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Sample records for cholesteryl ester synthesis

  1. How Well Does BODIPY-Cholesteryl Ester Mimic Unlabeled Cholesteryl Esters in High Density Lipoprotein Particles?

    DEFF Research Database (Denmark)

    Karilainen, Topi; Vuorela, Timo; Vattulainen, Ilpo

    2015-01-01

    We compare the behavior of unlabeled and BODIPY-labeled cholesteryl ester (CE) in high density lipoprotein by atomistic molecular dynamics simulations. We find through replica exchange umbrella sampling and unbiased molecular dynamics simulations that BODIPY labeling has no significant effect...... on the partitioning of CE between HDL and the water phase. However, BODIPY-CE was observed to diffuse more slowly and locate itself closer to the HDL-water interface than CE due to the BODIPY probe that is constrained to the surface region, and because the CE body in BODIPY-CE prefers to align itself away from...... the HDL surface. The implications as to the suitability of BODIPY to explore lipoprotein properties are discussed....

  2. Stimulation of cholesteryl ester synthesis in mouse peritoneal macrophages by cholesterol-rich very low density lipoproteins from the Watanabe heritable hyperlipidemic rabbit, an animal model of familial hypercholesterolemia

    International Nuclear Information System (INIS)

    Kita, T.; Yokode, M.; Watanabe, Y.; Narumiya, S.; Kawai, C.

    1986-01-01

    Cholesterol-rich very low density lipoproteins (VLDL) from the homozygous Watanabe heritable hyperlipidemic (WHHL) rabbit induced marked cholesteryl ester accumulation in mouse peritoneal macrophages. This WHHL rabbit, an animal model of human familial hypercholesterolemia, has severe hypercholesterolemia, cutaneous xanthomas, and fulminant atherosclerosis due to the deficiency of the low density lipoprotein (LDL) receptor. When incubated with mouse peritoneal macrophages, the VLDL from WHHL rabbit (WHHL-VLDL) stimulated cholesteryl [ 14 C]oleate synthesis 124-fold more than did VLDL from the normal Japanese White rabbit (control-VLDL). The enhancement in cholesteryl ester synthesis and accumulation of WHHL-VLDL was due to the presence of a high affinity binding receptor site on the macrophage cell surface that mediated the uptake and lysosomal degradation of WHHL-VLDL. Competition studies showed that the uptake and degradation of 125 I-WHHL-VLDL was inhibited by unlabeled excess WHHL-VLDL and beta-migrating VLDL (beta-VLDL), but not LDL. Furthermore, the degradation of WHHL-VLDL was not blocked by either fucoidin, polyinosinic acid, or polyguanylic acid, potent inhibitors of the acetylated (acetyl)-LDL binding site, or by acetyl-LDL. These results suggest that macrophages possess a high affinity receptor that recognizes the cholesterol-rich VLDL present in the plasma of the WHHL rabbit and that the receptor which mediates ingestion of WHHL-VLDL seems to be the same as that for beta-VLDL and leads to cholesteryl ester deposition within macrophages. Thus, the uptake of the cholesterol-rich VLDL from the WHHL rabbit by macrophages in vivo may play a significant role in the pathogenesis of atherosclerosis in the WHHL rabbit

  3. Preferential enrichment of large-sized very low density lipoprotein populations with transferred cholesteryl esters

    International Nuclear Information System (INIS)

    Eisenberg, S.

    1985-01-01

    The effect of lipid transfer proteins on the exchange and transfer of cholesteryl esters from rat plasma HDL2 to human very low (VLDL) and low density (LDL) lipoprotein populations was studied. The use of a combination of radiochemical and chemical methods allowed separate assessment of [ 3 H]cholesteryl ester exchange and of cholesteryl ester transfer. VLDL-I was the preferred acceptor for transferred cholesteryl esters, followed by VLDL-II and VLDL-III. LDL did not acquire cholesteryl esters. The contribution of exchange of [ 3 H]cholesteryl esters to total transfer was highest for LDL and decreased in reverse order along the VLDL density range. Inactivation of lecithin: cholesterol acyltransferase (LCAT) and heating the HDL2 for 60 min at 56 degrees C accelerated transfer and exchange of [ 3 H]cholesteryl esters. Addition of lipid transfer proteins increased cholesterol esterification in all systems. The data demonstrate that large-sized, triglyceride-rich VLDL particles are preferred acceptors for transferred cholesteryl esters. It is suggested that enrichment of very low density lipoproteins with cholesteryl esters reflects the triglyceride content of the particles

  4. Investigations on the transport and metabolism of high density lipoprotein cholesteryl esters in African green monkeys

    International Nuclear Information System (INIS)

    Sorci-Thomas, M.G.

    1984-01-01

    The metabolic fate of circulating high density lipoprotein cholesteryl esters was studied in African green monkeys to determine the significance of the lipid transfer reaction on the catabolism of lipoprotein cholesteryl esters. A method of doubly labeling both moieties of lipoprotein cholesteryl esters with [ 3 He]cholesteryl oleate and cholesteryl [ 14 C]oleate was developed for the purpose of studying plasma cholesteryl ester metabolism in vivo. In these studies the total plasma [ 3 He]cholesterol turnover resulted in production rates, which ranged from 10-17 mg/kg day, similar to previously reported values in African green monkeys and in normal lipoproteinemic humans. In contrast to the production rates calculated from the decay of plasma 3 He-radioactivity, the production rates calculated from lipoproteins labeled with cholesteryl [ 14 C]oleate were approximately 2-3 times greater. In addition to these studies, a plasma cholesteryl ester transacylation activity was demonstrated in vitro when HDL containing doubly labeled cholesteryl esters were incubated with fresh plasma. These results demonstrated that high density lipoprotein cholesteryl esters undergo transacylation in vitro, resulting in release and reesterification of free [ 3 H]cholesterol

  5. Radioiodinated cholesteryl ester analogs as residualizing tracers of lipoproteins disposition

    International Nuclear Information System (INIS)

    DeForge, L.E.

    1989-01-01

    Due to the importance of low density lipoprotein (LDL) in lipid metabolism and atherosclerosis, efforts were made to incorporate 125 I-cholesteryl iopanoate ( 125 I-CI), a residualizing cholesteryl ester (CE) analog, into the lipid core of LDL. This preparation is potentially useful as a scintigraphically detectable tracer of LDL uptake into atheroma and tissues such as the adrenal and liver. Initial studies using a cholesterol-fed rabbit model of atherosclerosis validated the use of 125 I-CI as a tracer of CE deposition. However, scintigraphy revealed considerable nonspecific 125 I-CI uptake due to tissue cholesterol loading. An alternative animal model was the guinea pig, which responds moderately to cholesterol feeding and carries the plasma cholesterol predominantly as LDL. Dietary fat and cholesterol, coupled with chronic aortic injury caused by an indwelling catheter, resulted in lipid containing, smooth muscle cell proliferative lesions in many animals. However, further studies are necessary to fully characterize this model. In additional studies, in vitro methods for incorporating 125 I-CI into LDL were examined. These included a reconstitution procedure described by Krieger et al. and a procedure involving incubation of detergent (Tween 20)-solubilized 125 I-CI with plasma. Although both LDL preparations were taken up normally by cultured fibroblasts, the plasma clearance rate of reconstituted LDL was markedly abnormal in guinea pigs. In contrast, LDL labeled by the detergent method cleared from the plasma identically to a radioiodinated LDL control. Therefore, this latter procedure was also used to incorporate two novel radioiodinated cholesteryl ether analogs 125 I-CI cholesteryl m-iodobenzyl ether [ 125 I-CIDE] and 125 I-cholesteryl 12-(miodophenyl)dodecyl ether [ 125 I-CIDE] into LDL

  6. Increased large VLDL particles confer elevated cholesteryl ester transfer in diabetes

    NARCIS (Netherlands)

    Dullaart, Robin P. F.; de Vries, Rindert; Kwakernaak, Arjan J.; Perton, Frank; Dallinga-Thie, Geesje M.

    BackgroundPlasma cholesteryl ester transfer (CET), reflecting transfer of cholesteryl esters from high density lipoproteins (HDL) towards apolipoprotein B-containing lipoproteins, may promote atherosclerosis development, and is elevated in Type 2 diabetes mellitus (T2DM). We determined the extent to

  7. Metabolism of cholesteryl esters of rat very low density lipoproteins.

    Science.gov (United States)

    Faergeman, O; Havel, R J

    1975-06-01

    Rat very low density lipoproteins (d smaller than 1.006), biologically labeled in esterified and free cholesterol, were obtained form serum 6 h after intravenous injection of particulate (3-H) cholesterol. When injected into recipient animals, the esterified cholesterol was cleared form plasma with a half-life of 5 min. After 15 min, 71% of the injected esterified (3-H) cholesterol had been taken up by the liver, where it was rapidly hydrolyzed. After 60 min only 3.3% of the amount injected had been transferred, via lipoproteins of intermediate density, to the low density lipoproteins of plasma (d 1.019-1.063). Both uptake in the liver and transfer to low density lipoproteins occurred without change of distribution of 3-H in the various cholesteryl esters. 3-H appearing in esterified cholesterol of high density lipoproteins (d greater than 1.063) was derived from esterification, presumably by lecithin: cholesterol acyltransferase, of simultaneously injected free (3-H) cholesterol. Content of free (3-H) cholesterol in the very low density lipoproteins used for injection could be reduced substantially by incubation with erythrocytes. This procedure, however, increased the rate of clearance of the lipoproteins after injection into recipient rats. These studies show that hepatic removal is the major catabolic pathway for cholesteryl esters of rat very low density lipoproteins and that transfer to low density lipoproteins occurs to only a minor extent.

  8. An alternative procedure for incorporating radiolabelled cholesteryl ester into human plasma lipoproteins in vitro

    International Nuclear Information System (INIS)

    Roberts, D.C.K.; Miller, N.E.; Price, S.G.L.; Crook, D.; Cortese, C.; Ville, A. La; Masana, L.; Lewis, B.

    1985-01-01

    A simple method has been developed for labelling human plasma lipoproteins to high specific radioactivity with radioactive cholesteryl esters in vitro. After isolation by preparative ultracentrifugation, the selected lipoprotein was incubated for 30 min at 4 0 C in human serum (d > 1.215) that had been prelabelled with [4- 14 C]cholesteryl oleate or [1,2- 3 H]cholesteryl linoleate, and was then re-isolated by ultracentrifugation. All major lipoprotein classes were labelled by the procedure. Specific radioactivities of up to 18 d.p.m. .pmol -1 (46d.p.m. .ng -1 ) were achieved. When radiolabelled high-density lipoprotein was infused intravenously, the radioactive cholesteryl ester behaved in vivo indistinguishably from endogenous cholesteryl esters produced by the lecithin (phosphatidylcholine): cholesterol acyltransferase reaction. (author)

  9. Decreased plasma cholesterol esterification and cholesteryl ester transfer in hypopituitary patients on glucocorticoid replacement therapy

    NARCIS (Netherlands)

    Beentjes, JAM; Van Tol, A; Sluiter, WJ; Dullaart, RPF

    Cardiovascular risk is increased in hypopituitary patients. No data are available with respect to the effect of glucocorticoid replacement therapy on high density lipoproteins (HDL) metabolism in such patients. Plasma lecithin:choresterol acyl transferase (LCAT), cholesteryl ester transfer protein

  10. [3H]cholesteryl ester labeling and transfer among human and honhuman primate plasma lipoproteins

    International Nuclear Information System (INIS)

    Thomas, M.S.; Rudel, L.L.

    1983-01-01

    Aliquots of human and nonhuman primate plasma containing 5,5'-dithiobis (2-nitrobenzoic acid) were incubated at 37 0 C in tubes previously coated with trace amounts of tritium-labeled cholesteryl oleate ([ 3 H]CO). Initially, cholesteryl esters were transferred at a rapid rate into plasma after which the rate slowed. During 24 h of incubation, an average of 55% of the [ 3 H]CO transferred from the side of the tube into African green monkey plasma, 44% into human plasma and 21% into rat plasma. Greater than 98% of the radioactive ester transferred into plasma was found to be associated with plasma lipoproteins that were then rapidly separated using vertical rotor density gradient ultracentrifugation. In very low density lipoprotein (VLDL)-poor plasma after 30 min incubations, high density lipoproteins (HDL) contained most of the [ 3 H]CO while 5- to 24-h incubations resulted in increased labeling of low density proteins (LDL). In VLDL-rich plasma, it was found that in addition to the labeling of HDL, VLDL contained about 25% of the labeled cholesteryl esters after 30-min incubations and, as above, the proportion in LDL subsequently increased. Compositional analyses showed that intermediate-sized LDL (ILDL) were accumulating cholesteryl ester mass while transfer occurred. LDL labeled using this method were injected intravenously into monkeys and their removal from plasma was found to be similar to that found for LDL labeled in vivo. It was concluded that this method of plasma lipoprotein cholesteryl ester labeling, presumably a result of cholesteryl ester transfer protein activity, was efficient, resulted in lipoproteins labeled only in the cholesteryl ester moiety, and induced minimal modification of lipoprotein particles that did not alter their biological activity

  11. Lecithin-cholesterol acyltransferase (LCAT) catalyzes transacylation of intact cholesteryl esters. Evidence for the partial reversal of the forward LCAT reaction

    International Nuclear Information System (INIS)

    Sorci-Thomas, M.; Babiak, J.; Rudel, L.L.

    1990-01-01

    Lecithin-cholesterol acyltransferase (LCAT) catalyzes the intravascular synthesis of lipoprotein cholesteryl esters by converting cholesterol and lecithin to cholesteryl ester and lysolecithin. LCAT is unique in that it catalyzes sequential reactions within a single polypeptide sequence. In this report we find that LCAT mediates a partial reverse reaction, the transacylation of lipoprotein cholesteryl oleate, in whole plasma and in a purified, reconstituted system. As a result of the reverse transacylation reaction, a linear accumulation of [3H]cholesterol occurred during incubations of plasma containing high density lipoprotein labeled with [3H]cholesteryl oleate. When high density lipoprotein labeled with cholesteryl [14C]oleate was also included in the incubation the labeled fatty acyl moiety remained in the cholesteryl [14C]oleate pool showing that the formation of labeled cholesterol did not result from hydrolysis of the doubly labeled cholesteryl esters. The rate of release of [3H]cholesterol was only about 10% of the forward rate of esterification of cholesterol using partially purified human LCAT and was approximately 7% in whole monkey plasma. Therefore, net production of cholesterol via the reverse LCAT reaction would not occur. [3H]Cholesterol production from [3H]cholesteryl oleate was almost completely inhibited by a final concentration of 1.4 mM 5,5'-dithiobis(nitrobenzoic acid) during incubation with either purified LCAT or whole plasma. Addition of excess lysolecithin to the incubation system did not result in the formation of [14C]oleate-labeled lecithin, showing that the reverse reaction found here for LCAT was limited to the last step of the reaction. To explain these results we hypothesize that LCAT forms a [14C]oleate enzyme thioester intermediate after its attack on the cholesteryl oleate molecule

  12. Plasma cholesteryl ester transfer protein mass and phospholipid transfer protein activity are associated with leptin in type 2 diabetes mellitus

    NARCIS (Netherlands)

    Dullaart, R. P. F.; de Vries, R.; Dallinga-Thie, G. M.; van Tol, A.; Sluiter, W. J.

    Adipose tissue contributes to plasma levels of lipid transfer proteins and is also the major source of plasma adipokines. We hypothesized that plasma cholesteryl ester transfer protein (CETP) mass, phospholipid transfer protein (PLTP) activity and cholesteryl ester transfer (CET, a measure of CETP

  13. In vitro incorporation of radiolabeled cholesteryl esters into high and low density lipoproteins

    International Nuclear Information System (INIS)

    Terpstra, A.H.; Nicolosi, R.J.; Herbert, P.N.

    1989-01-01

    We have developed and validated a method for in vitro incorporation of radiolabeled cholesteryl esters into low density (LDL) and high density lipoproteins (HDL). Radiolabeled cholesteryl esters dissolved in absolute ethanol were mixed with LDL or HDL in the presence of lipoprotein-deficient serum (LPDS) as a source of core lipid transfer activity. The efficiency of incorporation was dependent on: (a) the core lipid transfer activity and quantity of LPDS, (b) the mass of added radiolabeled cholesteryl esters, (c) the length of incubation, and (d) the amount of acceptor lipoprotein cholesterol. The tracer incorporation was documented by repeat density gradient ultracentrifugation, agarose gel electrophoresis, and precipitation with heparin-MnCl2. The radiolabeling conditions did not affect the following properties of the lipoproteins: (1) chemical composition, (2) electrophoretic mobility on agarose gels, (3) hydrated density, (4) distribution of apoproteins on SDS gels, (5) plasma clearance rates, and (6) immunoprecipitability of HDL apoproteins A-I and A-II. Rat HDL containing radiolabeled cholesteryl esters incorporated in vitro had plasma disappearance rates identical to HDL radiolabeled in vivo

  14. High plasma cholesteryl ester transfer protein levels may favour reduced incidence of cardiovascular events in men with low triglycerides

    NARCIS (Netherlands)

    Borggreve, Susanna E.; Hillege, Hans L.; Dallinga-Thie, Geesje M.; de Jong, Paul E.; Wolffenbuttel, Bruce H. R.; Grobbee, Diederik E.; van Tol, Arie; Dullaart, Robin P. F.

    2007-01-01

    High cholesteryl ester transfer protein (CETP) concentrations are associated with increased risk of cardiovascular disease (CVD) in subjects with high triglycerides. We determined the relationship of plasma CETP with incident CVD in a population with relatively low triglycerides. A nested

  15. Separating the mechanism-based and off-target actions of cholesteryl ester transfer protein inhibitors with CETP gene polymorphisms

    NARCIS (Netherlands)

    Sofat, Reecha; Hingorani, Aroon D.; Smeeth, Liam; Humphries, Steve E.; Talmud, Philippa J.; Cooper, Jackie; Shah, Tina; Sandhu, Manjinder S.; Ricketts, Sally L.; Boekholdt, S. Matthijs; Wareham, Nicholas; Khaw, Kay Tee; Kumari, Meena; Kivimaki, Mika; Marmot, Michael; Asselbergs, Folkert W.; van der Harst, Pim; Dullaart, Robin P. F.; Navis, Gerjan; van Veldhuisen, Dirk J.; van Gilst, Wiek H.; Thompson, John F.; McCaskie, Pamela; Palmer, Lyle J.; Arca, Marcello; Quagliarini, Fabiana; Gaudio, Carlo; Cambien, François; Nicaud, Viviane; Poirer, Odette; Gudnason, Vilmundur; Isaacs, Aaron; Witteman, Jacqueline C. M.; van Duijn, Cornelia M.; Pencina, Michael; Vasan, Ramachandran S.; D'Agostino, Ralph B.; Ordovas, Jose; Li, Tricia Y.; Kakko, Sakari; Kauma, Heikki; Savolainen, Markku J.; Kesäniemi, Y. Antero; Sandhofer, Anton; Paulweber, Bernhard; Sorli, Jose V.; Goto, Akimoto; Yokoyama, Shinji; Okumura, Kenji; Horne, Benjamin D.; Packard, Chris; Freeman, Dilys; Ford, Ian; Sattar, Naveed; McCormack, Valerie; Lawlor, Debbie A.; Ebrahim, Shah; Smith, George Davey; Kastelein, John J. P.; Deanfield, John; Casas, Juan P.

    2010-01-01

    BACKGROUND: Cholesteryl ester transfer protein (CETP) inhibitors raise high-density lipoprotein (HDL) cholesterol, but torcetrapib, the first-in-class inhibitor tested in a large outcome trial, caused an unexpected blood pressure elevation and increased cardiovascular events. Whether the

  16. Cholesteryl ester storage disease: a rare and possibly treatable cause of premature vascular disease and cirrhosis.

    Science.gov (United States)

    Reynolds, Tim

    2013-11-01

    Cholesteryl ester storage disease (CESD) is an autosomal recessive lysosomal storage disorder caused by a variety of mutations of the LIPA gene. These cause reduced activity of lysosomal acid lipase, which results in accumulation of cholesteryl esters in lysosomes. If enzyme activity is very low/absent, presentation is in infancy with failure to thrive, malabsorption, hepatosplenomegaly and rapid early death (Wolman disease). With higher but still low enzyme activity, presentation is later in life with hepatic fibrosis, dyslipidaemia and early atherosclerosis.Identification of this rare disorder is difficult as it is essential to assay leucocyte acid phosphatase activity. An assay using specific inhibitors has now been developed that facilitates measurement in dried blood spots. Treatment of CESD has until now been limited to management of the dyslipidaemia, but this does not influence the liver effects. A new enzyme replacement therapy (Sebelipase) has now been developed that could change treatment options for the future.

  17. How anacetrapib inhibits the activity of the cholesteryl ester transfer protein? Perspective through atomistic simulations

    DEFF Research Database (Denmark)

    Aijanen, T.; Koivuniemi, A.; Javanainen, M.

    2014-01-01

    Cholesteryl ester transfer protein (CETP) mediates the reciprocal transfer of neutral lipids (cholesteryl esters, triglycerides) and phospholipids between different lipoprotein fractions in human blood plasma. A novel molecular agent known as anacetrapib has been shown to inhibit CETP activity...... and thereby raise high density lipoprotein (HDL)-cholesterol and decrease low density lipoprotein (LDL)-cholesterol, thus rendering CETP inhibition an attractive target to prevent and treat the development of various cardiovascular diseases. Our objective in this work is to use atomistic molecular dynamics...... simulations to shed light on the inhibitory mechanism of anacetrapib and unlock the interactions between the drug and CETP. The results show an evident affinity of anacetrapib towards the concave surface of CETP, and especially towards the region of the N-terminal tunnel opening. The primary binding site...

  18. Quinoline-3-carboxamide Derivatives as Potential Cholesteryl Ester Transfer Protein Inhibitors

    Directory of Open Access Journals (Sweden)

    Jing-Kang Shen

    2012-05-01

    Full Text Available A series of novel quinoline-3-carboxamide derivatives 1017 and 2327 were designed and synthesized as cholesteryl ester transfer protein (CETP inhibitors. All of them exhibited activity against CETP. Particularly, compounds 24 and 26 displayed the best activity against CETP with the same inhibitory rate of 80.1%.

  19. Bolstering cholesteryl ester hydrolysis in liver: A hepatocyte-targeting gene delivery strategy for potential alleviation of atherosclerosis.

    Science.gov (United States)

    He, Hongliang; Lancina, Michael G; Wang, Jing; Korzun, William J; Yang, Hu; Ghosh, Shobha

    2017-06-01

    Current atherosclerosis treatment strategies primarily focus on limiting further cholesteryl esters (CE) accumulation by reducing endogenous synthesis of cholesterol in the liver. No therapy is currently available to enhance the removal of CE, a crucial step to reduce the burden of the existing disease. Given the central role of hepatic cholesteryl ester hydrolase (CEH) in the intrahepatic hydrolysis of CE and subsequent removal of the resulting free cholesterol (FC), in this work, we applied galactose-functionalized polyamidoamine (PAMAM) dendrimer generation 5 (Gal-G5) for hepatocyte-specific delivery of CEH expression vector. The data presented herein show the increased specific uptake of Gal-G5/CEH expression vector complexes (simply Gal-G5/CEH) by hepatocytes in vitro and in vivo. Furthermore, the upregulated CEH expression in the hepatocytes significantly enhanced the intracellular hydrolysis of high density lipoprotein-associated CE (HDL-CE) and subsequent conversion/secretion of hydrolyzed FC as bile acids (BA). The increased CEH expression in the liver significantly increased the flux of HDL-CE to biliary as well as fecal FC and BA. Meanwhile, Gal-G5 did not induce hepatic or renal toxicity. It was also not immunotoxic. Because of these encouraging pre-clinical testing results, using this safe and highly efficient hepatocyte-specific gene delivery platform to enhance the hepatic processes involved in cholesterol elimination is a promising strategy for the alleviation of atherosclerosis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. How anacetrapib inhibits the activity of the cholesteryl ester transfer protein? Perspective through atomistic simulations.

    Directory of Open Access Journals (Sweden)

    Tarja Äijänen

    2014-11-01

    Full Text Available Cholesteryl ester transfer protein (CETP mediates the reciprocal transfer of neutral lipids (cholesteryl esters, triglycerides and phospholipids between different lipoprotein fractions in human blood plasma. A novel molecular agent known as anacetrapib has been shown to inhibit CETP activity and thereby raise high density lipoprotein (HDL-cholesterol and decrease low density lipoprotein (LDL-cholesterol, thus rendering CETP inhibition an attractive target to prevent and treat the development of various cardiovascular diseases. Our objective in this work is to use atomistic molecular dynamics simulations to shed light on the inhibitory mechanism of anacetrapib and unlock the interactions between the drug and CETP. The results show an evident affinity of anacetrapib towards the concave surface of CETP, and especially towards the region of the N-terminal tunnel opening. The primary binding site of anacetrapib turns out to reside in the tunnel inside CETP, near the residues surrounding the N-terminal opening. Free energy calculations show that when anacetrapib resides in this area, it hinders the ability of cholesteryl ester to diffuse out from CETP. The simulations further bring out the ability of anacetrapib to regulate the structure-function relationships of phospholipids and helix X, the latter representing the structural region of CETP important to the process of neutral lipid exchange with lipoproteins. Altogether, the simulations propose CETP inhibition to be realized when anacetrapib is transferred into the lipid binding pocket. The novel insight gained in this study has potential use in the development of new molecular agents capable of preventing the progression of cardiovascular diseases.

  1. Cholesteryl ester transfer activity in plasma measured by using solid-phase-bound high-density lipoprotein

    International Nuclear Information System (INIS)

    Sparks, D.L.; Frohlich, J.; Cullis, P.; Pritchard, P.H.

    1987-01-01

    We studied the ability of lipid-transfer factors in plasma to promote transfer, to endogenous lipoproteins, of [ 3 H]cholesteryl ester from high-density lipoprotein (HDL) covalently bound to Sepharose 4B beads. After incubation for 2 h at 37 degrees C, 12 to 14% of the [ 3 H]cholesteryl ester had been transferred to the lipoproteins of the plasma, in the proportions 57% to HDL and 43% to low- and very-low-density lipoproteins. This process was a function of the amount of plasma present and was stimulated by addition of partly purified lipid-transfer protein. Transfer also depended on the concentration of donor HDL but was independent of the amount of acceptor lipoprotein. This simple evaluation of cholesteryl ester transfer does not require removal of lipoproteins from the plasma before incubation

  2. Plasma cholesteryl ester transfer is a determinant of intima-media thickness in type 2 diabetic and nondiabetic subjects: role of CETP and triglycerides

    NARCIS (Netherlands)

    de Vries, Rindert; Perton, Frank G.; Dallinga-Thie, Geesje M.; van Roon, Arie M.; Wolffenbuttel, Bruce H. R.; van Tol, Arie; Dullaart, Robin P. F.

    2005-01-01

    We tested whether carotid artery intima-media thickness (IMT) is associated with plasma cholesteryl ester transfer (CET) and/or the plasma cholesteryl ester transfer protein (CETP) concentration in type 2 diabetic and control subjects. In 87 male and female subjects with type 2 diabetes (nonsmokers,

  3. Plasma cholesteryl ester transfer is a determinant of intima-media thickness in type 2 diabetic and nondiabetic subjects : Role of CETP and triglycerides

    NARCIS (Netherlands)

    de Vries, R; Perton, FG; Dallinga-Thie, GM; van Roon, AM; Wolffenbuttel, BHR; van Tol, A; Dullaart, RPF

    2005-01-01

    We tested whether carotid artery intima-media thickness (IMT) is associated with plasma cholesteryl ester transfer (CET) and/or the plasma cholesteryl ester transfer protein (CETP) concentration in type 2 diabetic and control subjects. In 87 male and female subjects with type 2 diabetes (nonsmokers,

  4. In vivo transfer of cholesteryl ester from high and low density plasma lipoproteins into human aortic tissue

    International Nuclear Information System (INIS)

    Stender, S.; Hjelms, E.

    1988-01-01

    For the study of cholesteryl ester transfer from different plasma lipoproteins into human aortic tissue, patients scheduled for reconstructive aortic surgery were intravenously injected with autologous in vitro labeled lipoproteins 20 to 24 hours before aortic intima-media samples were obtained during the operation. The injectate contained high density lipoproteins (d greater than 1.063) labeled with 3H-cholesteryl ester and lipoproteins of lower density (d less than 1.063) labeled with 14C-cholesteryl ester or lipoproteins with the opposite labeling. In 16 aortic tissue samples (some with visible atherosclerosis) from 11 normocholesterolemic patients, the aortic influx of total cholesteryl ester was 1 to 50 nmol x cm-2 x day-1. Some 39% +/- 3% (mean +/- SEM) of the influx was derived from high density lipoproteins, which in plasma accounted for only 22% +/- 2% (mean +/- SEM) of the esterified cholesterol. The findings suggest that: 1) esterified cholesterol from the two lipoprotein fractions in plasma enter the aortic intima by the same mechanism, and 2) influx of cholesteryl ester from the smaller, high density lipoproteins is greater than influx from the larger, lower density lipoproteins considering their concentrations in plasma. In some patients, the cholesterol content in the intima-media tissue with no visible atherosclerosis corresponded to only a few months of continuous cholesteryl ester influx. This time is short considering the age of the patients and, therefore, indicates that removal of esterified cholesterol from the intima-media is of major importance in preventing cholesterol deposition in the arterial wall

  5. Fragment-based discovery of novel pentacyclic triterpenoid derivatives as cholesteryl ester transfer protein inhibitors.

    Science.gov (United States)

    Chang, Yongzhi; Zhou, Shuxi; Li, Enqin; Zhao, Wenfeng; Ji, Yanpeng; Wen, Xiaoan; Sun, Hongbin; Yuan, Haoliang

    2017-01-27

    Cholesteryl Ester Transfer Protein (CETP) is an important therapeutic target for the treatment of atherosclerotic cardiovascular disease. Our molecular modeling study revealed that pentacyclic triterpenoid compounds could mimic the protein-ligand interactions of the endogenous ligand cholesteryl ester (CE) by occupying its binding site. Alignment of the docking conformations of oleanolic acid (OA), ursolic acid (UA) and the crystal conformations of known CETP inhibitor Torcetrapib in the active site proposed the applicability of fragment-based drug design (FBDD) approaches in this study. Accordingly, a series of pentacyclic triterpenoid derivatives have been designed and synthesized as novel CETP inhibitors. The most potent compound 12e (IC 50 :0.28 μM) validated our strategy for molecular design. Molecular dynamics simulations illustrated that the more stable hydrogen bond interaction of the UA derivative 12e with Ser191 and stronger hydrophobic interactions with Val198, Phe463 than those of OA derivative 12b mainly led to their significantly different CETP inhibitory activity. These novel potent CETP inhibitors based on ursane-type scaffold should deserve further investigation. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  6. Wolman's disease and cholesteryl ester storage disorder: the phenotypic spectrum of lysosomal acid lipase deficiency.

    Science.gov (United States)

    Pericleous, Marinos; Kelly, Claire; Wang, Tim; Livingstone, Callum; Ala, Aftab

    2017-09-01

    Lysosomal acid lipase deficiency is a rare, autosomal recessive condition caused by mutations in the gene encoding lysosomal acid lipase (LIPA) that result in reduced or absent activity of this essential enzyme. The severity of the resulting disease depends on the nature of the underlying mutation and magnitude of its effect on enzymatic function. Wolman's disease is a severe disorder that presents during infancy, resulting in failure to thrive, hepatomegaly, and hepatic failure, and an average life expectancy of less than 4 months. Cholesteryl ester storage disorder arises later in life and is less severe, although the two diseases share many common features, including dyslipidaemia and transaminitis. The prevalence of these diseases has been estimated at one in 40 000 to 300 000, but many cases are undiagnosed and unreported, and awareness among clinicians is low. Lysosomal acid lipase deficiency-which can be diagnosed using dry blood spot testing-is often misdiagnosed as non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), hereditary dyslipidaemia, or cryptogenic cirrhosis. There are no formal guidelines for treatment of these patients, and treatment options are limited. In this Review we appraise the existing literature on Wolman's disease and cholesteryl ester storage disease, and discuss available treatments, including enzyme replacement therapy, oral lipid-lowering therapy, stem-cell transplantation, and liver transplantation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Tolerability, pharmacokinetics and pharmacodynamics of TA-8995, a selective cholesteryl ester transfer protein (CETP) inhibitor, in healthy subjects

    NARCIS (Netherlands)

    Ford, John; Lawson, Matt; Fowler, David; Maruyama, Nobuko; Mito, Seiji; Tomiyasu, Koichi; Kinoshita, Shuji; Suzuki, Chisa; Kawaguchi, Atsuhiro; Round, Patrick; Boyce, Malcolm; Warrington, Steve; Weber, Werner; van Deventer, Sander; Kastelein, John J. P.

    2014-01-01

    Two double-blind, randomized studies were conducted to assess the tolerability, pharmacokinetics and pharmacodynamics of oral TA-8995, a new cholesteryl ester transfer protein (CETP) inhibitor, in healthy subjects. Study 1: Subjects received single doses of TA-8995 or placebo (fasted). Doses were 5,

  8. High plasma cholesteryl ester transfer protein levels may favour reduced incidence of cardiovascular events in men with low triglycerides

    NARCIS (Netherlands)

    Borggreve, Susanna E.; Hillege, Hans L.; Dallinga-Thie, Geesje M.; de Jong, Paul E.; Wolffenbuttel, Bruce H. R.; Grobbee, Diederik E.; van Tol, Arie; Dullaart, Robin P. F.

    Aims High cholesteryl ester transfer protein (CETP) concentrations are associated with increased risk of cardiovascular disease (CVD) in subjects with high triglycerides. We determined the relationship of plasma CETP with incident CVD in a population with relatively low triglycerides. Methods and

  9. Cholesteryl ester transfer protein decreases high-density lipoprotein and severely aggravates atherosclerosis in APOE*3-Leiden mice

    NARCIS (Netherlands)

    Westerterp, M.; Hoogt, C.C. van der; Haan, W. de; Offerman, E.H.; Dallinga-Thie, G.M.; Jukema, J.W.; Havekes, L.M.; Rensen, P.C.N.

    2006-01-01

    OBJECTIVE - The role of cholesteryl ester transfer protein (CETP) in the development of atherosclerosis is still undergoing debate. Therefore, we evaluated the effect of human CETP expression on atherosclerosis in APOE*3-Leiden (E3L) mice with a humanized lipoprotein profile. METHODS AND RESULTS -

  10. ELEVATED CHOLESTERYL ESTER TRANSFER PROTEIN-ACTIVITY IN IDDM MEN WHO SMOKE - POSSIBLE FACTOR FOR UNFAVORABLE LIPOPROTEIN PROFILE

    NARCIS (Netherlands)

    DULLAART, RPF; GROENER, JEM; DIKKESCHEI, BD; ERKELENS, DW; DOORENBOS, H

    Objectives: To determine the effect of cigarette smoking on the activity of cholesteryl ester transfer protein (CETP) and high-density (HDL), low-density (LDL), and very-low-density (VLDL) lipoproteins in insulin-dependent diabetic (IDDM) men with microvascular complications. Research Design and

  11. Separating the Mechanism-Based and Off-Target Actions of Cholesteryl Ester Transfer Protein Inhibitors With CETP Gene Polymorphisms

    NARCIS (Netherlands)

    Sofat, Reecha; Hingorani, Aroon D.; Smeeth, Liam; Humphries, Steve E.; Talmud, Philippa J.; Cooper, Jackie; Shah, Tina; Sandhu, Manjinder S.; Ricketts, Sally L.; Boekholdt, S. Matthijs; Wareham, Nicholas; Khaw, Kay Tee; Kumari, Meena; Kivimaki, Mika; Marmot, Michael; Asselbergs, Folkert W.; van der Harst, Pim; Dullaart, Robin P. F.; Navis, Gerjan; van Veldhuisen, Dirk J.; Van Gilst, Wiek H.; Thompson, John F.; McCaskie, Pamela; Palmer, Lyle J.; Arca, Marcello; Quagliarini, Fabiana; Gaudio, Carlo; Cambien, Francois; Nicaud, Viviane; Poirer, Odette; Gudnason, Vilmundur; Isaacs, Aaron; Witteman, Jacqueline C. M.; van Duijn, Cornelia M.; Pencina, Michael; Vasan, Ramachandran S.; D'Agostino, Ralph B.; Ordovas, Jose; Li, Tricia Y.; Kakko, Sakari; Kauma, Heikki; Savolainen, Markku J.; Kesaniemi, Y. Antero; Sandhofer, Anton; Paulweber, Bernhard; Sorli, Jose V.; Goto, Akimoto; Yokoyama, Shinji; Okumura, Kenji; Horne, Benjamin D.; Packard, Chris; Freeman, Dilys; Ford, Ian; Sattar, Naveed; McCormack, Valerie; Lawlor, Debbie A.; Ebrahim, Shah; Smith, George Davey; Kastelein, John J. P.; Deanfield, John; Casas, Juan P.

    2010-01-01

    Background-Cholesteryl ester transfer protein (CETP) inhibitors raise high-density lipoprotein (HDL) cholesterol, but torcetrapib, the first-in-class inhibitor tested in a large outcome trial, caused an unexpected blood pressure elevation and increased cardiovascular events. Whether the hypertensive

  12. Studies on a microbially derived, high molecular weight inhibitor of plasma cholesteryl ester transfer protein

    International Nuclear Information System (INIS)

    Marschke, C.K.; McGee, J.E.; Melchior, G.W.; Castle, C.K.

    1989-01-01

    The authors have isolated an organism which accumulates an inhibitor of Cholesteryl Ester Transfer Protein (CETP). Purification of 100,000-fold was achieved by ammonium sulfate precipitation followed by Hydroxyl Apatite, Agarose AO.5, and Mono Q (Pharmacia) chromatographies. The use of 14 C-labelled protein molecular weight standards followed by SDS-PAGE revealed some proteolytic activity. However, inhibition of the proteases did not affect the inhibitor potency. The inhibitor has an estimated molecular weight of 40 Kd and appears to exist as two forms. One form was eluted from a Mono Q column by 100 mM NaCl while the other was not bound. Our evidence indicated that the bound form was progressively denatured, or proteolyzed, during storage of the fermentation beer, to the unbound form. Importantly though this molecular change did not affect either inhibitory activity or the apparent molecular weight

  13. Cholesteryl ester hydroperoxides increase macrophage CD36 gene expression via PPARα

    International Nuclear Information System (INIS)

    Jedidi, Iness; Couturier, Martine; Therond, Patrice; Gardes-Albert, Monique; Legrand, Alain; Barouki, Robert; Bonnefont-Rousselot, Dominique; Aggerbeck, Martine

    2006-01-01

    The uptake of oxidized LDL by macrophages is a key event in the development of atherosclerosis. The scavenger receptor CD36 is one major receptor that internalizes oxidized LDL. In differentiated human macrophages, we compared the regulation of CD36 expression by copper-oxidized LDL or their products. Only oxidized derivatives of cholesteryl ester (CEOOH) increased the amount of CD36 mRNA (2.5-fold). Both oxidized LDL and CEOOH treatment increased two to fourfold the transcription of promoters containing peroxisome-proliferator-activated-receptor responsive elements (PPRE) in the presence of PPARα or γ. Electrophoretic-mobility-shift-assays with nuclear extracts prepared from macrophages treated by either oxidized LDL or CEOOH showed increased binding of PPARα to the CD36 gene promoter PPRE. In conclusion, CEOOH present in oxidized LDL increase CD36 gene expression in a pathway involving PPARα

  14. Cholesteryl ester transfer protein alters liver and plasma triglyceride metabolism through two liver networks in female mice[S

    Science.gov (United States)

    Palmisano, Brian T.; Le, Thao D.; Zhu, Lin; Lee, Yoon Kwang; Stafford, John M.

    2016-01-01

    Elevated plasma TGs increase risk of cardiovascular disease in women. Estrogen treatment raises plasma TGs in women, but molecular mechanisms remain poorly understood. Here we explore the role of cholesteryl ester transfer protein (CETP) in the regulation of TG metabolism in female mice, which naturally lack CETP. In transgenic CETP females, acute estrogen treatment raised plasma TGs 50%, increased TG production, and increased expression of genes involved in VLDL synthesis, but not in nontransgenic littermate females. In CETP females, estrogen enhanced expression of small heterodimer partner (SHP), a nuclear receptor regulating VLDL production. Deletion of liver SHP prevented increases in TG production and expression of genes involved in VLDL synthesis in CETP mice with estrogen treatment. We also examined whether CETP expression had effects on TG metabolism independent of estrogen treatment. CETP increased liver β-oxidation and reduced liver TG content by 60%. Liver estrogen receptor α (ERα) was required for CETP expression to enhance β-oxidation and reduce liver TG content. Thus, CETP alters at least two networks governing TG metabolism, one involving SHP to increase VLDL-TG production in response to estrogen, and another involving ERα to enhance β-oxidation and lower liver TG content. These findings demonstrate a novel role for CETP in estrogen-mediated increases in TG production and a broader role for CETP in TG metabolism. PMID:27354419

  15. Cholesteryl ester transfer protein alters liver and plasma triglyceride metabolism through two liver networks in female mice.

    Science.gov (United States)

    Palmisano, Brian T; Le, Thao D; Zhu, Lin; Lee, Yoon Kwang; Stafford, John M

    2016-08-01

    Elevated plasma TGs increase risk of cardiovascular disease in women. Estrogen treatment raises plasma TGs in women, but molecular mechanisms remain poorly understood. Here we explore the role of cholesteryl ester transfer protein (CETP) in the regulation of TG metabolism in female mice, which naturally lack CETP. In transgenic CETP females, acute estrogen treatment raised plasma TGs 50%, increased TG production, and increased expression of genes involved in VLDL synthesis, but not in nontransgenic littermate females. In CETP females, estrogen enhanced expression of small heterodimer partner (SHP), a nuclear receptor regulating VLDL production. Deletion of liver SHP prevented increases in TG production and expression of genes involved in VLDL synthesis in CETP mice with estrogen treatment. We also examined whether CETP expression had effects on TG metabolism independent of estrogen treatment. CETP increased liver β-oxidation and reduced liver TG content by 60%. Liver estrogen receptor α (ERα) was required for CETP expression to enhance β-oxidation and reduce liver TG content. Thus, CETP alters at least two networks governing TG metabolism, one involving SHP to increase VLDL-TG production in response to estrogen, and another involving ERα to enhance β-oxidation and lower liver TG content. These findings demonstrate a novel role for CETP in estrogen-mediated increases in TG production and a broader role for CETP in TG metabolism. Copyright © 2016 by the American Society for Biochemistry and Molecular Biology, Inc.

  16. Influence of insulin sensitivity and the TaqIB cholesteryl ester transfer protein gene polymorphism on plasma lecithin:cholesterol acyltransferase and lipid transfer protein activities and their response to hyperinsulinemia in non-diabetic men

    NARCIS (Netherlands)

    S.C. Riemens; A. van Tol (Arie); B.K. Stulp; R.P.F. Dullaart (Robin)

    1999-01-01

    textabstractLecithin:cholesteryl acyl transferase (LCAT), cholesteryl ester transfer protein (CETP), phospholipid transfer protein (PLTP), and lipoprotein lipases are involved in high density lipoprotein (HDL) metabolism. We evaluated the influence of insulin

  17. Phagocytosis of cholesteryl ester is amplified in diabetic mouse macrophages and is largely mediated by CD36 and SR-A.

    Directory of Open Access Journals (Sweden)

    Christopher B Guest

    Full Text Available Type 2 diabetes (T2D is associated with accelerated atherosclerosis, which accounts for approximately 75% of all diabetes-related deaths. Here we investigate the link between diabetes and macrophage cholesteryl ester accumulation. When diabetic (db/db mice are given cholesteryl ester intraperitoneally (IP, peritoneal macrophages (PerMPhis recovered from these animals showed a 58% increase in intracellular cholesteryl ester accumulation over PerMPhis from heterozygote control (db/+ mice. Notably, PerMPhi fluid-phase endocytosis and large particle phagocytosis was equivalent in db/+and db/db mice. However, IP administration of CD36 and SR-A blocking antibodies led to 37% and 25% reductions in cholesteryl ester accumulation in PerMPhi. Finally, in order to determine if these scavenger receptors (SRs were part of the mechanism responsible for the increased accumulation of cholesteryl esters observed in the diabetic mouse macrophages, receptor expression was quantified by flow cytometry. Importantly, db/db PerMPhis showed a 43% increase in CD36 expression and an 80% increase in SR-A expression. Taken together, these data indicate that direct cholesteryl ester accumulation in mouse macrophages is mediated by CD36 and SR-A, and the magnitude of accumulation is increased in db/db macrophages due to increased scavenger receptor expression.

  18. Lipid Exchange Mechanism of the Cholesteryl Ester Transfer Protein Clarified by Atomistic and Coarse-grained Simulations

    DEFF Research Database (Denmark)

    Koivuniemi, A.; Vuorela, T.; Kovanen, P. T.

    2012-01-01

    molecular dynamics simulations to unravel the mechanisms associated with the CETP-mediated lipid exchange. To this end we used both atomistic and coarse-grained models whose results were consistent with each other. We found CETP to bind to the surface of high density lipoprotein (HDL) -like lipid droplets......Cholesteryl ester transfer protein (CETP) transports cholesteryl esters, triglycerides, and phospholipids between different lipoprotein fractions in blood plasma. The inhibition of CETP has been shown to be a sound strategy to prevent and treat the development of coronary heart disease. We employed...... evidence that helix X acts as a lid which conducts lipid exchange by alternating the open and closed states. The findings have potential for the design of novel molecular agents to inhibit the activity of CETP....

  19. Erabulenols, inhibitors of cholesteryl ester transfer protein produced by Penicillium sp. FO-5637. I.Production, isolation and biological properties.

    Science.gov (United States)

    Tomoda, H; Tabata, N; Masuma, R; Si, S Y; Omura, S

    1998-07-01

    Penicillium sp. FO-5637, a soil isolate, was found to produce a series of inhibitors of cholesteryl ester transfer protein (CETP). Novel active compounds, designated erabulenols A and B, were isolated from the fermentation broth of the producing strain by solvent extraction, ODS column chromatography and HPLC. Erabulenols A and B inhibit human CETP activity with IC50 values of 47.7 and 58.2 microM in an in vitro assay system containing 200 microM BSA, respectively.

  20. Impact of unhealthy lifestyle behaviors and obesity on cholesteryl ester transfer protein among adolescent males.

    Science.gov (United States)

    Hirschler, Valeria; Meroño, Tomas; Maccallini, Gustavo; Gomez Rosso, Leonardo; Aranda, Claudio; Brites, Fernando

    2011-01-01

    Cholesteryl ester transfer protein (CETP) has been proposed to be associated with high risk of cardiovascular disease. Increased CETP activity was previously reported in obese adults, although its association with lifestyle behaviors has not been assessed in healthy adolescents. We undertook this study to determine the association between CETP activity and overweight/obesity, insulin resistance markers, components of the metabolic syndrome and lifestyle behaviors in healthy adolescent males. Data were collected from 164 adolescents from an amateur rugby club. Body mass index (BMI), blood pressure (BP), Tanner stages, lipids, glucose, insulin and CETP activity were measured. Questionnaires for daily intake of breakfast, sweet drinks, milk, and hours of TV watching were completed. About 26% of the adolescents were obese and 23% overweight. The prevalence of metabolic syndrome was 6.7%. CETP activity was higher in obese than in normal and overweight adolescents (174 ± 35, 141 ± 30, and 149 ± 38%/ml/min, respectively; p 2 h/day (r = 0.17; p 0.02), and milk intake >3 glasses/day (r = 0.16; p = 0.03). Multivariate analysis showed that triglycerides, LDL-C, HDL-C, TV watching >2 h/day, milk intake >3 glasses/day and BMI were significant independent predictors for CETP (R(2) = 0.41). Unhealthy lifestyle habits such as TV watching >2 h daily and milk intake higher than three glasses per day and the increase in BMI were shown to be closely associated with high CETP activity in apparently healthy adolescent males. Future longitudinal studies should be performed to confirm these findings. Copyright © 2011 IMSS. Published by Elsevier Inc. All rights reserved.

  1. Longitudinal Associations of Phospholipid and Cholesteryl Ester Fatty Acids With Disorders Underlying Diabetes.

    Science.gov (United States)

    Johnston, Luke W; Harris, Stewart B; Retnakaran, Ravi; Zinman, Bernard; Giacca, Adria; Liu, Zhen; Bazinet, Richard P; Hanley, Anthony J

    2016-06-01

    Specific serum fatty acid (FA) profiles predict the development of incident type 2 diabetes; however, limited longitudinal data exist exploring their role in the progression of insulin sensitivity (IS) and β-cell function. To examine the longitudinal associations of the FA composition of serum phospholipid (PL) and cholesteryl ester (CE) fractions with IS and β-cell function over 6 years. The Prospective Metabolism and Islet Cell Evaluation (PROMISE) cohort is a longitudinal observational study, with clinic visits occurring every 3 years. Three visits have been completed, totaling 6 years of follow-up. Individuals (n = 477) at risk for diabetes recruited from the general population in London and Toronto, Canada. Values from an oral glucose tolerance test were used to compute 1/HOMA-IR and the Matsuda index for IS, the insulinogenic index over HOMA-IR, and the insulin secretion-sensitivity index-2 for β-cell function. Thin-layer chromatograph and gas chromatograph quantified FA. Generalized estimating equations were used for the analysis. IS and β-cell function declined by 8.3-19.4% over 6 years. In fully adjusted generalized estimating equation models, PL cis-vaccenate (18:1n-7) was positively associated with all outcomes, whereas γ-linolenate (GLA; 18:3n-6) and stearate (18:0) were negatively associated with IS. Tests for time interactions revealed that PL eicosadienoate (20:2n-6) and palmitate (16:0) and CE dihomo-γ-linolenate (20:3n-6), GLA, and palmitate had stronger associations with the outcomes after longer follow-up. In a Canadian population at risk for diabetes, we found that higher PL stearate and GLA and lower cis-vaccenic acid predicted consistently lower IS and β-cell function over 6 years.

  2. Fluorescent Sterols and Cholesteryl Esters as Probes for Intracellular Cholesterol Transport

    Science.gov (United States)

    Solanko, Katarzyna A.; Modzel, Maciej; Solanko, Lukasz M.; Wüstner, Daniel

    2015-01-01

    Cholesterol transport between cellular organelles comprised vesicular trafficking and nonvesicular exchange; these processes are often studied by quantitative fluorescence microscopy. A major challenge for using this approach is producing analogs of cholesterol with suitable brightness and structural and chemical properties comparable with those of cholesterol. This review surveys currently used fluorescent sterols with respect to their behavior in model membranes, their photophysical properties, as well as their transport and metabolism in cells. In the first part, several intrinsically fluorescent sterols, such as dehydroergosterol or cholestatrienol, are discussed. These polyene sterols (P-sterols) contain three conjugated double bonds in the steroid ring system, giving them slight fluorescence in ultraviolet light. We discuss the properties of P-sterols relative to cholesterol, outline their chemical synthesis, and explain how to image them in living cells and organisms. In particular, we show that P-sterol esters inserted into low-density lipoprotein can be tracked in the fibroblasts of Niemann–Pick disease using high-resolution deconvolution microscopy. We also describe fluorophore-tagged cholesterol probes, such as BODIPY-, NBD-, Dansyl-, or Pyrene-tagged cholesterol, and eventual esters of these analogs. Finally, we survey the latest developments in the synthesis and use of alkyne cholesterol analogs to be labeled with fluorophores by click chemistry and discuss the potential of all approaches for future applications. PMID:27330304

  3. HDL cholesterol response to GH replacement is associated with common cholesteryl ester transfer protein gene variation (-629C>A) and modified by glucocorticoid treatment

    NARCIS (Netherlands)

    Dullaart, Robin P. F.; van den Berg, Gerrit; van der Knaap, Aafke M.; Dijck-Brouwer, Janneke; Dallinga-Thie, Geesje M.; Zelissen, Peter M. J.; Sluiter, Wim J.; van Beek, André P.

    2010-01-01

    GH replacement lowers total cholesterol and low-density lipoprotein cholesterol (LDL-C) in GH-deficient adults, but effects on high-density lipoprotein (HDL) cholesterol (HDL-C) are variable. Both GH and glucocorticoids decrease cholesteryl ester transfer protein (CETP) activity, which is important

  4. Moderate intake of myristic acid in sn-2 position has beneficial lipidic effects and enhances DHA of cholesteryl esters in an interventional study.

