl mid-chain exhibited the most favorable low-temperature performance PP=– 47 °C). On the other hand, butyl 10,12-dihydroxy-9-octyloxystearate exhibited higher oxidation stability ( OT = 221 °C) than the other synthetic esters. It was discovered that increasing chain length of the mid-chain ester had a positive influence on the low temperature properties of synthesized compounds. Improved oxidation stability is achieved when the chain length of the mid-chain ester decreases. The synthesized ester structures were confirmed by NMR and FTIR analysis.
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