    Science.gov (United States)

    Dabadie, Henry; Peuchant, Evelyne; Bernard, Mireille; LeRuyet, Pascale; Mendy, François

    2005-06-01

    Among the saturated fatty acids (SFA), myristic acid is known to be one of the most atherogenic when consumed at high levels. Our purpose was to compare the effects of two moderate intakes of myristic acid on plasma lipids in an interventional study. Twenty-five male monks without dyslipidemia were given two isocaloric diets for 5 weeks each. In diet 1, 30% of the calories came from fat (8% SFA, 0.6% myristic acid) and provided 200 mg cholesterol/day. Calories of diet 2 were 34% fat (11% SFA, 1.2% myristic acid) with the same levels of oleate, linoleate, alpha-linolenate and cholesterol. A baseline diet was provided before each diet. In comparison with baseline, diets 1 and 2 induced a decrease in total cholesterol, LDL-cholesterol and triglycerides (Pdiet 2 than after diet 1 whereas HDL-cholesterol was higher (Pdiet 2 vs. baseline (Pdiet 1 (Pdiets were associated with an increase in alpha-linolenate of cholesteryl esters (Pdiet 2 was associated with an increase in DHA of cholesteryl esters (Pdiet 2, myristic acid intake was positively correlated with myristic acid of phospholipids, and alpha-linolenic acid intake was correlated with alpha-linolenic acid of cholesteryl esters. Moderate intake (1.2% of total calories) of myristic acid has beneficial lipidic effects and enhances DHA of cholesteryl esters.

  5. Acute and chronic effects of a 24-hour intravenous triglyceride emulsion challenge on plasma lecithin : cholesterol acyltransferase, phospholipid transfer protein, and cholesteryl ester transfer protein activities

    NARCIS (Netherlands)

    Riemens, SC; Van Tol, A; Sluiter, WJ; Dullaart, RPF

    Lecithin:cholesterol acyltransferase (LCAT), phospholipid transfer protein (PLTP), and cholesteryl ester transfer protein (CETP) are key factors in remodeling of high density lipoproteins (HDL) and triglyceride-rich lipoproteins. We examined the effect of a large, 24 h intravenous fat load on plasma

  6. In vivo regulation of scavenger receptor BI and the selective uptake of high density lipoprotein cholesteryl esters in rat liver parenchymal and Kupffer cells

    NARCIS (Netherlands)

    Fluiter, K.; van der Westhuijzen, D. R.; van Berkel, T. J.

    1998-01-01

    High density lipoprotein cholesteryl esters (HDL-CE) are selectively taken up by liver parenchymal cells without parallel apolipoprotein uptake. This selective uptake route forms an important step in the so-called reverse cholesterol transport. Scavenger receptor BI (SR-BI) is the only known HDL

  7. Type 2 diabetes mellitus is associated with differential effects on plasma cholesteryl ester transfer protein and phospholipid transfer protein activities and concentrations

    NARCIS (Netherlands)

    Dullaart, RPF; De Vries, R; Scheek, L; Borggreve, SE; Van Gent, T; Dallinga-Thie, GM; Ito, M; Nagano, M; Sluiter, WJ; Hattori, H; Van Tol, A

    Background: Human plasma contains two lipid transfer proteins, cholesteryl ester transfer protein (CETP) and phospholipid transfer protein (PLTP), which are crucial in reverse cholesterol transport. Methods: Plasma CETP and PLTP activity levels and concentrations in 16 type 2 diabetic patients and

  8. Plasma Cholesteryl Ester Transfer, But Not Cholesterol Esterification, Is Related to Lipoprotein-Associated Phospholipase A(2) : Possible Contribution to an Atherogenic Lipoprotein Profile

    NARCIS (Netherlands)

    Dullaart, Robin P. F.; Constantinides, Alexander; Perton, Frank G.; van Leeuwen, Jeroen J. J.; van Pelt, Joost L.; de Vries, Rindert; van Tol, Arie

    Context: Plasma lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) predicts incident cardiovascular disease and is associated preferentially with negatively charged apolipoprotein B-containing lipoproteins. The plasma cholesteryl ester transfer (CET) process, which contributes to low high-density

  9. Patient considerations and clinical impact of cholesteryl ester transfer protein inhibitors in the management of dyslipidemia: focus on anacetrapib

    Directory of Open Access Journals (Sweden)

    Miyares MA

    2012-08-01

    Full Text Available Marta A Miyares, Kyle DavisPharmacy Department, Jackson Memorial Hospital, Miami, FL, USAAbstract: Cardiovascular disease (CVD is responsible for significant morbidity and mortality within the United States and worldwide. Although targeting low-density lipoprotein cholesterol (LDL-C in the prevention of CVD has been shown to be effective, evidence exists to indicate that significant cardiovascular (CV risk remains in patients receiving 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statins – a risk that may be correlated with low levels of high-density lipoprotein cholesterol (HDL-C. Among the various tactics under investigation to increase HDL-C, inhibition of cholesteryl ester transfer protein (CETP appears the most adept to raise these levels. Although torcetrapib, a CETP inhibitor, demonstrated significant beneficial changes in HDL-C and LDL-C after 12 months of therapy when coadministered with atorvastatin, patients in the torcetrapib arm experienced a rise in mortality, including increased risk of death from CV and non-CV causes as well as a significant rise in major CV events. Later studies established that the adverse effects of torcetrapib were produced from molecule-specific off-target effects and not to the mechanism of CETP inhibition. These untoward outcomes have not been detected with anacetrapib, the third of the CETP inhibitors to enter Phase III trials. Furthermore, treatment with anacetrapib revealed both a statistically significant decrease in LDL-C and increase in HDL-C over placebo. While the place in therapy of niacin and fibrates to reduce CV events is currently in question secondary to the Atherothrombosis Intervention in Metabolic Syndrome with Low HDL Cholesterol/High Triglyceride and Impact on Global Health Outcomes and the Action to Control CV Risk in Diabetes trials, the ongoing large-scale, randomized–placebo, controlled-outcomes study with anacetrapib coadministered with statin treatment will not

  10. CoMFA, CoMSIA and Eigenvalue Analysis on Dibenzodioxepinone and Dibenzodioxocinone Derivatives as Cholesteryl Ester Transfer Protein Inhibitors

    Directory of Open Access Journals (Sweden)

    Mao-sheng Cheng

    2008-08-01

    Full Text Available Abstract: CoMFA, CoMSIA and eigenvalue analysis (EVA were performed to study the structural features of 61 diverse dibenzodioxepinone and dibenzodioxocinone analogues to probe cholesteryl ester transfer protein (CETP inhibitory activity. Three methods yielded statistically significant models upon assessment of cross-validation, bootstrapping, and progressive scrambling. This was further validated by an external set of 13 derivatives. Our results demonstrate that three models have a good interpolation as well as extrapolation. The hydrophobic features were confirmed to contribute significantly to inhibitor potencies, while a pre-oriented hydrogen bond provided by the hydroxyl group at the 3-position indicated a good correlation with previous SAR, and a hydrogen bond acceptor may play a crucial role in CETP inhibition. These derived models may help us to gain a deeper understanding of the binding interaction of these lactone-based compounds and aid in the design of new potent compounds against CETP.

  11. Basal-bolus insulin therapy reduces maternal triglycerides in gestational diabetes without modifying cholesteryl ester transfer protein activity.

    Science.gov (United States)

    Olmos, Pablo R; Borzone, Gisella R

    2017-09-01

    Macrosomia in the offspring of overweight/obese mothers with glucose-controlled gestational diabetes mellitus (GDM) is due to excessive rise of maternal triglycerides (TG). We aimed to ascertain whether basal-bolus insulin therapy (BBIT), or other components of the treatment, could reduce TG in GDM. We studied the records of 131 singleton pregnancies with GDM, using stepwise multiple linear regression, Mann-Whitney, χ 2 , and Jonckheere-Terpstra tests. As maternal TG increased steadily during normal pregnancy, these were transformed as z-scores. The atherogenic index of plasma (AIP) was calculated as a measure of cholesteryl ester transfer protein activity. Multiple regression showed that only BBIT (but neither limitation of weight gain nor metformin) reduced maternal TG z-scores (P = 0.011). When the 131 pregnancies were split into two groups - without BBIT (n = 58; HbA1c = 5.3 ± 0.3%) and with BBIT (n = 73; HbA1c = 5.4 ± 0.6; P = 0.2005) - we observed that BBIT (n = 73) reduced maternal TG z-scores in a dose-related fashion (Jonckheere-Terpstra P = 0.03817). The atherogenic index of plasma remained within normal range in both groups. BBIT (but not weight gain control nor metformin) reduced maternal TG in mothers with glucose-controlled GDM. This beneficial effect of BBIT was not related to changes in the cholesteryl ester transfer protein activity. © 2017 Japan Society of Obstetrics and Gynecology.

  12. Cholesteryl ester transfer-protein modulator and inhibitors and their potential for the treatment of cardiovascular diseases

    Directory of Open Access Journals (Sweden)

    Shinkai H

    2012-05-01

    Full Text Available Hisashi ShinkaiCentral Pharmaceutical Research Institute, JT Inc, Osaka, JapanAbstract: Elevated low-density lipoprotein (LDL cholesterol and lowered high-density lipoprotein (HDL cholesterol are important risk factors for cardiovascular disease. Accordingly, raising HDL cholesterol induced by cholesteryl ester transfer protein (CETP inhibition is an attractive approach for reducing the residual risk of cardiovascular events that persist in many patients receiving low-density LDL cholesterol-lowering therapy with statins. The development of torcetrapib, a CETP inhibitor, was terminated due to its adverse cardiovascular effects. These adverse effects did not influence the mechanism of CETP inhibition, but affected the molecule itself. Therefore a CETP modulator, dalcetrapib, and a CETP inhibitor, anacetrapib, are in Phase III of clinical trials to evaluate their effects on cardiovascular outcomes. In the dal-VESSEL (dalcetrapib Phase IIb endothelial function study and the dal-PLAQUE (safety and efficacy of dalcetrapib on atherosclerotic disease using novel non-invasive multimodality imaging clinical studies, dalcetrapib reduced CETP activity by 50% and increased HDL cholesterol levels by 31% without changing LDL cholesterol levels. Moreover, dalcetrapib was associated with a reduction in carotid vessel-wall inflammation at 6 months, as well as a reduced vessel-wall area at 24 months compared with the placebo. In the DEFINE (determining the efficacy and tolerability of CETP inhibition with anacetrapib clinical study, anacetrapib increased HDL cholesterol levels by 138% and decreased LDL cholesterol levels by 36%. In contrast with torcetrapib, anacetrapib had no adverse cardiovascular effects. The potential of dalcetrapib and anacetrapib in the treatment of cardiovascular diseases will be revealed by two large-scale clinical trials, the dal-OUTCOMES (efficacy and safety of dalcetrapib in patients with recent acute coronary syndrome study and the

  13. Overexpression of Cholesteryl Ester Transfer Protein Increases Macrophage-Derived Foam Cell Accumulation in Atherosclerotic Lesions of Transgenic Rabbits

    Directory of Open Access Journals (Sweden)

    Shoucui Gao

    2017-01-01

    Full Text Available High levels of plasma high-density lipoprotein-cholesterol (HDL-C are inversely associated with the risk of atherosclerosis and other cardiovascular diseases; thus, pharmacological inhibition of cholesteryl ester transfer protein (CETP is considered to be a therapeutic method of raising HDL-C levels. However, many CETP inhibitors have failed to achieve a clinical benefit despite raising HDL-C. In the study, we generated transgenic (Tg rabbits that overexpressed the human CETP gene to examine the influence of CETP on the development of atherosclerosis. Both Tg rabbits and their non-Tg littermates were fed a high cholesterol diet for 16 weeks. Plasma lipids and body weight were measured every 4 weeks. Gross lesion areas of the aortic atherosclerosis along with lesional cellular components were quantitatively analyzed. Overexpression of human CETP did not significantly alter the gross atherosclerotic lesion area, but the number of macrophages in lesions was significantly increased. Overexpression of human CETP did not change the plasma levels of total cholesterol or low-density lipoprotein cholesterol but lowered plasma HDL-C and increased triglycerides. These data revealed that human CETP may play an important role in the development of atherosclerosis mainly by decreasing HDL-C levels and increasing the accumulation of macrophage-derived foam cells.

  14. Levels of cholesteryl esters and other lipids in the plasma of patientswith end-stage renal failure

    International Nuclear Information System (INIS)

    Gillett, Michael P.T.; Obineche, Enyioma N.; Lakhani, Mohammad S.; Abdulle, Abdishakur M.; Amirlak, I.; Al-Rukhaimi, M.; Suleiman, Mustafa N.

    2001-01-01

    The importance of plasma lipid abnormalities in chronic renal failure(CRF) is well recognized, but surprisingly little attention has been given tothe study of some plasma lipid fractions, including cholesteryl esters (CE)and phospholipids, which might be expected to be important factors in thepathogenesis of disease. Fasting blood samples were taken from 25 controlsubjects and 53 CRF patients (29 predialysis and 24 on Hemodialysis). Sampleswere analyzed for urea nitrogen, creatinine, triacyglycerols, total andindividuals phospholipids, total and free cholesterol, as well as cholesterolbound to be very low-, and high- density lipoproteins (VDL, LDL and HDL).Plasma CE was calculated and expressed as a percentage of total cholesterol.Over half of the patients had CE levels more than two standard deviationsbelow the control value. In this subgroup of low CE patients, total LDL- andHDL-cholesterol levels were also significantly lower than for controls, whilelevels of phosphatidylcholine and lysophosphatidylcholine were decreased andincreased, respectively. In patients with high CE, no significant lipidabnormalities were observed. In this study, CE was an excellent marker forlipid disturbances-if CE was high, then the other lipid fractions wereabnormal. The changes noted appear to be consequences of or related todeficiency of the plasma enzyme lecithin-cholesterol acyltransferase. (author)

  15. The role of common variants of the cholesteryl ester transfer protein gene in left main coronary artery disease

    Directory of Open Access Journals (Sweden)

    Giannakopoulou Vasiliki

    2011-09-01

    Full Text Available Abstract Background The cholesteryl ester transfer protein (CETP has a central role in the lipid metabolism and therefore may alter the susceptibility to atherosclerosis. Methods The DNA of 471 subjects [133 subjects with angiographically documented left main coronary artery disease (LMCAD, 241 subjects with more peripheral coronary artery disease (MPCAD and 97 subjects self reported healthy (Controls] was analyzed for the frequency of TaqIB and I405V polymorphisms in the gene coding CETP. Results There is no significant difference in CETP allele frequency or genotype distribution among LMCAD and MPCAD patients although there is statistical difference between LMCAD and Controls (p = 0.001. Specifically, patients with LMCAD and B1B1 genotype of TaqIB polymorphism were more frequent present compared to Controls (33.8% vs 22.9%, respectively. The frequency of B2B2 genotype was 3 times lower in the LMCAD group compared to Controls (10.5% vs 30.2%, respectively. In the LMCAD group the frequency of B1 allele compared to Controls was higher (62% vs 46%, respectively, p = 0.001. The relationship between TaqIB gene polymorphism and the LMCAD was independent of lipid profile, with the exception of apolipoprotein A. Conclusions These findings indicate that the TaqIB polymorphism may have potential importance in screening individuals at high risk for developing CAD. However, this polymorphism cannot distinguish between LMCAD and MPCAD. Further prospective investigations in larger populations are required to confirm these findings.

  16. Comparative effects of cholesteryl ester transfer protein inhibition, statin or ezetimibe on lipid factors: The ACCENTUATE trial.

    Science.gov (United States)

    Nicholls, Stephen J; Ray, Kausik K; Ballantyne, Christie M; Beacham, Lauren A; Miller, Debra L; Ruotolo, Giacomo; Nissen, Steven E; Riesmeyer, Jeffrey S

    2017-06-01

    The optimal approaches to management of patients treated with moderate statin doses on lipid parameters are unknown. The ACCENTUATE study aimed to compare the effects of adding the cholesteryl ester transfer protein inhibitor (CETP) evacetrapib, ezetimibe or increasing statin dose in atorvastatin-treated high-vascular risk patients on lipid parameters. 366 patients with atherosclerotic cardiovascular disease (ASCVD) and/or diabetes were treated with atorvastatin 40 mg/day for 28 days prior to randomization to atorvastatin 40 mg plus evacetrapib 130 mg, atorvastatin 80 mg, atorvastatin 40 mg plus ezetimibe 10 mg or atorvastatin 40 mg plus placebo, daily for 90 days at 64 centers in the United States. Lipid parameters, safety and tolerability were measured. Addition of evacetrapib significantly reduced LDL-C (-33%) compared with ezetimibe (-27%, p=0.045), increasing statin dose (-6%) and statin alone (0%, pstatin dose (pstatin dose, and p=0.004 vs. statin alone). Addition of evacetrapib to atorvastatin produced an increase in hsCRP compared with ezetimibe (p=0.02). While evacetrapib improved traditional atherogenic and putative protective lipid measures compared with ezetimibe and increasing statin dose in patients with ASCVD and/or diabetes, it also adversely affected novel atherogenic risk factors. These findings may contribute to the lack of clinical benefit observed in the ACCELERATE trial. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Intratumor cholesteryl ester accumulation is associated with human breast cancer proliferation and aggressive potential: a molecular and clinicopathological study

    International Nuclear Information System (INIS)

    a Claret, 167 08025, Barcelona (Spain))" data-affiliation=" (Cardiovascular Research Center, CSIC-ICCC, IIB-Sant Pau, Hospital de la Santa Creu i Sant Pau, Sant Antoni Ma Claret, 167 08025, Barcelona (Spain))" >Gonzalo-Calvo, David de; López-Vilaró, Laura; a Claret, 167 08025, Barcelona (Spain))" data-affiliation=" (Cardiovascular Research Center, CSIC-ICCC, IIB-Sant Pau, Hospital de la Santa Creu i Sant Pau, Sant Antoni Ma Claret, 167 08025, Barcelona (Spain))" >Nasarre, Laura; Perez-Olabarria, Maitane; Vázquez, Tania; Escuin, Daniel; a Claret, 167 08025, Barcelona (Spain))" data-affiliation=" (Cardiovascular Research Center, CSIC-ICCC, IIB-Sant Pau, Hospital de la Santa Creu i Sant Pau, Sant Antoni Ma Claret, 167 08025, Barcelona (Spain))" >Badimon, Lina; Barnadas, Agusti; Lerma, Enrique; a Claret, 167 08025, Barcelona (Spain))" data-affiliation=" (Cardiovascular Research Center, CSIC-ICCC, IIB-Sant Pau, Hospital de la Santa Creu i Sant Pau, Sant Antoni Ma Claret, 167 08025, Barcelona (Spain))" >Llorente-Cortés, Vicenta

    2015-01-01

    The metabolic effect of intratumor cholesteryl ester (CE) in breast cancer remains poorly understood. The objective was to analyze the relationship between intratumor CE content and clinicopathological variables in human breast carcinomas. We classified 30 breast carcinoma samples into three subgroups: 10 luminal-A tumors (ER+/PR+/Her2-), 10 Her-2 tumors (ER-/PR-/Her2+), and 10 triple negative (TN) tumors (ER-/PR-/Her2-). We analyzed intratumor neutral CE, free cholesterol (FC) and triglyceride (TG) content by thin layer chromatography after lipid extraction. RNA and protein levels of lipid metabolism and invasion mediators were analyzed by real time PCR and Western blot analysis. Group-wise comparisons, linear regression and logistic regression models showed a close association between CE-rich tumors and higher histologic grade, Ki-67 and tumor necrosis. CE-rich tumors displayed higher mRNA and protein levels of low-density lipoprotein receptor (LDLR) and scavenger receptor class B member 1 (SCARB1). An increased expression of acetyl-Coenzyme A acetyltransferase 1 (ACAT1) in CE-rich tumors was also reported. Intratumor CE accumulation is intimately linked to proliferation and aggressive potential of breast cancer tumors. Our data support the link between intratumor CE content and poor clinical outcome and open the door to new antitumor interventions. The online version of this article (doi:10.1186/s12885-015-1469-5) contains supplementary material, which is available to authorized users

  18. Cholesteryl Ester Transfer Protein (CETP) genotype and cognitive function in persons aged 35 years or older

    NARCIS (Netherlands)

    Izaks, Gerbrand J.; van der Knaap, Aafke M.; Gansevoort, Ron T.; Navis, Gerjan; Slaets, Joris P. J.; Dullaart, Robin P. F.

    Common polymorphisms of the Cholestryl Ester Transfer Protein (CETP) gene may predict lower risk of cognitive decline. We investigated the association of cognitive function with CETP genotype in a population-based cohort of 4135 persons aged 35-82 years. Cognitive function was measured with the Ruff

  19. Cholesteryl ester transfer protein (cetp) inhibition in the treatment of cancer

    KAUST Repository

    Kaur, Mandeep

    2016-09-01

    In one embodiment, the invention provides methods of treatment which use therapeutically effective amounts of Choleste ryl Ester Transfer Protein (CETP) inhibitors to treat a variety of cancers. In certain embodiments, the inhibitor is a CETP-inhibiting small molecule, CETP-inhibiting antisense oligonucleotide, CETP-inhibiting siRNA or a CETP- inhibiting antibody. Related pharmaceutical compositions, kits, diagnostics and screens are also provided.

  20. Cholesteryl ester transfer protein (cetp) inhibition in the treatment of cancer

    KAUST Repository

    Kaur, Mandeep; Esau, Luke E.; Sagar, Sunii

    2016-01-01

    In one embodiment, the invention provides methods of treatment which use therapeutically effective amounts of Choleste ryl Ester Transfer Protein (CETP) inhibitors to treat a variety of cancers. In certain embodiments, the inhibitor is a CETP-inhibiting small molecule, CETP-inhibiting antisense oligonucleotide, CETP-inhibiting siRNA or a CETP- inhibiting antibody. Related pharmaceutical compositions, kits, diagnostics and screens are also provided.

  1. Regioselective Synthesis of Cellulose Ester Homopolymers

    Science.gov (United States)

    Daiqiang Xu; Kristen Voiges; Thomas Elder; Petra Mischnick; Kevin J. Edgar

    2012-01-01

    Regioselective synthesis of cellulose esters is extremely difficult due to the small reactivity differences between cellulose hydroxyl groups, small differences in steric demand between acyl moieties of interest, and the difficulty of attaching and detaching many protecting groups in the presence of cellulose ester moieties without removing the ester groups. Yet the...

  2. Accumulation and aberrant composition of cholesteryl esters in Scrapie-infected N2a cells and C57BL/6 mouse brains

    Directory of Open Access Journals (Sweden)

    Di Bari Michele A

    2011-08-01

    Full Text Available Abstract Objective Cholesterol changes have been described in prion-cell models and in experimental rodent scrapie; yet, the pattern of this association is still controversial. Methods To shed light on the matter, we analysed and compared cholesterol variations in ScN2a cells and in brains of Scrapie-infected C57Bl/6 mice, using two different methods: a fluorimetric-enzymatic cholesterol assay, and high performance liquid chromatography-mass spectroscopy (HPLC-MS. Results Compared to uninfected controls, similar cholesterol metabolism anomalies were observed in infected cells and brains by both methods; however, only HPLC-MS revealed statistically significant cholesterol variations, particularly in the cholesteryl esters (CE fraction. HPLC-MS analyses also revealed different fatty acid composition of the CE fraction in cells and brains. In N2a cells, their profile reflected that of serum, while in normal brains cholesteryl-linoleate only was found at detectable levels. Following prion infection, most CE species were increased in the CE pool of ScN2a cells, whereas a conspicuous amount of cholesteryl-arachidonate only was found to contribute to the cerebral increase of CE. Of interest, oral pravastatin administration to Scrapie-infected mice, was associated with a significant reduction of cerebral free cholesterol (FC along with a concomitant further increase of the CE pool, which included increased amounts of both cholesteryl-linoleate and cholesteryl-arachidonate. Conclusion Although mechanistic studies are needed to establish the pathophysiological relevance of changes in cerebral CE concentrations, to the best of our knowledge this is the first report to provide evidence of increased cholesterol esterification in brains of prion-infected mice, untreated and treated with pravastatin.

  3. The Relationship Between Genetic Variations of the Cholesteryl Ester Transfer Protein Gene and Coronary Artery Disease in Turkish Subjects

    Science.gov (United States)

    Gundogdu, Fuat; Gurlertop, Yekta; Pirim, Ibrahim; Sevimli, Serdar; Dogan, Hasan; Arslan, Sakir; Aksoy, Hulya; Karakelloglu, Sule; Senocak, Huseyin

    2009-01-01

    Objective Although the relationship between cholesteryl ester transfer protein (CETP) and cholesterol metabolism has been characterized in recent years, the effect of CETP genetic variants associated with coronary artery disease (CAD) is still unclear. Therefore, we investigated the association between CETP gene polymorphism and levels of lipid in patients with CAD. Materials and Methods We conducted a case-control study that included 194 unrelated subjects who underwent coronary angiography for suspected ischemic heart disease. This group was divided into 96 patients with angiographically documented CAD and 98 subjects (individuals matched for age and gender) without angiographically documented CAD (CAD-free subjects), all of whom were studied to examine the genotypic distribution of the CETP gene polymorphism in CAD. Genotyping was performed via polymerase chain reaction. Results Of the 96 patients with CAD, 38 (40%) were B1B1, 42 (44%) B1B2 and 16 (16%) B2B2, compared with the control subjects, of which 35 (36%) were B1B1, 44 (45%) B1B2 and 19 (19%) B2B2. There were no significant differences between patients with CAD and control subjects in the distribution of the CETP gene polymorphism. Patients with the B1B1 genotype had lower high-density lipoprotein-cholesterol (HDL-C) and higher triglyceride (TG) levels than patients with the B2B2 genotype (p<0.05). In addition, among control subjects HDL-C levels were significantly higher in subjects with the B2B2 genotype than in subjects with the B1B1 genotype (p<0.01). Conclusion Our results suggest that genetic variations of the CTEP gene may be responsible for low HDL-C levels but may not be considered as a risk factor for CAD in the Turkish population. PMID:25610061

  4. Associations of Cholesteryl Ester Transfer Protein TaqIB Polymorphism with the Composite Ischemic Cardiovascular Disease Risk and HDL-C Concentrations: A Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Shu-xia Guo

    2016-09-01

    Full Text Available Background: Previous studies have evaluated the associations between the cholesteryl ester transfer protein (CETP TaqIB polymorphism (rs708272, the risk of developing composite ischemic cardiovascular disease (CVD and the concentration of high-density lipoprotein cholesterol (HDL-C, but results remain controversial. The objective of this study was to investigate whether a relationship exists between these factors. Methods: We conducted a meta-analysis of available studies to clarify the associations of the CETP TaqIB polymorphism with HDL-C concentration and the composite ischemic CVD risk in both Asians and Caucasians. All statistical analyses were done with Stata 12.0. Results: Through utilization of the Cochrane Library, Embase, PubMed, Web of Science, Springer, China Science and Technology Journal Database, China National Knowledge Infrastructure, Google Scholar, and Baidu Library, a total of 45 studies from 44 papers with 20,866 cases and 21,298 controls were combined showing a significant association between the CETP TaqIB variant and composite ischemic CVD risk. Carriers of allele TaqIB-B1 were found to have a higher risk of composite ischemic CVD than non-carriers: OR = 1.15, 95% CI = 1.09–1.21, p < 0.001. Meanwhile, 28 studies with 23,959 subjects were included in the association between the CETP TaqIB polymorphism and the concentration of HDL-C. Results suggested that carriers of the B1B1 genotype had lower concentrations of HDL-C than those of the B2B2 genotype: SMD = 0.50, 95% CI = 0.36–0.65, p < 0.001. Conclusions: The synthesis of available evidence demonstrates that the CETP TaqIB polymorphism protects against composite ischemic CVD risk and is associated with a higher HDL-C concentration in both Asians and Caucasians.

  5. Upregulating reverse cholesterol transport with cholesteryl ester transfer protein inhibition requires combination with the LDL-lowering drug berberine in dyslipidemic hamsters.

    Science.gov (United States)

    Briand, François; Thieblemont, Quentin; Muzotte, Elodie; Sulpice, Thierry

    2013-01-01

    This study aimed to investigate whether cholesteryl ester transfer protein inhibition promotes in vivo reverse cholesterol transport in dyslipidemic hamsters. In vivo reverse cholesterol transport was measured after an intravenous injection of (3)H-cholesteryl-oleate-labeled/oxidized low density lipoprotein particles ((3)H-oxLDL), which are rapidly cleared from plasma by liver-resident macrophages for further (3)H-tracer egress in plasma, high density lipoprotein (HDL), liver, and feces. A first set of hamsters made dyslipidemic with a high-fat and high-fructose diet was treated with vehicle or torcetrapib 30 mg/kg (TOR) over 2 weeks. Compared with vehicle, TOR increased apolipoprotein E-rich HDL levels and significantly increased (3)H-tracer appearance in HDL by 30% over 72 hours after (3)H-oxLDL injection. However, TOR did not change (3)H-tracer recovery in liver and feces, suggesting that uptake and excretion of cholesterol deriving from apolipoprotein E-rich HDL is not stimulated. As apoE is a potent ligand for the LDL receptor, we next evaluated the effects of TOR in combination with the LDL-lowering drug berberine, which upregulates LDL receptor expression in dyslipidemic hamsters. Compared with TOR alone, treatment with TOR+berberine 150 mg/kg resulted in lower apolipoprotein E-rich HDL levels. After (3)H-oxLDL injection, TOR+berberine significantly increased (3)H-tracer appearance in fecal cholesterol by 109%. Our data suggest that cholesteryl ester transfer protein inhibition alone does not stimulate reverse cholesterol transport in dyslipidemic hamsters and that additional effects mediated by the LDL-lowering drug berberine are required to upregulate this process.

  6. Metabolism of high density lipoproteins reconstituted with [3H]cholesteryl ester and [14C]cholesterol in the rat, with special reference to the ovary

    International Nuclear Information System (INIS)

    Nestler, J.E.; Bamberger, M.; Rothblat, G.H.; Strauss, J.F. III

    1985-01-01

    In order to study the metabolism of high density lipoprotein (HDL)-carried sterol in the rat, human HDL was reconstituted with [ 14 C]cholesterol and [ 3 H]cholesteryl ester. After iv injection into immature PMSG-human CG primed rats pretreated with 4-aminopyrazolopyrimidine and aminoglutethimide, there was time-dependent accumulation of 3 H and 14 C in various organs which reached a maximum by 15-90 min. On a milligram wet weight basis, uptake of 3 H and 14 C was greatest in the adrenals, next in ovaries, followed by the liver, with little uptake by kidneys and spleen. On an organ basis, accumulation was greatest by the liver. Coadministration of excess unlabeled HDL, but not human low density lipoprotein, reduced accumulation of radioactivity by the ovaries and adrenals by 60%, indicating a specific and saturable uptake process. Granulosa cells cultured in lipoprotein-deficient medium with reconstituted HDL formed 3 H- and 14 C-labeled 20 alpha-hydroxypregn-4-en-3-one. Over a 24-h period, utilization of both [ 14 C]cholesterol and [ 3 H]cholesteryl ester was linear, but rates of utilization of the two sterol moieties were not parallel. Lysosomotropic agents had no effect on utilization of either free or esterified cholesterol for steroidogenesis but reduced degradation of 125 I-labeled low density lipoprotein apoprotein. These findings lend further support to the concept of a distinct HDL pathway in steroidogenic cells of the rat

  7. Low density lipoprotein receptor-related protein 1 expression correlates with cholesteryl ester accumulation in the myocardium of ischemic cardiomyopathy patients

    Directory of Open Access Journals (Sweden)

    Cal Roi

    2012-08-01

    Full Text Available Abstract Our hypothesis was that overexpression of certain lipoprotein receptors might be related to lipid accumulation in the human ischemic myocardium. Intramyocardial lipid overload contributes to contractile dysfunction and arrhythmias in cardiomyopathy. Thus, the purpose of this study was to assess the effect of hypercholesterolemic LDL and hypertrigliceridemic VLDL dose on LRP1 expression in cardiomyocytes, as well as the potential correlation between LRP1 expression and neutral lipid accumulation in the left ventricle tissue from ischemic cardiomyopathy patients. Cell culture experiments include control and LRP1-deficient cardiomyocytes exposed to lipoproteins under normoxic and hypoxic conditions. Explanted hearts from 18 ICM patients and eight non-diseased hearts (CNT were included. Low density lipoprotein receptor-related protein 1 (LRP1, very low density lipoprotein receptor (VLDLR and low density lipoprotein receptor (LDLR expression was analyzed by real time PCR and Western blotting. Cholesteryl ester (CE, triglyceride (TG and free cholesterol (FC content was assess by thin layer chromatography following lipid extraction. Western blotting experiments showed that protein levels of LRP1, VLDLR and HIF-1α were significantly upregulated in ischemic hearts. Immunohistochemistry and confocal microscopy analysis showed that LRP1 and HIF-1α were upregulated in cardiomyocytes of ICM patients. In vitro studies showed that VLDL, LDL and hypoxia exerted an upregulatory effect on LRP1 expression and that LRP1 played a major role in cholesteryl ester accumulation from lipoproteins in cardiomyocytes. Myocardial CE accumulation strongly correlated with LRP1 levels in ischemic hearts. Taken together, our results suggest that LRP1 upregulation is key for myocardial cholesterol ester accumulation in ischemic human hearts and that LRP1 may be a target to prevent the deleterious effects of myocardial cholesterol accumulation in ischemic cardiomyopathy.

  8. Hepatic expression of inflammatory genes and microRNAs in pigs with high “cholesteryl ester transfer protein” (CETP) activity

    DEFF Research Database (Denmark)

    Cirera, Susanna; Tørsleff, Benedicte C Juul; Ritz, Christian

    2016-01-01

    levels (designated as CETP-high and CETP-low, respectively). Furthermore, breed and gender differences were also investigated. We found significant difference (P hepatic expression levels of several mRNAs and microRNAs between the CETP-high and -low groups (C5, IL1RN, IL18, and miR-223-5p......) promoting the redistribution of cholesteryl esters, triglycerides, and phospholipids between plasma proteins. Moreover, obesity and ORD are often linked with chronic low-grade inflammation leading to insulin resistance and endothelial and microvascular dysfunctions. The aim of this study was to detect...... differences in the hepatic expression of genes involved in low-grade inflammation and of obesity- and cholesterol-related microRNAs in two mixed breed populations of pigs (Yorkshire-Göttingen minipig, YM and Duroc-Göttingen minipig, DM) including males and females, with extreme phenotypes for CETP activity...

  9. Cholesteryl Ester Transfer Protein Intimately Involved in Dyslipidemia-Related Susceptibility to Cognitive Deficits in Type 2 Diabetic Patients.

    Science.gov (United States)

    Sun, Jie; Cai, Rongrong; Huang, Rong; Wang, Pin; Tian, Sai; Sun, Haixia; Xia, Wenqing; Wang, Shaohua

    2016-08-01

    Cholesteryl ester transfer protein (CETP) is involved in diabetic dyslipidemia. We aim to test the hypothesis that CETP might be of importance in mediating dyslipidemia-related susceptibility to cognitive deficits in diabetic patients. We recruited 190 type 2 diabetic patients and divided them into two groups according to the Montreal Cognitive Assessment (MoCA) score. The association between CETP and cognitive decline was analyzed with logistic regression and stratification. There were 110 diabetic patients with mild cognition impairment (MCI) and 80 healthy cognition subjects as controls. Dyslipidemia is more common among diabetic patients with MCI; they had a significant increase of serum CETP concentrations, which was negatively correlated with MoCA (r = -0.638; p dyslipidemia-related susceptibility to cognitive decline, especially memory function in type 2 diabetic patients.

  10. Synthesis of a new energetic nitrate ester

    Energy Technology Data Exchange (ETDEWEB)

    Chavez, David E [Los Alamos National Laboratory

    2008-01-01

    Nitrate esters have been known as useful energetic materials since the discovery of nitroglycerin by Ascanio Sobrero in 1846. The development of methods to increase the safety and utility of nitroglycerin by Alfred Nobel led to the revolutionary improvement in the utility of nitroglycerin in explosive applications in the form of dynamite. Since then, many nitrate esters have been prepared and incorporated into military applications such as double-based propellants, detonators and as energetic plasticizers. Nitrate esters have also been shown to have vasodilatory effects in humans and thus have been studied and used for treatments of ailments such as angina. The mechanism of the biological response towards nitrate esters has been elucidated recently. Interestingly, many of the nitrate esters used for military purposes are liquids (ethylene glycol dinitrate, propylene glycol dinitrate, etc). Pentaerythritol tetranitrate (PETN) is one of the only solid nitrate esters, besides nitrocellulose, that is used in any application. Unfortunately, PETN melting point is above 100 {sup o}C, and thus must be pressed as a solid for detonator applications. A more practical material would be a melt-castable explosive, for potential simplification of manufacturing processes. Herein we describe the synthesis of a new energetic nitrate ester (1) that is a solid at ambient temperatures, has a melting point of 85-86 {sup o}C and has the highest density of any known nitrate ester composed only of carbon, hydrogen, nitrogen and oxygen. We also describe the chemical, thermal and sensitivity properties of 1 as well as some preliminary explosive performance data.

  11. A chimeric peptide of intestinal trefoil factor containing cholesteryl ester transfer protein B cell epitope significantly inhibits atherosclerosis in rabbits after oral administration.

    Science.gov (United States)

    Qi, Gaofu; Li, Jingjing; Wang, Shengying; Xin, Shanshan; Du, Peng; Zhang, Qingye; Zhao, Xiuyun

    2011-04-01

    Vaccination against cholesteryl ester transfer protein (CETP) is proven to be effective for inhibiting atherosclerosis in animal models. In this study, the proteases-resistant intestinal trefoil factor (TFF3) was used as a molecular vehicle to construct chimeric TFF3 (cTFF3) containing CETP B cell epitope and tetanus toxin helper T cell epitope. It was found that cTFF3 still preserved a trefoil structure, and can resist proteases digestion in vitro. After oral immunization with cTFF3, the CETP-specific IgA and IgG could be found in intestine lavage fluid and serum, and the anti-CETP antibodies could inhibit partial CETP activity to increase high-density lipoprotein cholesterol, decrease low-density lipoprotein cholesterol, and inhibit atherosclerosis in animals. Therefore, TFF3 is a potential molecular vehicle for developing oral peptide vaccines. Our research highlights a novel strategy for developing oral peptide vaccines in the future. Copyright © 2010 Elsevier Inc. All rights reserved.

  12. Aspartame-fed zebrafish exhibit acute deaths with swimming defects and saccharin-fed zebrafish have elevation of cholesteryl ester transfer protein activity in hypercholesterolemia.

    Science.gov (United States)

    Kim, Jae-Yong; Seo, Juyi; Cho, Kyung-Hyun

    2011-11-01

    Although many artificial sweeteners (AS) have safety issues, the AS have been widely used in industry. To determine the physiologic effect of AS in the presence of hyperlipidemia, zebrafish were fed aspartame or saccharin with a high-cholesterol diet (HCD). After 12 days, 30% of zebrafish, which consumed aspartame and HCD, died with exhibiting swimming defects. The aspartame group had 65% survivability, while the control and saccharin groups had 100% survivability. Under HCD, the saccharin-fed groups had the highest increase in the serum cholesterol level (599 mg/dL). Aspartame-fed group showed a remarkable increase in serum glucose (up to 125 mg/dL), which was 58% greater than the increase in the HCD alone group. The saccharin and HCD groups had the highest cholesteryl ester transfer protein (CETP) activity (52% CE-transfer), while the HCD alone group had 42% CE-transfer. Histologic analysis revealed that the aspartame and HCD groups showed more infiltration of inflammatory cells in the brain and liver sections. Conclusively, under presence of hyperlipidemia, aspartame-fed zebrafish exhibited acute swimming defects with an increase in brain inflammation. Saccharin-fed zebrafish had an increased atherogenic serum lipid profile with elevation of CETP activity. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Comparison of Electrospray Ionization and Atmospheric Chemical Ionization Coupled with the Liquid Chromatography-Tandem Mass Spectrometry for the Analysis of Cholesteryl Esters

    Directory of Open Access Journals (Sweden)

    Hae-Rim Lee

    2015-01-01

    Full Text Available The approach of two different ionization techniques including electrospray ionization (ESI and atmospheric pressure chemical ionization (APCI coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS was tested for the analysis of cholesteryl esters (CEs. The retention time (RT, signal intensity, protonated ion, and product ion of CEs were compared between ESI and APCI. RT of CEs from both ionizations decreased with increasing double bonds, while it increased with longer carbon chain length. The ESI process generated strong signal intensity of precursor ions corresponding to [M+Na]+ and [M+NH4]+ regardless of the number of carbon chains and double bonds in CEs. On the other hand, the APCI process produced a protonated ion of CEs [M+H]+ with a weak signal intensity, and it is selectively sensitive to detect precursor ions of CEs with unsaturated fatty acids. The ESI technique proved to be effective in ionizing more kinds of CEs than the APCI technique.

  14. Reversible flow of cholesteryl ester between high-density lipoproteins and triacylglycerol-rich particles is modulated by the fatty acid composition and concentration of triacylglycerols

    Directory of Open Access Journals (Sweden)

    E.C.R. Quintão

    2010-12-01

    Full Text Available We determined the influence of fasting (FAST and feeding (FED on cholesteryl ester (CE flow between high-density lipoproteins (HDL and plasma apoB-lipoprotein and triacylglycerol (TG-rich emulsions (EM prepared with TG-fatty acids (FAs. TG-FAs of varying chain lengths and degrees of unsaturation were tested in the presence of a plasma fraction at d > 1.21 g/mL as the source of CE transfer protein. The transfer of CE from HDL to FED was greater than to FAST TG-rich acceptor lipoproteins, 18% and 14%, respectively. However, percent CE transfer from HDL to apoB-containing lipoproteins was similar for FED and FAST HDL. The CE transfer from HDL to EM depended on the EM TG-FA chain length. Furthermore, the chain length of the monounsaturated TG-containing EM showed a significant positive correlation of the CE transfer from HDL to EM (r = 0.81, P < 0.0001 and a negative correlation from EM to HDL (r = -041, P = 0.0088. Regarding the degree of EM TG-FAs unsaturation, among EMs containing C18, the CE transfer was lower from HDL to C18:2 compared to C18:1 and C18:3, 17.7%, 20.7%, and 20%, respectively. However, the CE transfer from EMs to HDL was higher to C18:2 than to C18:1 and C18:3, 83.7%, 51.2%, and 46.3%, respectively. Thus, the EM FA composition was found to be the rate-limiting factor regulating the transfer of CE from HDL. Consequently, the net transfer of CE between HDL and TG-rich particles depends on the specific arrangement of the TG acyl chains in the lipoprotein particle core.

  15. Simultaneous Quantification of Free Cholesterol, Cholesteryl Esters, and Triglycerides without Ester Hydrolysis by UHPLC Separation and In-Source Collision Induced Dissociation Coupled MS/MS

    Science.gov (United States)

    Gardner, Michael S.; McWilliams, Lisa G.; Jones, Jeffrey I.; Kuklenyik, Zsuzsanna; Pirkle, James L.; Barr, John R.

    2017-08-01

    We demonstrate the application of in-source nitrogen collision-induced dissociation (CID) that eliminates the need for ester hydrolysis before simultaneous analysis of esterified cholesterol (EC) and triglycerides (TG) along with free cholesterol (FC) from human serum, using normal phase liquid chromatography (LC) coupled to atmospheric pressure chemical ionization (APCI) tandem mass spectrometry (MS/MS). The analysis requires only 50 μL of 1:100 dilute serum with a high-throughput, precipitation/evaporation/extraction protocol in one pot. Known representative mixtures of EC and TG species were used as calibrators with stable isotope labeled analogs as internal standards. The APCI MS source was operated with nitrogen source gas. Reproducible in-source CID was achieved with the use of optimal cone voltage (declustering potential), generating FC, EC, and TG lipid class-specific precursor fragment ions for multiple reaction monitoring (MRM). Using a representative mixture of purified FC, CE, and TG species as calibrators, the method accuracy was assessed with analysis of five inter-laboratory standardization materials, showing -10% bias for Total-C and -3% for Total-TG. Repeated duplicate analysis of a quality control pool showed intra-day and inter-day variation of 5% and 5.8% for FC, 5.2% and 8.5% for Total-C, and 4.1% and 7.7% for Total-TG. The applicability of the method was demonstrated on 32 serum samples and corresponding lipoprotein sub-fractions collected from normolipidemic, hypercholesterolemic, hypertriglyceridemic, and hyperlipidemic donors. The results show that in-source CID coupled with isotope dilution UHPLC-MS/MS is a viable high precision approach for translational research studies where samples are substantially diluted or the amounts of archived samples are limited. [Figure not available: see fulltext.

  16. SYNTHESIS OF FATTY ACID ETHYL ESTER FROM CHICKEN FAT ...

    African Journals Online (AJOL)

    eobe

    synthesis of fatty acid ethyl ester from chicken fat waste using ZnO/SiO fatty acid ethyl ester ... obtained in the range of 56−88%and a second order quadratic polynomial regression model that established the ... Transesterification is a chemical.

  17. Synthesis, biological evaluation, and baboon PET imaging of the potential adrenal imaging agent cholesteryl-p-[18f]fluorobenzoate

    International Nuclear Information System (INIS)

    Jonson, Stephanie D.; Welch, Michael J.

    1999-01-01

    Cholesteryl-p-[ 18 F]fluorobenzoate ([ 18 F]CFB) was investigated as a potential adrenal positron emission tomography (PET) imaging agent for the diagnostic imaging of adrenal disorders. We describe the synthesis, biodistribution, adrenal autoradiography, and baboon PET imaging of [ 18 F]CFB. The synthesis of [ 18 F]CFB was facilitated by the use of a specially designed microwave cavity that was instrumental in effecting 70-83% incorporation of fluorine-18 in 60 s via [ 18 F]fluoro-for-nitro exchange. Tissue distribution studies in mature female Sprague-Dawley rats showed good accumulation of [ 18 F]CFB in the steroid-secreting tissues, adrenals and ovaries, at 1 h postinjection. The effectiveness of [ 18 F]CFB to accumulate in diseased adrenals was shown through biodistribution studies in hypolipidemic rats, which showed a greater than threefold increase in adrenal uptake at 1 h and increased adrenal/liver and adrenal/kidney ratios. Analysis of the metabolites at 1 h in the blood, adrenals, spleen, and ovaries of hypolipidemic and control rats showed the intact tracer representing greater than 86%, 93%, 92%, and 82% of the accumulated activity, respectively. [ 18 F]CFB was confirmed to selectively accumulate in the adrenal cortex versus the adrenal medulla by autoradiography. Normal baboon PET imaging with [ 18 F]CFB effectively showed adrenal localization as early as 15 min after injection of the tracer, with enhanced adrenal contrast seen at 60-70 min. These results suggest that [ 18 F]CFB may be useful as an adrenal PET imaging agent for assessing adrenal disorders

  18. α-Imino Esters in Organic Synthesis: Recent Advances.

    Science.gov (United States)

    Eftekhari-Sis, Bagher; Zirak, Maryam

    2017-06-28

    α-Imino esters are useful precursors for the synthesis of a variety of types of natural and unnatural α-amino acid derivatives, with a wide range of biological activities. Due to the adjacent ester group, α-imino esters are more reactive relative to other types of imines and undergo different kinds of reactions, including organometallics addition, metal catalyzed vinylation and alkynylation, aza-Henry, aza-Morita-Baylis-Hillman, imino-ene, Mannich-type, and cycloaddition reactions, as well as hydrogenation and reduction. This review discusses the mechanism, scope, and applications of the reactions of α-imino esters and related compounds in organic synthesis, covering the literature from the last 12 years.

  19. Maximization of fructose esters synthesis by response surface methodology.

    Science.gov (United States)

    Neta, Nair Sampaio; Peres, António M; Teixeira, José A; Rodrigues, Ligia R

    2011-07-01

    Enzymatic synthesis of fructose fatty acid ester was performed in organic solvent media, using a purified lipase from Candida antartica B immobilized in acrylic resin. Response surface methodology with a central composite rotatable design based on five levels was implemented to optimize three experimental operating conditions (temperature, agitation and reaction time). A statistical significant cubic model was established. Temperature and reaction time were found to be the most significant parameters. The optimum operational conditions for maximizing the synthesis of fructose esters were 57.1°C, 100 rpm and 37.8 h. The model was validated in the identified optimal conditions to check its adequacy and accuracy, and an experimental esterification percentage of 88.4% (±0.3%) was obtained. These results showed that an improvement of the enzymatic synthesis of fructose esters was obtained under the optimized conditions. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Synthesis of new radiotracers based of Ethyl Ester

    International Nuclear Information System (INIS)

    Trabelsi, Donia

    2008-01-01

    The in vivo study of a biochemical or physiological process requires the synthesis of specific radiotracers but also the targeting of these compounds so that they can reach their target tissue. Methodologies original synthesis associated with radioisotopes used, the quantities and chemical forms often have to be available developed. The chemistry of metal complexes booming, we were able to use the ethyl ester combined with technetium, forming a stable radiotracer. Finally, a counting of radioactivity in different rat's organs completed our study. (Author)

  1. Steryl ester synthesis, storage and hydrolysis: A contribution to sterol homeostasis.

    Science.gov (United States)

    Korber, Martina; Klein, Isabella; Daum, Günther

    2017-12-01

    Sterols are essential lipids of all eukaryotic cells, appearing either as free sterols or steryl esters. Besides other regulatory mechanisms, esterification of sterols and hydrolysis of steryl esters serve to buffer both an excess and a lack of free sterols. In this review, the esterification process, the storage of steryl esters and their mobilization will be described. Several model organisms are discussed but the focus was set on mammals and the yeast Saccharomyces cerevisiae. The contribution of imbalanced cholesterol homeostasis to several human diseases, namely Wolman disease, cholesteryl ester storage disease, atherosclerosis and Alzheimer's disease, Niemann-Pick type C and Tangier disease is described. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Development of chemical process for synthesis of polyunsaturated esters

    OpenAIRE

    Vera LÃcia Viana do Nascimento

    2014-01-01

    This work aimed to develop refining processes, chemical alcoholysis followed by separation of fatty acids using the complexation with urea technique for the synthesis of poly-unsaturated esters from waste of fish oils. The special crude fish oil was purchased from Company Campestre - SÃo Paulo. Initially this oil has undergone a process of physical and chemical refining. From the refined oil, an alcoholysis process was carried out to obtain the mixture of free fatty acids. From the hydrolyzed...

  3. Gamma-aminobutyric acid esters. 1. Synthesis, brain uptake, and pharmacological studies of aliphatic and steroid esters of gamma-aminobutyric acid

    International Nuclear Information System (INIS)

    Shashoua, V.E.; Jacob, J.N.; Ridge, R.; Campbell, A.; Baldessarini, R.J.

    1984-01-01

    Labeled and unlabeled aliphatic and steroid esters of gamma-amino[U- 14 C]butyric acid (GABA) were synthesized and tested for their capacity to penetrate the blood-brain barrier and for evidence of central neuropharmacological activity in rodents. The uptake of the labeled 9,12,15-octadecatrienyl (linolenyl), 3-cholesteryl, 1-butyl, and the 9-fluoro-11 beta,17-dihydroxy-16 alpha-methyl-3,20-dioxopregna -1,4-dien-21-yl (dexamethasone) esters of GABA into mouse brain increased 2-, 25-, 74-, and 81-fold over GABA, respectively. The cholesteryl ester of GABA depressed the general motor activity of mice and rats in a dose-dependent manner, whereas the 1-butyl, linolenyl, and dexamethasone esters were inactive by this test. Studies of the rates of hydrolysis, GABA receptor binding capacity, and octanol/water partition coefficients indicated that pharmacological activity of the esters after entry into the central nervous system (CNS) was dependent on their capacity to release GABA by enzymatic hydrolysis and their lipid solubility

  4. Lipase catalyzed ester synthesis for food processing industries

    Directory of Open Access Journals (Sweden)

    Aravindan Rajendran

    2009-02-01

    Full Text Available Lipases are one of the most important industrial biocatalyst which catalyzes the hydrolysis of lipids. It can also reverse the reaction at minimum water activity. Because of this pliable nature, it is widely exploited to catalyze the diverse bioconversion reactions, such as hydrolysis, esterification, interesterification, alcoholysis, acidolysis and aminolysis. The property to synthesize the esters from the fatty acids and glycerol promotes its use in various ester synthesis. The esters synthesized by lipase finds applications in numerous fields such as biodiesel production, resolution of the recemic drugs, fat and lipid modification, flavour synthesis, synthesis of enantiopure pharmaceuticals and nutraceuticals. It plays a crucial role in the food processing industries since the process is unaffected by the unwanted side products. Lipase modifications such as the surfactant coating, molecular imprinting to suit for the non-aqueous ester synthesis have also been reported. This review deals with lipase catalyzed ester synthesis, esterification strategies, optimum conditions and their applications in food processing industries.Lipases são catalizadores industriais dos mais importantes, os quais catalizam a hidrólise de lipídeos. Também podem reverter a reação a um mínimo de atividade de água. Devido sua natureza flexível, é amplamente explorada para catalizar uma diversidade de reações de bioconversão como hidrólise, esterificação, interesterificação, alcoólise, acidólise e aminólise. A propriedade de síntese de esteres a partir de ácidos graxos e glicerol promoveu seu uso em várias sínteses de esteres. Os esteres sintetizados por lipases encontram aplicação em numerosos campos como a produção de biodiesel, resolução de drogas racêmicas, modificação de gorduras e lipídios, sintese de aromas, síntese de produtos farmacêuticos enantiopuro e nutracêuticos. As lipases possuem um papel crucial nas indústrias de

  5. Synthesis of thermoplastic poly(ester-olefin elastomers

    Directory of Open Access Journals (Sweden)

    Tanasijević Branka

    2004-01-01

    Full Text Available A series of thermoplastic poly(ester-olefin elastomers, based on poly(ethylene-stat-butylene, HO-PEB-OH, as the soft segment and poly (butylene terephthalate, PBT, as the hard segment, were synthesized by a catalyzed transesterification reaction in solution. The incorporation of soft hydrogenated poly(butadiene segments into the copolyester backbone was accomplished by the polycondensation of α, ω-dihydroxyl telechelic HO-PEB-OH, (PEB Mn = 3092 g/mol with 1,4-butanediol (BD and dimethyl terephthalate (DMT in the presence of a 50 wt-% high boiling solvent i.e., 1,2,4-trichlorobenzene. The molar ratio of the starting comonomers was selected to result in a constant hard to soft weight ratio of 60:40. The synthesis was optimized in terms of both the concentration of catalyst, tetra-n-butyl-titanate (Ti(OBu4, and stabilizer, N,N'-diphenyl-p-phenylenediamine (DPPD, as well as the reaction time. It was found that the optimal catalyst concentration (Ti(OBu4 for the synthesis of these thermoplastic elastomers was 1.0 mmol/mol ester and the optimal DPPD concentration was 1.0 wt-%. The extent of the reaction was followed by measuring the inherent viscosity of the reaction mixture. The effectiveness of the incorporation of the soft segments into the copolymer chains was proved by Soxhlet extraction with chloroform. The molecular structures, composition and the size of the synthesized poly(ester-butylenes were verified by 1H NMR spectroscopy, viscometry of dilute solutions and the complex dynamic melt viscosity. The thermal properties of poly(ester-olefins were investigated by differential scanning calorimetry (DSC. The degree of crystallinity was also determined by DSC. The thermal and thermo-oxidative stability were investigated by thermogravimetric analysis (TGA. The rheological properties of poly(ester-olefins were investigated by dynamic mechanical spectroscopy in the melt and solid state.

  6. Boronate esters: Synthesis, characterization and molecular base receptor analysis

    Science.gov (United States)

    Gómez-Jaimes, Gelen; Barba, Victor

    2014-10-01

    The synthesis of three boronate esters obtained by reacting 4-fluorophenylboronic (1), 4-iodophenylboronic (2) and 3,4-chlorophenylboronic (3) acids with 2,4,5-trihidroxybenzaldehyde is reported. The structural characterization was determined by spectroscopic and spectrometric techniques. The boron atom was evaluated to acts as Lewis acid center in the reaction with pyridine (Py), triethylamine (TEA) and fluoride anion (F-). The titration method was followed by UV-Vis and 11B NMR spectroscopy; results indicate the good interaction with the fluoride ion but poor coordination towards pyridine in solution.

  7. Green Synthesis of Acid Esters from Furfural via Stobbe Condensation

    Directory of Open Access Journals (Sweden)

    Shubhra Banerjee

    2013-01-01

    Full Text Available Solvent-free Stobbe condensation of furfural 1 with dimethyl succinate 2 under anhydrous conditions at room temperature using dry-solid potassium tertiary butoxide gave 3-carbomethoxy, 4-furyl-3-butenoic acid 3, which upon methylation followed by Stobbe condensation reaction with different aldehydes and/or ketones under anhydrous conditions at room temperature afforded substituted carbomethoxy acids 5a–f. These acid ester products were saponified to the corresponding dicarboxylic acids 6a–f which are useful in the synthesis of photochromic fulgides.

  8. Relations Between Atherogenic Index of Plasma, Ratio of Small Dense Low Density Lipoprotein/Lecithin Cholesterol Acyl Transferase and Ratio of Small Dense Low Density Lipoprotein/Cholesteryl Ester Transfer Protein of Controlled and Uncontrolled Type 2 DM

    Directory of Open Access Journals (Sweden)

    Ellis Susanti

    2009-08-01

    Full Text Available BACKGROUND: Patients with Diabetes Melitus are proven to be prone to atherosclerosis and coronary heart disease, especially type 2 Diabetes Melitus (T2DM patient who have higher risk and mortality for cardiovascular risk factor. The Dyslipidemia condition is very common in T2DM as one of the risk factors. Diabetic dyslipidemia is marked by the increased triglyceride (TG, low HDL cholesterol (HDL-C, and increased small dense LDL and apolipoprotein B. Therefore the aim of this study is to assess the differential and correlation between Atherogenic Index of Plasma (AIP, ratio of small dense low density lipoprotein (sdLDL/lecithin cholesterol acyl transferase (LCAT and ratio of sdLDL/cholesteryl ester transfer protein (CETP of controlled and uncontrolled T2DM. METHODS: This study was observational with cross sectional design. In total of 72 patients with T2DM consist of 36 controlled and 36 uncontrolled, participated in this study. The serum TG, HDL-C, sdLDL, LCAT and CETP were examined in their relationship with to T2DM risk. RESULTS: The results of the study indicate that the AIP (p<0.001 increase controlled and uncontrolled T2DM and the ratio of sdLDL/CETP (p=0.004, odds ratio of AIP was 4 (95% CI: 1.501-10.658 and odds ratio of sdLDL/CETP ratio was 4 (95% CI: 1.501-10.658 in uncontrolled T2DM. CONCLUSIONS: This study showed that the AIP and ratio of small dense LDL/CETP had a significant correlation with the uncontrolled T2DM. The AIP and ratio of small dense LDL/CETP increase was found at the uncontrolled T2DM to be 4 times greater than the controlled T2DM. KEYWORDS: T2DM, atherosclerosis, atherogenic index of plasma, small dense LDL, LCAT, CETP, ratio of sdLDL/LCAT, ratio of sdLDL/CETP.

  9. Synthesis, biological evaluation, and baboon PET imaging of the potential adrenal imaging agent cholesteryl-p-[{sup 18}f]fluorobenzoate

    Energy Technology Data Exchange (ETDEWEB)

    Jonson, Stephanie D.; Welch, Michael J. E-mail: welch@mirlink.wustl.edu

    1999-01-01

    Cholesteryl-p-[{sup 18}F]fluorobenzoate ([{sup 18}F]CFB) was investigated as a potential adrenal positron emission tomography (PET) imaging agent for the diagnostic imaging of adrenal disorders. We describe the synthesis, biodistribution, adrenal autoradiography, and baboon PET imaging of [{sup 18}F]CFB. The synthesis of [{sup 18}F]CFB was facilitated by the use of a specially designed microwave cavity that was instrumental in effecting 70-83% incorporation of fluorine-18 in 60 s via [{sup 18}F]fluoro-for-nitro exchange. Tissue distribution studies in mature female Sprague-Dawley rats showed good accumulation of [{sup 18}F]CFB in the steroid-secreting tissues, adrenals and ovaries, at 1 h postinjection. The effectiveness of [{sup 18}F]CFB to accumulate in diseased adrenals was shown through biodistribution studies in hypolipidemic rats, which showed a greater than threefold increase in adrenal uptake at 1 h and increased adrenal/liver and adrenal/kidney ratios. Analysis of the metabolites at 1 h in the blood, adrenals, spleen, and ovaries of hypolipidemic and control rats showed the intact tracer representing greater than 86%, 93%, 92%, and 82% of the accumulated activity, respectively. [{sup 18}F]CFB was confirmed to selectively accumulate in the adrenal cortex versus the adrenal medulla by autoradiography. Normal baboon PET imaging with [{sup 18}F]CFB effectively showed adrenal localization as early as 15 min after injection of the tracer, with enhanced adrenal contrast seen at 60-70 min. These results suggest that [{sup 18}F]CFB may be useful as an adrenal PET imaging agent for assessing adrenal disorders.

  10. Synthesis of methyl ester sulphonate by sulfonation of soybean oil methyl ester for chemical flooding application

    International Nuclear Information System (INIS)

    Richie Adi Putra; Renisa Ismayanti; Agam Duma Kalista W

    2018-01-01

    This research has accomplished the synthesis of Surfactant Methyl Ester Sulphonate from Methyl Soyate and Sodium Bisulfite as sulfonating agent. The Steps of the synthesis were reaction, purification, neutralization, and separation. The reaction done by several variated condition such as Reaction Temperature (100, 110, 120)°C, Reaction time (210, 270, 330)minute, and the mole ratio between Methyl Soyate and NaHSO 3 (1:1, 1:1.5, 1:2) with 1.5 % of Al 2 O 3 as catalyst of sulfonation reaction. The purification process was conducted at 55 °C and 60 minute by adding Methanol 35 % v/v. The neutralization done was conducted by 20 % of NaOH until pH 6-8. And the rest of the methanol are separated from MES using rotary evaporator. MES which is pass the compatibility Test is MES at the condition of reaction (100 °C, 210 minute and 1 : 2 mole ratio).This MES has tested by FT - IR to see the existence of the Sulphonate group.The FT-IR test result has shown the existence of the Sulphonate group at wave length between 1000 until 1300 cm -1 . Which is the highest peak at 1176 cm-1. From the qualitative test above, then the MES performed by IFT Test with light oil of X- field as comparison. The IFT results has shown a decrease of the interfacial tensions between 12,000 ppm of brine water and the light oil with addition of 0.3 % (v/v) MES, from 3.36 dyne/cm 2 to 1.54 dyne/cm 2 . (author)

  11. Synthesis and properties of fatty acid starch esters.

    Science.gov (United States)

    Winkler, Henning; Vorwerg, Waltraud; Wetzel, Hendrik

    2013-10-15

    Being completely bio-based, fatty acid starch esters (FASEs) are attractive materials that represent an alternative to crude oil-based plastics. In this study, two synthesis methods were compared in terms of their efficiency, toxicity and, especially, product solubility with starch laurate (C12) as model compound. Laurates (DS>2) were obtained through transesterification of fatty acid vinylesters in DMSO or reaction with fatty acid chlorides in pyridine. The latter lead to higher DS-values in a shorter reaction time. But due to the much better solubility of the products compared to lauroyl chloride esterified ones, vinylester-transesterification was preferred to optimize reaction parameters, where reaction time could be shortened to 2h. FASEs C6-C18 were also successfully prepared via transesterification. To determine the DS of the resulting starch laurates, the efficient ATR-IR method was compared with common methods (elementary analysis, (1)H NMR). Molar masses (Mw) of the highly soluble starch laurates were analyzed using SEC-MALLS (THF). High recovery rates (>80%) attest to the outstanding solubility of products obtained through transesterification, caused by a slight disintegration during synthesis. Particle size distributions (DLS) demonstrated stable dissolutions in CHCl3 of vinyl laurate esterified - contrary to lauroyl chloride esterified starch. For all highly soluble FASEs (C6-C18), formation of concentrated solutions (10 wt%) is feasible. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Experimental and Modeling Studies on the Synthesis and Properties of Higher Fatty Esters of Corn Starch

    NARCIS (Netherlands)

    Junistia, Laura; Sugih, Asaf K.; Manurung, Robert; Picchioni, Francesco; Janssen, Leon P. B. M.; Heeres, Hero J.

    This paper describes a systematic study on the synthesis of higher fatty esters of corn starch (starch laurate and starch stearate) by using the corresponding vinyl esters. The reactions were carried out in DMSO using basic catalysts (Na(2)HPO(4), K(2)CO(3), and Na-acetate). The effect of the

  13. Synthesis of Estolide 2-ethylhexyl Ester from Ricinus communis

    International Nuclear Information System (INIS)

    Nazrizawati Ahmad Tajuddin; Nor Habibah Rosli

    2013-01-01

    Estolide 2-ethylhexyl ester synthesized through condensation reaction between ricinoleic acid from castor oil (Ricinus communis) and lauric acid, and then capped with 2-ethylhexyl alcohol. The reaction was continuously conducted under vacuum for 24 hours. Product of 2-ethylhexyl ester was characterized by using Fourier Transform Infrared (FTIR) to determine functional group and Nuclear Magnetic Resonans (NMR) for structure's determination. The presence of ester group at 1738.23 cm -1 wavenumber indicates that the formation of estolide ester has occurred. The vibration peak of C-O at 1174.60 cm -1 and 1117.10 cm -1 support the formation of ester. The presence of CH 2 bending indicated the long-chain compound. The ester methine signal at 3.8669 ppm indicated the estolide linkage in the 1 H-NMR spectrum while the 13 C-NMR showed two carbonyl signals at 173.41 ppm for acid and 173.56 ppm for ester. (author)

  14. Actividad de la proteína transportadora de ésteres de colesterol. Polimorfismos del gen en pacientes colombianos con enfermedad coronaria Activity of cholesteryl ester transfer protein. Gene polymorphism in colombian patients with coronary artery disease

    Directory of Open Access Journals (Sweden)

    Alejandra M Giraldo

    2012-08-01

    Full Text Available Introducción: la literatura relaciona la actividad de la proteína transportadora de ésteres de colesterol (CETP con enfermedad coronaria, por reducir el colesterol en las lipoproteínas de alta densidad. Adicionalmente, estudios recientes han identificado variaciones en el gen de la CETP, aunque el papel funcional de algunas de estas variantes sobre la actividad enzimática y la enfermedad coronaria, es desconocido. Objetivos: examinar la asociación de los polimorfismos TaqIB, MspI y RsaI del gen de la CETP y la actividad de la enzima con enfermedad coronaria. Métodos: se evaluó la asociación entre la actividad de la enzima y los polimorfismos TaqIB, MspI y RsaI, en pacientes con obstrucción coronaria documentada por angiografía. Resultados: la angiografía permitió clasificar a los pacientes en dos grupos: uno (213 individuos con obstrucción coronaria no significativa (OC 50%. La edad fue significantemente mayor en el último grupo en comparación con el primero. La actividad de la CETP fue 95,8 y 94,7 pmol/μL.h, para los grupos OC 50%, respectivamente. Solo se encontró diferencia significativa entre los alelos M1 y M2 en la población general. Conclusión: no se halló asociación entre la actividad de la CETP, los polimorfismos TaqBI, MspI, Rsal y la obstrucción coronaria. En este trabajo se describen por primera vez los niveles de CETP en los polimorfismos TaqIB, MspI, Rsal para un grupo de pacientes colombianos. Se debe refinar la descripción del evento coronario, el contexto metabólico de los pacientes y el estudio de haplotipos para encontrar relaciones con enfermedad coronaria.Introduction: literature links the activity of cholesteryl ester transfer protein (CETP with coronary heart disease by lowering cholesterol in high density lipoproteins. Additionally, recent studies have identified variations in the CETP gene, although the functional role of some of these variants on enzyme activity and coronary heart disease is

  15. Facile synthesis of linear-dendritic cholesteryl-poly(epsilon-caprolactone)-b-(L-lysine)(G2) by thiol-ene and azide-alkyne "click" reactions

    DEFF Research Database (Denmark)

    Javakhishvili, Irakli; Binder, W.H.; Tanner, S.

    2010-01-01

    The construction of a linear-dendritic block copolymer consisting of terminal cholesteryl moiety, poly(epsilon-caprolactone), and a second generation L-lysine dendron has been accomplished by the combination of copper(I) catalyzed azide-alkyne and UV-triggered thiol-ene "click" reactions. Ring-op...... and thiocholesterol. Near to quantitative functionalization of the intermediate and final products has been attained as confirmed by NMR spectroscopy and MALDI-TOF spectrometry....

  16. Sugar ester surfactants: enzymatic synthesis and applications in food industry.

    Science.gov (United States)

    Neta, Nair S; Teixeira, José A; Rodrigues, Lígia R

    2015-01-01

    Sugar esters are non-ionic surfactants that can be synthesized in a single enzymatic reaction step using lipases. The stability and efficiency of lipases under unusual conditions and using non-conventional media can be significantly improved through immobilization and protein engineering. Also, the development of de novo enzymes has seen a significant increase lately under the scope of the new field of synthetic biology. Depending on the esterification degree and the nature of fatty acid and/or sugar, a range of sugar esters can be synthesized. Due to their surface activity and emulsifying capacity, sugar esters are promising for applications in food industry.

  17. One-pot synthesis of thermoplastic mixed paramylon esters using trifluoroacetic anhydride.

    Science.gov (United States)

    Shibakami, Motonari; Tsubouchi, Gen; Sohma, Mitsugu; Hayashi, Masahiro

    2015-03-30

    Mixed paramylon esters prepared from paramylon (a storage polysaccharide of Euglena), acetic acid, and a long-chain fatty acid by one-pot synthesis using trifluoroacetic anhydride as a promoter and solvent were shown to have thermoplasticity. Size exclusion chromatography indicated that the mixed paramylon esters had a weight average molecular weight of approximately 4.9-6.7×10(5). Thermal analysis showed that these esters were stable in terms of the glass transition temperature (>90°C) and 5% weight loss temperature (>320°C). The degree of substitution of the long alkyl chain group, a dominant factor determining thermoplasticity, was controlled by tuning the feed molar ratio of acetic acid and long-chain fatty acid to paramylon. These results implied that the one-pot synthesis is useful for preparing structurally-well defined thermoplastic mixed paramylon esters with high molecular weight. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Synthesis of novel naphthoquinone aliphatic amides and esters and their anticancer evaluation.

    Science.gov (United States)

    Kongkathip, Boonsong; Akkarasamiyo, Sunisa; Hasitapan, Komkrit; Sittikul, Pichamon; Boonyalai, Nonlawat; Kongkathip, Ngampong

    2013-02-01

    Fourteen new naphthoquinone aliphatic amides and seventeen naphthoquinone aliphatic esters were synthesized in nine to ten steps from 1-hydroxy-2-naphthoic acid with 9-25% overall yield for the amides, and 16-21% overall yield for the esters. The key step of the amide synthesis is a coupling reaction between amine and various aliphatic acids using 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM) as a coupling agent while for the ester synthesis, DCC/DMAP or CDI was used as the coupling reagent between aliphatic acids and naphthoquinone alcohol. Both naphthoquinone amides and esters were evaluated for their anticancer activity against KB cells. It was found that naphthoquinone aliphatic amides showed stronger anticancer activity than those of the esters when the chains are longer than 7-carbon atoms. The optimum chain of amides is expected to be 16-carbon atoms. In addition, naphthoquinone aliphatic esters with α-methyl on the ester moiety possessed much stronger anticancer activity than the straight chains. Decatenation assay revealed that naphthoquinone amide with 16-carbon atoms chain at 15 μM and 20 μM can completely inhibit hTopoIIα activity while at 10 μM the enzyme activity was moderately inhibited. Molecular docking result also showed the same trend as the cytotoxicity and decatenation assay. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  19. Synthesis of new fatty acids amides from aminolysis of fatty acid methyl esters (FAMEs)

    International Nuclear Information System (INIS)

    Lopes, Carolina R.; Montes D'Oca, Caroline da Ros; Duarte, Rodrigo da C.; Kurz, Marcia H.S.; Primel, Ednei G.; Clementin, Rosilene M.; Villarreyes, Joaquin Ariel M.; Montes D'Oca, Marcelo G.

    2010-01-01

    Recent biochemical and pharmacological studies have led to the characterization of different fatty acid amides as a new family of biologically active lipids. Here, we describe the synthesis of new amides from C16:0, 18:0, 18:1 and 18:1, OH fatty acids (FFA) families with cyclic and acyclic amines and demonstrate for the first time that these compounds produce cytotoxic effects. Application of this method to the synthesis of fatty acid amides was performed using the esters aminolysis as a key step and various carboxylic amides were prepared in good yield from fatty acid methyl esters (FAMEs). (author)

  20. Transesterification Synthesis of Chloramphenicol Esters with the Lipase from Bacillus amyloliquefaciens

    Directory of Open Access Journals (Sweden)

    Fengying Dong

    2017-09-01

    Full Text Available This work presents a synthetic route to produce chloramphenicol esters by taking advantage the high enantio- and regio-selectivity of lipases. A series of chloramphenicol esters were synthesized using chloramphenicol, acyl donors of different carbon chain length and lipase LipBA (lipase cloned from Bacillus amyloliquefaciens. Among acyl donors with different carbon chain lengths, vinyl propionate was found to be the best. The influences of different organic solvents, reaction temperature, reaction time, enzyme loading and water content on the synthesis of the chloramphenicol esters were studied. The synthesis of chloramphenicol propionate (0.25 M with 4.0 g L−1 of LipBA loading gave a conversion of ~98% and a purity of ~99% within 8 h at 50 °C in 1,4-dioxane as solvent. The optimum mole ratio of vinyl propionate to chloramphenicol was increased to 5:1. This is the first report of B. amyloliquefaciens lipase being used in chloramphenicol ester synthesis and a detailed study of the synthesis of chloramphenicol propionate using this reaction. The high enzyme activity and selectivity make lipase LipBA an attractive catalyst for green chemical synthesis of molecules with complex structures.

  1. Novel Synthesis of Phytosterol Ester from Soybean Sterol and Acetic Anhydride.

    Science.gov (United States)

    Yang, Fuming; Oyeyinka, Samson A; Ma, Ying

    2016-07-01

    Phytosterols are important bioactive compounds which have several health benefits including reduction of serum cholesterol and preventing cardiovascular diseases. The most widely used method in the synthesis of its ester analogous form is the use of catalysts and solvents. These methods have been found to present some safety and health concern. In this paper, an alternative method of synthesizing phytosterol ester from soybean sterol and acetic anhydride was investigated. Process parameters such as mole ratio, temperature and time were optimized. The structure and physicochemical properties of phytosterol acetic ester were analyzed. By the use of gas chromatography, the mole ratio of soybean sterol and acetic anhydride needed for optimum esterification rate of 99.4% was 1:1 at 135 °C for 1.5 h. FTIR spectra confirmed the formation of phytosterol ester with strong absorption peaks at 1732 and 1250 cm(-1) , which corresponds to the stretching vibration of C=O and C-O-C, respectively. These peaks could be attributed to the formation of ester links which resulted from the reaction between the hydroxyl group of soybean sterol and the carbonyl group of acetic anhydride. This paper provides a better alternative to the synthesis of phytosterol ester without catalyst and solvent residues, which may have potential application in the food, health-care food, and pharmaceutical industries. © 2016 Institute of Food Technologists®

  2. Catalytic Synthesis of Ethyl Ester From Some Common Oils ...

    African Journals Online (AJOL)

    Catalytic conversion of ethanol to fatty acid ethyl esters (FAEE) was carried out by homogeneous and heterogeneous transesterification of melon seed, shea butter and neem seed oils using NaOH, KOH and 5wt%CaO/Al2O3 catalyst systems respectively. Oil content of the seeds from n-hexane or hot water extract ranged ...

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

    Science.gov (United States)

    Gumel, Ahmad Mohammed; Annuar, M S M

    2016-06-01

    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.

  4. Synthesis of TMP-ester biolubricant basestock from palm stearin fatty acids

    Science.gov (United States)

    Fadzel, Fatimatuzzahraa Mohd; Salimon, Jumat; Derawi, Darfizzi

    2018-04-01

    A potential biolubricant; TMP-ester was produced via esterification of fatty acids (FA) from palm stearin (PS) with trimethylolpropane (TMP). The synthesis was conducted at four conditions; temperature, time, molar ratio of FA:TMP and H2SO4 as catalyst (by percent based on the weight of FA and TMP) that are 150 °C, 2 hours, 4:1 and 1% of H2SO4 respectively. The composition of ester produced was determined using gas chromatography (GC-FID). The presence of ester group was confirmed by the means of FTIR by the existence of strong carboxyl band of ester, v(C=O) at 1746cm-1 and 1H and 13C NMR spectroscopy shows the chemical shift, δ of ester, C=O at 2.27-2.31 ppm and 173.45 ppm accordingly. From the esterification reaction, 95% product of TMP-ester was formed. The thermal and oxidative stability of TMP-ester is 200°C.

  5. Intracellular trafficking of the free cholesterol derived from LDL cholesteryl ester is defective in vivo in Niemann-Pick C disease: insights on normal metabolism of HDL and LDL gained from the NP-C mutation.

    Science.gov (United States)

    Shamburek, R D; Pentchev, P G; Zech, L A; Blanchette-Mackie, J; Carstea, E D; VandenBroek, J M; Cooper, P S; Neufeld, E B; Phair, R D; Brewer, H B; Brady, R O; Schwartz, C C

    1997-12-01

    Niemann-Pick C disease (NP-C) is a rare inborn error of metabolism with hepatic involvement and neurological sequelae that usually manifest in childhood. Although in vitro studies have shown that the lysosomal distribution of LDL-derived cholesterol is defective in cultured cells of NP-C subjects, no unusual characteristics mark the plasma lipoprotein profiles. We set out to determine whether anomalies exist in vivo in the cellular distribution of newly synthesized, HDL-derived or LDL-derived cholesterol under physiologic conditions in NP-C subjects. Three affected and three normal male subjects were administered [14C]mevalonate as a tracer of newly synthesized cholesterol and [3H]cholesteryl linoleate in either HDL or LDL to trace the distribution of lipoprotein-derived free cholesterol. The rate of appearance of free [14C]- and free [3H]cholesterol in the plasma membrane was detected indirectly by monitoring their appearance in plasma and bile. The plasma disappearance of [3H]cholesteryl linoleate was slightly faster in NP-C subjects regardless of its lipoprotein origin. Appearance of free [14C] cholesterol ill the plasma (and in bile) was essentially identical in normal and affected individuals as was the initial appearance of free [3H]cholesterol derived from HDL, observed before extensive exchange occurred of the [3H]cholesteryl linoleate among lipoproteins. In contrast, the rate of appearance of LDL-derived free [3H]cholesterol in the plasma membrane of NP-C subjects, as detected in plasma and bile, was retarded to a similar extent that LDL cholesterol metabolism was defective in cultured fibroblasts of these affected subjects. These findings show that intracellular distribution of both newly synthesized and HDL-derived cholesterol are essentially unperturbed by the NP-C mutation, and therefore occur by lysosomal-independent paths. In contrast, in NP-C there is defective trafficking of LDL-derived cholesterol to the plasma membrane in vivo as well as in vitro

  6. Alcohol consumption and synthesis of ethyl esters of fatty acids in adipose tissue

    NARCIS (Netherlands)

    Björntorp, P; Depergola, G; Sjöberg, C; Pettersson-Kymmer, U.; Hallgren, P; Boström, K; Helander, K G; Seidell, J

    1990-01-01

    Ethyl esters of fatty acids (EEFA) have been found to be formed during ethanol metabolism. Human adipose tissue contains high concentrations of free fatty acids, the substrate for EEFA synthesis, and might therefore be a tissue with great potential for EEFA formation. In order to explore their

  7. Synthesis of γ-Nitro Aliphatic Methyl Esters Via Michael Additions Promoted by Microwave Irradiation

    Directory of Open Access Journals (Sweden)

    Francisco D. Díaz-Coutiño

    2009-04-01

    Full Text Available A simple and efficient protocol has been developed for the direct synthesis of γ-nitrobutyric acid methyl esters under microwave irradiation. This methodology reduces reaction times from days to minutes, compared to conventional conditions. Additionally, these conditions increased yields and provided cleaner reactions.

  8. Synthesis of γ-Nitro Aliphatic Methyl Esters Via Michael Additions Promoted by Microwave Irradiation

    OpenAIRE

    Escalante, Jaime; Díaz-Coutiño, Francisco D.

    2009-01-01

    A simple and efficient protocol has been developed for the direct synthesis of γ-nitrobutyric acid methyl esters under microwave irradiation. This methodology reduces reaction times from days to minutes, compared to conventional conditions. Additionally, these conditions increased yields and provided cleaner reactions.

  9. 1 Synthesis of Selected Phenylalanine Esters C1 to C4 and their ...

    African Journals Online (AJOL)

    Figure 1 Synthesis of Taxol via the Wieland Miescher Ketone. Important natural products .... ml) at 0°C. Thionyl chloride (1ml, 13.8 mmol) was added dropwise to the reaction mixture ... L-Phenylalanine propyl ester hydrochloride. (Yield: 93%).

  10. Aspergillus niger whole-cell catalyzed synthesis of caffeic acid phenethyl ester in ionic liquids.

    Science.gov (United States)

    Rajapriya, Govindaraju; Morya, Vivek Kumar; Mai, Ngoc Lan; Koo, Yoon-Mo

    2018-04-01

    Synthesis of caffeic acid ester essentially requires an efficient esterification process to produce various kinds of medicinally important ester derivatives. In the present study, a comprehensive and comparative analysis of whole-cell catalyzed caffeic acid esters production in ionic liquids (ILs) media was performed. Olive oil induced mycelial mass of halotolerant Aspergillus niger (A.niger) EXF 4321 was freeze dried and used as a catalyst. To ensure maximum solubilization of caffeic acid for highest substrate loading several ILs were screened and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Emim][Tf 2 N]) was found to have the maximum solubility and favoured for enzymatic activity of freeze dried mycelia. The whole-cell catalyzed synthesis of caffeic acid phenethyl ester (CAPE) conditions were optimized and bioconversion up to 84% was achieved at a substrate molar ratio of 1:20 (caffeic acid:2-phenyl ethanol), 30°C for 12h. Results obtained during this study were encouraging and helpful to design a bioreactor system to produce caffeic acid derived esters. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Fully convergent chemical synthesis of ester insulin: determination of the high resolution X-ray structure by racemic protein crystallography.

    Science.gov (United States)

    Avital-Shmilovici, Michal; Mandal, Kalyaneswar; Gates, Zachary P; Phillips, Nelson B; Weiss, Michael A; Kent, Stephen B H

    2013-02-27

    Efficient total synthesis of insulin is important to enable the application of medicinal chemistry to the optimization of the properties of this important protein molecule. Recently we described "ester insulin"--a novel form of insulin in which the function of the 35 residue C-peptide of proinsulin is replaced by a single covalent bond--as a key intermediate for the efficient total synthesis of insulin. Here we describe a fully convergent synthetic route to the ester insulin molecule from three unprotected peptide segments of approximately equal size. The synthetic ester insulin polypeptide chain folded much more rapidly than proinsulin, and at physiological pH. Both the D-protein and L-protein enantiomers of monomeric DKP ester insulin (i.e., [Asp(B10), Lys(B28), Pro(B29)]ester insulin) were prepared by total chemical synthesis. The atomic structure of the synthetic ester insulin molecule was determined by racemic protein X-ray crystallography to a resolution of 1.6 Å. Diffraction quality crystals were readily obtained from the racemic mixture of {D-DKP ester insulin + L-DKP ester insulin}, whereas crystals were not obtained from the L-ester insulin alone even after extensive trials. Both the D-protein and L-protein enantiomers of monomeric DKP ester insulin were assayed for receptor binding and in diabetic rats, before and after conversion by saponification to the corresponding DKP insulin enantiomers. L-DKP ester insulin bound weakly to the insulin receptor, while synthetic L-DKP insulin derived from the L-DKP ester insulin intermediate was fully active in binding to the insulin receptor. The D- and L-DKP ester insulins and D-DKP insulin were inactive in lowering blood glucose in diabetic rats, while synthetic L-DKP insulin was fully active in this biological assay. The structural basis of the lack of biological activity of ester insulin is discussed.

  12. Synthesis of palm oil fatty acid and trimethylolpropane based ester for biolubricant base stocks

    Science.gov (United States)

    Nor, Nurazira Mohd; Derawi, Darfizzi; Salimon, Jumat

    2018-04-01

    RBD palm oil become one of the interesting renewable resources in biolubricant application. However, palm oil cannot be used directly as lubricant due to some performance limitations such as thermal and oxidative stability. This drawback can be overcome by chemical modification through esterification with polyhydric alcohol such as trimethylolpropane (TMP). The synthesis of ester was carried out via esterification of palm oil fatty acid (POFA) with TMP in the presence of 2% sulphuric acid as catalyst at 150 °C for 5 hours. Gas Chromatography equipped with a Flame Ionization Detector (GC-FID) was used to determine the percentage composition of POTMP ester. The structure confirmation of POTMP ester was proven by Fourier Transformation Infra-Red (FTIR), proton and carbon Nuclear Magnetic Resonance (1H-NMR and 13C-NMR) spectroscopy analysis. The result showed that POTMP ester has successfully synthesized with 97.7% composition of triesters (TE), proved by GC chromatogram. Presence of ester group also evidenced by 1H NMR at 2.27-2.30 ppm and 13C NMR at 173.52-173.54 ppm. The percentage yield of POTMP ester produced was 82% and exist in liquid form at room temperature.

  13. Synthesis and characterization of ester and amide derivatives of titanium(IV) carboxymethylphosphonate

    International Nuclear Information System (INIS)

    Melánová, Klára; Beneš, Ludvík; Trchová, Miroslava; Svoboda, Jan; Zima, Vítězslav

    2013-01-01

    A set of layered ester and amide derivatives of titanium(IV) carboxymethylphosphonate was prepared by solvothermal treatment of amorphous titanium(IV) carboxymethylphosphonate with corresponding 1-alkanols, 1,ω-alkanediols, 1-aminoalkanes, 1,ω-diaminoalkanes and 1,ω-amino alcohols and characterized by powder X-ray diffraction, IR spectroscopy and thermogravimetric analysis. Whereas alkyl chains with one functional group form bilayers tilted to the layers, 1,ω-diaminoalkanes and most of 1,ω-alkanediols form bridges connecting the adjacent layers. In the case of amino alcohols, the alkyl chains form bilayer and either hydroxyl or amino group is used for bonding. This simple method for the synthesis of ester and amide derivatives does not require preparation of acid chloride derivative as a precursor or pre-intercalation with alkylamines and can be used also for the preparation of ester and amide derivatives of titanium carboxyethylphosphonate and zirconium carboxymethylphosphonate. - Graphical abstract: Ester and amide derivatives of layered titanium carboxymethylphosphonate were prepared by solvothermal treatment of amorphous solid with alkanol or alkylamine. - Highlights: • Ester and amide derivatives of titanium carboxymethylphosphonate. • Solvothermal treatment of amorphous solid with alkanol or alkylamine. • Ester and amide formation confirmed by IR spectroscopy

  14. Synthesis of carbon-14-labeled sodium palmoxirate and its coenzyme A ester

    Energy Technology Data Exchange (ETDEWEB)

    Weaner, L.E.; Hoerr, D.C.

    1986-04-01

    Synthetic procedures for the preparation of carbon-14-labeled sodium palmoxirate (TDGA), labeled either in the carboxyl position or in the tetradecyl hydrocarbon chain, are described. In addition, the synthesis of the coenzyme A ester of TDGA-14C with a specific activity of 51 mCi/mmol is reported. The coenzyme A ester was prepared by formation of the acyl chloride with oxalyl chloride followed by reaction with coenzyme A (CoA) in a borate-buffered tetrahydrofuran solution. Purification methods and analytical and stability data are reported for the compounds.

  15. Immobilized lipase from Lactobacillus plantarum in meat degradation and synthesis of flavor esters

    Directory of Open Access Journals (Sweden)

    Sita Ramyasree Uppada

    2017-12-01

    Full Text Available Microbial lipases owing to their broad substrate specificity are widely used in various industrial applications like food processing, organic synthesis, detergent formulation and oil manufacturing. In the current study the immobilized lipase from Lactobacillus plantarum was found novel in degrading meat which can be applied in medical field and also in synthesizing different short chain fatty acid esters like 2,3,4-hydroxybenzyl acetates and triazole ester which makes a great impingement in natural flavor industry. The 4-hydroxybenzyl acetate obtained can also be used in cosmetics.

  16. Synthesis and Structural Characterization of 1- and 2-Substituted Indazoles: Ester and Carboxylic Acid Derivatives

    Directory of Open Access Journals (Sweden)

    Isabel Bento

    2006-11-01

    Full Text Available A series of indazoles substituted at the N-1 and N-2 positions with ester-containing side chains -(CH2nCO2R of different lengths (n = 0-6, 9, 10 are described.Nucleophilic substitution reactions on halo esters (X(CH2nCO2R by 1H-indazole inalkaline solution lead to mixtures of N-1 and N-2 isomers, in which the N-1 isomerpredominates. Basic hydrolysis of the ester derivatives allowed the synthesis of thecorresponding indazole carboxylic acids. All compounds were fully characterised bymultinuclear NMR and IR spectroscopies, MS spectrometry and elemental analysis; theNMR spectroscopic data were used for structural assignment of the N-1 and N-2 isomers.The molecular structure of indazol-2-yl-acetic acid (5b was determined by X-raydiffraction, which shows a supramolecular architecture involving O2-H...N1intermolecular hydrogen bonds.

  17. Pyridine-promoted dediazoniation of aryldiazonium tetrafluoroborates: Application to the synthesis of SF5-substituted phenylboronic esters and iodobenzenes

    Directory of Open Access Journals (Sweden)

    George Iakobson

    2015-08-01

    Full Text Available Pyridine promotes dediazoniation of aryldiazonium tetrafluoroborates. The formed aryl radicals were trapped with B2pin2, iodine, or tetrahydrofuran to afford boronic esters, iodobenzenes and benzenes, respectively. The application to the synthesis of (pentafluorosulfanylphenylboronic esters, iodo(pentafluorosulfanylbenzenes and (pentafluorosulfanylbenzene is shown.

  18. Synthesis of amino ester-embedded benzimidazoles: a one-pot sequential protocol under metal-free neutral conditions.

    Science.gov (United States)

    Roy, Priyabrata; Bodhak, Chandan; Pramanik, Animesh

    2017-02-01

    A one-pot three-component protocol has been developed for the synthesis of amino ester-embedded benzimidazoles under metal-free neutral conditions. Sequentially, the methodology involves coupling of an amino ester with 1-fluoro-2-nitrobenzene, reduction of the coupled nitroarene by sodium dithionite, and cyclization of the corresponding diamine with an aldehyde.

  19. Synthesis of the Commercial Fragrance Compound Ethyl 6-Acetoxyhexanoate: A Multistep Ester Experiment for the Second-Year Organic Laboratory

    Science.gov (United States)

    McCullagh, James V.; Hirakis, Sophia P.

    2017-01-01

    This synthesis of ethyl 6-acetoxyhexanoate (Berryflor) is designed as an experiment for use in a second-year organic chemistry course focusing on the synthesis and reaction of esters. The compound is described as having a raspberry-like odor with jasmine and anise aspects. A two-step procedure for its synthesis beginning with inexpensive…

  20. Synthesis of sulfur-containing lubricant additives on the basis of fatty acid ethyl esters

    Directory of Open Access Journals (Sweden)

    Iurii S. Bodachivskyi

    2016-12-01

    Full Text Available The study reveals an energy-, resource- and eco-friendly method for preparation of sulfur-containing lubricant additives via interaction of fatty acid ethyl esters of rapeseed oil with elemental sulfur. The structure of synthesized compounds under various reactants ratio (5–50 wt.% of sulfur, duration (30–240 min and temperature of the process (160–215°С was investigated using various analytical techniques. According to the established data, aside from addition to double bonds, the side reaction of hydrogen substitution at α-methylene groups near these bonds occurs and induces the formation of conjugated systems and chromophoric sulfur-rich derivatives. Also, we found that increase of process duration evokes growth of polysulfane chains, in contrast to the raise of temperature, which leads to the formation of sulfur-containing heterocycles and hydrogen sulfide, as a result of elimination. Influence of accelerators on sulfurization of fatty acid ethyl esters was also examined. The most effective among them are mixtures of zinc dibutyldithiocarbamate with zinc oxide or stearic acid, which soften synthesis conditions and doubly decrease duration of the high-temperature stage. In addition, sulfur-containing compositions of ethyl esters and α-olefins, vulcanized esters by benzoyl peroxide, nonylphenols and zinc dinonylphenyldithiophosphate were designed. The study identified that lithium lubricant with sulfurized vulcanized esters provides improved tribological properties, in comparison with base lubricant or lubricant with the non-modified product.

  1. Synthesis of 11C labelled methyl esters: transesterification of enol esters versus BF3 catalysed esterification-a comparative study

    International Nuclear Information System (INIS)

    Ackermann, Uwe; Blanc, Paul; Falzon, Cheryl L.; Issa, William; White, Jonathan; Tochon-Danguy, Henri J.; Sachinidis, John I.; Scott, Andrew M.

    2006-01-01

    C-11 labelled methyl esters have been synthesized via the transesterification of enol esters in the presence of C-11 methanol and 1,3 dichlorodibutylstannoxane as catalyst. This method leaves functional groups intact and allows access to a wider variety of C-11 labelled methyl esters compared to the BF 3 catalysed ester formation, which uses carboxylic acids and C-11 methanol as starting materials

  2. Rearrangement of beta,gamma-unsaturated esters with thallium trinitrate: synthesis of indans bearing a beta-keto ester moiety

    Directory of Open Access Journals (Sweden)

    Silva Jr. Luiz F.

    2006-01-01

    Full Text Available The rearrangement of beta,gamma-unsaturated esters, such as 2-(3,4-dihydronaphthalen-1-yl-propionic acid ethyl ester, with thallium trinitrate (TTN in acetic acid leads to 3-indan-1-yl-2-methyl-3-oxo-propionic acid ethyl ester in good yield, through a ring contraction reaction. The new indans thus obtained feature a beta-keto ester moiety, which would be useful for further functionalization.

  3. The synthesis of 5-[1-11C]ethyl barbiturates from labelled malonic esters

    International Nuclear Information System (INIS)

    Gee, A.; Laangstroem, B.

    1991-01-01

    The synthesis of [ 11 C]phenobarbital, [ 11 C]pentobarbital and[ 11 C]amobarbital labelled in the 5-[1- 11 C]ethyl position is reported. The malonic esters R- CH(CO 2 Et) 2 [R phenyl-, 1-methylbutyl-, and 3- methylbutyl- were alkylated with [1- 11 C]ethyl iodide prepared from [ 11 C]carbon dioxide. Ring closure of the 2-[1- 11 C]ethyl-labelled malonic esters with urea afforded 5-[1- 11 C]ethyl-phenobarbital,-phenobarbital, -pentobarbital and -amobarbital synthesis times of 42-47 min, counted from [ 11 C] carbon dioxide. In typical syntheses starting with 3 GBq pentobarbitol and (81 mCi) [ 11 C]carbon dioxide, 150-215 MBq (4-6 mCi) were produced in 25-30% decay corrected -amobarbital radiochemical yields with radiochemical purities greater than 98%. (author)

  4. Synthesis of 2-(6-Acetamidobenzothiazolethioacetic Acid Esters as Photosynthesis Inhibitors

    Directory of Open Access Journals (Sweden)

    Dusan Loos

    1998-04-01

    Full Text Available The synthesis and photosynthesis-inhibiting activity of 13 new 2-(6-acetamidobenzothiazolethioacetic acid esters are reported. The new compounds were prepared by acetylation of 2-(alkoxycarbonylmethylthio-6-aminobenzothiazoles with acetic anhydride. The structure of the compounds was verified by 1H NMR spectra. The compounds inhibit photosynthetic electron transfer in spinach chloroplasts. The structure - activity relation was studied. Lipophilicity was found to influence substantially photosynthetic electron transfer.

  5. A Ketone Ester Drink Increases Postexercise Muscle Glycogen Synthesis in Humans.

    Science.gov (United States)

    Holdsworth, David A; Cox, Peter J; Kirk, Tom; Stradling, Huw; Impey, Samuel G; Clarke, Kieran

    2017-09-01

    Physical endurance can be limited by muscle glycogen stores, in that glycogen depletion markedly reduces external work. During carbohydrate restriction, the liver synthesizes the ketone bodies, D-β-hydroxybutyrate, and acetoacetate from fatty acids. In animals and in the presence of glucose, D-β-hydroxybutyrate promotes insulin secretion and increases glycogen synthesis. Here we determined whether a dietary ketone ester, combined with plentiful glucose, can increase postexercise glycogen synthesis in human skeletal muscle. After an interval-based glycogen depletion exercise protocol, 12 well-trained male athletes completed a randomized, three-arm, blinded crossover recovery study that consisted of consumption of either a taste-matched, zero-calorie control or a ketone monoester drink, followed by a 10-mM glucose clamp or saline infusion for 2 h. The three postexercise conditions were control drink then saline infusion, control drink then hyperglycemic clamp, or ketone ester drink then hyperglycemic clamp. Skeletal muscle glycogen content was determined in muscle biopsies of vastus lateralis taken before and after the 2-h clamps. The ketone ester drink increased blood D-β-hydroxybutyrate concentrations to a maximum of 5.3 versus 0.7 mM for the control drink (P glycogen was 50% higher (246 vs 164 mmol glycosyl units per kilogram dry weight, P glycogen synthesis.

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

    OpenAIRE

    Gumel, Ahmad Mohammed; Annuar, M. S. M.

    2016-01-01

    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 a...

  7. Clean synthesis of biolubricant range esters using novel liquid lipase enzyme in solvent free medium.

    Science.gov (United States)

    Trivedi, Jayati; Aila, Mounika; Sharma, Chandra Dutt; Gupta, Piyush; Kaul, Savita

    2015-01-01

    In view of the rising global problems of environment pollution and degradation, the present process provides a 'green solution' to the synthesis of higher esters of lubricant range, more specifically in the range C12-C36, using different combinations of acids and alcohols, in a single step reaction. The esters produced are biodegradable in nature and have a plethora of uses, such as in additives, as lubricating oils and other hydraulic fluids. The enzymatic esterification was performed using liquid (non-immobilized or free) lipase enzyme, without any additional organic solvent. Soluble lipase proves to be superior to immobilized enzymes as it is more cost effective and provides a faster process for the production of higher esters of lubricant range. An interesting finding was, that the lipase enzyme showed higher conversion rates with increasing carbon number of straight chain alcohols and acids. Reactions were carried out for the optimization of initial water concentration, temperature, pH of the substrate mixture and the chain length of the substrates. Under optimized conditions, the method was suitable to achieve ~ 99% conversion. Thus, the process provides an environment friendly, enzymatic alternative to the chemical route which is currently used in the industrial synthesis of lubricant components.

  8. Enzymatic synthesis of arbutin undecylenic acid ester and its inhibitory effect on melanin synthesis.

    Science.gov (United States)

    Tokiwa, Yutaka; Kitagawa, Masaru; Raku, Takao; Yanagitani, Shusaku; Yoshino, Kenji

    2007-06-01

    Transesterification of arbutin and undecylenic acid vinyl ester was catalyzed by alkaline protease, Bioprase, in dimethylformamide to get arbutin derivative having undecylenic acid at 6-position of glucose moiety, 6-O-undecylenoyl p-hydroxyphenyl beta-D-glucopyranoside. The reaction rate increased with increase of arbutin concentration, and when its concentration was 0.9 M, the conversion rate was more than 90% under addition of 2 M undecylenic acid vinyl ester. The obtained arbutin ester significantly suppressed melanin production in murine B16 melanoma cells.

  9. Production of wax esters via microbial oil synthesis from food industry waste and by-product streams.

    Science.gov (United States)

    Papadaki, Aikaterini; Mallouchos, Athanasios; Efthymiou, Maria-Nefeli; Gardeli, Chryssavgi; Kopsahelis, Nikolaos; Aguieiras, Erika C G; Freire, Denise M G; Papanikolaou, Seraphim; Koutinas, Apostolis A

    2017-12-01

    The production of wax esters using microbial oils was demonstrated in this study. Microbial oils produced from food waste and by-product streams by three oleaginous yeasts were converted into wax esters via enzymatic catalysis. Palm oil was initially used to evaluate the influence of temperature and enzyme activity on wax ester synthesis catalysed by Novozyme 435 and Lipozyme lipases using cetyl, oleyl and behenyl alcohols. The highest conversion yields (up to 79.6%) were achieved using 4U/g of Novozyme 435 at 70°C. Transesterification of microbial oils to behenyl and cetyl esters was achieved at conversion yields up to 87.3% and 69.1%, respectively. Novozyme 435 was efficiently reused for six and three cycles during palm esters and microbial esters synthesis, respectively. The physicochemical properties of microbial oil derived behenyl esters were comparable to natural waxes. Wax esters from microbial oils have potential applications in cosmetics, chemical and food industries. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Synthesis, characterization and application of lipase-conjugated citric acid-coated magnetic nanoparticles for ester synthesis using waste frying oil.

    Science.gov (United States)

    Patel, Unisha; Chauhan, Kishor; Gupte, Shilpa

    2018-04-01

    In the present work, magnetic nanoparticles (MNPs) were prepared by chemical precipitation of trivalent and divalent iron ions which were functionalized using citric acid. The bacterial isolate Staphylococcus epidermidis KX781317 was isolated from oil-contaminated site. The isolate produced lipase, which was purified and immobilized on magnetic nanoparticles (MNPs) for ester synthesis from waste frying oil (WFO). The characterization of MNPs employed conventional TEM, XRD and FTIR techniques. TEM analysis of MNPs showed the particle size in the range of 20-50 nm. FTIR spectra revealed the binding of citric acid to Fe 3 O 4 and lipase on citric acid-coated MNPs. The citric acid-coated MNPs and lipase-conjugated citric acid-coated MNPs had similar XRD patterns which indicate MNPs could preserve their magnetic properties. The maximum immobilization efficiency 98.21% of lipase-containing citric acid-coated MNPs was observed at ratio 10:1 of Cit-MNPs:lipase. The pH and temperature optima for lipase conjugated with Cit-MNPs were 7 and 35 °C, respectively. Isobutanol was found to be an effective solvent for ester synthesis and 1:2 ratio of oil:alcohol observed significant for ester formation. The ester formation was determined using TLC and the % yield of ester conversion was calculated. The rate of ester formation is directly proportional to the enzyme load. Formed esters were identified as isobutyl laurate ester and isobutyl myristate ester through GC-MS analysis.

  11. Zeolite/magnetite composites as catalysts on the Synthesis of Methyl Esters (MES) from cooking oil

    Science.gov (United States)

    Sriatun; Darmawan, Adi; Sriyanti; Cahyani, Wuri; Widyandari, Hendri

    2018-05-01

    The using of zeolite/magnetite composite as a catalyst for the synthesis of methyl esters (MES) of cooking oil has been performed. In this study the natural magnetite was extracted from the iron sand of Semarang marina beach and milled by high energy Milling (HEM) with ball: magnetite ratio: 1:1. The composites prepared from natural zeolite and natural magnetite with zeolite: magnetite ratio 1:1; 2:1; 3:1 and 4:1. Preparation of methyl ester was catalyzed by composite of zeolite/magnetite through transeserification reaction, it was studied on variation of catalyst concentration (w/v) 1%, 3%, 5% and 10% to feed volume. The reaction product are mixture of methyl Oleic (MES), methyl Palmitic (MES) and methyl Stearic (MES). Character product of this research include density, viscosity, acid number and iodine number has fulfilled to SNI standard 7182: 2015.

  12. [Synthesis and regulation of flavor compounds derived from brewing yeast: Esters].

    Science.gov (United States)

    Loviso, Claudia L; Libkind, Diego

    2018-04-04

    During brewing process yeast produce more than 500 chemical compounds that can negatively and positively impact beer at the organoleptic level. In recent years, and particularly thanks to the advancement of molecular biology and genomics, there has been considerable progress in our understanding about the molecular and cellular basis of the synthesis and regulation of many of these flavor compounds. This article focuses on esters, responsible for the floral and fruity beer flavor. Its formation depends on various enzymes and factors such as the concentration of wort nutrients, the amount of dissolved oxygen and carbon dioxide, fermentation temperature and mainly the genetics of the yeast used. We provide information about how the esters originate and how is the impact of different fermentative parameters on the final concentrations of these compounds and the quality of the end product. Copyright © 2018 The Authors. Publicado por Elsevier España, S.L.U. All rights reserved.

  13. Synthesis of methyl esters from waste cooking oil using construction waste material as solid base catalyst.

    Science.gov (United States)

    Balakrishnan, K; Olutoye, M A; Hameed, B H

    2013-01-01

    The current research investigates synthesis of methyl esters by transesterification of waste cooking oil in a heterogeneous system, using barium meliorated construction site waste marble as solid base catalyst. The pretreated catalyst was calcined at 830 °C for 4h prior to its activity test to obtained solid oxide characterized by scanning electron microscopy/energy dispersive spectroscopy, BET surface area and pore size measurement. It was found that the as prepared catalyst has large pores which contributed to its high activity in transesterification reaction. The methyl ester yield of 88% was obtained when the methanol/oil molar ratio was 9:1, reaction temperature at 65 °C, reaction time 3h and catalyst/oil mass ratio of 3.0 wt.%. The catalyst can be reused over three cycles, offer low operating conditions, reduce energy consumption and waste generation in the production of biodiesel. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Synthesis of esters of morpholino-4-carbothionothiolic acid as compounds of potential radioprotective action

    Energy Technology Data Exchange (ETDEWEB)

    Strzelczyk, M.; Kucharski, A. (Wojskowa Akademia Medyczna, Lodz (Poland))

    1979-01-01

    The compounds of the group of dithiocarbaminianes as complexing compounds are of importance in radioprotection. Present paper concerns the synthesis of 19, as yet undescribed dithiocarbaminianes esters of morpholino-4-carbothionothiolic acid. They were obtained in the reaction of the potassium salt of the mentioned acid with adequate alkyl or alkyloaryl halogenatas. Potassium salt of the morpholino-4-carbothionothiolic acid was obtained in the reaction of morpholine with carbon disulphite in the presence of potassium hydroxide. Obtaining of the pure potassium salt of the mentioned acid enabled the accurate calculation of the used substarate in further reactions and conduction of reaction in different solvents. Phenyloalkyl, phenacyl and morpholino-4-carbonyloalkyl esters were obtained. Their chemical structure was confirmed by elementary and spectral infrared analysis.

  15. Early effects of dietary orotic acid upon liver lipid synthesis and bile cholesterol secretion in rats

    International Nuclear Information System (INIS)

    Tokmakjian, S.D.; Haines, D.S.

    1985-01-01

    Dietary orotic acid is known to cause impaired fatty acid synthesis and increased cholesterol synthesis in rats. The authors found that the impaired fatty acid synthesis occurs during the first day of orotic acid feeding and, in studies with albumin-bound [1- 14 C]palmitic acid, an associated decrease in the rate of esterification of this fatty acid into triacylglycerol, phospholipid, and cholesteryl ester was observed. These changes may result from the known decreases in liver levels of adenine nucleotides or, as reported here, from decreased liver CoASH levels in orotic acid-fed rats. The increase in hepatic cholesterol synthesis occurred during the second day of orotic acid feeding. It was detected by increased incorporation of [1,2- 14 C]acetate into cholesterol by liver slices and by a 7-fold increase in HMG-CoA reductase activity. At the same time the biliary output of cholesterol was increased 2-fold and studies using 3 H 2 O revealed that the output of newly synthesized cholesterol in bile was increased 5-fold. The content of cholesteryl ester in hepatic microsomes decreased during orotic acid feeding but free cholesterol was unchanged. The findings are interpreted to suggest that the increased bile cholesterol secretion caused by orotic acid is a result of impaired hepatic cholesterol esterification and that the increase in HMG-CoA reductase activity is a result of diminished negative feedback due to the depleted content of cholesteryl ester in the hepatic microsomes

  16. A convenient synthesis of deuterated leukotriene A sub 4 methyl ester

    Energy Technology Data Exchange (ETDEWEB)

    Bestmann, H.J.; Roeder, T. (Erlangen-Nuernberg Univ., Erlangen (Germany, F.R.). Inst. fuer Organische Chemie); Meese, C.O. (Fischer-Bosch-Inst. fuer Klinische Pharmakologie, Stuttgart (Germany, F.R.))

    1989-11-01

    2,2,3,3-({sup 2}H{sub 4})-1-Iodopentane was prepared in four steps from propargyl alcohol and used in the C-alkylation of the THP-protected 3-butyne-1-ol. Subsequent protective group removal, semi-deuteration of the acetylenic alcohol and further transformation by known methods afforded the labelled key reagent 3,4,6,6,7,7-({sup 2}H{sub 6})-(Z)-(3-nonen-1-yl)triphenylphosphonium iodide. Wittig olefination of epoxy dienal with the ylide generated from the latter completed the convenient synthesis of hexadeuterated leukotriene A{sub 4} methyl ester. (author).

  17. Synthesis of [11C]-labelled methyl esters: transesterification of enol esters versus BF3 etherate catalysed esterification - a comparative study

    International Nuclear Information System (INIS)

    Ackermann, U.; Falzon, C.; Issa, W.; Tochon-Danguy, H.J.; Sachinidis, J.I.; Blanc, P.; White, J.; Scott, A.M.

    2005-01-01

    An important issue in Positron Emission Tomography (PET) is the development of labelling techniques to incorporate positron emitting radionuclides into biologically active compounds. When labelling with 11C, the short 20 minutes half-life of the radionuclide significantly limits the number of synthetic protocols available to the radiochemist. C-l synthons such as [HCJ-methyl iodide (1) or methyl triflate (2) are readily available and are frequently used as alkylating agents for the preparation of radiopharmaceuticals. However, the use of these alkylating agents often makes it necessary to introduce protecting groups in order to prevent labelling at unwanted sites on the molecule. Since the removal of protecting groups is a time-consuming process, a more direct synthesis strategy is desirable. This has prompted us to investigate the esterification of carboxylic acids using [1 lC]-mcthanol and BF3 etherate as Lewis acid catalyst. Our results have demonstrated that the reaction conditions necessary to promote the esterification can cleave functional groups such as ethers. We have therefore shifted our attention towards the irreversible transesterification of enol esters using [HCl-methanol and a tin catalyst as an alternative strategy to [HC]-methyl ester formation. We have prepared a series of 5 aromatic ethoxy vinyl esters bearing various functional groups. The transesterification (radiolabelling) was carried out in DMSO at 150 Degrees C for 7 minutes in the presence of [HQMeOH and 1.3-dichlo-rotetrabutyldistannoxane as catalyst. We have found that the transesterification of enol esters is a mild and efficient labelling method for the formation of [HCl-methyl esters. The reaction proceeds smoothly and leaves functional groups intact. It requires only one synthesis step compared to two steps for the conventional method, and gives a radiochemical yields of 25%

  18. Optimization of lipase-catalyzed synthesis of ginsenoside Rb1 esters using response surface methodology.

    Science.gov (United States)

    Hu, Jiang-Ning; Lee, Jeung-Hee; Zhu, Xue-Mei; Shin, Jung-Ah; Adhikari, Prakash; Kim, Jae-Kyung; Lee, Ki-Teak

    2008-11-26

    In the lipase (Novozyme 435)-catalyzed synthesis of ginsenoside Rb1 esters, different acyl donors were found to affect not only the degree of conversion but also the regioselectivity. The reaction of acyl donors with short carbon chain was more effective, showing higher conversion than those with long carbon chain. Among the three solvent systems, the reaction in tert-amyl alcohol showed the highest conversion rate, while the reaction in the mixed solvent of t-BuOH and pyridine (1:1) had the lowest conversion rate. To allow the increase of GRb1 lipophilicity, we decided to further study the optimal condition of synthesis of GRb1 with vinyl decanoate with 10 carbon chain fatty acids in tert-amyl alcohol. Response surface methodology (RSM) was employed to optimize the synthesis condition. From the ridge analysis with maximum responses, the maximum GRb1 conversion was predicted to be 61.51% in a combination of factors (40.2 h, 52.95 degrees C, substrate mole ratio 275.57, and enzyme amount 39.81 mg/mL). Further, the adequacy of the predicted model was examined by additional independent experiments at the predicted maximum synthesis conditions. Results showed that the RSM was effective to optimize a combination of factors for lipase-catalyzed synthesis of ginsenoside Rb1 with vinyl decanoate.

  19. The synthesis of 5-(1- sup 11 C)ethyl barbiturates from labelled malonic esters

    Energy Technology Data Exchange (ETDEWEB)

    Gee, A.; Laangstroem, B. (Uppsala Univ. (Sweden). Dept. of Organic Chemistry)

    1991-01-01

    The synthesis of ({sup 11}C)phenobarbital, ({sup 11}C)pentobarbital and({sup 11}C)amobarbital labelled in the 5-(1-{sup 11}C)ethyl position is reported. The malonic esters R- CH(CO{sub 2}Et){sub 2} R phenyl-, 1-methylbutyl-, and 3- methylbutyl- were alkylated with (1-{sup 11}C)ethyl iodide prepared from ({sup 11}C)carbon dioxide. Ring closure of the 2-(1-{sup 11}C)ethyl-labelled malonic esters with urea afforded 5-(1-{sup 11}C)ethyl-phenobarbital,-phenobarbital, -pentobarbital and -amobarbital synthesis times of 42-47 min, counted from ({sup 11}C) carbon dioxide. In typical syntheses starting with 3 GBq pentobarbitol and (81 mCi) ({sup 11}C)carbon dioxide, 150-215 MBq (4-6 mCi) were produced in 25-30% decay corrected -amobarbital radiochemical yields with radiochemical purities greater than 98%. (author).

  20. Influence of preparation conditions and heat treatment on the properties of supercooled smectic cholesteryl myristate nanoparticles

    DEFF Research Database (Denmark)

    Kuntsche, Judith; Bunjes, H

    2007-01-01

    is less effective even when applying the highest homogenization pressure possible but still leads to dispersions with particles in the colloidal size range. Since sterility is required for parenteral medications and is usually achieved by autoclaving for aqueous systems, the physical and chemical...... chromatography (HPTLC). The results indicate that cholesteryl myristate nanoparticles stabilized with phospholipid/sodium glycocholate, polyvinyl alcohol, poloxamer and poloxamine can be sterilized by autoclaving. Compared to cholesterol ester free dispersions of phospholipids, the phospholipid seems to be more...

  1. Direct Analysis in Real Time Mass Spectrometry of Potential By-Products from Homemade Nitrate Ester Explosive Synthesis

    OpenAIRE

    Sisco, Edward; Forbes, Thomas P.

    2015-01-01

    This work demonstrates the coupling of direct analysis in real time (DART) ionization with time-of-flight mass spectrometry (MS) in an off-axis configuration for the trace detection and analysis of potential partially nitrated and dimerized by-products of homemade nitrate ester explosive synthesis. Five compounds relating to the synthesis of nitroglycerin (NG) and pentaerythritol tetranitrate (PETN) were examined. Deprotonated ions and adducts with molecular oxygen, nitrite, and nitrate were ...

  2. Self-healing anticorrosive organic coating based on an encapsulated water reactive silyl ester: synthesis and proof of concept

    NARCIS (Netherlands)

    García, S.J.; Fischer, H.R.; White, P.A.; Mardel, J.; González-García, Y.; Mol, J.M.C.; Hughes, A.E.

    2011-01-01

    In this paper a self-healing anticorrosive organic coating based on an encapsulated water reactive organic agent is presented. A reactive silyl ester is proposed as a new organic reactive healing agent and its synthesis, performance, incorporation into an organic coating and evaluation of

  3. Fast and efficient green synthesis of thiosulfonate S-esters by microwave-supported permanganate oxidation of symmetrical disulfides

    DEFF Research Database (Denmark)

    Thi, Luu Thi Xuan; Thi Nguyen, Thao-Tran; Le, Thach Ngoc

    2015-01-01

    Potassium permanganate absorbed on copper(II) sulfate pentahydrate has been found to be an efficient, inexpensive, and green oxidation agent for the synthesis of “symmetrical” thiosulfonate S-esters by oxidation of the corresponding symmetrical disulfides. The oxidation reactions were carried out...

  4. Synthesis and Characterization of InS Nanorods in Sucrose Ester Water-in-Oil Microemulsion

    Directory of Open Access Journals (Sweden)

    N. M. Huang

    2011-01-01

    Full Text Available We report the synthesis of In2S3 nanorods in a nonionic sugar-based water-in-oil (w/o microemulsion system using food grade sucrose ester as biosurfactant. In2S3 was formed by mixing indium (III chloride and thioacetamide in the water core of the microemulsion system. The as-prepared yellowish In2S3 was characterized by X-ray diffractometry (XRD, UV-visible absorption spectroscopy (UV-Vis, transmission electron microscopy (TEM, and Fourier transform infrared spectroscopy (FTIR. Formation of spherical or rod-like In2S3 nanomaterials was dependent on reaction time. Rod-like In2S3, arranged in bundles, was formed only after 2 days of reaction time. Upon longer aging time, a mixture of rod-like and spherical In2S3 was formed. A plausible formation mechanism of the In2S3 nanorods in the sucrose ester microemulsion was postulated. The diameter of the In2S3 nanorods was found to be very small, which is 8.97±2.36 nm with aspect ratio of 20 : 1 (length : diameter.

  5. Synthesis and Antiradical Activity of Isoquercitrin Esters with Aromatic Acids and Their Homologues

    Directory of Open Access Journals (Sweden)

    Eva Heřmánková-Vavříková

    2017-05-01

    Full Text Available Isoquercitrin, (IQ, quercetin-3-O-β-d-glucopyranoside is known for strong chemoprotectant activities. Acylation of flavonoid glucosides with carboxylic acids containing an aromatic ring brings entirely new properties to these compounds. Here, we describe the chemical and enzymatic synthesis of a series of IQ derivatives at the C-6″. IQ benzoate, phenylacetate, phenylpropanoate and cinnamate were prepared from respective vinyl esters using Novozym 435 (Lipase B from Candida antarctica immobilized on acrylic resin. The enzymatic procedure gave no products with “hydroxyaromatic” acids, their vinyl esters nor with their benzyl-protected forms. A chemical protection/deprotection method using Steglich reaction yielded IQ 4-hydroxybenzoate, vanillate and gallate. In case of p-coumaric, caffeic, and ferulic acid, the deprotection lead to the saturation of the double bonds at the phenylpropanoic moiety and yielded 4-hydroxy-, 3,4-dihydroxy- and 3-methoxy-4-hydroxy-phenylpropanoates. Reducing capacity of the cinnamate, gallate and 4-hydroxyphenylpropanoate towards Folin-Ciocalteau reagent was significantly lower than that of IQ, while other derivatives displayed slightly better or comparable capacity. Compared to isoquercitrin, most derivatives were less active in 1,1-diphenyl-2-picrylhydrazyl (DPPH radical scavenging, but they showed significantly better 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid, ABTS scavenging activity and were substantially more active in the inhibition of tert-butylhydroperoxide induced lipid peroxidation of rat liver microsomes. The most active compounds were the hydroxyphenylpropanoates.

  6. Lipase mediated synthesis of rutin fatty ester: Study of its process parameters and solvent polarity.

    Science.gov (United States)

    Vaisali, C; Belur, Prasanna D; Regupathi, Iyyaswami

    2017-10-01

    Lipophilization of antioxidants is recognized as an effective strategy to enhance solubility and thus effectiveness in lipid based food. In this study, an effort was made to optimize rutin fatty ester synthesis in two different solvent systems to understand the influence of reaction system hydrophobicity on the optimum conditions using immobilised Candida antartica lipase. Under unoptimized conditions, 52.14% and 13.02% conversion was achieved in acetone and tert-butanol solvent systems, respectively. Among all the process parameters, water activity of the system was found to show highest influence on the conversion in each reaction system. In the presence of molecular sieves, the ester production increased to 62.9% in tert-butanol system, unlike acetone system. Under optimal conditions, conversion increased to 60.74% and 65.73% in acetone and tert-butanol system, respectively. This study shows, maintaining optimal water activity is crucial in reaction systems having polar solvents compared to more non-polar solvents. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Abiotic condensation synthesis of glyceride lipids and wax esters under simulated hydrothermal conditions.

    Science.gov (United States)

    Rushdi, Ahmed I; Simoneit, Bernd R T

    2006-04-01

    Precursor compounds for abiotic proto cellular membranes are necessary for the origin of life. Amphipathic compounds such as fatty acids and acyl glycerols are important candidates for micelle/bilayer/vesicle formation. Two sets of experiments were conducted to study dehydration reactions of model lipid precursors in aqueous media to form acyl polyols and wax esters, and to evaluate the stability and reactions of the products at elevated temperatures. In the first set, mixtures of n-nonadecanoic acid and ethylene glycol in water, with and without oxalic acid, were heated at discrete temperatures from 150 ( composite function)C to 300 ( composite function)C for 72 h. The products were typically alkyl alkanoates, ethylene glycolyl alkanoates, ethylene glycolyl bis-alkanoates and alkanols. The condensation products had maximum yields between 150 ( composite function)C and 250 ( composite function)C, and were detectable and thus stable under hydrothermal conditions to temperatures acid and glycerol were heated using the same experimental conditions, with and without oxalic acid, between 100 ( composite function)C and 250 ( composite function)C. The main condensation products were two isomers each of monoacylglycerols and diacylglycerols at all temperatures, as well as minor amounts of the fatty acid anhydride and methyl ester. The yield of glyceryl monoheptanoates generally increased with increasing temperature and glyceryl diheptanoates decreased noticeably with increasing temperature. The results indicate that condensation reactions and abiotic synthesis of organic lipid compounds under hydrothermal conditions occur easily, provided precursor concentrations are sufficiently high.

  8. Immobilized Rhizopus oryzae lipase catalyzed synthesis of palm stearin and cetyl alcohol wax esters: Optimization by Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Gargouri Youssef

    2011-06-01

    Full Text Available Abstract Background Waxes are esters of long-chain fatty acids and long-chain alcohols. Their principal natural sources are animals (sperm whale oil and vegetables (jojoba which are expensive and not easily available. Wax esters synthesized by enzymatic transesterification, using palm stearin as raw material, can be considered as an alternative to natural ones. Results Palm stearin is a solid fraction obtained by fractionation of palm oil. Palm stearin was esterified with cetyl alcohol to produce a mixture of wax esters. A non-commercial immobilized lipase from Rhizopus oryzae was used as biocatalyst. Response surface methodology was employed to determine the effects of the temperature (30-50°C, the enzyme concentration (33.34-300 IU/mL, the alcohol/palm stearin molar ratio (3-7 mol/mol and the substrate concentration (0.06-0.34 g/mL on the conversion yield of palm stearin. Under optimal conditions (temperature, 30°C; enzyme concentration, 300 IU/mL; molar ratio 3 and substrate concentration 0.21 g/mL a high conversion yield of 98.52% was reached within a reaction time of 2 h. Conclusions Response surface methodology was successfully applied to determine the optimum operational conditions for synthesis of palm stearin based wax esters. This study may provide useful tools to develop economical and efficient processes for the synthesis of wax esters.

  9. Anti-inflammatory agents of the carbamoylmethyl ester class: synthesis, characterization, and pharmacological evaluation

    Directory of Open Access Journals (Sweden)

    Sadek B

    2013-03-01

    Full Text Available Bassem Sadek,1 Amar Mansuor Hamruoni,2 Abdu Adem1 1Department of Pharmacology and Therapeutics, College of Medicine and Health Sciences, United Arab Emirates University, 2Department of Pharmaceutical Sciences, College of Pharmacy, Al Ain University of Science and Technology, Al-Ain, United Arab Emirates Abstract: In this study, target compounds 5–12 were synthesized via acid amine coupling of ibuprofen and naproxen with methyl ester derivatives of amino acids, namely, l-proline, sarcosine, l-tyrosine, and l-glutamic acid. When tested for anti-inflammatory activity using the acute carrageenan-induced hind paw method in rats, compounds 5–12 showed significantly greater anti-inflammatory activity, in the range of 40.64%–87.82%, compared with a placebo control group (P < 0.001. Among the newly synthesized compounds 5–12, naproxen derivatives 9–12 with anti-inflammatory activity ranging between 66.99% and 87.82% showed significantly higher (P < 0.05 potency than ibuprofen derivatives 5–8 with inhibition in the range of 22.03%–52.91% and control groups of ibuprofen (76.34% or naproxen (75.59%, P < 0.05. Moreover, derivatives 9–12 derived from naproxen, in particular compounds 9 and 10 which achieved 83.91% and 87.82% inhibition of inflammation, respectively, showed significantly (P < 0.05 higher potency than naproxen derivatives 11 and 12. Notably, among naproxen derivatives 9–12, the gastric ulcerogenicity for 9 (ulcer index 11.73 and 10 (ulcer index 12.30 was found to be significantly lower (P < 0.05 than that of the active ibuprofen and naproxen control groups with ulcer indices of 22.87 and 24.13, respectively. On the other hand, naproxen derivatives 9–11 showed significant inhibition (P < 0.05 of prostaglandin E2 synthesis when compared with the active control group receiving indomethacin, suggesting a correlation between the observed low ulcerogenicity and effect on prostaglandin E2 synthesis for compounds 9 and 10. However

  10. Immobilization of Yarrowia lipolytica lipase Ylip2 for the biocatalytic synthesis of phytosterol ester in a water activity controlled reactor.

    Science.gov (United States)

    Cui, Caixia; Guan, Nan; Xing, Chen; Chen, Biqiang; Tan, Tianwei

    2016-10-01

    In this work, phytosterol ester was synthesized using Yarrowia lipolytica lipase Ylip2 that had been immobilized on inorganic support in a solvent-free system and reacted in a computer-aided water activity controlled bioreactor. The immobilization of Ylip2 on celite led to a remarkable increase in the phytosterol conversion compared to that of free lipase. An investigation of the reaction conditions were oleic acid as the fatty acid variety, 10,000U/g substrate, and a temperature of 50°C for phytosterol ester synthesis. Controlling of the water activity at a set point was accomplished by the introduction of dry air through the reaction medium at a digital feedback controlled flow rate. For the esterification of phytosterol ester, a low (15%) water activity resulted in a considerable improvement in phytosterol conversion (91.1%) as well as a decreased reaction time (78h). Furthermore, Ylip2 lipase immobilized on celite retained 90% esterification activity for the synthesis of phytosterol oleate after reused 8 cycles, while free lipase was only viable for 5 batches with 90% esterification activity remained. Finally, the phytosterol oleate space time yield increased from 1.65g/L/h with free lipase to 2.53g/L/h with immobilized lipase. These results illustrate that the immobilized Yarrowia lipolytica lipase Ylip2 in a water activity controlled reactor has great potential for the application in phytosterol esters synthesis. Copyright © 2016. Published by Elsevier B.V.

  11. Effect of external mass transfer on activation energy of butyl oleate ester synthesis using a whole cell bio catalyst

    International Nuclear Information System (INIS)

    Shahhoseini, Sh.; Nasernejad, B.; Vahabzadeh, F.

    2016-01-01

    In the present research, synthesis of butyl oleate ester from oleic acid and butanol using loofa-immobilized Rhizopus oryzae as a whole cell biocatalyst (LIC) was studied in which hexane was used as the hydrophobic solvent. Decrease of mass transfer limitations as result of the interface formation between the two immiscible substrates, positively affected on the reaction progress (87% as the ester product yielded within 10 h). By applying Arrhenius equation, the activation energy of the ester synthesis was determined as Ea=18.2 kJ/mol within temperature range of 15-45°C. It was notable to test appearance of the nonlinearity in Arrhenius plot which was indicative of presence of two sections. The reaction limited region was 15-35°C; Ea=27 kJ/mol and diffusion limited region was >35°C; Ea=6.8 kJ/mol. Eventually, in this research, influence of external mass transfer on activation energy with reference to the catalytic role of the LIC in the ester synthesis was discussed.

  12. Kinetics of enzymatic synthesis of liquid wax ester from oleic acid and oleyl alcohol.

    Science.gov (United States)

    Radzi, Salina Mat; Mohamad, Rosfarizan; Basri, Mahiran; Salleh, Abu Bakar; Ariff, Arbakariya; Rahman, Mohammad Basyaruddin Abdul; Rahman, Raja Noor Zaliha Raja Abdul

    2010-01-01

    The kinetics of wax ester synthesis from oleic acid and oleyl alcohol using immobilized lipase from Candida antartica as catalyst was studied with different types of impeller (Rushton turbine and AL-hydrofoil) to create different mixing conditions in 2l stirred tank reactor. The effects of catalyst concentration, reaction temperature, and impeller tip speed on the synthesis were also evaluated. Rushton turbine impeller exhibited highest conversion rate at lower impeller tip speed as compared to AL-hydrofoil impeller. A second-order reversible kinetic model from single progress curve for the prediction of fractional conversion at given reaction time was proposed and the corresponding kinetic parameter values were calculated by non-linear regression method. The results from the simulation using the proposed model showed satisfactory agreement with the experimental data. Activation energy shows a value of 21.77 Kcal/mol. The thermodynamic parameters of the process, enthalpy and entropy, were 21.15 Kcal/mol and 52.07 cal/mol.K, respectively.

  13. Design and synthesis of new esters of terpenoid alcohols as 15-lipoxygenase inhibitors

    Directory of Open Access Journals (Sweden)

    Hamid Sadeghian

    2018-07-01

    Full Text Available Objective(s: 15-Lipoxygenases are one of the iron-containing proteins capable of performing peroxidation of unsaturated fatty acids in animals and plants. The critical role of enzymes in the formation of inflammations, sensitivities, and some cancers has been demonstrated in mammals. The importance of enzymes has led to the development of mechanistic studies, product analysis, and synthesis of inhibitors. Materials and Methods: The inhibitory activity of all synthetic compounds against SLO (soybean 15-lipoxygenase: L1; EC 1,13,11,12 was determined using the peroxide formation method. In this method, the basis of evaluation of lipoxygenase activity is measuring the concentration of fatty acid peroxide. All measurements were compared with  4-​methyl-​2-​(4-​methylpiperazinylpyrimido[4,​5-​b]benzothiazine (4-MMPB as one of the known lipoxygenase inhibitors. The radical scavenging ability of all synthetic compounds using stable free radicals (DPPH: 2,2-diphenyl-1-picrylhydrazyl was measured for further investigation.Results: In this study, a series of esters from phenolic acids with terpenoid alcohols was synthesized and their inhibitory potency against soybean 15-lipoxygenase and their free radical scavenging properties were determined. Among the synthetic compounds, adamantyl protocatetuate 2j and bornyl protocatetuate 2o showed the most potent inhibitory activity with IC50 values of 0.95 and 0.78 μm, respectively.Conclusion: By changing the alcohol and acyl portions of stylosin, it was found that electronic properties play main role in lipoxygenase inhibition potency in contrast with steric features. Insertion of more reductive phenolic moiety such as catechuate and gallate lead to more lipoxygenase inhibition potency of the esters as observed in their radical scavenging activity.

  14. A Chemo-Enzymatic Road Map to the Synthesis of CoA Esters

    Directory of Open Access Journals (Sweden)

    Dominik M. Peter

    2016-04-01

    Full Text Available Coenzyme A (CoA is a ubiquitous cofactor present in every known organism. The thioesters of CoA are core intermediates in many metabolic processes, such as the citric acid cycle, fatty acid biosynthesis and secondary metabolism, including polyketide biosynthesis. Synthesis of CoA-thioesters is vital for the study of CoA-dependent enzymes and pathways, but also as standards for metabolomics studies. In this work we systematically tested five chemo-enzymatic methods for the synthesis of the three most abundant acyl-CoA thioester classes in biology; saturated acyl-CoAs, α,β-unsaturated acyl-CoAs (i.e., enoyl-CoA derivatives, and α-carboxylated acyl-CoAs (i.e., malonyl-CoA derivatives. Additionally we report on the substrate promiscuity of three newly described acyl-CoA dehydrogenases that allow the simple conversion of acyl-CoAs into enoyl-CoAs. With these five methods, we synthesized 26 different CoA-thioesters with a yield of 40% or higher. The CoA esters produced range from short- to long-chain, include branched and α,β-unsaturated representatives as well as other functional groups. Based on our results we provide a general guideline to the optimal synthesis method of a given CoA-thioester in respect to its functional group(s and the commercial availability of the precursor molecule. The proposed synthetic routes can be performed in small scale and do not require special chemical equipment, making them convenient also for biological laboratories.

  15. Assessment of anti-atherogenic drugs in vivo and reconstitution of lipoproteins using radioiodinated cholesteryl iopanoate

    International Nuclear Information System (INIS)

    DeGalan, M.R.

    1987-01-01

    A nonhydrolyzable radioiodinated cholesteryl ester, 125I-cholesteryl iopanoate (125I-Cl), was found to accumulate in high concentrations in atherosclerotic aortas of cholesterol-fed rabbits after intravenous administration. Aortas from normal chow-fed rabbits did not exhibit significant 125I-Cl accumulation. When cholesterol-fed rabbits were intravenously administered Tween-solubilized 125I-Cl and simultaneously treated with either of two anti-atherogenic compounds, estradiol 17β-cypionate or colestipol, the extent of aortic atherosclerosis was found to dramatically decrease. Measurement of aortic radioactivity was found to strongly correlate with the severity of atherosclerosis. Although the specificity of 125I-Cl for atheromatous lesions was very good, gamma-camera scintigraphy of the abdomens of these rabbits 6 days after cessation of 125I-Cl administration was not able to consistently predict the severity of atherosclerosis. Tissue distribution studies suggested that high blood and spinal column bone marrow radioactivity produced aorta:nontarget radioactivity ratios unfavorable with respect to imaging. To improve this ratio so as to permit noninvasive imaging, attempts were made to incorporate 125I-Cl into serum lipoproteins. Labelling of either rabbit LDL by in vivo incorporation or human LDL by transfer of 125I-Cl from liposomes using cholesteryl ester transfer protein resulted in lipoproteins with low specific activity. Higher specific activity was achieved by reconstituting delipidated human LDL with a mixture of 125I-Cl and unlabeled cholesteryl oleate. These particles were taken up in high amounts by monolayers of human fibroblasts but not by fibroblasts deficient in LDL receptors or by normal fibroblasts during competition with unlabeled native LDL

  16. Synthesis of chiral N-phosphinyl α-imino esters and their application in asymmetric synthesis of α-amino esters by reduction.

    Science.gov (United States)

    Xiong, Yiwen; Mei, Haibo; Wu, Lingmin; Han, Jianlin; Pan, Yi; Li, Guigen

    2014-01-01

    A variety of chiral N-phosphinyl α-imino esters have been synthesized for the first time from ketoesters and phosphinylamide, which were then reduced by L-selectride to give the corresponding N-phosphinyl-protected α-amino esters. The reduction proceeded very well with excellent chemical yields (88-98%) as well as high diastereoselectivities (96:4 to 99:1). Some of these products could be obtained without column chromatography and recrystallization. The chiral phosphinyl auxiliary could be easily cleaved under acidic conditions.

  17. Synthesis of chiral N-phosphinyl α-imino esters and their application in asymmetric synthesis of α-amino esters by reduction

    Directory of Open Access Journals (Sweden)

    Yiwen Xiong

    2014-03-01

    Full Text Available A variety of chiral N-phosphinyl α-imino esters have been synthesized for the first time from ketoesters and phosphinylamide, which were then reduced by L-selectride to give the corresponding N-phosphinyl-protected α-amino esters. The reduction proceeded very well with excellent chemical yields (88–98% as well as high diastereoselectivities (96:4 to 99:1. Some of these products could be obtained without column chromatography and recrystallization. The chiral phosphinyl auxiliary could be easily cleaved under acidic conditions.

  18. Synthesis of chiral N-phosphinyl α-imino esters and their application in asymmetric synthesis of α-amino esters by reduction

    OpenAIRE

    Xiong, Yiwen; Mei, Haibo; Wu, Lingmin; Han, Jianlin; Pan, Yi; Li, Guigen

    2014-01-01

    A variety of chiral N-phosphinyl α-imino esters have been synthesized for the first time from ketoesters and phosphinylamide, which were then reduced by L-selectride to give the corresponding N-phosphinyl-protected α-amino esters. The reduction proceeded very well with excellent chemical yields (88–98%) as well as high diastereoselectivities (96:4 to 99:1). Some of these products could be obtained without column chromatography and recrystallization. The chiral phosphinyl auxiliary could be ea...

  19. Direct analysis in real time mass spectrometry of potential by-products from homemade nitrate ester explosive synthesis.

    Science.gov (United States)

    Sisco, Edward; Forbes, Thomas P

    2016-04-01

    This work demonstrates the coupling of direct analysis in real time (DART) ionization with time-of-flight mass spectrometry (MS) in an off-axis configuration for the trace detection and analysis of potential partially nitrated and dimerized by-products of homemade nitrate ester explosive synthesis. Five compounds relating to the synthesis of nitroglycerin (NG) and pentaerythritol tetranitrate (PETN) were examined. Deprotonated ions and adducts with molecular oxygen, nitrite, and nitrate were observed in the mass spectral responses of these compounds. A global optimum temperature of 350 °C for the by-products investigated here enabled single nanogram to sub nanogram trace detection. Matrix effects were examined through a series of mixtures containing one or more compounds (sugar alcohol precursors, by-products, and/or explosives) across a range of mass loadings. The explosives MS responses experienced competitive ionization in the presence of all by-products. The magnitude of this influence corresponded to both the degree of by-product nitration and the relative mass loading of the by-product to the explosive. This work provides a characterization of potential by-products from homemade nitrate ester synthesis, including matrix effects and potential challenges that might arise from the trace detection of homemade explosives (HMEs) containing impurities. Detection and understanding of HME impurities and complex mixtures may provide valuable information for the screening and sourcing of homemade nitrate ester explosives. Published by Elsevier B.V.

  20. Synthesis and characterization of new oxalate ester-polymer composites for practical applications

    Energy Technology Data Exchange (ETDEWEB)

    Petre, Razvan [Scientific Research Centre for CBRN Defense and Ecology, 225 Sos. Oltenitei, Bucharest 041309 (Romania); University POLITEHNICA of Bucharest, 149 Calea Victoriei, Bucharest 010072 (Romania); Zecheru, Teodora, E-mail: teodora.zecheru@yahoo.com [Scientific Research Centre for CBRN Defense and Ecology, 225 Sos. Oltenitei, Bucharest 041309 (Romania)

    2013-03-15

    The present study focused on the synthesis of high purity oxalate esters: bis(2,4,6-trichlorophenyl) oxalate (TCPO) and bis(2,4,5-trichloro-6-carbobutoxyphenyl) oxalate (TCCBPO), and further on their incorporation into potentially applicative polymer composites. The organic compounds were characterized through NMR and the composites obtained were evaluated for light capacity availability at room temperature and low temperatures. The concentrations of the peroxide, fluorescer, catalyst, and polymer additives were optimized. The chemiluminescent composites' performances were evaluated after 360 days and returned satisfactory results. - Highlights: Black-Right-Pointing-Pointer bis(2,4,6-Trichlorophenyl)-oxalate (TCPO) was synthesized. Black-Right-Pointing-Pointer bis(2,4,5-Trichloro-6-carbobutoxiphenyl)-oxalate (TCCBPO) was synthesized. Black-Right-Pointing-Pointer TCPO and TCCBPO-based composites were obtained. Black-Right-Pointing-Pointer The composites light emission was evaluated versus scotopic visual sensitivity. Black-Right-Pointing-Pointer The new compositions present superior performances within extensive emission time.

  1. Microbial synthesis of a branched-chain ester platform from organic waste carboxylates

    Directory of Open Access Journals (Sweden)

    Donovan S. Layton

    2016-12-01

    Full Text Available Processing of lignocellulosic biomass or organic wastes produces a plethora of chemicals such as short, linear carboxylic acids, known as carboxylates, derived from anaerobic digestion. While these carboxylates have low values and are inhibitory to microbes during fermentation, they can be biologically upgraded to high-value products. In this study, we expanded our general framework for biological upgrading of carboxylates to branched-chain esters by using three highly active alcohol acyltransferases (AATs for alcohol and acyl CoA condensation and modulating the alcohol moiety from ethanol to isobutanol in the modular chassis cell. With this framework, we demonstrated the production of an ester library comprised of 16 out of all 18 potential esters, including acetate, propionate, butanoate, pentanoate, and hexanoate esters, from the 5 linear, saturated C2-C6 carboxylic acids. Among these esters, 5 new branched-chain esters, including isobutyl acetate, isobutyl propionate, isobutyl butyrate, isobutyl pentanoate, and isobutyl hexanoate were synthesized in vivo. During 24 h in situ fermentation and extraction, one of the engineered strains, EcDL208 harnessing the SAAT of Fragaria ananassa produced ~63 mg/L of a mixture of butyl and isobutyl butyrates from glucose and butyrate co-fermentation and ~127 mg/L of a mixture of isobutyl and pentyl pentanoates from glucose and pentanoate co-fermentation, with high specificity. These butyrate and pentanoate esters are potential drop-in liquid fuels. This study provides better understanding of functional roles of AATs for microbial biosynthesis of branched-chain esters and expands the potential use of these esters as drop-in biofuels beyond their conventional flavor, fragrance, and solvent applications. Keywords: Carboxylate platform, Ester platform, Branched-chain ester, Modular cell, Biological upgrading, Organic waste, Lignocellulosic biomass, Isobutyl esters

  2. Synthesis of oleyl oleate wax esters in Arabidopsis thaliana and Camelina sativa seed oil.

    Science.gov (United States)

    Iven, Tim; Hornung, Ellen; Heilmann, Mareike; Feussner, Ivo

    2016-01-01

    Seed oil composed of wax esters with long-chain monoenoic acyl moieties represents a high-value commodity for industry. Such plant-derived sperm oil-like liquid wax esters are biodegradable and can have excellent properties for lubrication. In addition, wax ester oil may represent a superior substrate for biodiesel production. In this study, we demonstrate that the low-input oil seed crop Camelina sativa can serve as a biotechnological platform for environmentally benign wax ester production. Two biosynthetic steps catalysed by a fatty alcohol-forming acyl-CoA reductase (FAR) and a wax ester synthase (WS) are sufficient to achieve wax ester accumulation from acyl-CoA substrates. To produce plant-derived sperm oil-like liquid wax esters, the WS from Mus musculus (MmWS) or Simmondsia chinensis (ScWS) were expressed in combination with the FAR from Mus musculus (MmFAR1) or Marinobacter aquaeolei (MaFAR) in seeds of Arabidopsis thaliana and Camelina sativa. The three analysed enzyme combinations Oleo3:mCherry:MmFAR1∆c/Oleo3:EYFP:MmWS, Oleo3:mCherry:MmFAR1∆c/ScWS and MaFAR/ScWS showed differences in the wax ester molecular species profiles and overall biosynthetic performance. By expressing MaFAR/ScWS in Arabidopsis or Camelina up to 59% or 21% of the seed oil TAGs were replaced by wax esters, respectively. This combination also yielded wax ester molecular species with highest content of monounsaturated acyl moieties. Expression of the enzyme combinations in the Arabidopsis fae1 fad2 mutant background high in oleic acid resulted in wax ester accumulation enriched in oleyl oleate (18:1/18:1 > 60%), suggesting that similar values may be obtained with a Camelina high oleic acid line. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  3. Efficient and Scalable Synthesis of 4-Carboxy-Pennsylvania Green Methyl Ester: A Hydrophobic Building Block for Fluorescent Molecular Probes.

    Science.gov (United States)

    Woydziak, Zachary R; Fu, Liqiang; Peterson, Blake R

    2014-01-01

    Fluorinated fluorophores are valuable tools for studies of biological systems. However, amine-reactive single-isomer derivatives of these compounds are often very expensive. To provide an inexpensive alternative, we report a practical synthesis of 4-carboxy-Pennsylvania Green methyl ester. Derivatives of this hydrophobic fluorinated fluorophore, a hybrid of the dyes Oregon Green and Tokyo Green, are often cell permeable, enabling labeling of intracellular targets and components. Moreover, the low pKa of Pennsylvania Green (4.8) confers bright fluorescence in acidic cellular compartments such as endosomes, enhancing its utility for chemical biology investigations. To improve access to the key intermediate 2,7-difluoro-3,6-dihydroxyxanthen-9-one, we subjected bis-(2,4,5-trifluorophenyl)methanone to iterative nucleophilic aromatic substitution by hydroxide on scales of > 40 g. This intermediate was used to prepare over 15 grams of pure 4-carboxy-Pennsylvania Green methyl ester in 28% overall yield without requiring chromatography. This compound can be converted into the amine reactive N -hydroxysuccinimidyl ester in essentially quantitative yield for the synthesis of a wide variety of fluorescent molecular probes.

  4. Synthesis and Analysis of Methacryloyl-L-Alanine Methyl Ester using fourier Transform Nuclear Magnetic Resonance

    International Nuclear Information System (INIS)

    Tri Darwinto

    2008-01-01

    Methacryloyl-L-alanine methyl ester was synthesized by reacting methacrylic acid with L-alanine methyl ester hydrochloride in triethylamine at temperature of 90 o C. Hydrogel polymer of poly(methacryloyl-L-alanine methyl ester) was much used for diagnosis and therapy of vascular tumor. The molecular structure methacryloyl-L-alanine methyl ester analyzed by fourier transform nuclear magnetic resonance (FT-NMR) for analyzing of carbon atom ( 13 C) using Distortionless Enhancement by Polarization Transfer (DEPT) measurement mode with coupling as well as without coupling from proton atom ( 1 H). Molecular structure analysis result showed that DEPT FT-NMR measurement mode with coupling as well as without coupling from 1 H was very fast, exact and accurate method for molecular analysis of organic compound especially methacryloyl-L-alanine methyl ester. (author)

  5. Phenethyl ester and amide of Ferulic Acids: Synthesis and bioactivity against P388 Leukemia Murine Cells

    Science.gov (United States)

    Firdaus; Soekamto, N. H.; Seniwati; Islam, M. F.; Sultan

    2018-03-01

    Bioactivity of a compound is closely related to the molecular structure of the compound concerned, its strength being the quantitative relation of the strength of the activity of the group it possesses. The combining of moieties of the active compounds will produce more active compounds. Most phenolic compounds as well as compounds containing moiety phenethyl groups have potential activity as anticancer. Combining phenolic groups and phenethyl groups in a compound will result in compounds having strong anticancer bioactivity. This study aims to combine the feruloyl and phenethyl groups to form esters and amides by synthesize of phenethyl trans-3-(4-hydroxy-3-methoxyphenyl)acrylate (5) and trans-3-(4- hydroxy-3-methoxyphenyl)-N-phenethylacrylamide (6) from ferulic acid with phenethyl alcohol and phenethylamine, and to study their bioactivity as anticancer. The synthesis of both compounds was conducted via indirect reaction, including acetylation, chlorination, esterfication/amidation, and deacetylation. Structures of products were characterized by FTIR and NMR data, and their bioactivity assay of the compounds against P388 Leukemia Murine Cells was conducted by an MTT method. Results showed that the compound 5 was obtained as a yellow gel with the IC50 of 10.79 μg/mL (36.21 μΜ), and the compound 6 was a yellowish solid with a melting point of 118-120°C and the IC50 of 29.14 μg/mL (97.79 μΜ). These compounds were more active than the analog compounds.

  6. Parallel Synthesis of a Library of Symmetrically- and Dissymmetrically-disubstituted Imidazole-4,5-dicarboxamides Bearing Amino Acid Esters

    Directory of Open Access Journals (Sweden)

    Rosanna Solinas

    2009-01-01

    Full Text Available The imidazole-4,5-dicarboxylic acid scaffold is readily derivatized with amino acid esters to afford symmetrically- and dissymmetrically-disubstituted imidazole-4,5-dicarboxamides with intramolecularly hydrogen bonded conformations that predispose the presentation of amino acid pharmacophores. In this work, a total of 45 imidazole-4,5-dicarboxamides bearing amino acid esters were prepared by parallel synthesis. The library members were purified by column chromatography on silica gel and the purified compounds characterized by LC-MS with LC detection at 214 nm. A selection of the final compounds was also analyzed by 1H-NMR spectroscopy. The analytically pure final products have been submitted to the Molecular Library Small Molecule Repository (MLSMR for screening in the Molecular Library Screening Center Network (MLSCN as part of the NIH Roadmap.

  7. Lipase-Catalyzed Synthesis of Sugar Esters in Honey and Agave Syrup

    Directory of Open Access Journals (Sweden)

    Sascha Siebenhaller

    2018-02-01

    Full Text Available Honey and agave syrup are high quality natural products and consist of more than 80% sugars. They are used as sweeteners, and are ingredients of cosmetics or medical ointments. Furthermore, both have low water content, are often liquid at room temperature and resemble some known sugar-based deep eutectic solvents (DES. Since it has been shown that it is possible to synthesize sugar esters in these DESs, in the current work honey or, as vegan alternative, agave syrup are used simultaneously as solvent and substrate for the enzymatic sugar ester production. For this purpose, important characteristics of the herein used honey and agave syrup were determined and compared with other available types. Subsequently, an enzymatic transesterification of four fatty acid vinyl esters was accomplished in ordinary honey and agave syrup. Notwithstanding of the high water content for transesterification reactions of the solvent, the successful sugar ester formation was proved by thin-layer chromatography (TLC and compared to a sugar ester which was synthesized in a conventional DES. For a clear verification of the sugar esters, mass determinations by ESI-Q-ToF experiments and a NMR analysis were done. These environmentally friendly produced sugar esters have the potential to be used in cosmetics or pharmaceuticals, or to enhance their effectiveness.

  8. Lipase-Catalyzed Synthesis of Sugar Esters in Honey and Agave Syrup

    Science.gov (United States)

    Siebenhaller, Sascha; Gentes, Julian; Infantes, Alba; Muhle-Goll, Claudia; Kirschhöfer, Frank; Brenner-Weiß, Gerald; Ochsenreither, Katrin; Syldatk, Christoph

    2018-02-01

    Honey and agave syrup are high quality natural products and consist of more than 80% sugars. They are used as sweeteners, and are ingredients of cosmetics or medical ointments. Furthermore, both have low water content, are often liquid at room temperature and resemble some known sugar-based deep eutectic solvents. Since it has been shown that it is possible to synthesize sugar esters in these deep eutectic solvents, in the current work honey or, as vegan alternative, agave syrup are used simultaneously as solvent and substrate for the enzymatic sugar ester production. For this purpose, important characteristics of the herein used honey and agave syrup were determined and compared with other available types. Subsequently, an enzymatic transesterification of four fatty acid vinyl esters was accomplished in ordinary honey and agave syrup. Notwithstanding of the high water content for transesterification reactions of the solvent, the successful sugar ester formation was proved by thin-layer chromatography and compared to a sugar ester which was synthesized in a conventional deep eutectic solvent. For a clear verification of the sugar esters, mass determinations by ESI-Q-ToF experiments and a NMR analysis were done. These environmentally friendly produced sugar esters have the potential to be used in cosmetics or pharmaceuticals, or to enhance their effectiveness.

  9. Synthesis and cytotoxicity of boronated fatty esters for BNCT of cervix cancer

    International Nuclear Information System (INIS)

    Tambunchong, C.; Prachayasittikul, S.; Picha, P.; Tumpum, C.

    2000-01-01

    Esterification reactions of o-carboranic acid with six fatty alcohols, palmitoleyl, stearyl, oleyl, elaidyl, linoleyl and linoelaidyl alcohols, proceeded smoothly under nitrogen atmosphere with dimethylamino pyrimidine as a catalyst. The reaction gave the corresponding esters in moderate yields. Most of the synthetic esters are stable at room temperature except the linoleyl carboranate and linoelaidyl carboranate which decomposed within two weeks. The in vitro studies on Hela cells showed relatively low cytotoxic. The IC 50 of boronated esters were in range of 36-83 micrograms/cm 3 . (author)

  10. The effect of Maillard reaction products and yeast strain on the synthesis of key higher alcohols and esters in beer fermentations.

    Science.gov (United States)

    Dack, Rachael E; Black, Gary W; Koutsidis, Georgios; Usher, St John

    2017-10-01

    The effect of Maillard reaction products (MRPs), formed during the production of dark malts, on the synthesis of higher alcohols and esters in beer fermentations was investigated by headspace solid-phase microextraction GC-MS. Higher alcohol levels were significantly (p<0.05) higher in dark malt fermentations, while the synthesis of esters was inhibited, due to possible suppression of enzyme activity and/or gene expression linked to ester synthesis. Yeast strain also affected flavour synthesis with Saccharomyces cerevisiae strain A01 producing considerably lower levels of higher alcohols and esters than S288c and L04. S288c produced approximately double the higher alcohol levels and around twenty times more esters compared to L04. Further investigations into malt type-yeast strain interactions in relation to flavour development are required to gain better understanding of flavour synthesis that could assist in the development of new products and reduce R&D costs for the industry. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Functional Group Interconversion: Decarbonylative Borylation of Esters for the Synthesis of Organoboronates

    KAUST Repository

    Guo, Lin; Rueping, Magnus

    2016-01-01

    A new and efficient nickel-catalyzed decarbonylative borylation reaction of carboxylic acid esters with bis(pinacolato)-diboron has been developed. This transformation allows access to structurally diverse aryl as well as alkenyl and alkyl boronate esters with high reactivity, broad substrate scope, and excellent functional-group tolerance. Further experiments show that this protocol can be carried out on a gram scale and applied to orthogonal synthetic strategies.

  12. Functional Group Interconversion: Decarbonylative Borylation of Esters for the Synthesis of Organoboronates

    KAUST Repository

    Guo, Lin

    2016-09-26

    A new and efficient nickel-catalyzed decarbonylative borylation reaction of carboxylic acid esters with bis(pinacolato)-diboron has been developed. This transformation allows access to structurally diverse aryl as well as alkenyl and alkyl boronate esters with high reactivity, broad substrate scope, and excellent functional-group tolerance. Further experiments show that this protocol can be carried out on a gram scale and applied to orthogonal synthetic strategies.

  13. A simple synthesis of 2-keto-3-deoxy-D-erythro-hexonic acid isopropyl ester, a key sugar for the bacterial population living under metallic stress.

    Science.gov (United States)

    Grison, Claire M; Renard, Brice-Loïc; Grison, Claude

    2014-02-01

    2-Keto-3-deoxy-D-erythro-hexonic acid (KDG) is the key intermediate metabolite of the Entner Doudoroff (ED) pathway. A simple, efficient and stereoselective synthesis of KDG isopropyl ester is described in five steps from 2,3-O-isopropylidene-D-threitol with an overall yield of 47%. KDG isopropyl ester is studied as an attractive marker of a functional Entner Doudoroff pathway. KDG isopropyl ester is used to promote growth of ammonium producing bacterial strains, showing interesting features in the remediation of heavy-metal polluted soils. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Synthesis and Biological Evaluation of Liguzinediol Mono- and Dual Ester Prodrugs as Promising Inotropic Agents

    Directory of Open Access Journals (Sweden)

    Jing Zhang

    2014-11-01

    Full Text Available The potent positive inotropic effect, together with the relatively low safety risk of liguzinediol (LZDO, relative to currently available inotropic drugs, has prompted us to intensively research and develop LZDO as a potent positive inotropic agent. In this study, to obtain LZDO alternatives for oral chronic administration, a series of long-chain fatty carboxylic mono- and dual-esters of LZDO were synthesized, and preliminarily evaluated for physicochemical properties and bioconversion. Enhanced lipophilic properties and decreased solubility of the prodrugs were observed as the side chain length increased. All esters showed conspicuous chemical stability in phosphate buffer (pH 7.4. Moreover, the enzymatic hydrolysis of esters in human plasma and human liver microsomes confirmed that the majority of esters were converted to LZDO, with release profiles that varied due to the size and structure of the side chain. In vivo pharmacokinetic studies following oral administration of monopivaloyl (M5, monodecyl (M10 and monododecyl (M12 esters demonstrated the evidently extended half-lives relative to LZDO dosed alone. In particular the monopivaloyl ester M5 exhibited an optimal pharmacokinetic profile with appropriate physiochemical characteristics.

  15. Effect of 17alpha-ethinylestradiol on activity of rat liver enzymes for synthesis and hydrolysis of cholesterol esters

    International Nuclear Information System (INIS)

    Nikitin, Yu.P.; Dushkin, M.I.; Dolgov, A.V.; Gordienko, I.A.

    1987-01-01

    Administration of estrogens is known to lower the concentration of cholesterol esters in the blood vessel wall and may delay the development of arteriosclerosis. It is also known that under the influence of estrogens the redistribution of concentrations of free cholesterol and cholesterol esters takes place in rats between the blood and liver as a result of the intensification of receptor-dependent uptake of low-density lipoproteins by the hepatocytes. The mechanisms of this intracellular redistribution, however, have been inadequately studied. The purpose of this paper is to study the effects of 17alpha-ethinylestradiol on the activity of lysosomal and cytoplasmic cholesterol esterases, acyl-CoA-cholesterol-O-acyltransferase, lysosomal acid phosphatase, and beta-D-galactosidase. The activity was measured by using cholesterol [1-C 14]-oleate as the substrate. The influence of the estradiol is found to be based on cholesterol redistribution between the blood and liver. Accumulation of free cholesterol in the liver under these conditions stimulates bile acid formation. Depression of cholesterol ester synthesis as a result of direct inhibition of the acyltransferase by the estradiol is found to possibly contribute to the fall in the cholesterol level in the body. Liquid scintillation counting was used to measure distribution and accumulation

  16. Synthesis of Functionalized Pyrazoles via 1,3-Dipolar Cycloaddition of α-Diazo-β-ketophosphonates, Sufones and Esters with Electron-Deficient Alkenes.

    Science.gov (United States)

    Baiju, T V; Namboothiri, Irishi N N

    2017-10-01

    1,3-Dipolar cycloaddition of diazo compounds with olefinic substrates is a promising atom-economic strategy for the construction of functionalized pyrazoles. Over the last few years, our group has been engaged in the synthesis of phosphonyl/sulfonylpyrazoles and pyrazole esters by employing Bestmann-Ohira Reagent (BOR) and its sulfur and ester analogs as 1,3-dipole precursors with various dipolarophiles. This account describes the novel synthetic methods developed in our laboratory, in the perspective of closely related work by others, for the synthesis of phosphonyl/sulfonylpyrazoles, pyrazole esters and the total synthesis of Withasomnine, a natural product, by using 1,3-dipolar cycloaddition as the key step. © 2017 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. The cholesteryl octanoate breath test: a new procedure for detection of pancreatic insufficiency in the rat.

    Science.gov (United States)

    Mundlos, S; Rhodes, J B; Hofmann, A F

    1987-09-01

    A breath test for the detection of pancreatic insufficiency was developed and tested in rats. The test features the hydrophobic molecule cholesteryl-1-14C-octanoate, which liberates 14C-octanoic acid when hydrolyzed by carboxyl ester lipase (cholesterol esterase). The 14C-octanoate is absorbed passively and rapidly metabolized to 14CO2, which is excreted in expired air. The compound was administered as an emulsion of cholesteryl octanoate, triglyceride, and lecithin to rats with mild pancreatic insufficiency induced by injecting the pancreatic duct with zein. The animals had exocrine pancreatic hypofunction based on the enzyme content of pancreas at autopsy. Amylase was reduced by 97.1 +/- 1.4%, whereas chymotrypsin was reduced by 73 +/- 14%. The p-aminobenzoic acid test was abnormal at 1 wk (21.68 +/- 8.4%), but become normal at 3 months (72.08 +/- 5.8%) after zein injection. Despite this, the animals gained weight and absorbed fat normally. The 14CO2 excretion rate in the 110-min interval after feeding was significantly reduced to 60% of sham-operated animals. Peak 14CO2 collections 20 min after feeding were reduced by 75 +/- 11%. 14CO2 output was completely normalized by administration of pancreatin prior to the test meal. The results suggest that a sensitive, noninvasive method for detecting deficiency of pancreatic carboxyl ester lipase (cholesterol esterase) secretion in the rat has been developed.

  18. Synthesis and Proapoptotic Activity on Cervical Cancer Cell of Ester Eugenol 1-(3-Methoxy-4-hydroxy)phenyl-2-propylmethanoate

    Science.gov (United States)

    Farid Rahman, Moh.; Nazhif Haykal, Muhammad; Andriani Siagian, Novi; Maiselina Sriepindonnta, Priscilla; Tampubolon, Norman Alexander

    2018-01-01

    Proapoptotic activity of ester eugenol,1-(3-methoxy-4-hydroxy)phenyl-2-propylmethanoat, which synthesized from eugenol is reported. Eugenol as starting material in the synthesis of ester eugenol was obtained from fractional distillation of clove oil with the yield of 70.66%. Synthesis of ester eugenol was camed out by addition-esterification reaction through reaction between eugenol and formic acid with mol ratio of 1:27 and reaction time for11 h. GC-MS analysis showed ester eugenol was afforded purity of 92.42% and the yield in of 93.34%. UV spectra of ester eugenol was observed the formation of carbonyl group at λmax 290 nm and supported by FT-IR analysis at 1714.60 cm-1 (carbonyl group), 1193.65 cm-1 (C-O-C ester group) and the absence of vynil group in eugenol structure at region 914.20 and 995.20 cm-1. Mass spectra showed ion molecule at m/z 210 was accordance with molecular weight of ester eugenol. Afterward, HeLa cell culture media was prepared for cervical cancer antiproliferative test. The result which showed in histogram indicated that LC50 of ester eugenol was reached at concentration below 0.01% while eugenol was up to 0.01% that observed cervical cancer cell apoptotic activity. LC50 value of ester eugenol was obtained at concentration 48.73 ppm. This research reported that natural product modified its structure has potency to cure cervical cancer.

  19. Helicobacter pylori cholesteryl α-glucosides contribute to its pathogenicity and immune response by natural killer T cells.

    Directory of Open Access Journals (Sweden)

    Yuki Ito

    Full Text Available Approximately 10-15% of individuals infected with Helicobacter pylori will develop ulcer disease (gastric or duodenal ulcer, while most people infected with H. pylori will be asymptomatic. The majority of infected individuals remain asymptomatic partly due to the inhibition of synthesis of cholesteryl α-glucosides in H. pylori cell wall by α1,4-GlcNAc-capped mucin O-glycans, which are expressed in the deeper portion of gastric mucosa. However, it has not been determined how cholesteryl α-glucosyltransferase (αCgT, which forms cholesteryl α-glucosides, functions in the pathogenesis of H. pylori infection. Here, we show that the activity of αCgT from H. pylori clinical isolates is highly correlated with the degree of gastric atrophy. We investigated the role of cholesteryl α-glucosides in various aspects of the immune response. Phagocytosis and activation of dendritic cells were observed at similar degrees in the presence of wild-type H. pylori or variants harboring mutant forms of αCgT showing a range of enzymatic activity. However, cholesteryl α-glucosides were recognized by invariant natural killer T (iNKT cells, eliciting an immune response in vitro and in vivo. Following inoculation of H. pylori harboring highly active αCgT into iNKT cell-deficient (Jα18(-/- or wild-type mice, bacterial recovery significantly increased in Jα18(-/- compared to wild-type mice. Moreover, cytokine production characteristic of Th1 and Th2 cells dramatically decreased in Jα18(-/- compared to wild-type mice. These findings demonstrate that cholesteryl α-glucosides play critical roles in H. pylori-mediated gastric inflammation and precancerous atrophic gastritis.

  20. Synthesis and biological evaluation of arctigenin ester and ether derivatives as activators of AMPK.

    Science.gov (United States)

    Shen, Sida; Zhuang, Jingjing; Chen, Yijia; Lei, Min; Chen, Jing; Shen, Xu; Hu, Lihong

    2013-07-01

    A series of new arctigenin and 9-deoxy-arctigenin derivatives bearing different ester and ether side chains at the phenolic hydroxyl positions are designed, synthesized, and evaluated for activating AMPK potency in L6 myoblasts. Initial biological evaluation indicates that some alkyl ester and phenethyl ether arctigenin derivatives display potential activities in AMPK phosphorylation improvement. Further structure-activity relationship analysis shows that arctigenin ester derivatives 3a, 3h and 9-deoxy-arctigenin phenethyl ether derivatives 6a, 6c, 6d activate AMPK more potently than arctigenin. Moreover, the 2-(3,4-dimethoxyphenyl)ethyl ether moiety of 6c has been demonstrated as a potential functional group to improve the effect of AMPK phosphorylation. The structural optimization of arctigenin leads to the identification of 6c as a promising lead compound that exhibits excellent activity in AMPK activation. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Enzymatic synthesis of arbutin undecylenic acid ester and its inhibitory effect on mushroom tyrosinase.

    Science.gov (United States)

    Tokiwa, Y; Kitagawa, M; Raku, T

    2007-03-01

    A novel tyrosinase inhibitor, an arbutin derivative having undecylenic acid at the 6-position of its glucose moiety, was enzymatically synthesized. Its inhibitory activity was studied in vitro by using catechol and phenol as substrates. The IC(50) value of the arbutin ester on tyrosinase using catechol (4 x 10(-4) M) was 1% of that when arbutin (4 x 10(-2) M) was used. Using phenol, IC(50) of the arbutin ester (3 x 10(-4) M) as substrate was 10% of that of arbutin (3 x 10(-3) M). These results suggest that the arbutin ester inhibits the latter part of the tyrosinase reaction, which consists of hydroxylation and oxidation.

  2. Synthesis of amide-functionalized cellulose esters by olefin cross-metathesis.

    Science.gov (United States)

    Meng, Xiangtao; Edgar, Kevin J

    2015-11-05

    Cellulose esters with amide functionalities were synthesized by cross-metathesis (CM) reaction of terminally olefinic esters with different acrylamides, catalyzed by Hoveyda-Grubbs 2nd generation catalyst. Chelation by amides of the catalyst ruthenium center caused low conversions using conventional solvents. The effects of both solvent and structure of acrylamide on reaction conversion were investigated. While the inherent tendency of acrylamides to chelate Ru is governed by the acrylamide N-substituents, employing acetic acid as a solvent significantly improved the conversion of certain acrylamides, from 50% to up to 99%. Homogeneous hydrogenation using p-toluenesulfonyl hydrazide successfully eliminated the α,β-unsaturation of the CM products to give stable amide-functionalized cellulose esters. The amide-functionalized product showed higher Tg than its starting terminally olefinic counterpart, which may have resulted from strong hydrogen bonding interactions of the amide functional groups. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Synthesis and antiproliferative properties of new hydrophilic esters of triterpenic acids.

    Science.gov (United States)

    Eignerova, Barbara; Tichy, Michal; Krasulova, Jana; Kvasnica, Miroslav; Rarova, Lucie; Christova, Romana; Urban, Milan; Bednarczyk-Cwynar, Barbara; Hajduch, Marian; Sarek, Jan

    2017-11-10

    To improve the properties of cytotoxic triterpenoid acids 1-5, a large set of hydrophilic esters was synthesized. We choose betulinic acid (1), dihydrobetulinic acid (2), 21-oxoacid 3 along with highly active des-E lupane acids 4 and 5 as a model set of compounds for esterification of which the properties needed to be improved. As ester moieties were used - methoxyethanol and 2-(2-methoxyethoxy)ethanol and glycolic unit (type a-d), pyrrolidinoethanol, piperidinoethanol and morpholinoethanol (type f-h), and monosaccharide groups (type i-l). As a result, 56 triterpenic esters (49 new compounds) were obtained and their cytotoxicity on four cancer cell lines and normal human fibroblasts was tested. All new compounds were fully soluble at all tested concentrations, which used to be a problem of the parent compounds 1 and 2. 16 compounds had IC 50  acids 1-5. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  4. Convenient synthesis of 6-nor-9,10-dihydrolysergic acid methyl ester.

    Science.gov (United States)

    Crider, A M; Grubb, R; Bachmann, K A; Rawat, A K

    1981-12-01

    6-Nor-9,10-dihydrolysergic acid methyl ester (IV) was prepared by demethylation of 9,10-dihydrolysergic acid methyl ester (II) with 2,2,2-trichloroethyl chloroformate, followed by reduction of the intermediate carbamate (III) with zinc in acetic acid. The 6-ethyl-V and 6-n-propyl-VI derivatives were prepared by alkylation of IV with the appropriate halide. All of the ergoline derivatives were evaluated for stereotyped behavior in rats, with 6-nor-6-ethyl-9,10-dihydrolysergic acid methyl ester (V) being active but much less potent than apomorphine. Compound VI was evaluated for its effect on blood pressure; at a dose of 30 mg/kg ip, it significantly lowered, diastolic pressure in normotensive rats.

  5. Synthesis of Fluoroalkoxy Substituted Arylboronic Esters by Iridium-Catalyzed Aromatic C–H Borylation

    KAUST Repository

    Batool, Farhat

    2015-08-17

    The preparation of fluoroalkoxy arylboronic esters by iridium-catalyzed aromatic C–H borylation is described. The fluoroalkoxy groups employed include trifluoromethoxy, difluoromethoxy, 1,1,2,2-tetrafluoroethoxy, and 2,2-difluoro-1,3-benzodioxole. The borylation reactions were carried out neat without the use of a glovebox or Schlenk line. The regioselectivities available through the iridium-catalyzed C–H borylation are complementary to those obtained by the electrophilic aromatic substitution reactions of fluoroalkoxy arenes. Fluoroalkoxy arylboronic esters can serve as versatile building blocks.

  6. Synthesis of Chiral, Enantiopure Allylic Amines by the Julia Olefination of α-Amino Esters

    Directory of Open Access Journals (Sweden)

    Fabio Benedetti

    2016-06-01

    Full Text Available The four-step conversion of a series of N-Boc-protected l-amino acid methyl esters into enantiopure N-Boc allylamines by a modified Julia olefination is described. Key steps include the reaction of a lithiated phenylalkylsulfone with amino esters, giving chiral β-ketosulfones, and the reductive elimination of related α-acetoxysulfones. The overall transformation takes place under mild conditions, with good yields, and without loss of stereochemical integrity, being in this respect superior to the conventional Julia reaction of α-amino aldehydes.

  7. Synthesis of Chiral, Enantiopure Allylic Amines by the Julia Olefination of α-Amino Esters.

    Science.gov (United States)

    Benedetti, Fabio; Berti, Federico; Fanfoni, Lidia; Garbo, Michele; Regini, Giorgia; Felluga, Fulvia

    2016-06-21

    The four-step conversion of a series of N-Boc-protected l-amino acid methyl esters into enantiopure N-Boc allylamines by a modified Julia olefination is described. Key steps include the reaction of a lithiated phenylalkylsulfone with amino esters, giving chiral β-ketosulfones, and the reductive elimination of related α-acetoxysulfones. The overall transformation takes place under mild conditions, with good yields, and without loss of stereochemical integrity, being in this respect superior to the conventional Julia reaction of α-amino aldehydes.

  8. Synthesis of Fluoroalkoxy Substituted Arylboronic Esters by Iridium-Catalyzed Aromatic C–H Borylation

    KAUST Repository

    Batool, Farhat; Parveen, Shehla; Emwas, Abdul-Hamid M.; Sioud, Salim; Gao, Xin; Munawar, Munawar A.; Chotana, Ghayoor A.

    2015-01-01

    The preparation of fluoroalkoxy arylboronic esters by iridium-catalyzed aromatic C–H borylation is described. The fluoroalkoxy groups employed include trifluoromethoxy, difluoromethoxy, 1,1,2,2-tetrafluoroethoxy, and 2,2-difluoro-1,3-benzodioxole. The borylation reactions were carried out neat without the use of a glovebox or Schlenk line. The regioselectivities available through the iridium-catalyzed C–H borylation are complementary to those obtained by the electrophilic aromatic substitution reactions of fluoroalkoxy arenes. Fluoroalkoxy arylboronic esters can serve as versatile building blocks.

  9. Ultrasonic pretreatment for lipase-catalyed synthesis of phytosterol esters with different acyl donors.

    Science.gov (United States)

    Zheng, Ming-Ming; Wang, Lian; Huang, Feng-Hong; Dong, Ling; Guo, Ping-Mei; Deng, Qian-Chun; Li, Wen-Lin; Zheng, Chang

    2012-09-01

    This study is focused on the enzymatic esterification of phytosterols with different acyl donors to produce the corresponding phytosterol esters catalyzed by Canadia sp. 99-125 lipase under ultrasound irradiation. An ultrasonic frequency of 35 kHz, power of 200 W and time of 1h was determined to guarantee satisfactory degree of esterification and lipase activity. The influence of temperature, substrates concentration and molar ratio was investigated subsequently. The optimum production was achieved in isooctane system at 60°C with phytosterol concentration of 150 μmol/mL and phytosterol to fatty acid molar ratio of 1:1.5, resulting in a phytosterol esters conversion of above 85.7% in short reaction time (8h). Phytosterols esters could also be converted in high yields to the corresponding long-chain acyl esters via transesterification with triacylglycerols (above 90.3%) under ultrasound irradiation. In optimum conditions, the overall esterification reaction rate using the ultrasonic pretreatment process was above 2-fold than that of mechanical stirring process without damage the lipase activity. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Synthesis of Dipeptide Benzoylalanylglycine Methyl Ester and Corrosion Inhibitor Evaluation by Tafel Equation

    International Nuclear Information System (INIS)

    Abdurrahman, J.; Wahyuningrum, D.; Achmad, S.; Bundjali, B.

    2011-01-01

    Corrosion is one of the major problems in petroleum mining and processing industry. The pipelines used to transport crude oil from reservoir to the processing installation were made from carbon steel that is susceptible towards corrosion. One of the best methods to prevent corrosion that occurred at the inner parts of carbon steel pipelines is to use organic corrosion inhibitor. One of the potent organic corrosion inhibitors is amino acids derivatives. In this study, dipeptide compound namely benzoylalanylglycine methyl ester and benzoylalanylglycine have been synthesized. The structure elucidation of the products was performed by IR, MS and NMR spectroscopy. The determination of corrosion inhibition activity utilized the Tafel method. The corrosion inhibition efficiency of glycine methyl ester, benzoyl alanine, dipeptide benzoylalanylglycine methyl ester and dipeptide benzoylalanylglycine were 63.34 %, 35.86 %, 68.40 % and 27.72 %, respectively. These results showed that the formation of dipeptide benzoylalanylglycine methyl ester, derived from carboxylic protected glycine and amine protected alanine, increased the corrosion inhibition activity due to the loss of acidity center in the structure of glycine and L-alanine that would induce the corrosive environment towards carbon steel. (author)

  11. Asymmetric synthesis of α-amino acids by reduction of N-tert-butanesulfinyl ketimine esters.

    Science.gov (United States)

    Reddy, Leleti Rajender; Gupta, Aditya P; Liu, Yugang

    2011-05-06

    A highly regio- and diastereoselective reduction of various N-tert-butanesulfinyl ketimine esters with L-Selectride resulting in the formation of α-amino acids is reported. This method is quite general and also practical for the preparation of both enantiomers of aryl or aliphatic α-amino acids in high yields. © 2011 American Chemical Society

  12. Synthesis and antiproliferative properties of new hydrophilic esters of triterpenic acids

    Czech Academy of Sciences Publication Activity Database

    Eignerová, Barbara; Tichý, Michal; Krasulová, Jana; Kvasnica, Miroslav; Rárová, L.; Christová, R.; Urban, M.; Bednarczyk-Cwynar, B.; Hajdúch, M.; Šarek, J.

    2017-01-01

    Roč. 140, Nov 10 (2017), s. 403-420 ISSN 0223-5234 R&D Projects: GA MŠk(CZ) LO1304 Institutional support: RVO:61388963 ; RVO:61389030 Keywords : cytotoxicity * triterpenic acids * betulinic acid * hydrophilic ester * prodrug Subject RIV: CC - Organic Chemistry OBOR OECD: Organic chemistry Impact factor: 4.519, year: 2016

  13. SYNTHESIS OF SOME PROLINE DERIVATIVES BY MEANS OF MICHAEL ADDITIONS OF GLYCINE ESTERS

    NARCIS (Netherlands)

    VANDERWERF, A; KELLOGG, RM

    1991-01-01

    Addition of the Schiff bases derived from reaction of glycine alkyl esters with benzophenoneimine to alpha,beta-unsaturated ketones, followed by hydrogenation of the addition products, leads to 5- or 3,5-substituted prolines. Hydrolysis of the Michael adducts rather than hydrogenation allows

  14. Synthesis, cross-coupling, and anionic cyclization of ortho-substituted naphthaleneboronic esters

    DEFF Research Database (Denmark)

    Lysén, M.; Madden, M.; Kristensen, Jesper Langgaard

    2006-01-01

    1-Fluoro-, 1-chloro- and 1-cyanonaphthalene were lithiated and then borylated at the 2-position. The 1-substituted naphthaleneboronic esters were cross-coupled with aryl halides to give 2-aryl-1-fluoro-, 2-aryl-1-chloro- and 2-aryl-1-cyanonaphthalenes. The 2-aryl-1-cyano- and 2-aryl-1-fluoronapht...

  15. Synthesis of Ortho Substituted Arylboronic Esters by in Situ Trapping of Unstable Lithio Intermediates

    DEFF Research Database (Denmark)

    Kristensen, Jesper Langgaard; Lysén, M.; Vedsø, Per

    2001-01-01

    matrix presented Ortho lithiation-in situ boration using lithium 2,2,6,6-tetramethylpiperidide (LTMP) in combination with triisopropylborate (B(OiPr) ) is a highly efficient and experimentally straightforward process for the preparation of ortho substituted arylboronic esters. The mild reaction c...

  16. Process Intensification of Enzymatic Fatty Acid Butyl Ester Synthesis Using a Continuous Centrifugal Contactor Separator

    NARCIS (Netherlands)

    Ilmi, Miftahul; Abduh, Muhammad Yusuf; Hommes, Arne; Winkelman, Jozef; Hidayat, C.; Heeres, Hero

    2018-01-01

    Fatty acid butyl esters were synthesized from sunflower oil with 1-butanol using a homogeneous Rhizomucor miehei lipase in a biphasic organic (triglyceride, 1-butanol, hexane)– water (with enzyme) system in a continuous setup consisting of a cascade of a stirred tank reactor and a continuous

  17. Synthesis of Polyformate Esters of Vegetable Oils: Milkweed, Pennycress, and Soy

    Directory of Open Access Journals (Sweden)

    Rogers E. Harry-O’kuru

    2016-01-01

    Full Text Available In a previous study of the characteristics of acyl derivatives of polyhydroxy milkweed oil (PHMWO, it was observed that the densities and viscosities of the respective derivatives decreased with increased chain length of the substituent acyl group. Thus from the polyhydroxy starting material, attenuation in viscosity of the derivatives relative to PHMWO was found in the order: PHMWO ≫ PAcMWE ≫ PBuMWE ≫ PPMWE (2332 : 1733 : 926.2 : 489.4 cSt, resp., at 40°C, where PAcMWE, PBuMWE, and PPMWE were the polyacetyl, polybutyroyl, and polypentanoyl ester derivatives, respectively. In an analogous manner, the densities also decreased as the chain length increased although not as precipitously compared to the viscosity drop. By inference, derivatives of vegetable oils with short chain length substituents on the triglyceride would be attractive in lubricant applications in view of their higher densities and possibly higher viscosity indices. Pursuant to this, we have explored the syntheses of formyl esters of three vegetable oils in order to examine the optimal density, viscosity, and related physical characteristics in relation to their suitability as lubricant candidates. In the absence of ready availability of formic anhydride, we opted to employ the epoxidized vegetable oils as substrates for formyl ester generation using glacial formic acid. The epoxy ring-opening process was smooth but was apparently followed by a simultaneous condensation reaction of the putative α-hydroxy formyl intermediate to yield vicinal diformyl esters from the oxirane. All three polyformyl esters milkweed, soy, and pennycress derivatives exhibited low coefficient of friction and a correspondingly much lower wear scar in the 4-ball antiwear test compared to the longer chain acyl analogues earlier studied.

  18. Synthesis of Polyformate Esters of Vegetable Oils: Milkweed, Pennycress, and Soy.

    Science.gov (United States)

    Harry-O'kuru, Rogers E; Biresaw, Girma; Tisserat, Brent; Evangelista, Roque

    2016-01-01

    In a previous study of the characteristics of acyl derivatives of polyhydroxy milkweed oil (PHMWO), it was observed that the densities and viscosities of the respective derivatives decreased with increased chain length of the substituent acyl group. Thus from the polyhydroxy starting material, attenuation in viscosity of the derivatives relative to PHMWO was found in the order: PHMWO ≫ PAcMWE ≫ PBuMWE ≫ PPMWE (2332 : 1733 : 926.2 : 489.4 cSt, resp., at 40°C), where PAcMWE, PBuMWE, and PPMWE were the polyacetyl, polybutyroyl, and polypentanoyl ester derivatives, respectively. In an analogous manner, the densities also decreased as the chain length increased although not as precipitously compared to the viscosity drop. By inference, derivatives of vegetable oils with short chain length substituents on the triglyceride would be attractive in lubricant applications in view of their higher densities and possibly higher viscosity indices. Pursuant to this, we have explored the syntheses of formyl esters of three vegetable oils in order to examine the optimal density, viscosity, and related physical characteristics in relation to their suitability as lubricant candidates. In the absence of ready availability of formic anhydride, we opted to employ the epoxidized vegetable oils as substrates for formyl ester generation using glacial formic acid. The epoxy ring-opening process was smooth but was apparently followed by a simultaneous condensation reaction of the putative α-hydroxy formyl intermediate to yield vicinal diformyl esters from the oxirane. All three polyformyl esters milkweed, soy, and pennycress derivatives exhibited low coefficient of friction and a correspondingly much lower wear scar in the 4-ball antiwear test compared to the longer chain acyl analogues earlier studied.

  19. Fatty acid methyl esters synthesis from non-edible vegetable oils using supercritical methanol and methyl tert-butyl ether

    International Nuclear Information System (INIS)

    Lamba, Neha; Modak, Jayant M.; Madras, Giridhar

    2017-01-01

    Highlights: • FAMEs were synthesized from non-edible oils using supercritical MeOH and MTBE. • Effect of time, temperature, pressure and molar ratio on conversions was studied. • Rate constants of reaction with methanol and MTBE differ by an order of magnitude. • Non-catalytic supercritical reactions are one order faster than acid catalyzed synthesis. - Abstract: Fatty acid methyl esters (FAMEs) are useful as biodiesel and have environmental benefits compared to conventional diesel. In this study, these esters were synthesized non-catalytically from non-edible vegetable oils: neem oil and mahua oil with two different methylating agents: methanol and methyl tert-butyl ether (MTBE). The effects of temperature, pressure, time and molar ratio on the conversion of triglycerides were studied. The temperature was varied in the range of 523–723 K with molar ratios upto 50:1 and a reaction time of upto 150 min. Conversion of neem and mahua oil to FAMEs with supercritical methanol was found to be 83% in 15 min and 99% in 10 min, respectively at 698 K. Further, a conversion of 46% of mahua oil and 59% of neem oil was obtained in 15 min at 723 K using supercritical MTBE. The rate constants evaluated using pseudo first order reaction kinetics were in the range of 4.7 × 10"−"6 to 1.0 × 10"−"3 s"−"1 for the investigated range of temperatures. The activation energies obtained were in the range of 62–113 kJ/mol for the reaction systems investigated. The supercritical synthesis was found to be superior to the catalytic synthesis of the corresponding FAMEs.

  20. Effect of fatty acids on the synthesis and secretion of apolipoprotein B by rat hepatocytes

    International Nuclear Information System (INIS)

    Suresh Kumar, N.; Abraham, Rita; Suresh Kumar, G.; Sudhakaran, P.R.; Kurup, P.A.

    1992-01-01

    The modulation of apolipoprotein B synthesis and secretion by fatty acids in rat hepatocytes was studied. Maximum apolipoprotein B production was obtained in the case of oleic acid followed by linoleic, stearic and palmitic/linolenic acid when compared to control which was not supplemented with any fatty acids. Oleic acid was found to exert a concentration dependent increase in the secretion of [ 3 H] apolipoprotein B into the medium while that associated with the cell layer was not affected. Pulse chase experiments in the presence of oleic acid showed that it caused an increase in the secretion of apolipoprotein B into the medium. 14 C-acetate incorporation into cholesterol and cholesteryl ester associated with the cell layer and secreted very low density lipoproteins also showed an increase in the presence of oleic acid indicating an increase in cholesterogenesis. The effect of oleic acid on [ 3 H] apolipoprotein B and very low density lipoprotein secretion appeared to be mediated through cholesterol as (i)ketoconazole, an inhibitor of cholesterol synthesis caused significant reduction in the stimulatory effect of oleic acid on apolipoprotein secretion and (ii) mevinolin, another inhibitor of cholesterol synthesis also reversed the stimulatory effect of oleic acid on apolipoprotein B secretion. These results indicated that oleic acid may influence apolipoprotein B synthesis and secretion in hepatocytes probably by affecting cholesterol/cholesteryl ester formation which may be a critical component in the secretion of apolipoprotein B as lipoproteins. (author). 21 refs., 4 figs., 2 tabs

  1. Synthesis of chromatographic standards and establishment of a method for the quantification of the fatty ester composition of biodiesel from babassu oil

    International Nuclear Information System (INIS)

    Urioste, Daniele; Castro, Matheus B.A.; Biaggio, Francisco C.; Castro, Heizir F. de

    2008-01-01

    Several alkyl esters were synthesized, purified, characterized by 1 H NMR and employed as standards for establishing chromatographic methods to monitor their formation in the synthesis of biodiesel. The efficiency of the chromatographic methods was confirmed with the products of enzymatic transesterification of babassu oil with different alcohols (C 2 to C 4 ), using Lipozyme as catalyst. (author)

  2. An Efficient Procedure Based on a MW-Assisted Horner–Wadsworth-Emmons Reaction for the Synthesis of (Z-3,3-Trisubstituted-a,b-unsaturated Esters

    Directory of Open Access Journals (Sweden)

    Ornella Azzolina

    2010-08-01

    Full Text Available A microwave-assisted HWE olefination process of readily accessible aryl-alkyl ketones has been developed to provide a rapid access to (Z-3,3-trisubstituted-α,β-unsaturated methyl esters, key building blocks for the synthesis of biologically active compounds.

  3. Process parameters optimization for synthesis of methyl ester from sunflower oil using Taguchi technique

    Directory of Open Access Journals (Sweden)

    G. Senthilkumar

    2014-09-01

    Full Text Available In this work, transesterification of sunflower oil for obtaining biodiesel was studied. Taguchi’s methodology (L9 orthogonal array was selected to optimize the most significant variables (methanol, catalyst concentration and stirrer speed in transesterification process. Experiments have conducted based on development of L9 orthogonal array by using Taguchi technique. Analysis of Variance (ANOVA and the regression equations were used to find the optimum yield of sunflower methyl ester under the influence of methanol, catalyst & stirrer speed. The study resulted in a maximum yield of sun flower methyl ester as 96% with the optimal conditions of methanol 110 ml with 0.5% by wt. of sodium hydroxide (NaOH stirred at 1200 rpm. The yield was analyzed on the basis of “larger is better”. Finally, confirmation tests were carried out to verify the experimental results.

  4. 4-Hydroxy-3-methoxycinnamate esters of milkweed oil: synthesis and characterization.

    Science.gov (United States)

    Harry-O'kuru, Rogers E

    2005-11-01

    The common milkweed (Asclepias syriaca L.) is a new industrial crop. Its seed oil (TAG) is highly polyunsaturated. In the search for novel applications for milkweed seed oil, the olefinic groups in the TAG were oxidized to polyhydroxy TAG via epoxidation and subsequent epoxy ring-opening reactions. These polyhydroxy TAG exhibit unique industrially desirable emulsoid properties in water. Esterification of the secondary polyhydroxy functionalities of the TAG derivatives of the oil with trans-4-hydroxy-3-methoxycinnamic acid (ferulic acid) has resulted in the development of novel cinnamate esters of milkweed oil. These cinnamates are also obtainable via direct ring-opening of the epoxy TAG intermediate with ferulic acid. Among the interesting characteristics of the ester derivatives is their UV radiation-absorbing property.

  5. Synthesis and characterization of poly(ester amide from remewable resources through melt polycondensation

    Directory of Open Access Journals (Sweden)

    B. B. Wang

    2014-01-01

    Full Text Available Biodegradable poly(ester amides (PEAs were synthesized from lactic acid and 11-aminoundecanoic acid via melt polycondensation. Molecular weights, chemical structures and thermal properties of the poly(ester amides were characterized in terms of gel permeation chromatography (GPC, Fourier transform infrared spectroscopy (FTIR, 1H nuclear magnetic resonance (1H NMR, differential scanning calorimetry (DSC and thermogravimetric analysis (TGA, respectively. The PEAs have low molecular weights and display a lower cold crystallization temperature as well as smaller crystallinity by comparison with the pure poly(lactic acid (PLA. The incorporation of the 11-aminoundecanoic acid into the PLA chain not only improved the thermal stability but changed the decomposition process.

  6. Highly regioselective synthesis of undecylenic acid esters of purine nucleosides catalyzed by Candida antarctica lipase B.

    Science.gov (United States)

    Gao, Wen-Li; Li, Ning; Zong, Min-Hua

    2011-11-01

    Regioselective undecylenoylation of purine nucleosides as potential dual prodrugs was achieved by Candida antarctica lipase B using adenosine as a model reactant. The optimum organic solvent, molar ratio of vinyl ester to nucleoside, enzyme dosage, reaction temperature and molecular sieve amount were anhydrous THF, 5:1, 20 U/ml, 45°C and 75 mg/ml, respectively. Under the optimum conditions, the initial reaction rate, yield and 5'-regioselectivity were 1.1 mM/h, 90% and >99%, respectively. The enzymatic acylation of various nucleosides furnished the desired 5'-ester derivatives with the yields of 60-95% and 5'-regioselectivities of >99%. In addition, the lipase displayed excellent operational stability in THF, and retained 96% of its initial activity after reused for five batches.

  7. New heparin–indomethacin conjugate with an ester linkage: Synthesis, self aggregation and drug delivery behavior

    Energy Technology Data Exchange (ETDEWEB)

    Li, Nan-Nan; Zheng, Bing-Na [DSAPM Lab and PCFM Lab, Institute of Polymer Science, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Lin, Jian-Tao [DSAPM Lab and PCFM Lab, Institute of Polymer Science, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Guangdong Medical College, Dongguan 523808 (China); Zhang, Li-Ming, E-mail: ceszhlm@mail.sysu.edu.cn [DSAPM Lab and PCFM Lab, Institute of Polymer Science, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China)

    2014-01-01

    New heparin–indomethacin conjugate with an ester linkage was prepared by the carbodiimide-mediated condensation reaction, and then characterized by FTIR and {sup 1}HNMR analyses. Due to its amphiphilic character, such a conjugate could self-aggregate into spherical nanoparticles in aqueous system, as confirmed by fluorescence spectroscopy, dynamic light scattering and transmission electron microscopy. By the in vitro drug release tests, the resultant conjugate nanoparticles were found to have a sustained and esterase-sensitive release behavior for conjugated indomethacin. In addition, the uptake of these conjugate nanoparticles into human nasopharyngeal carcinoma CNE1 cells was confirmed by fluorescence microscopy. - Highlights: • New heparin–indomethacin conjugate with an ester linkage was prepared. • Such a conjugate could self-aggregate into spherical nanoparticles in aqueous system. • The resultant conjugate nanoparticles exhibited an esterase-sensitive drug release behavior. • The resultant conjugate nanoparticles showed the cellular uptake ability in CNE1 cells.

  8. Silicon-Containing Tri- and Tetra-Functional Cyanate Esters: Synthesis, Cure Kinetics, and Network Properties

    Science.gov (United States)

    2014-01-01

    organosilane monomers have also been described recently for use in the formation of microporous structures.15 Though the incorporation of silicon at...Song, J. K.; Alagar, M. Microporous Mesoporous Mater. 2013, 179, 157-164. 26. Wu, G. L.; Kou, K. C.; Chao, M.; Zhuo, L. H.; Zhang, J. Q. J. Wuhan Univ...Cambrea, L. R. Insights into moisture uptake and processability from new cyanate ester monomer and blend studies. SAMPE International Technical

  9. Synthesis and Antimicrobial Activity of 2-(Aminoacid ester)-3-(6 ...

    African Journals Online (AJOL)

    NJD

    2008-11-06

    Nov 6, 2008 ... synthesized new 6-membered heterocycles in which aminoacid esters are linked to the phosphorus .... analysis run in a 3:7 mixture of ethyl acetate and hexane and the average Rf value observed was 0.75. ..... 7 K.G. Devine, C. McGuigan, T.J. O'Connor, S.R. Nicholis and. D. Kinchington, AIDS, 1990, 4, ...

  10. Synthesis, Structural and Antioxidant Studies of Some Novel N-Ethyl Phthalimide Esters

    Science.gov (United States)

    Chandraju, Siddegowda; Win, Yip-Foo; Tan, Weng Kang; Quah, Ching Kheng; Fun, Hoong-Kun

    2015-01-01

    A series of N-ethyl phthalimide esters 4(a-n) were synthesized and characterized by spectroscopic studies. Further, the molecular structure of majority of compounds were analysed by single crystal X-ray diffraction studies. The X-ray analysis revealed the importance of substituents on the crystal stability and molecular packing. All the synthesized compounds were tested for in vitro antioxidant activity by DPPH radical scavenging, FRAP and CUPRAC methods. Few of them have shown good antioxidant activity. PMID:25742494

  11. Prebiotic synthesis of 2-deoxy-d-ribose from interstellar building blocks promoted by amino esters or amino nitriles.

    Science.gov (United States)

    Steer, Andrew M; Bia, Nicolas; Smith, David K; Clarke, Paul A

    2017-09-25

    Understanding the prebiotic genesis of 2-deoxy-d-ribose, which forms the backbone of DNA, is of crucial importance to unravelling the origins of life, yet remains open to debate. Here we demonstrate that 20 mol% of proteinogenic amino esters promote the selective formation of 2-deoxy-d-ribose over 2-deoxy-d-threopentose in combined yields of ≥4%. We also demonstrate the first aldol reaction promoted by prebiotically-relevant proteinogenic amino nitriles (20 mol%) for the enantioselective synthesis of d-glyceraldehyde with 6% ee, and its subsequent conversion into 2-deoxy-d-ribose in yields of ≥ 5%. Finally, we explore the combination of these two steps in a one-pot process using 20 mol% of an amino ester or amino nitrile promoter. It is hence demonstrated that three interstellar starting materials, when mixed together with an appropriate promoter, can directly lead to the formation of a mixture of higher carbohydrates, including 2-deoxy-d-ribose.

  12. Microwave-assisted methyl esters synthesis of Kapok (Ceiba pentandra seed oil: parametric and optimization study

    Directory of Open Access Journals (Sweden)

    Awais Bokhari

    2015-09-01

    Full Text Available The depleting fossil fuel reserves and increasing environmental concerns have continued to stimulate research into biodiesel as a green fuel alternative produced from renewable resources. In this study, Kapok (Ceiba pentandra oil methyl ester was produced by using microwave-assisted technique. The optimum operating conditions for the microwave-assisted transesterification of Kapok seed oil including temperature, catalyst loading, methanol to oil molar ratio, and irradiation time were investigated by using Response Surface Methodology (RSM based on Central Composite Design (CCD. A maximum conversion of 98.9 % was obtained under optimum conditions of 57.09 °C reaction temperature, 2.15 wt% catalyst (KOH loading, oil to methanol molar ratio of 1:9.85, and reaction time of 3.29 min. Fourier Transform Infra-Red (FT-IR spectroscopy was performed to verify the conversion of the fatty acid into methyl esters. The properties of Kapok oil methyl ester produced under the optimum conditions were characterized and found in agreement with the international ASTM D 6751 and EN 14214 standards.

  13. Acylation of lithiated trimethylsilyl malonates and esters applied to the synthesis of molecules of biological interest, labelled with carbon 14

    International Nuclear Information System (INIS)

    Gorichon, Liliane

    1978-01-01

    This research thesis first reports an attempt to generalise the method of acylation of lithiated trimethylsilyl (TMS) malonates by introduction of new organic functions into the radical. This leads to the synthesis of some alkaloids such as nicotine and contine. The author also shows that fat acids can be labelled with carbon 14 in any position of the carbon chain. Thus, acylation of these malonates have been performed by using different acid chlorides. Then, the author reports attempts to simplify this method by using α-lithiated trimethylsilyl esters instead of malonates. He reports attempts of acylation of TMS isobutyrate, TMS proprionate and TMS acetate, by using different radioactive acid chlorides (benzoyl chloride, nicotinoyl chloride, lauryl chloride, and oleyl chloride). The author finally shows that both methods are equivalent by synthesising muscalure from TMS butylmalonate as well as from TMS hexanoate

  14. One-pot synthesis of enantiomerically pure N-protected allylic amines from N-protected α-amino esters

    Directory of Open Access Journals (Sweden)

    Gastón Silveira-Dorta

    2016-05-01

    Full Text Available An improved protocol for the synthesis of enantiomerically pure allylic amines is reported. N-Protected α-amino esters derived from natural amino acids were submitted to a one-pot tandem reduction–olefination process. The sequential reduction with DIBAL-H at −78 °C and subsequent in situ addition of organophosphorus reagents yielded the corresponding allylic amines without the need to isolate the intermediate aldehyde. This circumvents the problem of instability of the aldehydes. The method tolerates well both Wittig and Horner–Wadsworth–Emmons organophosphorus reagents. A better Z-(diastereoselectivity was observed when compared to the previous one-pot method. The (diastereoselectivity of the process was affected neither by the reaction solvent nor by the amount of DIBAL-H employed. The method is compatible with the presence of free hydroxy groups as shown with serine and threonine derivatives.

  15. Synthesis of palm-based ethylhexyl ester as a synthetic base oil for drilling fluids using chemical transesterification

    Directory of Open Access Journals (Sweden)

    Habib, N. S.H.A.

    2014-03-01

    Full Text Available In the present study the synthesis of a palm based ethylhexyl ester was examined through a transesterification reaction of palm oil methyl ester (POME with 2-ethylhexanol (EH. A sodium methoxide in methanol solution was used as a catalyst. The reaction was carried out at a fixed pressure of 1.5 mbar by varying the temperature (80–140 °C, POME/2EH molar ratio (1:1.5–1:2.2, reaction time (0.5–4 h and catalyst concentration (1–2% w/w. The reaction with 2-ethylhexanol involved a single step reversible reaction, thus, the reaction was completed in a very short time. The optimum conditions were obtained in less than 30 minutes with 1.5 mbar pressure, 70 °C, and 1:2 molar ratio of POME to 2EH. The analysis of the final product (ethylhexyl ester was performed using gas chromatography which exhibited 98% of ethyl hexyl ester yield. The gas chromatography analysis of ethyl hexyl ester revealed two major esters peaks i.e. ethyl hexyl palmitate and ethylhexyl oleate.En el presente estudio se analizó la síntesis de ésteres de acetato de hexilo de palma mediante reacción de transesterificación de los ésteres metílicos de aceite de palma (PME con 2-etilhexanol (EH. Como catalizador se utiliza una solución de metóxido de sodio en metanol. La reacción se lleva a cabo a presión fija de 1,5 mbar mediante la variación de temperatura (80–140 °C, relación molar POME/2EH (1:1.5–1:2.2, tiempo de reacción (0,5–4 h y concentración de catalizador (1–2% w / w. La reacción con 2-etilhexanol implica un solo paso de una reacción reversible, por lo tanto, ésta se completa en un tiempo muy corto. Las condiciones óptimas se obtuvieron en menos de 30 min a 1,5 mbar, 70 °C y una relación molar de 1:2 de POME al 2EH. El análisis del producto final se realizó usando cromatografía de gases que mostró un rendimiento del 98% del etilhexil éster. El análisis de la cromatografía de gases del etilhexil éster muestra dos grandes picos

  16. Lubricating and waxy esters, I. Synthesis, crystallization, and melt behavior of linear monoesters.

    Science.gov (United States)

    Bouzidi, Laziz; Li, Shaojun; Di Biase, Steve; Rizvi, Syed Q; Narine, Suresh S

    2012-01-01

    Four pure jojoba wax-like esters (JLEs), having carbon chain length of 36, 40 (two isomers) and 44, were prepared by Steglish esterification of fatty acids (or acid chlorides) with fatty alcohols at room temperature. Calorimetric and diffraction data was used to elucidate the phase behavior of the esters. The primary thermal parameters (crystallization and melting temperatures) obtained from the DSC of the symmetrical molecules correspond well with the carbon numbers of the JLEs. However, the data also suggests that carbon number is not the only factor since the symmetry of the molecule also plays a significant role in the phase behavior. Overall, the JLEs show very little polymorphic activity at the experimental conditions used, suggesting that they are likely to transform the same way during melting as well as crystallization, a characteristic which may be useful in designing new waxes and lubricants. The XRD data clearly show that the solid phase in all samples consists of a mixture of a β-phase and a β'-phase; fully distinguishable by their characteristic diffraction peaks. Subtle differences between the subcell patterns and phase development of the samples were observed. Different layering of the samples was also observed, understandably because of the chain length differences between the compounds. The long spacings were perfectly linearly proportional to the number of carbon atoms. The length of the ester layers with n carbon atoms can be calculated by a formula similar to that used for the layers in linear alkane molecules. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  17. Immobilization of lipases in PSS/PEO blends and applications in esters synthesis

    International Nuclear Information System (INIS)

    Vecchia, Roberto D.; Nascimento, Maria G.; Soldi, Valdir

    2001-01-01

    Various lipases were immobilized in PSS/PEO blends and used as bio catalysts in the esterification reaction of lauric acid with n-pentanol, in hexane as a solvent for 24 h at 35 deg C. The best results in the ester conversion, were obtained by using lipase from Rhryzopus oryzae immobilized in PSS/PEO 80:20 blend. The data are in agreement with DSC and TGA values, which showed that these systems (blend/lipase) were very stable with low mass loss. No product was obtained by using lipase FAP-15 immobilized in PSS film , showing the strong influence of the polymer on enzyme activity. (author)

  18. Synthesis, Crystal Structure and Biological Activities of Novel Anthranilic(Isophthalic) Acid Esters

    Institute of Scientific and Technical Information of China (English)

    YAN Tao; YU Guan-ping; LIU Peng-fei; XIONG Li-xia; YU Shu-jing; LI Zheng-ming

    2012-01-01

    In search of environmentally benign insecticides with high activity,low toxicity and low resistance,a series of novel anthranilic(isophthalic) acid esters was designed and synthesized based on the structure of ryanodine modulating agent.All the compounds were characterized by 1H NMR spectra,elemental analysis or high resolution mass spectrometry(HRMS).The preliminary results of biological activity assessment indicate that some of the title compounds exhibit certain but unremarkable insecticidal activity against Mythimna separata Walker at 200 mg/L and fungicidal activities against five funguses at 50 mg/L.

  19. Scalable preparation of high purity rutin fatty acid esters following enzymatic synthesis

    DEFF Research Database (Denmark)

    Lue, Bena-Marie; Guo, Zheng; Xu, Xuebing

    2010-01-01

    Investigations into expanded uses of modified flavonoids are often limited by the availability of these high purity compounds. As such, a simple, effective and relatively fast method for isolation of gram quantities of both long and medium chain fatty acid esters of rutin following scaled......-up biosynthesis reactions was established. Acylation reactions of rutin and palmitic or lauric acids were efficient in systems containing dried acetone and molecular sieves, yielding from 70–77% bioconversion after 96 h. Thereafter, high purity isolates (>97%) were easily obtained in significant quantities...

  20. Enzymatic synthesis of hydrophilic undecylenic acid sugar esters and their biodegradability.

    Science.gov (United States)

    Raku, Takao; Kitagawa, Masaru; Shimakawa, Hiromi; Tokiwa, Yutaka

    2003-01-01

    To enhance water solubility of 10-undecylenic acid, which has anti-fungus, anti-bacterial and anti-virus activity, D-glucose, trehalose and sucrose were regioselectively esterified with vinyl 10-undecylenic acid ester in dimethyl formamide by a commercial protease, Bioprase conc., from Bacillus subtilis. 6-O-(10-Undecylenoyl) D-glucose, 6-O-(10-undecylenoyl) trehalose and 1'-O-(10-undecylenoyl) sucrose were obtained. The influence of structural variation by changing the sugar moiety was analyzed the surface tension and biodegradability.

  1. Enzymatic synthesis of sorbitan esters using a low-boiling-point azeotrope as a reaction solvent.

    Science.gov (United States)

    Sarney, D B; Barnard, M J; Virto, M; Vulfson, E N

    1997-05-20

    Sorbitan esters were prepared by controlled dehydration of sorbitol followed by lipase-catalyzed esterification of the resulting "sorbitan." The reaction was carried out in azeotropic mixtures of tert-butanol/n-hexane. A partial phase diagram to determine the temperature required for the distillation of the azeotrope at a given ratio of the solvents was constructed. The effect of varying concentrations of the two solvents on the rate of esterification and the monoester/diester ratio of the final product was investigated in detail. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 54: 351-356, 1997.

  2. Enantioselective Synthesis of α-Mercapto-β-amino Esters via Rh(II)/Chiral Phosphoric Acid-Cocatalyzed Three-Component Reaction of Diazo Compounds, Thiols, and Imines.

    Science.gov (United States)

    Xiao, Guolan; Ma, Chaoqun; Xing, Dong; Hu, Wenhao

    2016-12-02

    An enantioselective method for the synthesis of α-mercapto-β-amino esters has been developed via a rhodium(II)/chiral phosphoric acid-cocatalyzed three-component reaction of diazo compounds, thiols, and imines. This transformation is proposed to proceed through enantioselective trapping of the sulfonium ylide intermediate generated in situ from the diazo compound and thiol by the phosphoric acid-activated imine. With this method, a series of α-mercapto-β-amino esters were obtained in good yields with moderate to good stereoselectivities.

  3. Stereo-controlled synthesis of polyheterocycles via the diene-transmissive hetero-Diels-Alder reaction of β,γ-unsaturated α-keto esters.

    Science.gov (United States)

    Otani, Takashi; Tamai, Yumiko; Seki, Kazunori; Kikuchi, Tomohiro; Miyazawa, Taiichiro; Saito, Takao

    2015-06-07

    We describe the stereoselective synthesis of polyring-fused heterocyclic compounds based on diene-transmissive hetero-Diels-Alder reactions utilizing β,γ-unsaturated α-keto esters. This protocol involves the initial endo- or exo-selective Diels-Alder (DA) reactions with electron-rich dienophiles, methylenation of the ester carbonyl groups with the Tebbe reagent, and a stereoselective second DA reaction with electron-deficient dienophiles. The use of enantioselective DA reactions in the initial reaction enables access to chiral polyring-fused heterocyclic compounds with multiple chiral centres.

  4. Regulation of triglyceride metabolism. I. Eukaryotic neutral lipid synthesis: "Many ways to skin ACAT or a DGAT".

    Science.gov (United States)

    Turkish, Aaron; Sturley, Stephen L

    2007-04-01

    Esterification of sterols, fatty acids and other alcohols into biologically inert forms conserves lipid resources for many cellular functions. Paradoxically, the accumulation of neutral lipids such as cholesteryl ester or triglyceride, is linked to several major disease pathologies. In a remarkable example of genetic expansion, there are at least eleven acyltransferase reactions that lead to neutral lipid production. In this review, we speculate that the complexity and apparent redundancy of neutral lipid synthesis may actually hasten rather than impede the development of novel, isoform-specific, therapeutic interventions for acne, type 2 diabetes, obesity, hyperlipidemia, fatty liver disease, and atherosclerosis.

  5. High-level accumulation of oleyl oleate in plant seed oil by abundant supply of oleic acid substrates to efficient wax ester synthesis enzymes.

    Science.gov (United States)

    Yu, Dan; Hornung, Ellen; Iven, Tim; Feussner, Ivo

    2018-01-01

    Biotechnology enables the production of high-valued industrial feedstocks from plant seed oil. The plant-derived wax esters with long-chain monounsaturated acyl moieties, like oleyl oleate, have favorite properties for lubrication. For biosynthesis of wax esters using acyl-CoA substrates, expressions of a fatty acyl reductase (FAR) and a wax synthase (WS) in seeds are sufficient. For optimization of the enzymatic activity and subcellular localization of wax ester synthesis enzymes, two fusion proteins were created, which showed wax ester-forming activities in Saccharomyces cerevisiae . To promote the formation of oleyl oleate in seed oil, WSs from Acinetobactor baylyi ( Ab WSD1) and Marinobacter aquaeolei ( Ma WS2), as well as the two created fusion proteins were tested in Arabidopsis to evaluate their abilities and substrate preference for wax ester production. The tested seven enzyme combinations resulted in different yields and compositions of wax esters. Expression of a FAR of Marinobacter aquaeolei ( Ma FAR) with Ab WSD1 or Ma WS2 led to a high incorporation of C 18 substrates in wax esters. The Ma FAR/TM Mm AWAT2- Ab WSD1 combination resulted in the incorporation of more C 18:1 alcohol and C 18:0 acyl moieties into wax esters compared with Ma FAR/ Ab WSD1. The fusion protein of a WS from Simmondsia chinensis ( Sc WS) with MaFAR exhibited higher specificity toward C 20:1 substrates in preference to C 18:1 substrates. Expression of Ma FAR/ Ab WSD1 in the Arabidopsis fad2 fae1 double mutant resulted in the accumulation of oleyl oleate (18:1/18:1) in up to 62 mol% of total wax esters in seed oil, which was much higher than the 15 mol% reached by Ma FAR/ Ab WSD1 in Arabidopsis Col-0 background. In order to increase the level of oleyl oleate in seed oil of Camelina , lines expressing Ma FAR/ Sc WS were crossed with a transgenic high oleate line. The resulting plants accumulated up to >40 mg g seed -1 of wax esters, containing 27-34 mol% oleyl oleate. The

  6. Synthesis and Insecticidal Activities of New Ester-Derivatives of Celangulin-V

    Directory of Open Access Journals (Sweden)

    Wenjun Wu

    2011-12-01

    Full Text Available In order to develop new biorational pesticides, ten new 6-substituted ester derivatives of Celangulin-V were designed and synthesized. The structures of the new derivatives were confirmed by IR, 1H-NMR, 13C-NMR and ESI-MS spectral analysis. Insecticidal activities of these compounds were tested against the third-instar larvae of Mythimna separata. Two derivatives (1.1, 1.2 showed higher insecticidal activities than Celangulin-V, with mortality of 75.0% and 83.3%, respectively. While four compounds (1.3, 1.4, 1.7, 1.8 denoted lower insecticidal activities, the others (1.5, 1.6, 1.9, 1.10 revealed no activities at a concentration of 10 mg.mL−1. The results suggest that C-6 substitutions of Celangulin-V are very important in determining the insecticidal activities of its ester-derivatives. That the acetyl (1.1 and propionyl (1.2 derivatives possessed much higher insecticidal activities than Celangulin-V itself supported the view that Celangulin-V has the potential to be a lead structure of semi-synthetic green insecticides.

  7. Cavitation assisted synthesis of fatty acid methyl esters from sustainable feedstock in presence of heterogeneous catalyst using two step process.

    Science.gov (United States)

    Dubey, Sumit M; Gole, Vitthal L; Gogate, Parag R

    2015-03-01

    The present work reports the intensification aspects for the synthesis of fatty acid methyl esters (FAME) from a non-edible high acid value Nagchampa oil (31 mg of KOH/g of oil) using two stage acid esterification (catalyzed by H₂SO₄) followed by transesterification in the presence of heterogeneous catalyst (CaO). Intensification aspects of both stages have been investigated using sonochemical reactors and the obtained degree of intensification has been established by comparison with the conventional approach based on mechanical agitation. It has been observed that reaction temperature for esterification reduced from 65 to 40 °C for the ultrasonic approach whereas there was a significant reduction in the optimum reaction time for transesterification from 4h for the conventional approach to 2.5h for the ultrasound assisted approach. Also the reaction temperature reduced marginally from 65 to 60 °C and yield increased from 76% to 79% for the ultrasound assisted approach. Energy requirement and activation energy for both esterification and transesterification was lower for the ultrasound based approach as compared to the conventional approach. The present work has clearly established the intensification obtained due to the use of ultrasound and also illustrated the two step approach for the synthesis of FAME from high acid value feedstock based on the use of heterogeneous catalyst for the transesterification step. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Decarbonylative Silylation of Esters by Combined Nickel and Copper Catalysis for the Synthesis of Arylsilanes and Heteroarylsilanes

    KAUST Repository

    Guo, Lin

    2016-08-25

    An efficient nickel/copper-catalyzed decarbonylative silylation reaction of carboxylic acid esters with silylboranes is described. This reaction provides access to structurally diverse silanes with high efficiency and excellent functional-group tolerance starting from readily available esters.

  9. Decarbonylative Silylation of Esters by Combined Nickel and Copper Catalysis for the Synthesis of Arylsilanes and Heteroarylsilanes

    KAUST Repository

    Guo, Lin; Chatupheeraphat, Adisak; Rueping, Magnus

    2016-01-01

    An efficient nickel/copper-catalyzed decarbonylative silylation reaction of carboxylic acid esters with silylboranes is described. This reaction provides access to structurally diverse silanes with high efficiency and excellent functional-group tolerance starting from readily available esters.

  10. Indium-catalyzed synthesis of keto esters from cyclic 1,3-diketones and alcohols and application to the synthesis of seratrodast.

    Science.gov (United States)

    Kuninobu, Yoichiro; Kawata, Atsushi; Noborio, Taihei; Yamamoto, Syun-Ichi; Matsuki, Takashi; Takata, Kazumi; Takai, Kazuhiko

    2010-04-01

    Esterification reactions from cyclic 1,3-diketones and alcohols are carried out in the presence of several Lewis acids. In particular, indium(III) triflate, In(OTf)(3), iron(III) triflate, Fe(OTf)(3), copper(II) triflate, Cu(OTf)(2), and silver(I) triflate, AgOTf, show high catalytic activities. These reactions proceed through the carbon-carbon bond cleavage by a retro-aldol reaction and were found to be highly regioselective even in the presence of other functional groups. This type of reaction can also be applied to the preparation of the keto esters during the synthesis of seratrodast, which is an antiasthmatic and eicosanoid antagonist.

  11. New Homologues Series of Heterocyclic Schiff Base Ester: Synthesis and Characterization

    Directory of Open Access Journals (Sweden)

    Yee-Ting Chong

    2016-01-01

    Full Text Available A homologous series of liquid crystal bearing with heterocyclic thiophene Schiff base ester with alkanoyloxy chain (CH3(CH2nCOO–, where n=4, 6, 8, 10, 12, 14, 16 was successfully synthesized through the modification of some reported methods. The structural information of these compounds was isolated and characterized through some spectroscopic techniques, such as FTIR, 1H, and 13C NMR and elemental analysis. Textural observation was carried out using a polarizing optical microscope (POM over heating and cooling cycles. It was found that all synthesized compounds (3a–g exhibited an enantiotropic nematic phase upon the heating and cooling cycle with high thermal stability. Moreover, a characteristic bar transition texture was observed for compounds 3f and 3g which have shown transition of nematic-to-smectic C phase. This has been further confirmed by obtaining relative phase transition temperature using the differential scanning calorimetry (DSC.

  12. Synthesis and Characterization of Novel Polyurethanes Based on Vegetable Oils Amide and Ester Polyols

    Directory of Open Access Journals (Sweden)

    Vladimir YAKUSHIN

    2014-09-01

    Full Text Available Amide and ester type polyols were synthesized from rapeseed, sunflower and castor oils, and two types of ethanolamine (diethanolamine and triethanolamine at different molar ratio. Poly(urethane amides and polyester urethanes based on the synthesized polyols were prepared. The effect of the chemical structure of the obtained polyurethanes on density, glass transition temperature, thermal stability and mechanical properties was investigated. The influence of the content of OH groups in the synthesized polyols on the specified characteristics was estimated. It has been found that poly(urethane amides have better mechanical characteristics, but their thermal stability is lower than that of polyester urethanes. The chemical structure of the synthesized polyols and polyurethanes is qualitatively confirmed by IR-spectroscopy data. DOI: http://dx.doi.org/10.5755/j01.ms.20.3.4532

  13. Synthesis of Titanium Dioxide nanoparticles via sucrose ester micelle-mediated hydrothermal processing route

    International Nuclear Information System (INIS)

    Anwar, N.S.; Kassim, A.; Lim, H.N.; Zakarya, S.A.; Huang, N.M.

    2010-01-01

    Titanium dioxide nanoparticles were synthesized via low-temperature sucrose ester micelle-mediated hydrothermal processing route using titanium isopropoxide as the precursor. X-ray diffractometer revealed that the samples possessed a mixed crystalline phases consisting of anatase and brookite in which anatase was the main phase. Upon increasing the hydrothermal reaction temperature, the degree of crystallinity of the nanoparticles improved and their morphology transformed from bundles of needles to rods and to spheres. Photo catalytic behaviour of the as-synthesized nanoparticles was investigated by photodegradation of methylene blue solution in an ultraviolet A irradiating photo reactor. The as-synthesized nanoparticles exhibited higher photo catalytic performance as compared to the commercial counterpart. (author)

  14. Synthesis and Antifungal Activity of Novel 3-Caren-5-One Oxime Esters

    Directory of Open Access Journals (Sweden)

    Min Huang

    2017-09-01

    Full Text Available A series of novel 3-caren-5-one oxime esters were designed and synthesized by multi-step reactions in an attempt to develop potent antifungal agents. Two E-Z stereoisomers of the intermediate 3-caren-5-one oxime were separated by column chromatography for the first time. The structures of all the intermediates and target compounds were confirmed by UV-Vis, FTIR, NMR, ESI-MS, and elemental analysis. The antifungal activity of the target compounds was preliminarily evaluated by the in vitro method against Fusarium oxysporum f. sp. cucumerinum, Physalospora piricola, Alternaria solani, Cercospora arachidicola, Gibberella zeae, Rhizoeotnia solani, Bipolaris maydis, and Colleterichum orbicalare at 50 µg/mL. The target compounds exhibited best antifungal activity against P. piricola, in which compounds (Z-4r (R = β-pyridyl, (Z-4q (R = α-thienyl, (E-4f′ (R = p-F Ph, (Z-4i (R = m-Me Ph, (Z-4j (R = p-Me Ph, and (Z-4p (R = α-furyl had inhibition rates of 97.1%, 87.4%, 87.4%, 85.0%, 81.9%, and 77.7%, respectively, showing better antifungal activity than that of the commercial fungicide chlorothanil. Also, compound (Z-4r (R = β-pyridyl displayed remarkable antifungal activity against all the tested fungi, with inhibition rates of 76.7%, 82.7%, 97.1%, 66.3%, 74.7%, 93.9%, 76.7% and 93.3%, respectively, showing better or comparable antifungal activity than that of the commercial fungicide chlorothanil. Besides, the E-Z isomers of the target oxime esters were found to show obvious differences in antifungal activity. These results provide an encouraging framework that could lead to the development of potent novel antifungal agents.

  15. Synthesis and Antifungal Activity of Novel 3-Caren-5-One Oxime Esters.

    Science.gov (United States)

    Huang, Min; Duan, Wen-Gui; Lin, Gui-Shan; Li, Kun; Hu, Qiong

    2017-09-12

    A series of novel 3-caren-5-one oxime esters were designed and synthesized by multi-step reactions in an attempt to develop potent antifungal agents. Two E - Z stereoisomers of the intermediate 3-caren-5-one oxime were separated by column chromatography for the first time. The structures of all the intermediates and target compounds were confirmed by UV-Vis, FTIR, NMR, ESI-MS, and elemental analysis. The antifungal activity of the target compounds was preliminarily evaluated by the in vitro method against Fusarium oxysporum f. sp. cucumerinum , Physalospora piricola , Alternaria solani , Cercospora arachidicola , Gibberella zeae, Rhizoeotnia solani , Bipolaris maydis , and Colleterichum orbicalare at 50 µg/mL. The target compounds exhibited best antifungal activity against P. piricola , in which compounds ( Z )- 4r (R = β -pyridyl), ( Z )- 4q (R = α -thienyl), ( E )- 4f' (R = p -F Ph), ( Z )- 4i (R = m -Me Ph), ( Z )- 4j (R = p -Me Ph), and ( Z )- 4p (R = α -furyl) had inhibition rates of 97.1%, 87.4%, 87.4%, 85.0%, 81.9%, and 77.7%, respectively, showing better antifungal activity than that of the commercial fungicide chlorothanil. Also, compound ( Z )- 4r (R = β -pyridyl) displayed remarkable antifungal activity against all the tested fungi, with inhibition rates of 76.7%, 82.7%, 97.1%, 66.3%, 74.7%, 93.9%, 76.7% and 93.3%, respectively, showing better or comparable antifungal activity than that of the commercial fungicide chlorothanil. Besides, the E-Z isomers of the target oxime esters were found to show obvious differences in antifungal activity. These results provide an encouraging framework that could lead to the development of potent novel antifungal agents.

  16. Biocatalytic Asymmetric Synthesis of (1R, 2S)-N-Boc-vinyl-ACCA Ethyl Ester with a Newly Isolated Sphingomonas aquatilis.

    Science.gov (United States)

    Zhu, Shaozhou; Shi, Ying; Zhang, Xinyu; Zheng, Guojun

    2018-02-01

    1-amino cyclopropane-1-carboxylic acid (ACCA) and its derivatives are essential pharmacophoric unit that widely used in drug research and development. Specifically, (1R, 2S)-N-Boc-vinyl-ACCA ethyl ester (vinyl-ACCA) is a key chiral intermediate in the synthesis of highly potent hepatitis C virus (HCV) NS3/4A protease inhibitors such as asunaprevir and simeprevir. Developing strategies for the asymmetric synthesis of vinyl-ACCA is thus extremely high demand. In this study, 378 bacterial strains were isolated from soil samples using N-Boc-vinyl-ACCA ethyl ester as the sole carbon source and were screened for esterase activity. Fourteen of which worked effectively for the asymmetric synthesis of (1R, 2S)-N-Boc-1-vinyl ACCA ethyl ester. The strain CY-2, identified as Sphingomonas aquatilis, which showed the highest stability and enantioselectivity was selected as whole cell biocatalyst for further study. A systematic study of all factors influencing the enzymatic hydrolysis was performed. Under optimized conditions, resolution of rac-vinyl-ACCA to (1R, 2S)-N-Boc-1-vinyl ACCA ethyl ester with 88.2% ee and 62.4% conversion (E = 9) was achieved. Besides, S. aquatilis was also used to transform other 10 different substrates. Notably, it was found that 7 of them could be stereoselectively hydrolyzed, especially for (1R,2S)-1-amino-vinyl-ACCA ethyl ester hydrochloride (99.6% ee, E>200). Our investigations provide a new efficient whole cell biocatalyst for resolution of ACCA and might be developed for industry application.

  17. Entrainer-based reactive distillation versus conventional reactive distillation for the synthesis of fatty acid esters

    NARCIS (Netherlands)

    Jong, de M.C.; Dimian, A.C.; Haan, de A.B.

    2008-01-01

    In this paper different reactive distillation configurations for the synthesis of isopropyl myristate were compared with the use of process models made in Aspen Plus. It can be concluded that the configurations in which an entrainer is added are more capable to reach the required conversion of

  18. Cross-Aldol Reaction of Activated Carbonyls with Nitrosocarbonyl Intermediates: Stereoselective Synthesis toward α-Hydroxy-β-amino Esters and Amides.

    Science.gov (United States)

    Mallik, Sumitava; Bhajammanavar, Vinod; Ramakrishna, Isai; Baidya, Mahiuddin

    2017-07-21

    A practical and flexible strategy toward α-hydroxy-β-amino esters and amides, which are important biological motifs, based on an organocatalytic cross-aldol reaction of in situ-generated nitrosocarbonyl intermediates followed by hydrogenation is presented. The protocol features operational simplicity, high yields, a wide substrate scope, and high regio- and diastereoselectivity profiles. The utility of this method was showcased through the synthesis of bestatin analogues and indole formation.

  19. A library synthesis of 4-hydroxy-3-methyl-6-phenylbenzofuran-2-carboxylic acid ethyl ester derivatives as anti-tumor agents.

    Science.gov (United States)

    Hayakawa, Ichiro; Shioya, Rieko; Agatsuma, Toshinori; Furukawa, Hidehiko; Naruto, Shunji; Sugano, Yuichi

    2004-09-06

    As a result of a hit-to-lead program using a technique of solution-phase parallel synthesis, a highly potent (2,4-dimethoxyphenyl)-[6-(3-fluorophenyl)-4-hydroxy-3-methylbenzofuran-2-yl]methanone (15b) was synthesized as an optimized derivative of 4-hydroxy-3-methyl-6-phenylbenzofuran-2-carboxylic acid ethyl ester (1), which was discovered as a screening hit from small-molecule libraries and exhibited selective cytotoxicity against a tumorigenic cell line.

  20. The use of fatty acid esters to enhance free acid sophorolipid synthesis.

    Science.gov (United States)

    Ashby, Richard D; Solaiman, Daniel K Y; Foglia, Thomas A

    2006-02-01

    Fatty acid esters were prepared by transesterification of soy oil with methanol (methyl-soyate, Me-Soy), ethanol (ethyl-soyate, Et-Soy) and propanol (propyl-soyate, Pro-Soy) and used with glycerol as fermentation substrates to enhance production of free-acid sophorolipids (SLs). Fed-batch fermentations of Candida bombicola resulted in SL yields of 46 +/- 4 g/l, 42 +/- 7 g/l and 18 +/- 6 g/l from Me-Soy, Et-Soy, and Pro-Soy, respectively. Liquid chromatography with atmospheric pressure ionization mass spectrometry (LC/API-MS) showed that Me-Soy resulted in 71% open-chain SLs with 59% of those molecules remaining esterified at the carboxyl end of the fatty acids. Et-Soy and Pro-Soy resulted in 43% and 80% open-chain free-acid SLs, respectively (containing linoleic acid and oleic acid as the principal fatty acid species linked to the sophorose sugar at the omega-1 position), with no evidence of residual esterification.

  1. A concise flow synthesis of indole-3-carboxylic ester and its derivatisation to an auxin mimic

    Directory of Open Access Journals (Sweden)

    Marcus Baumann

    2017-11-01

    Full Text Available An assembled suite of flow-based transformations have been used to rapidly scale-up the production of a novel auxin mimic-based herbicide which was required for preliminary field trials. The overall synthetic approach and optimisation studies are described along with a full description of the final reactor configurations employed for the synthesis as well as the downstream processing of the reaction streams.

  2. Synthesis of Formate Esters and Formamides Using an Au/TiO2-Catalyzed Aerobic Oxidative Coupling of Paraformaldehyde

    Directory of Open Access Journals (Sweden)

    Ioannis Metaxas

    2017-12-01

    Full Text Available A simple method for the synthesis of formate esters and formamides is presented based on the Au/TiO2-catalyzed aerobic oxidative coupling between alcohols or amines and formaldehyde. The suitable form of formaldehyde is paraformaldehyde, as cyclic trimeric 1,3,5-trioxane is inactive. The reaction proceeds via the formation of an intermediate hemiacetal or hemiaminal, respectively, followed by the Au nanoparticle-catalyzed aerobic oxidation of the intermediate. Typically, the oxidative coupling between formaldehyde (2 equiv and amines occurs quantitatively at room temperature within 4 h, and there is no need to add a base as in analogous coupling reactions. The oxidative coupling between formaldehyde (typically 3 equiv and alcohols is unprecedented and occurs more slowly, yet in good to excellent yields and selectivity. Minor side-products (2–12% from the acetalization of formaldehyde by the alcohol are also formed. The catalyst is recyclable and can be reused after a simple filtration in five consecutive runs with a small loss of activity.

  3. Designing, synthesis, and antimicrobial action of oxazoline and thiazoline derivatives of fatty acid esters.

    Science.gov (United States)

    Ahmad, Anis; Ahmad, Aiman; Sudhakar, Raja; Varshney, Himani; Subbarao, Naidu; Ansari, Saba; Rauf, Abdul; Khan, Asad U

    2017-11-01

    In this study, a novel series of oxazoline and thiazoline were designed as inhibitors of cytochrome P450 14 alpha-sterol demethylase (CYP51) from Candida albicans and peptide deformylase (PDF) of Escherichia coli. The long chain dibromo derivative of fatty acid esters on reaction with urea and thiourea gave their corresponding oxazolines and thiazolines, respectively. All the compounds were characterized by their spectral data (IR, 1 H NMR, 13 C NMR and MS) and tested for antibacterial and antifungal activity by disk diffusion assay and minimum inhibitory concentration by the broth microdilution method against gram-positive and gram-negative strains of bacteria as well as fungus strains. The investigation into antimicrobial screening revealed that all the compounds were found to be potent antimicrobial agents. After calculating likeness drug properties of the compounds by Prediction of Activity Spectra for Substances software, ADMET-related descriptors were computed to predict the pharmacokinetic properties for the active and bioavailable compounds by discovery studio 2.5. Molecular docking studies have been performed on PDF of E. coli and CYP 450-14DM of C. albicans to understand the mode of binding of the molecules in the active site of the receptor. Compounds (2-amino-5-(carbomethoxyoctyl)-1,3-oxazoline, 2-amino-5-(carbomethoxyoctyl)-1,3-thiazoline and 2-amino-4-pentyl-5-[(8'R)-8' hydroxy (carbomethoxydecyl)-1,3-oxazoline) showed excellent antimicrobial activity nearly equivalent to the control compounds and compounds, 2-amino-4-octyl-5-(carbomethoxyheptyl)-1,3-oxazolin, 2-amino-4-(2'R)(2'-hydroxy octyl)-5-(carbomethoxyheptyl)-1,3-oxazoline and 2-amino-4-pentyl-5-[(8'R)-8'-hydroxy(carbomethoxy decyl)-1,3-oxazolineshowed vasodilation and antihypertensive properties. Furthermore, a computational analysis of physicochemical parameters revealed that the most of the compounds possessed drug-like attributes. Using Bioinformatics approach, we found a correlation

  4. Simultaneous microwave extraction and synthesis of fatty acid methyl ester from the oleaginous yeast Rhodotorula glutinis

    International Nuclear Information System (INIS)

    Chuck, Christopher J.; Lou-Hing, Daniel; Dean, Rebecca; Sargeant, Lisa A.; Scott, Rod J.; Jenkins, Rhodri W.

    2014-01-01

    Microbial lipids have the potential to substantially reduce the use of liquid fossil fuels, though one obstacle is the energy costs associated with the extraction and subsequent conversion into a biofuel. Here we report a one-step method to produce FAME (fatty acid methyl esters) from Rhodotorula glutinis by combining lipid extraction in a microwave reactor with acid-catalysed transesterification. The microwave did not alter the FAME profile and over 99% of the lipid was esterified when using 25 wt% H 2 SO 4 over 20 min at 120 °C. On using higher loadings of catalyst, similar yields were achieved over 30 s. Equivalent amounts of FAME were recovered in 30 s using this method as with a 4 h Soxhlet extraction, run with the same solvent system. When water was present at less than a 1:1 ratio with methanol, the main product was FAME, above this the major products were FFA (free fatty acids). Under the best conditions, the energy required for the microwave was less than 20% of the energy content of the biodiesel produced. Increasing the temperature did not change the EROI (energy return on investment) substantially; however, longer reaction times used an equivalent amount of energy to the total energy content of the biodiesel. - Highlights: • The extraction and transesterification of yeast lipid were achieved using a microwave reactor. • The lipid was extracted from Rhodotorula glutinis within 30 s under all conditions. • Addition of 25 wt% H 2 SO 4 catalyst converted 95% glycerides to FAME over 5 min. • Water could be tolerated up to 25 wt% without high FFA production. • The temperature of the microwave had less impact on EROI than the length of extraction

  5. Bacillus sp. PS35 Lipase-Immobilization on Styrene-Divinyl Benzene Resin and Application in Fatty Acid Methyl Ester Synthesis.

    Science.gov (United States)

    Palanisamy, Kanmani; Kuppamuthu, Kumaresan; Jeyaseelan, Aravind

    2015-09-01

    Lipase is an enzyme with immense application potential. Ester synthesis by lipase catalysis in organic media is an area of key industrial relevance. Enzymatic preparations with traits that cater to the needs of this function are hence being intensely researched. The objectives of the study were to immobilize the lipase from Bacillus sp. PS35 by cross-linking and adsorption onto styrene-divinyl benzene (Sty-Dvb) hydrophobic resin and to comparatively characterize the free and immobilized lipase preparations. The work also aimed to apply the immobilized lipase for catalysing the fatty acid methyl ester (FAME) synthesis from palm oil and optimize the process parameters for maximizing the yield. In this study, the purified lipase from Bacillus sp. PS35 was immobilized by adsorption onto styrene-divinyl benzene hydrophobic resin with gluteraldehyde cross-linking. The immobilized enzyme showed better pH and temperature stabilities than the free lipase. Organic solvent stability was also enhanced, with the relative activity in the presence of methanol being shifted from 53% to 81%, thereby facilitating the enzyme's application in fatty acid methyl ester synthesis. It exhibited remarkable storage stability over a 30-day period and after 20 repetitive uses. Cross-linking also reduced enzyme leakage by 49%. The immobilized lipase was then applied for biodiesel production from palm oil. Methanol and oil molar ratio of 5:1, three step methanol additions, and an incubation temperature of 50°C were established to be the ideal conditions favoring the transesterification reaction, resulting in 97% methyl ester yield. These promising results offer scope for further investigation and process scale up, permitting the enzyme's commercial application in a practically feasible and economically agreeable manner.

  6. Synthesis of fatty acid methyl ester from crude jatropha (Jatropha curcas Linnaeus) oil using aluminium oxide modified Mg-Zn heterogeneous catalyst.

    Science.gov (United States)

    Olutoye, M A; Hameed, B H

    2011-06-01

    The synthesis of fatty acid methyl esters (FAME) as a substitute to petroleum diesel was investigated in this study from crude jatropha oil (CJO), a non-edible, low-cost alternative feedstock, using aluminium modified heterogeneous basic oxide (Mg-Zn) catalyst. The transesterification reaction with methanol to methyl esters yielded 94% in 6h with methanol-oil ratio of 11:1, catalyst loading of 8.68 wt.% at 182°C and the properties of CJO fuel produced were determine and found to be comparable to the standards according to ASTM. In the range of experimental parameters investigated, it showed that the catalyst is selective to production of methyl esters from oil with high free fatty acid (FFA) and water content of 7.23% and 3.28%, respectively in a single stage process. Thus, jatropha oil is a promising feedstock for methyl ester production and large scale cultivation will help to reduce the product cost. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Synthesis and Suzuki Cross-Coupling Reactions of 2,6-Bis(trifluoromethyl)pyridine-4-boronic Acid Pinacol Ester

    KAUST Repository

    Batool, Farhat

    2016-11-18

    Iridium-catalyzed aromatic borylation provides quick one-step access to 2,6-bis(trifluoromethyl)pyridine-4-boronic acid pinacol ester. Suzuki couplings of this highly electron-deficient pyridine-4-boronic ester with various (hetero)aryl bromides was successfully carried out and the coupled products were obtained in 46–95% isolated yields. Double and triple Suzuki couplings, with dibromo- and tribromoarenes, respectively, were also achieved. Thus demonstrating that this pyridine-4-boronic ester can be a useful source for the installation of one of the strongest electron-withdrawing aromatic group in organic compounds. Copyright © 2016, Georg Thieme Verlag. All rights reserved.

  8. Synthesis and Suzuki Cross-Coupling Reactions of 2,6-Bis(trifluoromethyl)pyridine-4-boronic Acid Pinacol Ester

    KAUST Repository

    Batool, Farhat; Emwas, Abdul-Hamid M.; Gao, Xin; Munawar, Munawar A.; Chotana, Ghayoor A.

    2016-01-01

    Iridium-catalyzed aromatic borylation provides quick one-step access to 2,6-bis(trifluoromethyl)pyridine-4-boronic acid pinacol ester. Suzuki couplings of this highly electron-deficient pyridine-4-boronic ester with various (hetero)aryl bromides was successfully carried out and the coupled products were obtained in 46–95% isolated yields. Double and triple Suzuki couplings, with dibromo- and tribromoarenes, respectively, were also achieved. Thus demonstrating that this pyridine-4-boronic ester can be a useful source for the installation of one of the strongest electron-withdrawing aromatic group in organic compounds. Copyright © 2016, Georg Thieme Verlag. All rights reserved.

  9. A general approach for the synthesis of bimetallic M–Sn (M = Ru, Rh and Ir) catalysts for efficient hydrogenolysis of ester

    KAUST Repository

    Samal, Akshaya Kumar

    2016-11-24

    A versatile synthetic method was applied for the preparation of Sn containing bimetallic catalysts. The synthesis was performed by simply mixing the super hydride [LiB(C2H5)(3)H], with a metal (Ru, Rh or Ir) salt and an organotin complex in tetrahydrofuran solvent without using any surfactant. This leads to the formation of monodispersed M-Sn (M = Ru, Rh or Ir) bimetallic nanoparticles (NPs). These bimetallic catalysts show high performances in the hydrogenolysis of ester to the corresponding alcohol.

  10. High-oleic canola oil consumption enriches LDL particle cholesteryl oleate content and reduces LDL proteoglycan binding in humans.

    Science.gov (United States)

    Jones, Peter J H; MacKay, Dylan S; Senanayake, Vijitha K; Pu, Shuaihua; Jenkins, David J A; Connelly, Philip W; Lamarche, Benoît; Couture, Patrick; Kris-Etherton, Penny M; West, Sheila G; Liu, Xiaoran; Fleming, Jennifer A; Hantgan, Roy R; Rudel, Lawrence L

    2015-02-01

    Oleic acid consumption is considered cardio-protective according to studies conducted examining effects of the Mediterranean diet. However, animal models have shown that oleic acid consumption increases LDL particle cholesteryl oleate content which is associated with increased LDL-proteoglycan binding and atherosclerosis. The objective was to examine effects of varying oleic, linoleic and docosahexaenoic acid consumption on human LDL-proteoglycan binding in a non-random subset of the Canola Oil Multi-center Intervention Trial (COMIT) participants. COMIT employed a randomized, double-blind, five-period, cross-over trial design. Three of the treatment oil diets: 1) a blend of corn/safflower oil (25:75); 2) high oleic canola oil; and 3) DHA-enriched high oleic canola oil were selected for analysis of LDL-proteoglycan binding in 50 participants exhibiting good compliance. LDL particles were isolated from frozen plasma by gel filtration chromatography and LDL cholesteryl esters quantified by mass-spectrometry. LDL-proteoglycan binding was assessed using surface plasmon resonance. LDL particle cholesterol ester fatty acid composition was sensitive to the treatment fatty acid compositions, with the main fatty acids in the treatments increasing in the LDL cholesterol esters. The corn/safflower oil and high-oleic canola oil diets lowered LDL-proteoglycan binding relative to their baseline values (p = 0.0005 and p = 0.0012, respectively). At endpoint, high-oleic canola oil feeding resulted in lower LDL-proteoglycan binding than corn/safflower oil (p = 0.0243) and DHA-enriched high oleic canola oil (p = 0.0249), although high-oleic canola oil had the lowest binding at baseline (p = 0.0344). Our findings suggest that high-oleic canola oil consumption in humans increases cholesteryl oleate percentage in LDL, but in a manner not associated with a rise in LDL-proteoglycan binding. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  11. Radiolabeled cholesteryl ethers: A need to analyze for biological stability before use

    Directory of Open Access Journals (Sweden)

    Denny Joseph Manual Kollareth

    2018-03-01

    Full Text Available Radiolabeled cholesteryl ethers are widely used as non-metabolizable tracers for lipoproteins and lipid emulsions in a variety of in vitro and in vivo experiments. Since cholesteryl ethers do not leave cells after uptake and are not hydrolyzed by mammalian cellular enzymes, these compounds can act as markers for cumulative cell uptakes of labeled particles. We have employed [3H]cholesteryl oleoyl ether to study the uptake and distribution of triglyceride-rich emulsion particles on animal models. However, questionable unexpected results compelled us to analyze the stability of these ethers. We tested the stability of two commercially available radiolabeled cholesteryl ethers - [3H]cholesteryl oleoyl ether and [3H]cholesteryl hexadecyl ether from different suppliers, employing in vitro, in vivo and chemical model systems. Our results show that, among the two cholesteryl ethers tested, one ether was hydrolyzed to free cholesterol in vitro, in vivo and chemically under alkaline hydrolyzing agent. Free cholesterol, unlike cholesteryl ether, can then re-enter the circulation leading to confounding results. The other ether was not hydrolyzed to free cholesterol and remained as a stable ether. Hence, radiolabeled cholesteryl ethers should be analyzed for biological stability before utilizing them for in vitro or in vivo experiments. Keywords: Cholesteryl ether, J774 A2 macrophages, Soy oil emulsion, Thin layer chromatography, triDHA emulsion

  12. Synthesis and Evaluation of the Antioxidant Activity of Lipophilic Phenethyl Trifluoroacetate Esters by In Vitro ABTS, DPPH and in Cell-Culture DCF Assays

    Directory of Open Access Journals (Sweden)

    Roberta Bernini

    2018-01-01

    Full Text Available Polyphenols are natural compounds showing a variety of health-promoting effects. Unfortunately, due to low lipid solubility, their applications in the pharmaceutical, food, and cosmetic industries are limited. With the aim of obtaining novel lipophilic derivatives, the present study reports the synthesis of a series of phenethyl trifluoroacetate esters containing up to two hydroxyl groups in the aromatic ring. Experimental logP values confirmed a greater lipophilicity of the novel compounds compared to the parent compounds. The radical scavenging capacity of all phenethyl trifluoroacetate esters was evaluated by in vitro assays (ABTS, DPPH and in cultured cells (L6 myoblasts and THP-1 leukemic monocytes using 2′,7′-dichlorodihydrofluorescein diacetate. These data revealed that the esters showed a good antioxidant effect that was strictly dependent on the grade of hydroxylation of the phenyl ring. The lack of toxicity, evaluated by the MTT assay and proliferation curves, makes these trifluoroacetates attractive derivatives for pharmaceutical, food, and cosmetic applications.

  13. Two bifunctional enzymes from the marine protist Thraustochytrium roseum: biochemical characterization of wax ester synthase/acyl-CoA:diacylglycerol acyltransferase activity catalyzing wax ester and triacylglycerol synthesis.

    Science.gov (United States)

    Zhang, Nannan; Mao, Zejing; Luo, Ling; Wan, Xia; Huang, Fenghong; Gong, Yangmin

    2017-01-01

    Triacylglycerols (TAGs) and wax esters (WEs) are important neutral lipids which serve as energy reservoir in some plants and microorganisms. In recent years, these biologically produced neutral lipids have been regarded as potential alternative energy sources for biofuel production because of the increased interest on developing renewable and environmentally benign alternatives for fossil fuels. In bacteria, the final step in TAG and WE biosynthetic pathway is catalyzed by wax ester synthase/acyl coenzyme A (acyl-CoA):diacylglycerol acyltransferase (WS/DGAT). This bifunctional WS/DGAT enzyme is also a key enzyme in biotechnological production of liquid WE via engineering of plants and microorganisms. To date, knowledge about this class of biologically and biotechnologically important enzymes is mainly from biochemical characterization of WS/DGATs from Arabidopsis, jojoba and some bacteria that can synthesize both TAGs and WEs intracellularly, whereas little is known about WS/DGATs from eukaryotic microorganisms. Here, we report the identification and characterization of two bifunctional WS/DGAT enzymes (designated TrWSD4 and TrWSD5) from the marine protist Thraustochytrium roseum . Both TrWSD4 and TrWSD5 comprise a WS-like acyl-CoA acyltransferase domain and the recombinant proteins purified from Escherichia coli Rosetta (DE3) have substantial WS and lower DGAT activity. They exhibit WS activity towards various-chain-length saturated and polyunsaturated acyl-CoAs and fatty alcohols ranging from C 10 to C 18 . TrWSD4 displays WS activity with the lowest K m value of 0.14 μM and the highest k cat / K m value of 1.46 × 10 5  M -1  s -1 for lauroyl-CoA (C 12:0 ) in the presence of 100 μM hexadecanol, while TrWSD5 exhibits WS activity with the lowest K m value of 0.96 μM and the highest k cat / K m value of 9.83 × 10 4  M -1  s -1 for decanoyl-CoA (C 10:0 ) under the same reaction condition. Both WS/DGAT enzymes have the highest WS activity at 37 and 47

  14. Synthesis and antimalarial testing of neocryptolepine analogues: addition of ester function in SAR study of 2,11-disubstituted indolo[2,3-b]quinolines.

    Science.gov (United States)

    Lu, Wen-Jie; Wicht, Kathryn J; Wang, Li; Imai, Kento; Mei, Zhen-Wu; Kaiser, Marcel; El Sayed, Ibrahim El Tantawy; Egan, Timothy J; Inokuchi, Tsutomu

    2013-06-01

    This report describes the synthesis, and in vitro and in vivo antimalarial evaluations of certain ester-modified neocryptolepine (5-methyl-5H-indolo[2,3-b]quinoline) derivatives. The modifications were carried out by introducing ester groups at the C2 and/or C9 position on the neocryptolepine core and the terminal amino group of the 3-aminopropylamine substituents at the C11 position with a urea/thiourea unit. The antiplasmodial activities of our derivative agents against two different strains (CQS: NF54, and CQR: K1) and the cytotoxic activity against normal L6 cells were evaluated. The test results showed that the ester modified neocryptolepine derivatives have higher antiplasmodial activities against both strains and a low cytotoxic activity against normal cells. The best results were achieved by compounds 9c and 12b against the NF54 strain with the IC50/SI value as 2.27 nM/361 and 1.81 nM/321, respectively. While against K1 strain, all the tested compounds showed higher activity than the well-known antimalarial drug chloroquine. Furthermore, the compounds were tested for β-haematin inhibition and 12 were found to be more active than chloroquine (IC50 = 18 μM). Structure activity relationship studies exposed an interesting linear correlation between polar surface area of the molecule and β-haematin inhibition for this series. In vivo testing of compounds 7 and 8a against NF54 strain on Plasmodium berghei female mice showed that the introduction of the ester group increased the antiplasmodial activity of the neocryptolepine core substantially. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Khairulazhar Jumbri

    Full Text Available 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.

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

    Science.gov (United States)

    Jumbri, Khairulazhar; Al-Haniff Rozy, Mohd Fahruddin; Ashari, Siti Efliza; Mohamad, Rosfarizan; Basri, Mahiran; Fard Masoumi, Hamid Reza

    2015-01-01

    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.

  17. Synthesis of β-phenylchalcogeno-α, β-unsaturated esters, ketones and nitriles using microwave and solvent-free conditions

    International Nuclear Information System (INIS)

    Lenardao, Eder J.; Silva, Marcio S.; Mendes, Samuel R.; Azambuja, Francisco de; Jacob, Raquel G.; Perin, Gelson; Santos, Paulo Cesar Silva dos

    2007-01-01

    A simple, clean and efficient solvent-free protocol was developed for hydrochalcogenation of alkynes containing a Michael acceptor (ester, ketone and nitrile) with phenylchalcogenolate anions generated in situ from the respective diphenyl dichalcogenide (Se, Te, S), using alumina supported sodium borohydride. This efficient and improved method is general and furnishes the respective (Z)-β-phenylchalcogeno-α,β-unsaturated esters, ketones and nitriles, in good yield and higher selectivity, compared with those that use organic solvent and inert atmosphere. The use of microwave (MW) irradiation facilitates the procedure and accelerates the reaction. (author)

  18. Evaluation of the influence of base and alkyl bromide on synthesis of pyrazinoic acid esters through factorial design

    International Nuclear Information System (INIS)

    Fernandes, Joao Paulo dos Santos; Felli, Veni Maria Andres

    2009-01-01

    Pyrazinoic acid esters have been synthesized as prodrugs of pyrazinoic acid. In the literature, its preparation is reported through the reaction of pyrazinoyl chloride with alcohols and the reaction with DCC/DMAP. In this work, it is reported a 22 factorial design to evaluate the preparation of these esters through the substitution of alkyl bromides with carboxylate anion. The controlled factors were alkyl chain length of bromides (ethyl and hexyl) and the used base (triethylamine and DBU). Results revealed that the used base used has significant effect on yield, and alkyl bromide used has neither significant influence, nor its interaction effect with base. (author)

  19. Radiolabeled cholesteryl ethers: A need to analyze for biological stability before use.

    Science.gov (United States)

    Manual Kollareth, Denny Joseph; Chang, Chuchun L; Hansen, Inge H; Deckelbaum, Richard J

    2018-03-01

    Radiolabeled cholesteryl ethers are widely used as non-metabolizable tracers for lipoproteins and lipid emulsions in a variety of in vitro and in vivo experiments. Since cholesteryl ethers do not leave cells after uptake and are not hydrolyzed by mammalian cellular enzymes, these compounds can act as markers for cumulative cell uptakes of labeled particles. We have employed [ 3 H]cholesteryl oleoyl ether to study the uptake and distribution of triglyceride-rich emulsion particles on animal models. However, questionable unexpected results compelled us to analyze the stability of these ethers. We tested the stability of two commercially available radiolabeled cholesteryl ethers - [ 3 H]cholesteryl oleoyl ether and [ 3 H]cholesteryl hexadecyl ether from different suppliers, employing in vitro , in vivo and chemical model systems. Our results show that, among the two cholesteryl ethers tested, one ether was hydrolyzed to free cholesterol in vitro , in vivo and chemically under alkaline hydrolyzing agent. Free cholesterol, unlike cholesteryl ether, can then re-enter the circulation leading to confounding results. The other ether was not hydrolyzed to free cholesterol and remained as a stable ether. Hence, radiolabeled cholesteryl ethers should be analyzed for biological stability before utilizing them for in vitro or in vivo experiments.

  20. Ultrasound-Accelerated Synthesis of Asymmetrical Thiosulfonate S-Esters by Base-Promoted Reaction of Sulfonyl Chlorides with Thiols

    DEFF Research Database (Denmark)

    Pham, Hien Thi; Nguyen, Ngoc-Lan Thi; Duus, Fritz

    2015-01-01

    Amberlyst A-26, Mg-Al hydrotalcite, potassium fluoride absorbed on alumina, triethylamine and pyridine have been tested as base catalysts and reagents for the reaction of sulfonyl chlorides with thiols to prepare thiosulfonate S-esters. The reactions were performed under solvent-free conditions...

  1. Synthesis and Characterization of Fatty Acid Methyl Ester by In-Situ Transesterification in Capparis Deciduas Seed

    Directory of Open Access Journals (Sweden)

    Prasad E FUNDE

    2008-12-01

    Full Text Available (FAME Fatty acid methyl ester is made virgin or used vegetable oils (both edible and non-edible and animal fats. Fatty acid methyl ester operates in compression ignition engines like petro-diesel. Fatty acid methyl ester can be blended in any ratio with petroleum diesel fuels. It can be stored just like the petroleum diesel fuel. Petrodiesel can be replaced by biodiesel due to its superiority. It has various advantages. The seeds of Capparis deciduas are found to contain non-edible oil in the range of about 63.75 %. The percentage of biodiesel yield increases with concentration of KOH as a catalyst. The aim of this article is to demonstrate the cost effective new source of energy by single step reaction i.e. production of oil by combining extraction and reaction of extract with the mixture of alcohols. In this article the effect of catalyst concentration, time, water content and temperature on in-situ transesterification is studied to obtain optimum yield and Fatty acid methyl ester (Biodiesel Fuel characterization tests show the striking similarity of various physical & chemical properties and campers to ASTM standards.

  2. Tung oil-based unsaturated co-ester macromonomer for thermosetting polymers: Synergetic synthesis and copolymerization with styrene

    Science.gov (United States)

    A novel unsaturated co-ester (co-UE) macromonomer containing both maleates and acrylates was synthesized from tung oil (TO) and its chemical structure was characterized by FT-IR, 1H-NMR, 13C-NMR, and gel permeation chromatography (GPC). The monomer was synthesized via a new synergetic modification o...

  3. Multicomponent Synthesis of a N-Protected Alpha-Amino Ester: Ethyl 2-((4-Methoxyphenyl)Amino)-3-Phenylpropanoate

    Science.gov (United States)

    Le Gall, Erwan; Pignon, Antoine

    2012-01-01

    This laboratory experiment describes the preparation of a N-protected phenylalanine ethyl ester by a zinc-mediated Mannich-like multicomponent reaction between benzyl bromide, "p"-anisidine, and ethyl glyoxylate. The one-step reaction involves the in situ metallation of benzyl bromide into a benzylzinc reagent and its addition onto imine (Barbier…

  4. A facile one-pot synthesis of (Z-α-chloro-α,β-unsaturated esters from alcohols

    Directory of Open Access Journals (Sweden)

    U. Karama

    2017-05-01

    Full Text Available Treatment of N-Chlorosuccinimide with (ethoxycarbonylmethylene-triphenylphosphorane followed by oxidation of alcohol using DMSO/SO3.Pyridine complex as a mild oxidant and trapping of the aldehydes constitutes a stereoselective single flask procedure for the preparation of Z-configured α-chloro-α,β-unsaturated esters.

  5. 15th International Sunflower Conference Synthesis of new derivatives from vegetable sunflower oil methyl esters via epoxydation and oxirane opening

    Directory of Open Access Journals (Sweden)

    Pages Xavier

    2001-03-01

    Full Text Available Recently, epoxides have received increased attention because they are of interest both as end-products and as chemical intermediates; epoxidized oils, mainly High Oleic Sunflower Oil, and their ester derivatives have thus found important applications as plasticizers and additives for polyvinyl chloride (PVC. Epoxidized esters have been produced classically from High Oleic Sunflower Methyl Esters (HOSME using H2O2 and formic acid. The epoxidation reaches 90% on pilot scale (5kg. Epoxidized esters produced from HOSME have respectively hydroxyl values of 0, oxirane values of 5.2/4.5 and iodine values of 1.7/1.5. Cleavage trials of the oxirane group of the epoxidized esters with different reactants have been undertaken in order to produce on pilot scale new derivatives to be characterized and tested in different fields of application (lubrication, detergency and as chemical intermediates. Reaction of Epoxy-HOSME with an excess of oleic acid was conducted under atmospheric pressure without any catalyst and solvent. The oxirane opening leads to complete estolide formation: after neutralization, analytical controls (chemical values, GC and HPLC analysis indicate that the estolides are composed of a mixture of C36 (oleate of methyl hydroxystearate and C54 (di-oleate of methyl dihydroxystearate. Oxirane opening with alcohols (ethanol and octanol was preferentially performed by acid catalysis at 100°C under atmospheric pressure. Analytical controls show the formation of different etheralcohols and secondary products resulting from dehydration, transesterification and dimerization side-reactions. Cleavage reaction of Epoxy-HOSME with a primary amine (butylamine was conducted under pressure, at high temperature (180/200°C. Both transesterification and opening of the oxirane group occur under these conditions. Reaction products are composed of amides formed by transesterification and a mixture of fatty amines/imines obtained by ring opening as established

  6. Synthesis, Purification, and Quantification of Fatty Acid Ethyl Esters After trans-Esterification of Large Batches of Tobacco Seed Oil

    Directory of Open Access Journals (Sweden)

    Ashraf-Khorassani Mehdi

    2015-03-01

    Full Text Available L'objectif de la présente étude était de quantifier les esters éthyliques d'acides gras (FAEE produits à partir de deux grands lots d'huile de graines de tabac soumis à une transéstérification éthanolique en présence d'un catalyseur d'acide sulfurique. La purification des produits combinés de la réaction des esters éthyliques visait la suppression, autant que faire se peut, de la couleur et de l'odeur du produit final et fut accomplie via une chromatographie sur colonne conventionnelle avec silice sublimée et une élution en tandem de l'hexane, dans un premier temps et de l'alcool éthylique, dans un deuxième temps, en guise de phase mobile. La chromatographie en phase gazeuse fut utilisée afin de quantifier les esters éthyliques des acides gras spécifiques dans la matière purifiée. Le pourcentage d'esters éthyliques d'acides gras purs récupérés dans le lot n°1 s'éleva à près de 87% tandis que le pourcentage d'esters éthyliques d'acides gras purs récupérés dans le lot n°2 fut supérieur à 89% avec des rendements à la préparation supérieurs à 400 g d'esters éthyliques par essai d'estérification. Les esters éthyliques d'acides gras ne possédaient pas d'arome détectable et ne présentaient qu'une légère coloration jaune à l'issue de ce traitement chromatographique. Pour caractériser la pureté de chaque lot d'esters éthyliques d'acides gras produits, une chromatographie en phase supercritique dont la phase mobile était un fluide composé de dioxyde de carbone modifié au méthanol/acétonitrile et une phase fixe composée d'une silice greffée avec groupement fonctionnel octadécyle furent utilisées. Aucune impureté liée au glycérol ou à des acides gras libres ne fut détectée dans le produit transestérifié purifié. Notre article est le premier rapport décrivant la transestérification optimisée de l'huile de graines de tabac à une échelle relativement grande, ladite transest

  7. Synthesis of Cyclohexane-Fused Isocoumarins via Cationic Palladium(II)-Catalyzed Cascade Cyclization Reaction of Alkyne-Tethered Carbonyl Compounds Initiated by Intramolecular Oxypalladation of Ester-Substituted Aryl Alkynes.

    Science.gov (United States)

    Zhang, Jianbo; Han, Xiuling; Lu, Xiyan

    2016-04-15

    A cationic Pd(II)-catalyzed cascade cyclization reaction of alkyne-tethered carbonyl compounds was developed. This reaction is initiated by intramolecular oxypalladation of alkynes with an ester group followed by 1,2-addition of the formed C-Pd(II) bond to the carbonyl group, providing a highly efficient method for the synthesis of cyclohexane-fused isocoumarins.

  8. Synthesis of 4-methoxybenzyl ester of monochloro pyrethrum acid%偏氯菊酸对甲氧基苄酯的合成研究

    Institute of Scientific and Technical Information of China (English)

    陈震; 张昌军; 林晓辉

    2011-01-01

    Synthesis of a new ester of monochloro pyrethrum acid was reported. 4, 6, 6-Trichloro-3, 3-dimethyl-hexahoic acid methyl ester was synthesized from methyl 3,3-dimethyl pentenoate and chloroform initiated with ferrous chloride in a confined system. Followed by ring-closure, elimination, hydrolysis and acidification,3-(2-chloro-ethenyl)-2,2-dimethyl-cy-clopropanecarboxylic acid ( monochloro pyrethrum acid) was obtained. 4-Methoxybenzyl ester of monochloro pyrethrum acid was obtained by the reaction between sodium of monochloro pyrethrum acid and a quaternary ammonium salt. Three undocumented compounds were obtained. Using the method reported in ' Tetrahedron letter ', benzoyl peroxide or nitrile azo used as initiator and reaction under atmospheric pressure, target product was not obtained.%报道了一种新的拟除虫菊酯——偏氯菊酯的合成方法.以贲亭酸甲酯为原料,氯化亚铁作为引发剂在密闭体系中与氯仿加成后得到3,3-二甲基-4,6,6-三氯己酸甲酯,再成环、脱卤化氢,水解酸化后得到2,2-二甲基-3-(乙氯乙烯基)-环丙烷羧酸(偏氯菊酸),偏氯菊酸钠与季铵盐回流得到标题化合物.在合成中得到了3种未见文献报道的新化合物.而采用文献原有的方法,使用过氧化苯甲酰或偶氮异丁腈在常压下反应则没有获得目标产物.

  9. Synthesis, physical-chemical properties of 2-((5-(adamantan-1-yl-4-R-4H-1,2,4-triazole-3-ylthioacetic acid esters

    Directory of Open Access Journals (Sweden)

    V. M. Odyntsova

    2017-04-01

    Full Text Available The nitrogen-containing heterocyclic systems from the class of 1,2,4-triazole derivatives, which exhibit wide range of actions, occupy special place among the variety of heterocyclic compounds. Derived biologically active substances are actively introduced into practice as new original and effective drugs. We were interested in esters of 2-((5-(adamantan-1-yl-4-R-4H-1,2,4-triazole-3-ylthioacetic acids, which exhibit high biological activity and can be intermediates for the synthesis of amides, hydrazides, ylidenderivatives of corresponding acids. The aim of this work is the synthesis of new esters of 2-((5-(adamantan-1-yl-4-R-4H-1,2,4-triazole-3-ylthioacetic acids and the establishment of their physical-chemical properties. Materials and methods. Melting point was determined by open capillary method on the device OptiMelt MPA100. The elemental composition of the synthesized compounds was determined on the universal analyzer ElementarVario ЕL cube (CHNS (standard – sulfanilamide. 1H NMR spectra were recorded on spectrometer Varian Mercury VX-200 (1H, 200 MHz in the solvent dimethyl sulfoxide-d6 (tetramethylsilane internal standard and decoded using a program ADVASP(tm Analyzer program (Umatek International Inc.. Chromato-mass-spectral studies were performed on hazarding chromatograph Agilent 1260 Infinity HPLC equipped with mass spectrometer Agilent 6120 (ionization electro-spray (ESI. The results and discussion. Synthesis of 11 new compounds, namely esters of 2-((5-(adamantan-1-yl-4-R-4H-1,2,4-triazole-3-ylthioacetic acids was carried out by two methods. According to the A method the alkylation of previously synthesized 3-(adamantan-1-yl-1H-1,2,4-triazole-5-thiol was performed with the use of corresponding methyl ester of 2-chloroacetic acid and the presence of equivalent amount of sodium hydroxide. The B method involves the etherification of 2-((5-(adamantan-1-yl-4-R-4H-1,2,4-triazole-3-ylthioacetic acid with the use of methyl, ethyl, i

  10. New Flame-Retardant Poly(ester-imide)s Containing Phosphine Oxide Moieties in the Main Chain: Synthesis and Properties

    OpenAIRE

    FAGHIHI, Khalil

    2014-01-01

    Six new flame-retardant poly(ester-imide)s (9a-f) with high inherent viscosity and containing phosphine oxide moieties in the main chain were synthesized from the polycondensation reaction of N,N-(3,3-diphenylphenyl phosphine oxide) bistrimellitimide diacid chloride (7) with 6 aromatic diols (8a-f) by 2 different methods:--solution and microwave-assisted polycondensation. The results showed that compared to solution polycondensation, the microwave-assisted polycondensation reaction us...

  11. Synthesis of 1-Methyl-3-oxo-7-oxabicyclo[2.2.1]hept-5-ene-2-carboxylic Acid Methyl Ester

    Directory of Open Access Journals (Sweden)

    Gil Valdo José da Silva

    2005-11-01

    Full Text Available A simple and efficient method for the preparation of 1-methyl-3-oxo-7- oxabicyclo[2.2.1]hept-5-en-2-carboxylic acid methyl ester (1 is described. The first step is a highly regioselective Diels-Alder reaction between 2-methylfuran and methyl-3-bromo- propiolate. A remarkably difficult ketal hydrolysis reaction was effected by treatment with HCl, a simple reagent that was shown to be more efficient, in this case, than commonly used more elaborate methods.

  12. SYNTHESIS OF UNSATURATED ESTERS VIA HIGHLY EFFICIENT ESTERIFICATION CATALYZED BY POLYMER GRAFTED QUARTERNARY AMMONIUM SALTS AS TRIPHASE CATALYSTS

    OpenAIRE

    LIANG, ZHENG YONG; WANG, LILI; LIU, HUI; HUANG, JIN SHUO

    2013-01-01

    A series of unsaturated esters were prepared via condensation of sodium carboxylates and alkenyl halide under the condition of macroporous polystyrene grafted quarternary ammonium salt as recyclable phase transfer catalyst, NaI as co-catalyst, Cu powder as inhibitor and H2O as solvent. Under optimal conditions, products yields are 78.2~ 96.0%. The catalyst can be convenient recycled and reutilized for about five times without losing its activity obviously.

  13. Regiospecific synthesis of new fatty N-acyl trihalomethylated pyrazoline derivatives from fatty acid methyl esters (FAMEs)

    Energy Technology Data Exchange (ETDEWEB)

    Beck, Paulo; Santos, Juliane M. dos; D' Oca, Marcelo G. M.; Piovesan, Luciana A., E-mail: lpiovesan@gmail.com [Universidade Federal do Rio Grande (UFRS), RS (Brazil). Escola de Quimica e Alimentos; Kuhn, Bruna L.; Moreira, Dayse N.; Flores, Alex F.C.; Martins, Marcos A.P. [Universidade Federal de Santa Maria (UFSM), RS (Brazil). Dept. de Quimica

    2012-11-15

    A series of new fatty N-acyl trihalomethylated pyrazoline derivatives from fatty acid methyl esters was synthesized by the cyclo condensation of respective fatty hydrazides with 4-alkoxy- 1,1,1-trial omethyl-3-alquen-2-ones. Efficient and regiospecific cyclizations catalyzed by BF{sub 3}-MeOH gave the desired products in good to excellent yields and at high purity. (author)

  14. Synthesis of carbonate esters by carboxymethylation using NaAlO2 as a highly active heterogeneous catalyst

    OpenAIRE

    Ramesh, Sreerangappa; Indukuri, Kiran; Riant, Olivier; Debecker, Damien

    2018-01-01

    Sodium aluminate is presented as a highly active heterogeneous catalyst able to convert a range of alcohols into the corresponding mixed carbonate esters, in high yield and under green conditions. The reaction is carried out using dimethyl carbonate both as a reactant and solvent, at 90°C. Allylic, aliphatic and aromatic alcohols are converted in good yields. The solid catalyst is shown to be truly heterogeneous, resistant to leaching, and recyclable.

  15. Commercial- and whitewashing-grade limestone as a heterogeneous catalyst for synthesis of fatty acid methyl esters from used frying oil (UFO)

    Energy Technology Data Exchange (ETDEWEB)

    Agrawal, Shweta; Singh, Bhaskar; Sharma, Yogesh C. [Banaras Hindu University, Department of Applied Chemistry, Institute of Technology, Varanasi (India); Frometa, Amado Enrique N. [Universidad Tecnologica de Izucar de Matamoros, Puebla (Mexico)

    2012-12-15

    Commercial-grade limestone used in whitewashing which is a low-cost material has been used as a catalyst for the synthesis of fatty acid methyl esters. The catalyst was characterized by differential thermal analysis/thermogravimetric analysis, X-ray diffraction, and Fourier transform infrared spectroscopy for the study of its physicochemical nature. The catalyst was calcined at 900 C for 2.5 h for the decomposition of calcium carbonate to calcium oxide. The catalyst was further activated by dissolving 1.5 wt% of catalyst in 30 ml methanol (7.5:1, methanol to used frying oil molar ratio) and stirred at 25 C for 1 h on a magnetic stirrer. The transesterification reaction was performed using calcium oxide as a catalyst and then with the ''activated calcium oxide.'' The conversion obtained was 94.4 % with calcium oxide and was found to be lower for the ''activated calcium oxide'' (i.e., 87.36 %). The conversion increased to 96.8 % on increasing the catalyst amount to 2.0 wt% in 5 h. A high yield (>95 %) of fatty acid methyl esters was observed when either calcium oxide or ''activated calcium oxide'' was taken as catalyst. The catalytic activity of calcium oxide obtained from low-grade limestone has been found to be comparable with the laboratory-grade CaO. (orig.)

  16. Synthesis and emulsifying properties of carbohydrate fatty acid esters produced from Agave tequilana fructans by enzymatic acylation.

    Science.gov (United States)

    Casas-Godoy, Leticia; Arrizon, Javier; Arrieta-Baez, Daniel; Plou, Francisco J; Sandoval, Georgina

    2016-08-01

    Carbohydrate fatty acid esters are non-ionic surfactants with a broad spectrum of applications. These molecules are generally synthesized using short carbohydrates or linear fructans; however in this research carbohydrate fatty acid esters were produced for the first time with branched fructans from Agave tequilana. Using immobilized lipases we successfully acylated A. tequilana fructans with vinyl laurate, obtaining products with different degrees of polymerization (DP). Lipozyme 435 was the most efficient lipase to catalyze the transesterification reaction. HPLC and ESI-MS analysis proved the presence of a mixture of acylated products as a result of the chemical complexity of fructans in the A. tequilana. The ESI-MS spectra showed a molecular mass shift between 183 and 366g/mol for fructooligosaccharides with a DP lower than 6, which indicated the presence of Agave fructans that had been mono- and diacylated with lauric acid. The carbohydrate fatty acid esters (CFAE) obtained showed good emulsifying properties in W/O emulsions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Synthesis and characterization of wide range mesogenic esters based on asymmetrical 2,5-disubstituted 1,3,4-thiadiazole

    Science.gov (United States)

    Tomi, Ivan H. R.; Jaffer, Hamed J.; Aldhaif, Yasmeen A.

    2018-04-01

    A homologous series of new 13 esters, 4-(5-(p-tolyl)-1,3,4-thiadiazol-2-yl)-phenyl-4-alkoxybenzoate, (IVn), based on 1,3,4-thiadiazole core has been synthesized. The structures of these esters were confirmed by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance and mass techniques. Their mesophases behavior was investigated with hot-stage polarizing optical microscope and differential scanning calorimetry. The thermal stability for most of these derivatives was measured by thermal gravimetric analysis. All the target esters showed enantiotropic mesomorphic behaviors with nematic and nematic/smectic C phases. The phase transition temperatures and liquid crystalline properties were affected by the nature of heterocyclic ring and the length of the alkoxy chain. Only the nematic phase was observed in the first 10 derivatives, (n = 1-10), while the last 3, (n = 12, 16 and 18) showed nematic and smectic C phases. These compounds demonstrated high liquid crystalline ranges, both in heating and cooling cycles. The mesomorphic results obtained were compared with the reported analogs of similar constituents.

  18. Chromium–tungsten–titanium mixed oxides solid catalyst for fatty acid methyl ester synthesis from palm fatty acid distillate

    International Nuclear Information System (INIS)

    Wan, Zuraida; Hameed, B.H.

    2014-01-01

    Highlights: • Chromium–tungsten–titanium mixed oxides as solid catalyst. • Catalyst used for esterification of palm fatty acid distillate to methyl esters. • The maximum methyl ester content is 83%. • Catalyst has shown good activity and can be recycled for 4 times. - Abstract: Chromium–tungsten–titanium mixed oxides solid catalysts were prepared and evaluated in the esterification of palm fatty acid distillate (PFAD) to produce fatty acid methyl ester (FAME). Esterification was conducted in a batch reactor at 110–200 °C temperature ranges. The catalysts were characterized by several techniques such as BET, TEM, FTIR, TGA, XRD, EDX and SEM. The treatment conditions during catalyst preparation, effect of reaction parameters, leaching of the active species and the recycled use of the catalyst were investigated. The catalyst with formula CrWTiO 2 was found to be the most active with maximum FAME content of 83% obtained at best reaction conditions of 170 °C for 3 h, 2:1 (methanol to oil molar ratio) and 2 wt.% catalyst dosage. The catalyst can be recycled for 4 times. The results revealed CrWTiO 2 good potentials for use in esterification of high acid value oil

  19. Synthesis of carboxylic acids, esters, alcohols and ethers containing a tetrahydropyran ring derived from 6-methyl-5-hepten-2-one.

    Science.gov (United States)

    Hanzawa, Yohko; Hashimoto, Kahoko; Kasashima, Yoshio; Takahashi, Yoshiko; Mino, Takashi; Sakamoto, Masami; Fujita, Tsutomu

    2012-01-01

    3-hydroxy acids, 3-hydroxy-3,7-dimethyloct-6-enoic acid (1) and 3-hydroxy-2,2,3,7-tetramethyloct-6-enoic acid (2), were prepared from 6-methyl-5-hepten-2-one, and they were subsequently used to prepare (2,6,6-trimethyltetrahydropyran-2-yl)acetic acid (3) and 2-methyl-2-(2,6,6-trimethyltetrahydropyran-2-yl)propanoic acid (4), respectively, via cyclization with an acidic catalyst such as boron trifluoride diethyl etherate or iodine. The reaction of carboxylic acids 3 and 4 with alcohols, including methanol, ethanol, and 1-propanol, produced the corresponding methyl, ethyl, and propyl esters, which all contained a tetrahydropyran ring. Reduction of carboxylic acids 3 and 4 afforded the corresponding alcohols. Subsequent reactions of these alcohols with several acyl chlorides produced novel esters. The alcohols also reacted with methyl iodide and sodium hydride to provide novel ethers. A one-pot cyclization-esterification of 1 to produce esters containing a tetrahydropyran ring, using iodine as a catalyst, was also investigated.

  20. Highly selective synthesis of conjugated dienoic and trienoic esters via alkyne elementometalation–Pd-catalyzed cross-coupling

    Science.gov (United States)

    Wang, Guangwei; Mohan, Swathi; Negishi, Ei-ichi

    2011-01-01

    All four stereoisomers (7–10) of ethyl undeca-2,4-dienoate were prepared in ≥98% isomeric purity by Pd-catalyzed alkenylation (Negishi coupling) using ethyl (E)- and (Z)-β-bromoacrylates. Although the stereoisomeric purity of the 2Z,4E-isomer (8) prepared by Suzuki coupling using conventional alkoxide and carbonate bases was ≤ 95%, as reported earlier, the use of CsF or nBu4NF as a promoter base has now been found to give all of 7–10 in ≥98% selectivity. Other widely known methods reveal considerable limitations. Heck alkenylation was satisfactory for the syntheses of the 2E,4E and 2E,4Z isomers of ≥98% purity, but the purity of the 2Z,4E isomer was ≤ 95%. Mutually complementary Horner–Wadsworth–Emmons and Still–Gennari (SG) olefinations are also of considerably limited scopes. Neither 2E,4Z nor 2Z,4Z isomer is readily prepared in ≥90% selectivity. In addition to (2Z,4E)-dienoic esters, some (2Z,4E,6E)- and (2Z,4E,6Z)-trienoic esters have been prepared in ≥98% selectivity by a newly devised Pd-catalyzed alkenylation–SG olefination tandem process. As models for conjugated higher oligoenoic esters, all eight stereoisomers for ethyl trideca-2,4,6-trienoate (23–30) have been prepared in ≥98% overall selectivity. PMID:21709262

  1. Synthesis, properties and applications of biodegradable polymers derived from diols and dicarboxylic acids: from polyesters to poly(ester amide)s.

    Science.gov (United States)

    Díaz, Angélica; Katsarava, Ramaz; Puiggalí, Jordi

    2014-04-25

    Poly(alkylene dicarboxylate)s constitute a family of biodegradable polymers with increasing interest for both commodity and speciality applications. Most of these polymers can be prepared from biobased diols and dicarboxylic acids such as 1,4-butanediol, succinic acid and carbohydrates. This review provides a current status report concerning synthesis, biodegradation and applications of a series of polymers that cover a wide range of properties, namely, materials from elastomeric to rigid characteristics that are suitable for applications such as hydrogels, soft tissue engineering, drug delivery systems and liquid crystals. Finally, the incorporation of aromatic units and α-amino acids is considered since stiffness of molecular chains and intermolecular interactions can be drastically changed. In fact, poly(ester amide)s derived from naturally occurring amino acids offer great possibilities as biodegradable materials for biomedical applications which are also extensively discussed.

  2. How well does cholesteryl hemisuccinate mimic cholesterol in saturated phospholipid bilayers?

    DEFF Research Database (Denmark)

    Kulig, W.; Tynkkynen, J.; Javanainen, M.

    2014-01-01

    Cholesteryl hemisuccinate is a detergent that is often used to replace cholesterol in crystallization of membrane proteins. Here we employ atomistic molecular dynamics simulations to characterize how well the properties of cholesteryl hemisuccinate actually match those of cholesterol in saturated...... protein-free lipid membranes. We show that the protonated form of cholesteryl hemisuccinate mimics many of the membrane properties of cholesterol quite well, while the deprotonated form of cholesteryl hemisuccinate is less convincing in this respect. Based on the results, we suggest that cholesteryl...... hemisuccinate in its protonated form is a quite faithful mimic of cholesterol for membrane protein crystallization, if specific cholesterol-protein interactions (not investigated here) are not playing a crucial role....

  3. Cholesteryl esters of omega-(O-acyl)-hydroxy fatty acids in vernix caseosa

    Czech Academy of Sciences Publication Activity Database

    Kalužíková, Aneta; Vrkoslav, Vladimír; Harazim, Eva; Hoskovec, Michal; Plavka, R.; Buděšínský, Miloš; Bosáková, Z.; Cvačka, Josef

    2017-01-01

    Roč. 58, č. 8 (2017), s. 1579-1590 ISSN 0022-2275 R&D Projects: GA ČR GAP206/12/0750 Institutional support: RVO:61388963 Keywords : skin lipids * neutral lipids * cholesterol * lipidomics * mass spectrometry Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 4.810, year: 2016

  4. Cultured human astrocytes secrete large cholesteryl ester- andtriglyceride-rich lipoproteins along with endothelial lipase

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Lin; Liu, Yanzhu; Forte, Trudy M.; Chisholm, Jeffrey W.; Parks, John S.; Shachter, Neil S.

    2003-12-01

    We cultured normal human astrocytes and characterized their secreted lipoproteins. Human astrocytes secreted lipoproteins in the size range of plasma VLDL (Peak 1), LDL (Peak 2), HDL (Peak 3) and a smaller peak (Peak 4), as determined by gel filtration chromatography, nondenaturing gradient gel electrophoresis and transmission electron microscopy. Cholesterol enrichment of astrocytes led to a particular increase in Peak 1. Almost all Peak 2, 3 and 4 cholesterol and most Peak 1 cholesterol was esterified (unlike mouse astrocyte lipoproteins, which exhibited similar peaks but where cholesterol was predominantly non-esterified). Triglycerides were present at about 2/3 the level of cholesterol. LCAT was detected along with two of its activators, apolipoprotein (apo) A-IV and apoC-I. ApoA-I and apoA-II mRNA and protein were absent. ApoJ was present equally in all peaks but apoE was present predominantly in peaks 3 and 4. ApoB was not detected. The electron microscopic appearance of Peak 1 lipoproteins suggested partial lipolysis leading to the detection of a heparin-releasable triglyceride lipase consistent with endothelial lipase. The increased neuronal delivery of lipids from large lipoprotein particles, for which apoE4 has greater affinity than does apoE3, may be a mechanism whereby the apoE {var_epsilon}4 allele contributes to neurodegenerative risk.

  5. Natural Product Total Synthesis in the Organic Laboratory: Total Synthesis of Caffeic Acid Phenethyl Ester (CAPE), a Potent 5-Lipoxygenase Inhibitor from Honeybee Hives

    Science.gov (United States)

    Touaibia, Mohamed; Guay, Michel

    2011-01-01

    Natural products play a critical role in modern organic synthesis and learning synthetic techniques is an important component of the organic laboratory experience. In addition to traditional one-step organic synthesis laboratories, a multistep natural product synthesis is an interesting experiment to challenge students. The proposed three-step…

  6. Optimization of reaction parameters for enzymatic glyceride synthesis from fish oil: Ethyl esters versus free fatty acids

    DEFF Research Database (Denmark)

    Ravn, Helle Christine; Damstrup, Marianne L.; Meyer, Anne S.

    2012-01-01

    Enzymatic conversion of fish oil free fatty acids (FFA) or fatty acid ethyl esters (FAE) into glycerides via esterification or transesterification was examined. The reactions catalyzed by Lipozyme™ 435, a Candida antarctica lipase, were optimized. Influence on conversion yields of fatty acid chain...... length, saturation degree, temperature, enzyme dosage, molar ratio glycerol:fatty acids, acyl source composition (w/w ratio FFA:FAE), and reaction time was evaluated collectively by multiple linear regression. All reaction variables influenced the conversion into glycerides. Transesterification of FAE...

  7. Synthesis and Antiradical/Antioxidant Activities of Caffeic Acid Phenethyl Ester and Its Related Propionic, Acetic, and Benzoic Acid Analoguesc

    Directory of Open Access Journals (Sweden)

    Mohamed Touaibia

    2012-12-01

    Full Text Available Caffeic acid phenethyl ester (CAPE is a bioactive component isolated from propolis. A series of CAPE analogues was synthesized and their antiradical/antioxidant effects analyzed. The effect of the presence of the double bond and of the conjugated system on the antioxidant effect is evaluated with the analogues obtained from 3-(3,4-dihydroxyphenyl propanoic acid. Those obtained from 2-(3,4-dihydroxyphenyl acetic acid and 3,4-dihydroxybenzoic acid allow the evaluation of the effect of the presence of two carbons between the carbonyl and aromatic system.

  8. Synthesis, In Vitro and In Vivo Evaluation of the N-ethoxycarbonylmorpholine Ester of Diclofenac as a Prodrug

    OpenAIRE

    Jilani, Jamal; Idkaidek, Nasir; Alzoubi, Karem

    2014-01-01

    The N-ethoxycarbonylmorpholine moiety was evaluated as a novel prodrug moiety for carboxylic acid containing drugs represented by diclofenac (1). Compound 2, the N-ethoxycarbonylmorpholine ester of diclofenac was synthesized and evaluated as a potential prodrug. The stability of the synthesized prodrug was evaluated in solutions of pH 1 and 7.4, and in plasma. The ester’s half lives were found to be 8 h, 47 h and 21 min in pH 1, pH 7.4 and plasma, respectively. Equimolar doses of diclofenac...

  9. Synthesis and Odor Evaluation of Five New Sulfur-Containing Ester Flavor Compounds from 4-Ethyloctanoic Acid

    Directory of Open Access Journals (Sweden)

    Baoguo Sun

    2010-07-01

    Full Text Available Five sulfur-containing flavor compounds were synthesized for the first time by the reaction of 4-ethyloctanoyl chloride with sulfur-containing alcohols or mercaptans. The synthesized compounds are 3-(methylthiopropyl 4-ethyloctanoate, 2-methyl-3-tetrahydro-furanthiol 4-ethyloctanoate, 4-methyl-5-thiazoleethanol 4-ethyloctanoate, 2-furan-methanethiol 4-ethyloctanoate and 2-methyl-3-furanthiol 4-ethyloctanoate. These five synthetic sulfur-containing ester flavor compounds all have meaty odor and might be used in foods if approved for this purpose in the future.

  10. Synthesis and odor evaluation of five new sulfur-containing ester flavor compounds from 4-ethyloctanoic acid.

    Science.gov (United States)

    Liu, Yuping; Chen, Haitao; Yin, Decai; Sun, Baoguo

    2010-07-29

    Five sulfur-containing flavor compounds were synthesized for the first time by the reaction of 4-ethyloctanoyl chloride with sulfur-containing alcohols or mercaptans. The synthesized compounds are 3-(methylthio)propyl 4-ethyloctanoate, 2-methyl-3-tetrahydro-furanthiol 4-ethyloctanoate, 4-methyl-5-thiazoleethanol 4-ethyloctanoate, 2-furan-methanethiol 4-ethyloctanoate and 2-methyl-3-furanthiol 4-ethyloctanoate. These five synthetic sulfur-containing ester flavor compounds all have meaty odor and might be used in foods if approved for this purpose in the future.

  11. Optimization and modeling for the synthesis of sterol esters from deodorizer distillate by lipase-catalyzed esterification.

    Science.gov (United States)

    Zhang, Xinyu; Yu, Jiang; Zeng, Aiwu

    2017-03-01

    In this paper, cotton seed oil deodorizer distillate (CSODD), was recovered to obtain fatty acid sterol ester (FASE), which is one of the biological activated substances added as human therapeutic to lower cholesterol. Esterification reactions were carried out using Candida rugosa lipase as a catalyst, and the conversion of phytosterol was optimized using response surface methodology. The highest conversion (90.8 ± 0.4%) was reached at 0.84 wt% enzyme load, 1:25 solvent/CSODD mass ratio, and 44.2 °C after 12 H reaction. A kinetic model based on the reaction rate equation was developed to describe the reaction process. The activation energy of the reaction was calculated to be 56.9 kJ/mol and the derived kinetic parameters provided indispensable basics for further study. The optimization and kinetic research of synthesizing FASE from deodorizer distillate provided necessary information for the industrial applications in the near future. Experimental results showed that the proposed process is a promising alternative to recycle sterol esters from vegetable oil deodorizer distillates in a mild, efficient, and environmental friendly method. © 2016 International Union of Biochemistry and Molecular Biology, Inc.

  12. Synthesis, In Vitro and In Vivo Evaluation of the N-ethoxycarbonylmorpholine Ester of Diclofenac as a Prodrug

    Directory of Open Access Journals (Sweden)

    Jamal A. Jilani

    2014-04-01

    Full Text Available The N-ethoxycarbonylmorpholine moiety was evaluated as a novel prodrug moiety for carboxylic acid containing drugs represented by diclofenac (1. Compound 2, the N-ethoxycarbonylmorpholine ester of diclofenac was synthesized and evaluated as a potential prodrug. The stability of the synthesized prodrug was evaluated in solutions of pH 1 and 7.4, and in plasma. The ester’s half lives were found to be 8 h, 47 h and 21 min in pH 1, pH 7.4 and plasma, respectively. Equimolar doses of diclofenac sodium and its synthesized prodrug were administered orally to a group of rabbits in a crossover study to evaluate their pharmacokinetic parameters. The prodrug 2 shows a similar rate and extent of absorption as the parent drug (1. The ulcerogenicity of the prepared prodrug was evaluated and compared with the parent drug. The prodrug showed less ulcerogenicity as detected by fewer number and smaller size of ulcers. In conclusion, the newly synthesized N-ethoxycarbonylmorpholine ester of diclofenac prodrug showed appropriate stability properties at different pHs, similar pharmacokinetic profile, and much less ulcerogenecity at the GIT compared to the parent drug diclofenac.

  13. Phorbol ester tumor promoter induced the synthesis of two major cytoplasmic proteins: identity with two proteins induced under heat-shocked and glucose-starved conditions

    International Nuclear Information System (INIS)

    Zhang, H.; Chen, K.Y.; Liu, A.Y.C.

    1987-01-01

    The regulation of specific protein synthesis by the phorbol ester tumor promoter, 12-O-tetradecanoyl-phorbol-13-acetate (TPA), was evaluated using the L-8 and C-2 myoblast and the 3T3-L1 fibroblast cell cultures. TPA increased, by 2-4 fold, the synthesis rates of two cytoplasmic proteins with apparent molecular weights of 89,000 and 74,000 as determined by SDS-polyacrylamide gel electrophoresis and autoradiography. The concentration of TPA and the time of incubation needed to elicit this induction was determined to be 10 μg/ml and 20 hrs, respectively. Increasing the concentration of TPA to 100, 200, and 500 ng/ml did not result in a greater magnitude of induction. The possibility that these two TPA-induced proteins may be identical to proteins with similar molecular weights induced under heat-shocked or glucose-starved conditions was evaluated by 1-D and 2-D gel electrophoresis and autoradiography. Results provided evidence that the TPA-induced 89,000- and 74,000-dalton proteins were identical to hsp 89 and hsp 74, 2 out of a set of 8-9 proteins induced under heat shocked conditions. Furthermore, they are identical to two of the set of glucose-regulated proteins induced under a glucose-starved condition

  14. OxymaPure/DIC: An Efficient Reagent for the Synthesis of a Novel Series of 4-[2-(2-Acetylaminophenyl-2-oxo-acetylamino] Benzoyl Amino Acid Ester Derivatives

    Directory of Open Access Journals (Sweden)

    Ayman El-Faham

    2013-11-01

    Full Text Available OxymaPure (ethyl 2-cyano-2-(hydroxyiminoacetate was tested as an additive for use in the carbodiimide (DIC approach for the synthesis of a novel series of α-ketoamide derivatives (4-[2-(2-acetylaminophenyl-2-oxo-acetylamino]benzoyl amino acid ester derivatives. OxymaPure showed clear superiority to HOBt/DIC or carbodiimide alone in terms of purity and yield. The title compounds were synthesized via the ring opening of N-acylisatin. First, N-acetylisatin was reacted with 4-aminobenzoic acid under conventional heating as well as microwave irradiation to afford 4-(2-(2-acetamidophenyl-2-oxoacetamidobenzoic acid. This α-ketoamide was coupled to different amino acid esters using OxymaPure/DIC as a coupling reagent to afford 4-[2-(2-acetylaminophenyl-2-oxo-acetylamino]benzoyl amino acid ester derivatives in excellent yield and purity. The synthesized compounds were characterized using FT-IR, NMR, and elemental analysis.

  15. Synthesis, Formulation, and Adjuvanticity of Monodesmosidic Saponins with Olenanolic Acid, Hederagenin and Gypsogenin Aglycones, and some C-28 Ester Derivatives

    DEFF Research Database (Denmark)

    Greatrex, Ben W.; Daines, Alison M.; Hook, Sarah

    2015-01-01

    In an attempt to discover a new synthetic vaccine adjuvant, the glycosylation of hederagenin, gypsogenin, and oleanolic acid acceptors with di- and trisaccharide donors to generate a range of mimics of natural product QS-21 was carried out. The saponins were formulated with phosphatidylcholine...... of cholesterol and phospholipid, the choline ester derivatives produced nanocrystalline rods or helical micelles. The effects of modifying sugar stereochemistry and the aglycone on the immunostimulatory effects of the saponins was then evaluated using the activation markers MHC class II and CD86 in murine bone...... marrow dendritic cells. The most active saponin, 3-O-(Manp(13)Glcp)hederagenin, was stimulatory at high concentrations in cell culture, but this did not translate to strong responses in vivo....

  16. Synthesis and Characterization of Modified Epoxy Resins by Silicic Acid Tetraethyl Ester and Nano-SiO2

    Institute of Scientific and Technical Information of China (English)

    李海燕; 张之圣

    2004-01-01

    A kind of modified epoxy resins was obtained by condensation of epoxy resin with silicic acid tetraethyl ester(TEOS) and nano-SiO2. The reactions were performed with hydrochloric acid as a catalyst at 63 °C.The structure, thermal stability and morphological characteristics of the modified epoxy resins were studied through infrared spectra(FT-IR) analysis, thermogravimetric (TG) analysis and scanning electron microscopy respectively. It has been found from the IR and TG study that modified epoxy resins have greater thermal stability than epoxy resins, and its thermal stability has been improved by the formation of inter-crosslinked network structure. The modified epoxy resins exhibit heterogeneous morphology and heterogeneity increases with more TEOS feeding, which in turn confirms the formation of inter-crosslinked network structure in modified epoxy resins.

  17. Synthesis and Physicochemical Characterization of a Diethyl Ester Prodrug of DTPA and Its Investigation as an Oral Decorporation Agent in Rats.

    Science.gov (United States)

    Huckle, James E; Sadgrove, Matthew P; Leed, Marina G D; Yang, Yu-Tsai; Mumper, Russell J; Semelka, Richard C; Jay, Michael

    2016-07-01

    The increasing threats of nuclear terrorism have made the development of medical countermeasures a priority for international security. Injectable formulations of diethylenetriaminepentaacetic acid (DTPA) have been approved by the FDA; however, an oral formulation is more amenable in a mass casualty situation. Here, the diethyl ester of DTPA, named C2E2, is investigated for potential as an oral treatment for internal radionuclide contamination. C2E2 was synthesized and characterized using NMR, MS, and elemental analysis. The physiochemical properties of solubility, lipophilicity, and stability were investigated in order to predict its oral bioavailability. Finally, an animal efficacy study was conducted in Sprague Dawley rats pre-contaminated by intramuscular injection with (241)Am(NO3)3 to establish effectiveness of the therapy via the oral route. Synthesis of C2E2 yielded a crystalline powder with high solubility and improved lipophilicity over DTPA. The ester was stable in both simulated gastric and intestinal fluids over the anticipated time course of absorption. Capsules containing C2E2 were demonstrated to be stable for 12 months under accelerated stability conditions. After a single dose, C2E2 enhanced the elimination of (241)Am in a dose-dependent manner. Significant improvement was seen in both total (241)Am decorporation and reduction of (241)Am liver and skeletal burden. C2E2 was concluded to be effective when orally administered to (241)Am-contaminated rats. It may therefore have potential for medical countermeasure in treating humans contaminated with (241)Am or other transuranic elements. An oral capsule or powder for reconstitution may be suitable formulations for future development based on the physiochemical properties and anticipated dose required for efficacy.

  18. Plant sterol ester diet supplementation increases serum plant sterols and markers of cholesterol synthesis, but has no effect on total cholesterol levels.

    Science.gov (United States)

    Weingärtner, Oliver; Bogeski, Ivan; Kummerow, Carsten; Schirmer, Stephan H; Husche, Constanze; Vanmierlo, Tim; Wagenpfeil, Gudrun; Hoth, Markus; Böhm, Michael; Lütjohann, Dieter; Laufs, Ulrich

    2017-05-01

    This double-blind, randomized, placebo-controlled, cross-over intervention-study was conducted in healthy volunteers to evaluate the effects of plant sterol ester supplemented margarine on cholesterol, non-cholesterol sterols and oxidative stress in serum and monocytes. Sixteen volunteers, average age 34 years, with no or mild hypercholesterolemia were subjected to a 4 week period of daily intake of 3g plant sterols per day supplied via a supplemented margarine on top of regular eating habits. After a wash-out period of one week, volunteers switched groups. Compared to placebo, a diet supplementation with plant sterols increased serum levels of plant sterols such as campesterol (+0.16±0.19mg/dL, p=0.005) and sitosterol (+0.27±0.18mg/dL, psynthesis such as desmosterol (+0.05±0.07mg/dL, p=0.006) as well as lathosterol (+0.11±0.16mg/dL, p=0.012). Cholesterol serum levels, however, were not changed significantly (+18.68±32.6mg/dL, p=0.052). These findings could not be verified in isolated circulating monocytes. Moreover, there was no effect on monocyte activation and no differences with regard to redox state after plant sterol supplemented diet. Therefore, in a population of healthy volunteers with no or mild hypercholesterolemia, consumption of plant sterol ester supplemented margarine results in increased concentrations of plant sterols and cholesterol synthesis markers without affecting total cholesterol in the serum, activation of circulating monocytes or redox state. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Organic synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, S.E.

    1991-01-01

    This paper reports on reactions of organoboranes. Organoboron routes to unsaturated hydrocarbons. Boronic ester homologation. Properties of organosilicon compounds. Alkene synthesis (Peterson olefination). Allylsilanes and acylsilanes.

  20. An inproved synthesis of 24- 13C-labeled bile acids using formyl esters and a modified lead tetraacetate procedure

    International Nuclear Information System (INIS)

    Tserng, K.Y.; Klein, P.D.

    1977-01-01

    An improved synthesis of 24- 13 C-labeled bile acids has been achieved using formyl derivatives of bile acids and a modified lead tetraacetate procedure. The formylated bile acids were degraded by lead tetraacetate and lithium chloride to formylated 23-chloronorcholanes in 72 to 83% yield. Formylated 23-chloronorcholanes were converted to nitriles in dimethylformamide, which were then hydrolyzed to obtain C-24 labeled bile acids in yield of 80 to 90% of labeled sodium cyanide used. This method results in a higher yield and a purer product with less manipulation than previously reported procedures for synthesis of labeled bile acids

  1. A Novel Methodology for the Synthesis of Acyloxy Castor Polyol Esters: Low Pour Point Lubricant Base Stocks.

    Science.gov (United States)

    Kamalakar, Kotte; Mahesh, Goli; Prasad, Rachapudi B N; Karuna, Mallampalli S L

    2015-01-01

    Castor oil, a non-edible oil containing hydroxyl fatty acid, ricinoleic acid (89.3 %) was chemically modified employing a two step procedure. The first step involved acylation (C(2)-C(6) alkanoic anhydrides) of -OH functionality employing a green catalyst, Kieselguhr-G and solvent free medium. The catalyst after reaction was filtered and reused several times without loss in activity. The second step is esterification of acylated castor fatty acids with branched mono alcohol, 2-ethylhexanol and polyols namely neopentyl glycol (NPG), trimethylolpropane (TMP) and pentaerythritol (PE) to obtain 16 novel base stocks. The base stocks when evaluated for different lubricant properties have shown very low pour points (-30 to -45°C) and broad viscosity ranges 20.27 cSt to 370.73 cSt, higher viscosity indices (144-171), good thermal and oxidative stabilities, and high weld load capacities suitable for multi-range industrial applications such as hydraulic fluids, metal working fluids, gear oil, forging and aviation applications. The study revealed that acylated branched mono- and polyol esters rich in monounsaturation is desirable for developing low pour point base stocks.

  2. Soluble lipase-catalyzed synthesis of methyl esters using a blend of edible and nonedible raw materials.

    Science.gov (United States)

    Wancura, João H C; Rosset, Daniela V; Brondani, Michel; Mazutti, Marcio A; Oliveira, J Vladimir; Tres, Marcus V; Jahn, Sérgio L

    2018-04-26

    This work investigates the use of blends of edible and nonedible raw materials as an alternative feedstock to fatty acid methyl esters (FAME) production through enzymatic catalysis. As biocatalyst, liquid lipase from Thermomyces lanuginosus (Callera™ Trans L), was used. Under reaction conditions of 35 °C, methanol to feedstock molar ratio of 4.5:1 and 1.45% of catalyst load, the best process performance was reached using 9% of water concentration in the medium-yield of 79.9% after 480 min of reaction. In terms of use of tallow mixed with soybean oil, the best yield was obtained when 100% of tallow was used in the process-84.6% after 480 min of reaction-behavior that was associated with the degree of unsaturation of the feedstock, something by that time, not addressed in papers of the area. The results show that tallow can be used as an alternative to FAME production, catalyzed by soluble lipase.

  3. Synthesis of methyl esters from relevant palm products in near-critical methanol with modified-zirconia catalysts.

    Science.gov (United States)

    Laosiripojana, N; Kiatkittipong, W; Sutthisripok, W; Assabumrungrat, S

    2010-11-01

    The transesterification and esterification of palm products i.e. crude palm oil (CPO), refined palm oil (RPO) and palm fatty acid distillate (PFAD) under near-critical methanol in the presence of synthesized SO(4)-ZrO(2), WO(3)-ZrO(2) and TiO(2)-ZrO(2) (with various sulfur- and tungsten loadings, Ti/Zr ratios, and calcination temperatures) were studied. Among them, the reaction of RPO with 20%WO(3)-ZrO(2) (calcined at 800 degrees C) enhanced the highest fatty acid methyl ester (FAME) yield with greatest stability after several reaction cycles; furthermore, it required shorter time, lower temperature and less amount of methanol compared to the reactions without catalyst. These benefits were related to the high acid-site density and tetragonal phase formation of synthesized WO(3)-ZrO(2). For further improvement, the addition of toluene as co-solvent considerably reduced the requirement of methanol to maximize FAME yield, while the addition of molecular sieve along with catalyst significantly increased FAME yield from PFAD and CPO due to the inhibition of hydrolysis reaction. Copyright 2010 Elsevier Ltd. All rights reserved.

  4. Targeting (cellular) lysosomal acid ceramidase by B13: design, synthesis and evaluation of novel DMG-B13 ester prodrugs.

    Science.gov (United States)

    Bai, Aiping; Szulc, Zdzislaw M; Bielawski, Jacek; Pierce, Jason S; Rembiesa, Barbara; Terzieva, Silva; Mao, Cungui; Xu, Ruijuan; Wu, Bill; Clarke, Christopher J; Newcomb, Benjamin; Liu, Xiang; Norris, James; Hannun, Yusuf A; Bielawska, Alicja

    2014-12-15

    Acid ceramidase (ACDase) is being recognized as a therapeutic target for cancer. B13 represents a moderate inhibitor of ACDase. The present study concentrates on the lysosomal targeting of B13 via its N,N-dimethylglycine (DMG) esters (DMG-B13 prodrugs). Novel analogs, the isomeric mono-DMG-B13, LCL522 (3-O-DMG-B13·HCl) and LCL596 (1-O-DMG-B13·HCl) and di-DMG-B13, LCL521 (1,3-O, O-DMG-B13·2HCl) conjugates, were designed and synthesized through N,N-dimethyl glycine (DMG) esterification of the hydroxyl groups of B13. In MCF7 cells, DMG-B13 prodrugs were efficiently metabolized to B13. The early inhibitory effect of DMG-B13 prodrugs on cellular ceramidases was ACDase specific by their lysosomal targeting. The corresponding dramatic decrease of cellular Sph (80-97% Control/1h) by DMG-B13 prodrugs was mainly from the inhibition of the lysosomal ACDase. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Synthesis, DFT and antimicrobial activity assays in vitro for novel cis/trans-but-2-enedioic acid esters

    Science.gov (United States)

    Ma, Yan-Long; Zhou, Ru-Jin; Zeng, Xing-Ye; An, Ya-Xiong; Qiu, Song-Shan; Nie, Li-Jun

    2014-04-01

    Six novel cis/trans-but-2-enedioic acid esters had been synthesized to discover the new bioactive molecules that could kill food-related bacteria and fungi. Their structures were analyzed by melting point, LC-MS, 1H NMR and 13C NMR. 4-(Methoxycarbonyl) phenyl ethyl fumarate (6b) was also characterized by single-crystal X-ray diffraction. Their antimicrobial activities were evaluated in vitro by measuring the minimal inhibitory concentration (MIC). Compared with the single monomethyl fumarate and methyl 4-hydroxybenzoate, these compounds had stronger antimicrobial activity against all the eight microorganisms. Among the antibacterial and antifungal compounds, 4-(methoxycarbonyl) phenyl methyl fumarate (6a) showed the best antimicrobial activity. The electronic properties of these compounds were calculated by the density functional theory (DFT) method with 6-31G (d, p) basis set. DFT studies indicated that molecular electrostatic potential (MEP) map, ELUMO, energy gap, electronegativity and electrophilicity index could be helpful to understand the various antimicrobial activities among these compounds. The antimicrobial activity of compound 6a was evaluated in vitro against Salmonellacholeraesuis subsp. choleraesuis, Lactococcus lactis subsp. lactis and Saccharomyces cerevisiae by time-kill, and it was found that compound 6a exhibited significant microbiocidal activity against the three microorganisms.

  6. Synthesis of Enantiomerically Pure 6-Substituted-Piperazine-2-Acetic Acid Esters as Intermediates for Library Production.

    Science.gov (United States)

    Chamakuri, Srinivas; Jain, Prashi; Guduru, Shiva Krishna Reddy; Arney, Joseph Winston; MacKenzie, Kevin; Santini, Conrad; Young, Damian W

    2018-05-11

    Amino acids from the chiral pool have been used to produce a 24-member branch of 2,6-disubstituted piperazine scaffolds suitable for use in compound library production. Each scaffold was obtained as a single absolute stereoisomer in multi-gram quantities. Stereochemistry was confirmed by 2D NMR protocols and enantiomeric purity was determined by chiral HPLC. The scaffolds are intended for use as intermediates in parallel synthesis of small-molecule libraries.

  7. Recent advances in H-phosphonate chemistry. Part 1. H-phosphonate esters: synthesis and basic reactions.

    Science.gov (United States)

    Sobkowski, Michal; Kraszewski, Adam; Stawinski, Jacek

    2015-01-01

    This review covers recent progress in the preparation of H-phosphonate mono- and diesters, basic studies on mechanistic and stereochemical aspects of this class of phosphorus compounds, and their fundamental chemistry in terms of transformation of P-H bonds into P-heteroatom bonds. Selected recent applications of H-phosphonate derivatives in basic organic phosphorus chemistry and in the synthesis of biologically important phosphorus compounds are also discussed.

  8. Enantioselective synthesis of α-phenyl- and α-(dimethylphenylsilyl)alkylboronic esters by ligand mediated stereoinductive reagent-controlled homologation using configurationally labile carbenoids.

    Science.gov (United States)

    Barsamian, Adam L; Wu, Zhenhua; Blakemore, Paul R

    2015-03-28

    Chain extension of boronic esters by the action of configurationally labile racemic lithium carbenoids in the presence of scalemic bisoxazoline ligands was explored for the enantioselective synthesis of the two title product classes. Enantioenriched 2° carbinols generated by oxidative work-up (NaOOH) of initial α-phenylalkylboronate products were obtained in 35-83% yield and 70-96% ee by reaction of B-alkyl and B-aryl neopentyl glycol boronates with a combination of O-(α-lithiobenzyl)-N,N-diisopropylcarbamate and ligand 3,3-bis[(4S)-4,5-dihydro-4-isopropyloxazol-2-yl] pentane in toluene solvent (-78 °C to rt) with MgBr2·OEt2 additive. Enantioenriched α-(dimethylsilylphenylsilyl)alkylboronates were obtained in 35-69% yield and 9-57% ee by reaction of B-alkyl pinacol boronates with a combination of lithio(dimethylphenylsilyl)methyl 2,4,6-triisopropylbenzoate and ligand 2,2-bis[(4S)-4,5-dihydro-4-isopropyloxazol-2-yl]propane in cumene solvent (-45 °C to -95 °C to rt). The stereochemical outcome of the second type of reaction depended on the temperature history of the organolithium·ligand complex indicating that the stereoinduction mechanism in this case involves some aspect of dynamic thermodynamic resolution.

  9. Biocatalytic Synthesis of Flavor Ester “Pentyl Valerate” Using Candida rugosa Lipase Immobilized in Microemulsion Based Organogels: Effect of Parameters and Reusability

    Directory of Open Access Journals (Sweden)

    Tripti Raghavendra

    2014-01-01

    Full Text Available Pentyl valerate was synthesized biocatalytically using Candida rugosa lipase (CRL immobilized in microemulsion based organogels (MBGs. The optimum conditions were found to be pH 7.0, temperature of 37°C, ratio of concentration of water to surfactant (Wo of 60, and the surfactant sodium bis-2-(ethylhexylsulfosuccinate (AOT for MBG preparation. Although kinetic studies revealed that the enzyme in free form had high affinity towards substrates (Km = 23.2 mM for pentanol and 76.92 mM for valeric acid whereas, after immobilization, the Km values increased considerably (74.07 mM for pentanol and 83.3 mM for valeric acid resulting in a slower reaction rate, the maximum conversion was much higher in case of immobilized enzyme (~99% as compared to free enzyme (~19%. Simultaneous effects of important parameters were studied using response surface methodology (RSM conjugated with Box-Behnken design (BBD with five variables (process parameters, namely, enzyme concentration, initial water content (Wo, solvent used for MBG preparation, substrate ratio and time, and response as the final product formation, that is, pentyl valerate (%. The MBGs were reused for 10 consecutive cycles for ester synthesis. Efficacy of AOT/isooctane as dehydrating agent for extracting excess water from MBGs was found to exert a positive effect on the esterification reaction.

  10. Chemo-enzymatic Synthesis of Propionyl-ester-linked Taxol-monosaccharide Conjugate and its Drug Delivery System Using Hybrid-Bio-nanocapsules Targeting Brain Glioma Cells

    Directory of Open Access Journals (Sweden)

    Hiroki Hamada

    2013-01-01

    Full Text Available Taxol is recognized as one of the most potent anticancer agents used in the treatment of breast and ovarian cancers, which are common cancers in women. To overcome its shortcomings, that is, its low water-solubility that reduces drug loading capacity of DDS carriers when incorporating taxol, chemo-enzymatic synthesis of ester-linked taxol-glucose conjugate, i.e., 7-propionyltaxol 2′- O -α-D-glucoside, as a water soluble taxol prodrug was achieved by using a-glucosidase as a glucosylation catalyst. The water-solubility of 7-propionyltaxol 2′- O -α-D-glucoside (25 mM was 63 fold higher than that of taxol (0.4 mM. The pre-S1 peptide which displays on the surface of bio-nanocapsules, which are nanoparticles composed of the hepatitis B virus surface antigen, was replaced with the antibody affinity motif of protein A. Conjugation of such bio-nanocapsules with anti-human epidermal growth factor receptor antibody gave hybrid bio-nanocapsules. The hybrid bio-nanocapsules were effective for delivering 7-propionyltaxol 2′- O -α-D-glucoside to human brain glioma cells. 7-Propionyltaxol 2′- O -α-D-glucoside was effectively hydrolyzed to give taxol in 95% by human glioma cells. The drug loading capacity of hybrid bio-nanocapsules incorporating 7-propionyltaxol 2′- O -α-D-glucoside was 120 times higher than that incorporating taxol itself.

  11. Synthesis and characterization of N-hydroxysuccinimide ester chemical affinity derivatives of asialoorosomucoid that covalently cross-link to galactosyl receptors on isolated rat hepatocytes

    International Nuclear Information System (INIS)

    Herzig, M.C.S.; Weigel, P.H.

    1989-01-01

    The authors have developed chemical affinity reagents for the hepatic galactosyl receptor. Asialoorosomucoid (ASOR) was derivatized with five homobifunctional N-hydroxysuccinimide (NHS) ester cross-linkers. NHS/ASOR derivatives were synthesized, purified, and applied within 10 min to isolated rat hepatocytes at 4 degree C. Specific binding of these 125 I-labeled derivatives was ∼90% in the presence of either EGTA or excess ASOR. Specific cross-linking assessed by the resistance of specifically bound NHS/ 125 I-ASOR to release by EGTA, was 50-75% of the specifically bound ligand. The extent of specific cross-linking correlated with the average number of NHS groups per ASOR and was controlled by varying the molar ratio of cross-linker to ASOR during the synthesis. After being cross-linked with any of the NHS/ 125 I-ASOR derivatives, cells were washed with EGTA, solubilized in Triton X-100, and analyzed by SDA-PAGE and autoradiography. They conclude that all three receptor subunits can cross-link to ligand. They propose a model in which the native receptor is a heterohexamer composed of four subunits of RHL 1 and two subunits of RHL 2 and/or RHL 3

  12. Synthesis of pH-sensitive poly(β-amino ester)-coated mesoporous silica nanoparticles for the controlled release of drugs

    Science.gov (United States)

    Talavera-Pech, William A.; Esparza-Ruiz, Adriana; Quintana-Owen, Patricia; Vilchis-Nestor, Alfredo R.; Barrón-Zambrano, Jesus A.; Ávila-Ortega, Alejandro

    2018-03-01

    This report describes the synthesis of a controlled drug delivery system that was obtained by coating mesoporous silica nanoparticles (MSNs) with poly(β-amino ester) (PbAE), which is a solid and stable material at physiological pH, but is dissolved at acidic pH values, such as those in tumor tissues (from 5.0 to 6.5). To synthesize the system, PbAE chains were grafted onto amino-functionalized MSNs through a reaction between the surface amino groups of MSNs and the ends of acrylate chains of a PbAE. The system was physicochemically characterized by dynamic light scattering (DLS), Fourier transform infrared spectroscopy, transmission electron microscopy, thermogravimetric analysis, X-ray photoelectron spectrometry, and X-ray diffraction analyses. In addition, the in vitro release of doxorubicin (DOX) and doxycycline (DXY) in acidic and physiological media was evaluated. It was observed that the PbAE modification did not affect the mesoporous structure of MSNs. When the amount of 3-aminopropyltriethoxysilane was increased during functionalization, the amount of PbAE binding to MSNs increased as well. With respect to drug release, the sample with the highest amount of PbAE showed better control in the delivery of DXY and DOX in acidic media, because at pH 5.5, the release of both drugs was 40% higher than that at pH 7.4. These results reveal two aspects about the presence of PbAE in MSNs: PbAE does not affect the mesoporous structure of the nanoparticles, and PbAE is the main factor controlling the delivery of drugs in acidic media.

  13. Feeding Unprotected CLA Methyl Esters Compared to Sunflower Seeds Increased Milk CLA Level but Inhibited Milk Fat Synthesis in Cows

    Directory of Open Access Journals (Sweden)

    F. Dohme-Meier

    2012-01-01

    Full Text Available An experiment was conducted to compare the effect of the same amount of 18:2 offered either as 18:2n-6 or as a mixture of unprotected 18:2c9t11 and 18:2t10c12 on feed intake, milk components as well as plasma and milk fatty acid profile. Fifteen cows were blocked by milk yield and milk fat percentage and within block assigned randomly to 1 of 3 treatments (n = 5. Each cow passed a 12-d adjustment period (AP on a basal diet. After the AP cows received 1 of 3 supplements during an 18-d experimental period (EP. The supplements contained either 1.0 kg ground sunflower seeds (S, 0.5 kg conjugated linoleic acid (CLA-oil (C or 0.75 kg of a mixture of ground sunflower seeds and CLA-oil (2:1; SC. All 3 supplements contained the same amount of 18:2 either as CLA (∑18:2c9t11+18:2t10c12, 1:1 or as 18:2c9c12. During the last 2 d of AP and the last 4 d of EP feed intake and milk yield were recorded daily and milk samples were collected at each milking. Blood samples were collected from the jugular vein on d 11 of AP and d 15 and 18 of EP. The 18:2 intake increased in all treatments from AP to EP. Regardless of the amount of supplemented CLA, the milk fat percentage decreased by 2.35 and 2.10%-units in treatment C and SC, respectively, whereas in the treatment S the decrease was with 0.99%-unit less pronounced. Thus, C and SC cows excreted daily a lower amount of milk fat than S cows. The concentration of trans 18:1 in the plasma and the milk increased from AP to EP and increased with increasing dietary CLA supply. While the concentration of 18:2c9t11 and 18:2t10c12 in the plasma and that of 18:2t10c12 in the milk paralleled dietary supply, the level of 18:2c9t11 in the milk was similar in C and CS but still lower in S. Although the dietary concentration of CLA was highest in treatment C, the partial replacement of CLA by sunflower seeds had a similar inhibitory effect on milk fat synthesis. Comparable 18:2c9t11 levels in the milk in both CLA treatments

  14. Stereoselective formation of a cholesterol ester conjugate from fenvalerate by mouse microsomal carboxyesterase(s).

    Science.gov (United States)

    Miyamoto, J; Kaneko, H; Takamatsu, Y

    1986-06-01

    In accordance with in vivo findings, of the four chiral isomers of fenvalerate (S-5602 Sumicidin, Pydrin, [RS]-alpha-cyano-3-phenoxybenzyl [RS]-2-(4-chlorophenyl)isovalerate), only the [2R, alpha S]-isomer (B-isomer) yielded cholesteryl [2R]-2-(4-chlorophenyl)isovalerate (CPIA-cholesterol ester) in the in vitro study using several tissue homogenates of mice, rats, dogs, and monkeys. There were species differences in the extent of CPIA-cholesterol-ester formation, with mouse tissues showing relatively higher activity than those of other animals. The kidney, brain, and spleen of mice showed relatively higher capacities to form this ester compared to other tissues, and the enzyme activity was mainly localized in microsomal fractions. The CPIA-cholesterol ester did not seem to be produced by three known biosynthetic pathways of endogenous cholesterol esters--acyl-CoA:cholesterol O-acyltransferase (ACAT), lecithin:cholesterol O-acyltransferase (LCAT), and cholesterol esterase. Carboxyesterase(s) of mouse kidney microsomes solubilized by digitonin hydrolyzed only the B alpha-isomer of fenvalerate, yielding CPIA, whereas they yielded the corresponding cholesterol ester in the presence of artificial liposomes containing cholesterol. Thus, it appears that the stereoselective formation of the CPIA-cholesterol ester results from the stereoselective formation of the CPIA-carboxyesterase complex only from the B alpha-isomer, which subsequently undergoes cleavage by cholesterol to yield the CPIA-cholesterol ester.

  15. An efficient method for the synthesis of phenacyl ester-protected dipeptides using neutral alumina-supported sodium carbonate 'Na2 CO3 /n-Al2 O3 '.

    Science.gov (United States)

    Hashimoto, Chikao; Sugimoto, Kazuhiro; Takahashi, Youhei; Kodomari, Mitsuo

    2013-10-01

    In the synthesis of dipeptides (Boc-AA(1)-AA(2)-OPac: AA(1) and AA(2) represent amino acids) protected by phenacyl (Pac) ester, amines and solid bases as the base for the conversion of the trifluoroacetic acid (TFA) salt of the amino component (TFA·H-AA(2)-OPac) into the corresponding free amino component (H-AA(2)-OPac) were examined. The synthesis of a dipeptide (Boc-Ala-Gly-OPac) using amines for the conversion afforded an unsatisfactory yield with by-products. On the other hand, the use of neutral alumina-supported Na(2) CO(3) (Na(2)CO(3) /n-Al(2)O(3)) as a solid base for the conversion provided the dipeptide in a quantitative yield without by-products. The application of Na(2)CO(3) /n-Al2 O3 to the synthesis of some dipeptides protected by Pac ester gave the desired peptides in excellent yields. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd.

  16. B2O3/Al2O3 as a new, highly efficient and reusable heterogeneous catalyst for the selective synthesis of β-enamino ketones and esters under solvent-free conditions

    International Nuclear Information System (INIS)

    Chen, Jiu-Xi; Gao, Wen-Xia; Jin, Hui-Le; Ding, Jin-Chang; Wu, Hua-Yue

    2010-01-01

    Boron oxide adsorbed on alumina (B 2 O 3 /Al 2 O 3 ) has been found to be a new and highly efficient heterogeneous catalyst for the synthesis of β-enamino ketones and esters by the enamination of various primary and secondary amines with β-dicarbonyl compounds under solvent-free conditions. The important features of this methodology are broad substrate scope, high yield, no requirement of metal catalysts, high regio- and chemoselectivity and environmental friendliness. In addition, the catalyst could be recovered easily after the reactions and reused without evident loss of reactivity. (author)

  17. Synthesis and tissue distribution studies of two novel esters of haloperidol and the application of radiolabelling techniques using short-lived radionuclides in the study of the deposition characteristics of suspended aerosol particles

    International Nuclear Information System (INIS)

    Smith, M.F.

    1982-01-01

    In the present work, the Schotten-Baumann reaction conditions were modified to esterify the tertiary hydroxyl group of haloperidol. The rapid synthesis (less than 20 min) makes this procedure applicable to the preparation of esters of haloperidol containing fluorine-18 (t/sup (1/2)/ 110 min), a γ-emitting radioisotope useful in external scintigraphy. In vivo distribution studies of the synthesized tritiated esters and haloperidol in the rat demonstrated that neither ester prodrug achieved overall higher brain concentration levels than haloperidol. In this study, radiotracer techniques were developed to examine parameters that characterize pressurized aerosols designed to utilize insoluble particles suspended in the aerosol formulation. The suspended micro-aggregated bovine albumin microspheres were labelled with iodine-131 (t/sup (1/2)/ 8 days). The techniques developed illustrate the use of short-lived radionuclides for: 1) quantitation of each metered dose; 2) characterization of particle size distribution by the aerosol; and 3) determination of the extent of deposition of the particles in the aerosol and all of its components

  18. Solvent-Free Lipase-Catalyzed Synthesis of Technical-Grade Sugar Esters and Evaluation of Their Physicochemical and Bioactive Properties

    Directory of Open Access Journals (Sweden)

    Ran Ye

    2016-05-01

    Full Text Available Technical-grade oleic acid esters of sucrose and fructose were prepared using solvent-free biocatalysis at 65 °C, without any downstream purification applied, and their physicochemical and bioactivity-related properties were evaluated and compared to a commercially available sucrose laurate emulsifier. To increase the conversion of sucrose and fructose oleate, prepared previously using solvent-free lipase-catalyzed esterification catalyzed by Rhizomucor miehei lipase (81% and 83% ester, respectively, the enzymatic reaction conditions was continued using CaSO4 to control the reactor’s air headspace and a lipase (from Candida antarctica B with a hydrophobic immobilization matrix to provide an ultralow water activity, and high-pressure homogenation, to form metastable suspensions of 2.0–3.3 micron sized saccharide particles in liquid-phase reaction media. These measures led to increased ester content of 89% and 96% for reactions involving sucrose and fructose, respectively. The monoester content among the esters decreased from 90% to <70% due to differences in regioselectivity between the lipases. The resultant technical-grade sucrose and fructose lowered the surface tension to <30 mN/m, and possessed excellent emulsification capability and stability over 36 h using hexadecane and dodecane as oils, comparable to that of sucrose laurate and Tween® 80. The technical-grade sugar esters, particularly fructose oleate, more effectively inhibited gram-positive foodborne pathogens (Lactobacillus plantarum, Pediococcus pentosaceus and Bacillus subtilis. Furthermore, all three sugar esters displayed antitumor activity, particularly the two sucrose esters. This study demonstrates the importance of controlling the biocatalysts’ water activity to achieve high conversion, the impact of a lipase’s regioselectivity in dictating product distribution, and the use of solvent-free biocatalysis to important biobased surfactants useful in foods, cosmetics

  19. Synthesis of Amide and Ester Derivatives of Cinnamic Acid and Its Analogs: Evaluation of Their Free Radical Scavenging and Monoamine Oxidase and Cholinesterase Inhibitory Activities.

    Science.gov (United States)

    Takao, Koichi; Toda, Kazuhiro; Saito, Takayuki; Sugita, Yoshiaki

    2017-01-01

    A series of cinnamic acid derivatives, amides (1-12) and esters (13-22), were synthesized, and structure-activity relationships for antioxidant activity, and monoamine oxidases (MAO) A and B, acetylcholinesterase, and butyrylcholinesterase (BChE) inhibitory activities were analyzed. Among the synthesized compounds, compounds 1-10, 12-18, and rosmarinic acid (23), which contained catechol, o-methoxyphenol or 5-hydroxyindole moieties, showed potent 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity. Compounds 9-11, 15, 17-22 showed potent and selective MAO-B inhibitory activity. Compound 20 was the most potent inhibitor of MAO-B. Compounds 18 and 21 showed moderate BChE inhibitory activity. In addition, compound 18 showed potent antioxidant activity and MAO-B inhibitory activity. In a comparison of the cinnamic acid amides and esters, the amides exhibited more potent DPPH free radical scavenging activity, while the esters showed stronger inhibitory activities against MAO-B and BChE. These results suggested that cinnamic acid derivatives such as compound 18, p-coumaric acid 3,4-dihydroxyphenethyl ester, and compound 20, p-coumaric acid phenethyl ester, may serve as lead compounds for the development of novel MAO-B inhibitors and candidate lead compounds for the prevention or treatment of Alzheimer's disease.

  20. Aortic smooth muscle cell proteoglycan synthesis in relation to atherosclerosis

    International Nuclear Information System (INIS)

    Edwards, I.J.

    1989-01-01

    Proteoglycans (PG) are implicated in atherogenesis by their effects on tissue permeability and cell proliferation and their interaction with plasma low density lipoproteins. Using the pigeon model in which an atherosclerosis-susceptible (WC) and -resistant (SR) breed can be compared, PG synthesis by cultured aortic smooth muscle cells was examined by the use of [ 35 S]-sodium sulfate and [ 3 H]-serine or [ 3 H]-glucosamine as labeling precursors. In both SR and WC cells, the majority of newly synthesized PG were secreted into the media. Chondroitin sulfate (CS) PG and dermatan sulfate (DS) PG were the major PG produced. Total PG production was consistently lower in WC compared to SR cultures due in part to reduce PG synthesis but also to degradation of newly synthesized PG. Since increased DS-PG accompanines atherosclerosis progression, experiments were designed to test the hypothesis that macrophages modulate smooth muscle cell metabolism to cause increase DS-PG production. Cultured WC aortic smooth muscle cells were exposed to the media of cholesteryl ester-loaded pigeon peritoneal macrophages or a macrophage cell line P388D1 and the production of PG examined. Increasing concentration of conditioned media from both types of macrophages caused increased incorporation of 35 S-sulfate into secreted PG, but no change in cell-associated PG. Lipopolysaccharide activation of P388D1 cells enhanced the effect

  1. Chlorzoxazone esters of some non-steroidal anti-inflammatory (NSAI) carboxylic acids as mutual prodrugs: design, synthesis, pharmacological investigations and docking studies.

    Science.gov (United States)

    Abdel-Azeem, Ahmed Z; Abdel-Hafez, Atef A; El-Karamany, Gamal S; Farag, Hassan H

    2009-05-15

    The discovery of the inducible isoform of cyclooxygenase enzyme (COX-2) spurred the search for anti-inflammatory agents devoid of the undesirable effects associated with classical NSAIDs. New chlorzoxazone ester prodrugs (6-8) of some acidic NSAIDs (1-3) were designed, synthesized and evaluated as mutual prodrugs with the aim of improving the therapeutic potency and retard the adverse effects of gastrointestinal origin. The structure of the synthesized mutual ester prodrugs (6-8) were confirmed by IR, (1)H NMR, mass spectroscopy (MS) and their purity was ascertained by TLC and elemental analyses. In vitro chemical stability revealed that the synthesized ester prodrugs (6-8) are chemically stable in hydrochloric acid buffer pH 1.2 as a non-enzymatic simulated gastric fluid (SGF) and in phosphate buffer pH 7.4 as non-enzymatic simulated intestinal fluid (SIF). In 80% human plasma, the mutual prodrugs were found to be susceptible to enzymatic hydrolysis at relatively faster rate (t(1/2) approximately 37 and 34 min for prodrugs 6 and 7, respectively). Mutual ester prodrugs (6-8) were evaluated for their anti-inflammatory and muscle relaxation activities. Scanning electromicrographs of the stomach showed that the ester prodrugs induced very little irritancy in the gastric mucosa of rats after oral administration for 4days. In addition, docking of the mutual ester prodrugs (6-8) into COX-2 active site was conducted in order to predict the affinity and orientation of these prodrugs at the enzyme active site.

  2. Lipid-lowering effect of bergamot polyphenolic fraction: role of pancreatic cholesterol ester hydrolase.

    Science.gov (United States)

    Musolino, V; Gliozzi, M; Carresi, C; Maiuolo, J; Mollace, R; Bosco, F; Scarano, F; Scicchitano, M; Maretta, A; Palma, E; Iannone, M; Morittu, V M; Gratteri, S; Muscoli, C; Fini, M; Mollace, V

    2017-01-01

    Bergamot polyphenolic fraction (BPF) has been shown to positively modulate several mechanisms involved in metabolic syndrome, suggesting its use in therapy. In particular, it is able to induce a significant amelioration of serum lipid profile in hyperlipemic patients at different levels. The purpose of our study was to investigate the effect of BPF on cholesterol absorption physiologically mediated by pancreatic cholesterol ester hydrolase (pCEH). An in vitro activity assay was performed to study the effect of BPF on pCEH, whereas the rate of cholesterol absorption was evaluated through in vivo studies. In particular, male, Sprague-Dawley rats (200–225 g) were fed either normal chow or chow supplemented with 0.5% cholic acid, 5.5% peanut oil, and varying amounts of cholesterol (0 to 1.5%). BPF (10 mg/Kg) was daily administrated by means of a gastric gavage to animals fed with lipid supplemented diet for 4 weeks and, at the end of the study, plasma lipids and liver cholesteryl esters were measured in all experimental groups. Our results show that BPF was able to inhibit pCEH activity and this effect was confirmed, in vivo, via detection of lymphatic cholesteryl ester in rats fed with a cholesterol-rich diet. This evidence clarifies a further mechanism responsible for the hypolipemic properties of BPF previously observed in humans, confirming its beneficial effect in the therapy of hypercholesterolemia and in the treatment of metabolic syndrome.

  3. New entry for synthesis of N-acylhydrazones, pyridazinones, and 1,3,4-oxadiazin-6-ones from alpha-amino acid esters.

    Science.gov (United States)

    Yasui, Eiko; Wada, Masao; Takamura, Norio

    2007-11-01

    Versatile electrophiles N-acylhydrazones are synthesized via diazotization, reduction, and acylation of alpha-amino acid esters. Reduction of diazo esters with L-selectride or tributylphosphine affords the corresponding hydrazones in good yields. Both reducing agents give anti-hydrazones as the major product although the reactivity of each reductant is slightly different. The resulting hydrazones are acylated to give N-acylhydrazones, which are subjected to further reactions to give 1,3,4-oxadiazin-6-ones that serve as useful synthetic intermediates for the Diels-Alder reaction.

  4. An innovative method to selectively ablate cholesterol esters from an arteriosclerotic region of the arterial wall using a free-electron laser

    International Nuclear Information System (INIS)

    Awazu, K.; Nagai, A.; Tomimasu, T.; Aizawa, K.

    1998-01-01

    The selective removal of cholesterol esters accumulated in the intra-cellular or extra-cellular spaces has clinical significance. In the present work we investigate the removal of cholesterol esters by using a free electron laser (FEL) in an arteriosclerotic region. Thin films of cholesteryl oleate and albumin, and the cross-section of a rabbit artery were placed on an inverted microscope stage and the changes caused by the FEL irradiation of 5.75 and 6.1 μm with 1.5-3 mW in average were monitored continuously by a CCD camera in real time. FEL irradiation at a wavelength of 5.75 μm, which is a stretching vibrational mode of the ester, was able to ablate cholesterol esters without affecting albumin and that it can also remove cholesterol esters from rabbits' arteriosclerotic arterial walls. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  5. Substituted thiobenzoic acid S-benzyl esters as potential inhibitors of a snake venom phospholipase A2: Synthesis, spectroscopic and computational studies

    Science.gov (United States)

    Henao Castañeda, I. C.; Pereañez, J. A.; Jios, J. L.

    2012-11-01

    4-Chlorothiobenzoic acid S-benzyl ester (I), 3-nitrothiobenzoic acid S-benzyl ester (II), 4-nitrothiobenzoic acid S-benzyl ester (III) and 4-methylthiobenzoic acid S-benzyl ester (IV) were prepared and characterized by 1H and 13C NMR, Mass spectrometry and IR spectroscopy. Quantum chemical calculations were performed with Gaussian 09 to calculate the geometric parameters and vibrational spectra. Phospholipase A2 (PLA2) was purified from Crotalus durissus cumanensis venom by molecular exclusion chromatography, followed by reverse phase-high performance liquid chromatography. Two studies of the inhibition of phospholipase A2 activity were performed using phosphatidilcholine and 4-nitro-3-octanoyloxybenzoic acid as substrates, in both cases compound II showed the best inhibitory ability, with 74.89% and 69.91% of inhibition, respectively. Average percentage of inhibition was 52.49%. Molecular docking was carried out with Autodock Vina using as ligands the minimized structures of compounds (I-IV) and as protein PLA2 (PDB code 2QOG). The results suggest that compounds I-IV could interact with His48 at the active site of PLA2. In addition, all compounds showed Van der Waals interactions with residues from hydrophobic channel of the enzyme. This interaction would impede normal catalysis cycle of the PLA2.

  6. Enzymatically and reductively degradable α-amino acid-based poly(ester amide)s: Synthesis, cell compatibility, and intracellular anticancer drug delivery

    NARCIS (Netherlands)

    Sun, H.; Cheng, Ru; Deng, Chao; Meng, Fenghua; Dias, Aylvin A.; Hendriks, Marc; Feijen, Jan; Zhong, Zhiyuan

    2015-01-01

    A novel and versatile family of enzymatically and reductively degradable α-amino acid-based poly(ester amide)s (SS-PEAs) were developed from solution polycondensation of disulfide-containing di-p-toluenesulfonic acid salts of bis-l-phenylalanine diesters (SS-Phe-2TsOH) with di-p-nitrophenyl adipate

  7. Synthesis and application of a novel environmental C26 diglycidyl ester plasticizer based on castor oil for poly(vinyl chloride)

    Science.gov (United States)

    In this work, for the first time, a castor oil derived diglycidyl ester plasticizer (C26-DGE) was prepared and incorporated into poly(vinyl chloride) (PVC). The chemical structure of the product was characterized by Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (...

  8. CYP98A22, a phenolic ester 3’-hydroxylase specialized in the synthesis of chlorogenic acid, as a new tool for enhancing the furanocoumarin concentration in Ruta graveolens

    Directory of Open Access Journals (Sweden)

    Karamat Fazeelat

    2012-08-01

    Full Text Available Abstract Background Furanocoumarins are molecules with proven therapeutic properties and are produced in only a small number of medicinal plant species such as Ruta graveolens. In vivo, these molecules play a protective role against phytophageous insect attack. Furanocoumarins are members of the phenylpropanoids family, and their biosynthetic pathway is initiated from p-coumaroyl coA. The enzymes belonging to the CYP98A cytochrome P450 family have been widely described as being aromatic meta-hydroxylases of various substrates, such as p-coumaroyl ester derivatives, and are involved in the synthesis of coumarins such as scopoletin. In furanocoumarin-producing plants, these enzymes catalyze the step directly downstream of the junction with the furanocoumarin biosynthetic pathway and might indirectly impact their synthesis. Results In this work, we describe the cloning and functional characterization of the first CYP98A encoding gene isolated from R. graveolens. Using Nicotiana benthamiana as a heterologous expression system, we have demonstrated that this enzyme adds a 3-OH to p-coumaroyl ester derivatives but is more efficient to convert p-coumaroyl quinate into chlorogenic acid than to metabolize p-coumaroyl shikimate. Plants exposed to UV-B stress showed an enhanced expression level of the corresponding gene. The R. graveolens cyp98a22 open reading frame and the orthologous Arabidopsis thaliana cyp98a3 open reading frame were overexpressed in stable transgenic Ruta plants. Both plant series were analyzed for their production of scopoletin and furanocoumarin. A detailed analysis indicates that both genes enhance the production of furanocoumarins but that CYP98A22, unlike CYP98A3, doesn’t affect the synthesis of scopoletin. Conclusions The overexpression of CYP98A22 positively impacts the concentration of furanocoumarins in R. graveolens. This gene is therefore a valuable tool to engineer plants with improved therapeutical values that might

  9. Fatty acid methyl ester profiles of bat wing surface lipids.

    Science.gov (United States)

    Pannkuk, Evan L; Fuller, Nathan W; Moore, Patrick R; Gilmore, David F; Savary, Brett J; Risch, Thomas S

    2014-11-01

    Sebocytes are specialized epithelial cells that rupture to secrete sebaceous lipids (sebum) across the mammalian integument. Sebum protects the integument from UV radiation, and maintains host microbial communities among other functions. Native glandular sebum is composed primarily of triacylglycerides (TAG) and wax esters (WE). Upon secretion (mature sebum), these lipids combine with minor cellular membrane components comprising total surface lipids. TAG and WE are further cleaved to smaller molecules through oxidation or host enzymatic digestion, resulting in a complex mixture of glycerolipids (e.g., TAG), sterols, unesterified fatty acids (FFA), WE, cholesteryl esters, and squalene comprising surface lipid. We are interested if fatty acid methyl ester (FAME) profiling of bat surface lipid could predict species specificity to the cutaneous fungal disease, white nose syndrome (WNS). We collected sebaceous secretions from 13 bat spp. using Sebutape(®) and converted them to FAME with an acid catalyzed transesterification. We found that Sebutape(®) adhesive patches removed ~6× more total lipid than Sebutape(®) indicator strips. Juvenile eastern red bats (Lasiurus borealis) had significantly higher 18:1 than adults, but 14:0, 16:1, and 20:0 were higher in adults. FAME profiles among several bat species were similar. We concluded that bat surface lipid FAME profiling does not provide a robust model predicting species susceptibility to WNS. However, these results provide baseline data that can be used for lipid roles in future ecological studies, such as life history, diet, or migration.

  10. Receptor-mediated uptake of low density lipoprotein stimulates bile acid synthesis by cultured rat hepatocytes

    International Nuclear Information System (INIS)

    Junker, L.H.; Davis, R.A.

    1989-01-01

    The cellular mechanisms responsible for the lipoprotein-mediated stimulation of bile acid synthesis in cultured rat hepatocytes were investigated. Adding 280 micrograms/ml of cholesterol in the form of human or rat low density lipoprotein (LDL) to the culture medium increased bile acid synthesis by 1.8- and 1.6-fold, respectively. As a result of the uptake of LDL, the synthesis of [14C]cholesterol from [2-14C]acetate was decreased and cellular cholesteryl ester mass was increased. Further studies demonstrated that rat apoE-free LDL and apoE-rich high density lipoprotein (HDL) both stimulated bile acid synthesis 1.5-fold, as well as inhibited the formation of [14C]cholesterol from [2-14C]acetate. Reductive methylation of LDL blocked the inhibition of cholesterol synthesis, as well as the stimulation of bile acid synthesis, suggesting that these processes require receptor-mediated uptake. To identify the receptors responsible, competitive binding studies using 125I-labeled apoE-free LDL and 125I-labeled apoE-rich HDL were performed. Both apoE-free LDL and apoE-rich HDL displayed an equal ability to compete for binding of the other, suggesting that a receptor or a group of receptors that recognizes both apolipoproteins is involved. Additional studies show that hepatocytes from cholestyramine-treated rats displayed 2.2- and 3.4-fold increases in the binding of apoE-free LDL and apoE-rich HDL, respectively. These data show for the first time that receptor-mediated uptake of LDL by the liver is intimately linked to processes activating bile acid synthesis

  11. Lipase immobilization on hyper-cross-linked polymer-coated silica for biocatalytic synthesis of phytosterol esters with controllable fatty acid composition.

    Science.gov (United States)

    Zheng, Ming-Ming; Lu, Yong; Huang, Feng-Hong; Wang, Lian; Guo, Ping-Mei; Feng, Yu-Qi; Deng, Qian-Chun

    2013-01-09

    In this study, a novel mixed-mode composite material, SiO(2)@P(MAA-co-VBC-co-DVB), was prepared via the hyper-cross-linking of its precursor, which was produced via suspension polymerization in the presence of SiO(2) particles. Candida rugosa lipase (CRL) was immobilized on the SiO(2)@P(MAA-co-VBC-co-DVB) particles via hydrophobic and weak cation-exchange interaction. The resulting immobilized CRL showed much better thermal stability and reusability in comparison to free CRL. On the basis of the excellent biocatalyst prepared, a method for high-efficiency enzymatic esterification of phytosterols with different fatty acids to produce the corresponding phytosterol esters was developed. Six phytosterol esters with conversions above 92.1% and controllable fatty acid composition were obtained under the optimized conditions: 80 μmol/mL phytosterols, 160 μmol/mL linolenic acid, and 15 mg/mL CRL@HPCS at 300 rpm and 50 °C for 7 h in 30 mL of isooctane. The prepared phytosterol esters possessed a low acid value (≤0.86 mg of KOH/g), peroxide value (≤3.3 mequiv/kg), and conjugated diene value (≤1.74 mmol/kg) and high purity (≥97.8%) and fatty solubility (≥28.9 g/100 mL). All the characteristics favored the wide application of phytosterol esters with controllable fatty acid composition in different fields of functional food.

  12. Short-chain flavor ester synthesis in organic media by an E. coli whole-cell biocatalyst expressing a newly characterized heterologous lipase.

    Directory of Open Access Journals (Sweden)

    Guillaume Brault

    Full Text Available Short-chain aliphatic esters are small volatile molecules that produce fruity and pleasant aromas and flavors. Most of these esters are artificially produced or extracted from natural sources at high cost. It is, however, possible to 'naturally' produce these molecules using biocatalysts such as lipases and esterases. A gene coding for a newly uncovered lipase was isolated from a previous metagenomic study and cloned into E. coli BL21 (DE3 for overexpression using the pET16b plasmid. Using this recombinant strain as a whole-cell biocatalyst, short chain esters were efficiently synthesized by transesterification and esterification reactions in organic media. The recombinant lipase (LipIAF5-2 showed good affinity toward glyceryl trioctanoate and the highest conversion yields were obtained for the transesterification of glyceryl triacetate with methanol. Using a simple cetyl-trimethylammonium bromide pretreatment increased the synthetic activity by a six-fold factor and the whole-cell biocatalyst showed the highest activity at 40°C with a relatively high water content of 10% (w/w. The whole-cell biocatalyst showed excellent tolerance to alcohol and short-chain fatty acid denaturation. Substrate affinity was equally effective with all primary alcohols tested as acyl acceptors, with a slight preference for methanol. The best transesterification conversion of 50 mmol glyceryl triacetate into isoamyl acetate (banana fragrance provided near 100% yield after 24 hours using 10% biocatalyst loading (w/w in a fluidized bed reactor, allowing recycling of the biocatalyst up to five times. These results show promising potential for an industrial approach aimed at the biosynthesis of short-chain esters, namely for natural flavor and fragrance production in micro-aqueous media.

  13. Concerted actions of cholesteryl ester transfer protein and phospholipid transfer protein in type 2 diabetes : effects of apolipoproteins

    NARCIS (Netherlands)

    Dallinga-Thie, Geesje M.; Dullaart, Robin P. F.; van Tol, Arie

    Purpose of review Type 2 diabetes frequently coincides with dyslipidemia, characterized by elevated plasma triglycerides, low high-density lipoprotein cholesterol levels and the presence of small dense low-density lipoprotein particles. Plasma lipid transfer proteins play an essential role in

  14. Association of a cholesteryl ester transfer protein variant (rs1800777) with fat mass, HDL cholesterol levels, and metabolic syndrome.

    Science.gov (United States)

    de Luis, Daniel; Izaola, Olatz; Primo, David; Gomez, Emilia; Lopez, Juan Jose; Ortola, Ana; Aller, Rocio

    2018-04-25

    There is little evidence of the association between CETP SNPs and obesity and/or related metabolic parameters. To analyze the association of the polymorphism rs1800777 of the CETP gene with anthropometric parameters, lipid profile, metabolic syndrome and its components, and adipokine levels in obese subjects without type 2 diabetes mellitus or hypertension. A population of 1005 obese subjects was analyzed. Electrical bioimpedance was performed, and blood pressure, presence of metabolic syndrome, dietary intake, physical activity, and biochemical tests were recorded. Nine hundred and sixty eight patients (96.3%) had the GG genotype, 37 patients the GA genotype (3.7%) (no AA genotype was detected). Fat mass (delta: 4.4±1.1kg; p=0.04), waist circumference (delta: 5.6±2.1cm; p=0.02), and waist to hip ratio (delta: 0.04±0.01cm; p=0.01) were higher in A allele carriers than in non-A allele carriers. HDL cholesterol levels were lower in A allele carriers than in non-A allele carriers (delta: 4.2±1.0mg/dL; p=0.04). In the logistic regression analysis, the GA genotype was associated to an increased risk of central obesity (OR 7.55, 95% CI 1.10-55.70, p=0.02) and low HDL cholesterol levels (OR 2.46, 95% CI 1.23-4.91, p=0.014). The CETP variant at position +82 is associated to lower HDL cholesterol levels, increased fat mass, and central obesity in obese subjects. These results may suggest a potential role of this variant gene in pathophysiology of adipose tissue. Copyright © 2018 SEEN y SED. Publicado por Elsevier España, S.L.U. All rights reserved.

  15. In situ generation of nitrilium from nitrile ylide and the subsequent Mumm rearrangement: copper-catalyzed synthesis of unsymmetrical diacylglycine esters.

    Science.gov (United States)

    Chen, Jijun; Shao, Ying; Ma, Liang; Ma, Meihua; Wan, Xiaobing

    2016-12-07

    A novel in situ generation of nitrilium from a nitrile ylide and the subsequent Mumm rearrangement of carboxylic acid, nitrile, and diazo compounds gave various unsymmetrical diacylglycine esters in moderate to high yields. This copper-catalyzed cascade reaction enables one-pot generation of two C-N bonds, one C[double bond, length as m-dash]O bond, and one C-H bond, with nitrogen as the only byproduct. The reaction has a broad functional-group tolerance, is rapid, easily scales up to the 100 mmol scale, and is insensitive to air and moisture.

  16. Synthesis, Anti-HCV, Antioxidant and Reduction of Intracellular Reactive Oxygen Species Generation of a Chlorogenic Acid Analogue with an Amide Bond Replacing the Ester Bond.

    Science.gov (United States)

    Wang, Ling-Na; Wang, Wei; Hattori, Masao; Daneshtalab, Mohsen; Ma, Chao-Mei

    2016-06-08

    Chlorogenic acid is a well known natural product with important bioactivities. It contains an ester bond formed between the COOH of caffeic acid and the 3-OH of quinic acid. We synthesized a chlorogenic acid analogue, 3α-caffeoylquinic acid amide, using caffeic and quinic acids as starting materials. The caffeoylquinc acid amide was found to be much more stable than chlorogenic acid and showed anti-Hepatitis C virus (anti-HCV) activity with a potency similar to chlorogenic acid. The caffeoylquinc acid amide potently protected HepG2 cells against oxidative stress induced by tert-butyl hydroperoxide.

  17. Synthesis and characterization of a thermo-sensitive poly( N-methyl acryloylglycine methyl ester) used as a drug release carrier

    Science.gov (United States)

    Deng, Kui-Lin; Zhong, Hai-Bin; Jiao, Yi-Suo; Fan, Ting; Qiao, Xiao; Zhang, Peng-Fei; Ren, Xiao-Bo

    2010-06-01

    In this article, poly( N-methyl acryloylglycine methyl ester) (PNMAME) was prepared as a novel thermosensitive material with a lower critical solution temperature (LCST) at around 49.5°C. The chemical structures of the monomer NMAME and PNMAME were characterized by 1H NMR and IR measurements. The LCST was investigated systematically as a function of PNMAME concentration, inorganic salt solution and pH value. The results indicated that LCST of PNMAME was obviously dependent on PNMAME concentration and pH. The LCST was increased with a decrease in pH value and PNMAME concentration. To obtain a thermo-sensitive hydrogel with the phase transition temperature close to human body temperature, the copolymerization was conducted between NMAME and N-acryloylglycine ethyl ester (NAGEE). The release behavior of caffeine was evaluated at different temperatures and contents of cross-linkers ( N, N-methylenebis(acrylamide) (NMBA)). The increase of cross-linker content led to a decrease in the release rate of caffeine due to higher crossing density in the hydrogel network. In addition, a faster release of caffeine from the hydrogel with 3% NMBA at 37°C was found in contrast to that at 18°C.

  18. Rhodotorulaglutinis phenylalanine/tyrosine ammonia lyase enzyme catalyzed synthesis of the methyl ester of para-hydroxycinnamic acid and its potential antibacterial activity

    Directory of Open Access Journals (Sweden)

    Marybeth C MacDonald

    2016-03-01

    Full Text Available Biotransformation of L-tyrosine methyl ester (L-TM to the methyl ester of para- hydroxycinnamic acid (p-HCAM using Rhodotorula glutinis yeast phenylalanine/tyrosine ammonia lyase (PTAL; EC 4.3.1.26 enzyme was successfully demonstrated for the first time; progress of the reaction was followed by spectrophotometric determination at 315 nm. The following conditions were optimized for maximal formation of p-HCAM: pH (8.5, temperature (37 C, speed of agitation (50 rpm, enzyme concentration (0.080 µM, and substrate concentration (0.50 mM. Under these conditions, the yield of the reaction was ~15% in 1 h incubation period and ~63% after an overnight (~18 h incubation period. The product (p-HCAM of the reaction of PTAL with L-TM was confirmed using Nuclear Magnetic Resonance spectroscopy (NMR. Fourier Transform Infra-Red spectroscopy (FTIR was carried out to rule out potential hydrolysis of p-HCAM during overnight incubation. Potential antibacterial activity of p-HCAM was tested against several strains of Gram positive and Gram negative bacteria. This study describes a synthetically useful transformation, and could have future clinical and industrial applications.

  19. Radioiodinated fatty acid carnitine ester: synthesis and biodistribution of 15-(p-iodo[131I]-phenyl)pentadecanoyl-D,L-carnitine chloride

    International Nuclear Information System (INIS)

    Eisenhut, M.; Liefhold, J.

    1986-01-01

    After the uptake into heart muscle cells long chain fatty acids enter predominantly into the triglyceride and phospholipid pool before they are degraded in the mitochondria by β-oxidation. Therefore the formation of fatty acid esters with glycerine obscures the functional ability of the heart namely to catabolize free fatty acids. The sum of the two reaction pathways are visualized by sequential heart scintigraphy with e.g. 131 I labeled 15-(p-iodo-phenyl)-pentadecanoic acid (IPPA). Before the fatty acids can be degraded by β-oxidation they are bound to carnitine for mitochondrial membrane transport. Thus IPPA would not participate in lipid formation, if it is offered as 15-(p-iodo[ 131 I]-phenyl)-pentadecanoyl-D,L-carnitine chloride (IPPA-CE) to the heart muscle cells. Additionally carnitine esters of fatty acids are known to be better substrates for β-oxidation than free fatty acids. We were therefore interested in the biochemical fate of radioiodinated IPPA-CE in rats. (author)

  20. Synthesis of fatty acid methyl ester from palm oil (Elaeis guineensis) with Ky(MgCa)2xO3 as heterogeneous catalyst.

    Science.gov (United States)

    Olutoye, M A; Lee, S C; Hameed, B H

    2011-12-01

    Fatty acid methyl esters (FAME) were produced from palm oil using eggshell modified with magnesium and potassium nitrates to form a composite, low-cost heterogeneous catalyst for transesterification. The catalyst, prepared by the combination of impregnation/co-precipitation was calcined at 830 °C for 4 h. Transesterification was conducted at a constant temperature of 65 °C in a batch reactor. Design of experiment (DOE) was used to optimize the reaction parameters, and the conditions that gave highest yield of FAME (85.8%) was 5.35 wt.% catalyst loading at 4.5 h with 16:1 methanol/oil molar ratio. The results revealed that eggshell, a solid waste, can be utilized as low-cost catalyst after modification with magnesium and potassium nitrates for biodiesel production. Copyright © 2011 Elsevier Ltd. All rights reserved.

  1. Synthesis, characterization and thermal degradation of cross-linked polystyrene using the alkyne-functionalized esters as a cross-linker agent by click chemistry method

    Directory of Open Access Journals (Sweden)

    Hakan Akat

    2015-08-01

    Full Text Available AbstractIn this study, it has been demonstrated that cross-linked polystyrene (CPS was successfully prepared by using click chemistry. For this purpose, firstly, poly (styrene-co-4 chloromethylstyrene with 4-chloromethylstyrene was synthesized. Secondly, alkyne-functionalized esters (dipropargyl adipate, dipropargyl succinate were obtained using propargyl alcohol, adipoyl chloride and succinyl chloride. Azide-functionalized polystrene (PS-N3 and dipropargyl adipate (or dipropargyl succinate were reacted in N,N-dimethylformamide for 24 h at room temperature to give CPS. The synthesized polymer and compounds were characterized by nuclear magnetic resonance (1H-NMR, gel permeation chromatography (GPC, fourier transform infrared spectroscopy (FT-IR and thermogravimetric (TG/DTG analysis.. The surface properties were investigated by Scanning Electron Micrography (SEM.

  2. Internalization, lysosomal degradation and new synthesis of surface membrane CD4 in phorbol ester-activated T-lymphocytes and U-937 cells

    DEFF Research Database (Denmark)

    Petersen, C M; Christensen, E I; Andresen, B S

    1992-01-01

    degradation was low in resting cells. Endocytosis and/or degradation of anti-CD4 mAb was suppressed by H7, and by inhibitors of membrane traffic (Monensin) and lysosome function (methylamine, chloroquine). Immunocytochemistry localized CD4 to the surface of unstimulated T-cells. Upon PMA stimulation...... occasional labeling was seen in endosomes but whole cell CD4 decreased dramatically. However, methylamine-treated PMA blasts showed accumulation of CD4 in lysosomes and accordingly, pulse-chase experiments in biolabeled cell cultures suggested a manifest reduction of CD4 half-life in response to PMA. Despite...... in activated cells was further evidenced by metabolic labeling and Northern blot analysis demonstrating unaltered or slightly increased CD4 protein and mRNA levels resulting from PMA. Our findings demonstrate that phorbol esters downregulate the cellular CD4 pool by endocytosis and subsequent lysosomal...

  3. Synthesis and biological evaluation of 2-(phenyl-3H-benzo[d]imidazole-5-carboxylic acids and its methyl esters as potent anti-breast cancer agents

    Directory of Open Access Journals (Sweden)

    Chandrabose Karthikeyan

    2017-05-01

    Full Text Available A series of novel substituted 2-(phenyl-3H-benzo[d]imidazole-5-carboxylic acids (1a–1j and its methyl esters (2a–2f were synthesized and examined for their antiproliferative effects against three breast cancer cell lines (MDA-MB231, MDA-MB468 and MCF7 in vitro. Most of the compounds exhibited comparable or greater antiproliferative effects than the reference compound cisplatin. Compound 2e bearing 5-fluoro-2-hydroxyphenyl substituent was found to be the most active derivative of the series with GI50 values of 6.23, 4.09 and 0.18 μM against MDA-MB468, MDA-MB231 and MCF7 breast cancer cell lines, respectively. Our findings described here exemplify the usefulness of the title compounds as a lead for the development of more effective cancer therapeutics for the treatment of breast cancer.

  4. Ester Tuiksoo / Ester Tuiksoo ; interv. Piret Tali

    Index Scriptorium Estoniae

    Tuiksoo, Ester, 1965-

    2007-01-01

    Juhan Partsi valitsuse (05.04.2004-13.04.2005) ja Andrus Ansipi valitsuse (13.04.2005-) põllumajandusminister Ester Tuiksoo oma lapsepõlvest ja elukutsevalikust, poliitilise karjääri algusest ja erakonna valikust, ministritöö kogemustest, naistest poliitikas

  5. Effect of chlorpromazine on lipid metabolism in aortas from cholesterol-fed rabbits and normal rats, in vitro: inhibition of sterol esterification and modification of phospholipid synthesis

    International Nuclear Information System (INIS)

    Bell, F.P.

    1983-01-01

    Chlorpromazine (CPZ), a major tranquilizer, was found to be a potent inhibitor of acylCoA:cholesterol acyltransferase (ACAT, EC 2.3.1.26) in isolated arterial microsomes and in intact arterial tissue from the rat and cholesterol-fed rabbit in vitro. In isolated rabbit arterial microsomes, CPZ resulted in a concentration-dependent inhibition of ACAT with 50% inhibition of [1-14C]oleoylCoA incorporation into [14C]cholesteryl esters occurring at 0.1 mM CPZ. CPZ also effectively inhibited the incorporation of [14C]oleate into triglycerides without affecting incorporation into diglycerides. Additionally, CPZ altered the pattern of arterial phospholipids synthesized from [1-14C]oleate. Incorporation into phosphatidylcholine was depressed while incorporation into phosphatidylinositol was increased. Since diglyceride synthesis appeared to be unaffected by CPZ, a redirection of phosphatidic acid into the CDP-diglyceride pathway of glycerolipid synthesis does not adequately account for the effect of CPZ on arterial phospholipid and triglyceride synthesis in these experiments

  6. Toward the Elucidation of the Metabolism of 15-E2-Isoprostane: The Total Synthesis of the Methyl Ester of a Potential Central Metabolite

    Czech Academy of Sciences Publication Activity Database

    Jahn, Ullrich; Dinca, E.

    2010-01-01

    Roč. 75, č. 13 (2010), s. 4480-4491 ISSN 0022-3263 Grant - others:DFG(DE) Ja896/3-1 Institutional research plan: CEZ:AV0Z40550506 Keywords : isoprostane * total synthesis * radical anion cyclization Subject RIV: CC - Organic Chemistry Impact factor: 4.002, year: 2010

  7. Enzymatically and reductively degradable α-amino acid-based poly(ester amide)s: synthesis, cell compatibility, and intracellular anticancer drug delivery.

    Science.gov (United States)

    Sun, Huanli; Cheng, Ru; Deng, Chao; Meng, Fenghua; Dias, Aylvin A; Hendriks, Marc; Feijen, Jan; Zhong, Zhiyuan

    2015-02-09

    A novel and versatile family of enzymatically and reductively degradable α-amino acid-based poly(ester amide)s (SS-PEAs) were developed from solution polycondensation of disulfide-containing di-p-toluenesulfonic acid salts of bis-l-phenylalanine diesters (SS-Phe-2TsOH) with di-p-nitrophenyl adipate (NA) in N,N-dimethylformamide (DMF). SS-PEAs with Mn ranging from 16.6 to 23.6 kg/mol were obtained, depending on NA/SS-Phe-2TsOH molar ratios. The chemical structures of SS-PEAs were confirmed by (1)H NMR and FTIR spectra. Thermal analyses showed that the obtained SS-PEAs were amorphous with a glass transition temperature (Tg) in the range of 35.2-39.5 °C. The in vitro degradation studies of SS-PEA films revealed that SS-PEAs underwent surface erosion in the presence of 0.1 mg/mL α-chymotrypsin and bulk degradation under a reductive environment containing 10 mM dithiothreitol (DTT). The preliminary cell culture studies displayed that SS-PEA films could well support adhesion and proliferation of L929 fibroblast cells, indicating that SS-PEAs have excellent cell compatibility. The nanoparticles prepared from SS-PEA with PVA as a surfactant had an average size of 167 nm in phosphate buffer (PB, 10 mM, pH 7.4). SS-PEA nanoparticles while stable under physiological environment undergo rapid disintegration under an enzymatic or reductive condition. The in vitro drug release studies showed that DOX release was accelerated in the presence of 0.1 mg/mL α-chymotrypsin or 10 mM DTT. Confocal microscopy observation displayed that SS-PEA nanoparticles effectively transported DOX into both drug-sensitive and -resistant MCF-7 cells. MTT assays revealed that DOX-loaded SS-PEA nanoparticles had a high antitumor activity approaching that of free DOX in drug-sensitive MCF-7 cells, while more than 10 times higher than free DOX in drug-resistant MCF-7/ADR cells. These enzymatically and reductively degradable α-amino acid-based poly(ester amide)s have provided an appealing platform for

  8. Synthetic Methods for Ester Bond Formation and Conformational Analysis of Ester-Containing Carbohydrates

    Science.gov (United States)

    Hackbusch, Sven

    This dissertation encompasses work related to synthetic methods for the formation of ester linkages in organic compounds, as well as the investigation of the conformational influence of the ester functional group on the flexibility of inter-saccharide linkages, specifically, and the solution phase structure of ester-containing carbohydrate derivatives, in general. Stereoselective reactions are an important part of the field of asymmetric synthesis and an understanding of their underlying mechanistic principles is essential for rational method development. Here, the exploration of a diastereoselective O-acylation reaction on a trans-2-substituted cyclohexanol scaffold is presented, along with possible reasons for the observed reversal of stereoselectivity dependent on the presence or absence of an achiral amine catalyst. In particular, this work establishes a structure-activity relationship with regard to the trans-2-substituent and its role as a chiral auxiliary in the reversal of diastereoselectivity. In the second part, the synthesis of various ester-linked carbohydrate derivatives, and their conformational analysis is presented. Using multidimensional NMR experiments and computational methods, the compounds' solution-phase structures were established and the effect of the ester functional group on the molecules' flexibility and three-dimensional (3D) structure was investigated and compared to ether or glycosidic linkages. To aid in this, a novel Karplus equation for the C(sp2)OCH angle in ester-linked carbohydrates was developed on the basis of a model ester-linked carbohydrate. This equation describes the sinusoidal relationship between the C(sp2)OCH dihedral angle and the corresponding 3JCH coupling constant that can be determined from a J-HMBC NMR experiment. The insights from this research will be useful in describing the 3D structure of naturally occurring and lab-made ester-linked derivatives of carbohydrates, as well as guiding the de novo-design of

  9. Chromatographic, Spectrometric and NMR Characterization of a New Set of Glucuronic Acid Esters Synthesized by Lipase

    Directory of Open Access Journals (Sweden)

    Michel Marlier

    2007-01-01

    Full Text Available An enzymatic synthesis was developed on a new set of D-glucuronic acid esters and particularly the tetradecyl-D-glucopyranosiduronate also named tetradecyl D-glucuronate. Chromatographic analyses revealed the presence of the ester as a mixture of anomeric forms for carbon chain lengths superior to 12. TOF/MS and MS/MS studies confirmed the synthesis of glucuronic acid ester. The NMR study also confirmed the structure of glucuronic acid esters and clearly revealed an anomeric (α/β ratio equivalent to 3/2

  10. Synthesis and biological evaluation of N-(carbobenzyloxy)-l-phenylalanine and N-(carbobenzyloxy)-l-aspartic acid-β-benzyl ester derivatives as potent topoisomerase IIα inhibitors.

    Science.gov (United States)

    Han, Xiaoyan; Zhong, Yifan; Zhou, Guan; Qi, Hui; Li, Shengbin; Ding, Qiang; Liu, Zhenming; Song, Yali; Qiao, Xiaoqiang

    2017-06-15

    A new series of thirteen N-(carbobenzyloxy)-l-phenylalanine and N-(carbobenzyloxy)-l-aspartic acid-β-benzyl ester compounds were synthesized and evaluated for antiproliferative activity against four different human cancer cell lines: cervical cancer (HeLa), lung cancer (A549), gastric cancer (MGC-803) and breast cancer (MCF-7) as well as topoisomerase I and IIα inhibitory activity. Compounds (5a, 5b, 5e, 8a, 8b) showed significant antiproliferative activity with low IC 50 values against the four cancer cell lines. Equally, compounds 5a, 5b, 5e, 5f, 8a, 8d, 8e and 8f showed topoisomerase IIα inhibitory activity at 100μM with 5b, 5e, 8f exhibiting potential topoisomerase IIα inhibitory activity compared to positive control at 100μM and 20μM, respectively. Conversely compounds 5e, 5f, 5g and 8a showed weaker topoisomerase I inhibitory activity compared to positive control at 100μM. Compound 5b exhibited the most potent topoisomerase IIα inhibitory activity at low concentration and better antiproliferative activity against the four human cancer cell lines. The molecular interactions between compounds 5a-5g, 8a-8f and the topoisomerase IIα (PDB ID: 1ZXM) were further investigated through molecular docking. The results indicated that these compounds could serve as promising leads for further optimization as novel antitumor agents. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Design and synthesis of pH-sensitive polyamino-ester magneto-dendrimers: Surface functional groups effect on viability of human prostate carcinoma cell lines DU145.

    Science.gov (United States)

    Dayyani, Nahid; Khoee, Sepideh; Ramazani, Ali

    2015-06-15

    Novel pH-sensitive, biocompatible and biodegradable magneto-dendrimers with OH and/or NH2 functional groups based on poly amino-ester were synthesized for delivery of anti-cancer drugs. Magnetite nanoparticles (MNPs) were synthesized by the co-precipitation method and their surfaces were modified by 3-aminopropyl triethoxysilane. The first and second generations of the magneto-dendrimer with hydroxyl end groups were produced by sequential acrylation and Michael addition reactions using the required amounts of acryloyl chloride and diethanolamine, respectively. The dendrimer containing amino functional surface groups up to second generation was synthesized by the same method using the necessary amounts of acryloyl chloride and ethylenediamine. These dendrimers were fully characterized by the Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), dynamic light scattering (DLS) and zeta potential analysis, vibrating-sample magnetometer (VSM), scanning electron microscope (SEM), transmission electron microscopy (TEM) and selected area electron diffraction (SAED). In-vitro release profiles of the drug-loaded magnetic nanoparticles and their cytotoxicity assay were investigated at two pHs (7.4 and 5.8). The hydrolytic degradation behavior of magneto-dendrimers was evaluated in PBS buffer. Our research suggests that magneto-dendrimers having amine or hydroxyl functional groups could be considered as the suitable nanocarriers for therapy applications. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  12. Preparation of polyol esters based on vegetable and animal fats.

    Science.gov (United States)

    Gryglewicz, S; Piechocki, W; Gryglewicz, G

    2003-03-01

    The possibility of using some natural fats: rapeseed oil, olive oil and lard, as starting material for the preparation of neopentyl glycol (NPG) and trimethylol propane (TMP) esters is reported. The syntheses of final products were performed by alcoholysis of fatty acid methyl esters, obtained from natural fats studied, with the appropriate polyhydric alcohol using calcium methoxide as a catalyst. The basic physicochemical properties of the NPG and TMP esters synthesized were the following: viscosity at 40 degrees C in the range of 13.5-37.6 cSt, pour point between -10.5 and -17.5 degrees C and very high viscosity indices, higher than 200. Generally, the esters of neopentyl alcohols were characterized by higher stability in thermo-oxidative conditions in comparison to native triglycerides. Due to the low content of polyunsaturated acids, the olive oil based esters showed the highest thermo-oxidative resistance. Also, methyl esters of fatty acids of lard would constitute a good raw material for the synthesis of lubricating oils, provided that their saturated acids content was lowered. This permits synthesis of NPG and TMP esters with a lower pour point (below -10 degrees C) than natural lard (+33 degrees C).

  13. Synthesis of fatty acid methyl ester from the transesterification of high- and low-acid-content crude palm oil (Elaeis guineensis) and karanj oil (Pongamia pinnata) over a calcium-lanthanum-aluminum mixed-oxides catalyst.

    Science.gov (United States)

    Syamsuddin, Y; Murat, M N; Hameed, B H

    2016-08-01

    The synthesis of fatty acid methyl ester (FAME) from the high- and low-acid-content feedstock of crude palm oil (CPO) and karanj oil (KO) was conducted over CaO-La2O3-Al2O3 mixed-oxide catalyst. Various reaction parameters were investigated using a batch reactor to identify the best reaction condition that results in the highest FAME yield for each type of oil. The transesterification of CPO resulted in a 97.81% FAME yield with the process conditions of 170°C reaction temperature, 15:1 DMC-to-CPO molar ratio, 180min reaction time, and 10wt.% catalyst loading. The transesterification of KO resulted in a 96.77% FAME yield with the conditions of 150°C reaction temperature, 9:1 DMC-to-KO molar ratio, 180min reaction time, and 5wt.% catalyst loading. The properties of both products met the ASTM D6751 and EN 14214 standard requirements. The above results showed that the CaO-La2O3-Al2O3 mixed-oxide catalyst was suitable for high- and low-acid-content vegetable oil. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Fatty acid methyl ester synthesis catalyzed by solid superacid catalyst SO{sub 4}{sup 2-}/ZrO{sub 2}-TiO{sub 2}/La{sup 3+}

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yan; Zhang, Xiao-Dong; Sun, Li; Zhang, Jie; Xu, Hai-Peng [Energy Research Institute of Shandong Academy of Sciences, Jinan 250014 (China)

    2010-01-15

    A new type of solid superacid catalyst with the composition of SO{sub 4}{sup 2-}/ZrO{sub 2}-TiO{sub 2} loaded with lanthanum was prepared by precipitation and impregnation. The catalytic performance for the synthesis of fatty acid methyl ester from fatty acid and methanol was investigated. The influences of preparation conditions on catalyst performance were studied, the optimum results of which showed that amount of La(NO{sub 3}){sub 3} was 0.1 wt.%, the concentration of H{sub 2}SO{sub 4} for impregnation was 0.5 mol l{sup -1} and calcination temperature was 550 C. In addition, the effects of reaction parameters on esterification efficiency were also studied. With the catalyst amount of 5 wt.%, methanol amount of 1 ml/g fatty acid (FA) and reaction duration of 5 h at 60 C, the conversion ratio could reach above 95%. The catalyst recycled without any treatments could exhibit high activity with the conversion efficiency of above 90% after being reused five times. (author)

  15. Synthesis and characterisation of new types of side chain cholesteryl polymers.

    Science.gov (United States)

    Wang, Bin; Du, Haiyan; Zhang, Junhua

    2011-01-01

    A series of cholesterol derivatives have been synthesised via the alkylation reaction of the 3-hydroxyl group with the aliphatic bromide compounds with different chain lengths, namely 3β-alkyloxy-cholesterol. The double bond between the C5 and C6 positions in these cholesterol derivatives was oxidised into epoxy, followed by an epoxy-ring-opening reaction with the treatment with acrylic acid, resulting in a series of 3β-alkyloxy-5α-hydroxy-6β-acryloyloxycholesterol, C(n)OCh (n=1, 2, 4, 6, 8, 10, 12), The acrylate group is connected to the C6 position, which is confirmed by the single crystal structure analysis. The corresponding polymers, PC(n)OCh, were prepared via free radical polymerisation. The structure of monomers and the resulting polymers were characterised with nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FT-IR) and gel permeation chromatography (GPC). The thermal properties of PC(n)OCh were studied using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). To determine the secondary structure of polymers, circular dichroism (CD) spectra were performed. It was found that not all monomers produce high-molecular-weight polymers because of steric hindrance. However, all polymers have a helical structure, which can be enhanced by increasing the alkoxy chain length. In addition, increasing the alkoxy chain length decreases the glass transition temperature and increases the decomposition temperature of the polymers. Copyright © 2010 Elsevier Inc. All rights reserved.

  16. Enzymatic Synthesis of Glyserol-Coconut Oil Fatty Acid and Glycerol-Decanoic Acis Ester as Emulsifier and Antimicrobial Agents Using Candida rugosa Lipase EC 3.1.1.3

    Science.gov (United States)

    Handayani, Sri; Putri, Ayu Tanissa Tamara; Setiasih, Siswati; Hudiyono, Sumi

    2018-01-01

    In this research, enzymatic esterification was carried out between glycerol and fatty acid from coconut oil and decanoic acid using n-hexane as solvent. In this reaction Candida rugosa lipase was used as biocatalyst. Optimization esterification reaction was carried out for parameter of the substrate ratio. The mmol ratio between fatty acid and glycerol were used are 1:1, 1:2, 1:3, and 1: 4. The highest conversion percentage obtained at the mole ratio of 1: 4 with the value of 78.5% for the glycerol-decanoic acid ester and 55.4% for the glycerol coconut oil fatty acid ester. Esterification products were characterized by FT-IR. The FT-IR spectrum showed that the ester bond was formed as indicated by the wave number 1750-1739 cm-1. The esterification products were then examined by simple emulsion test and was proved to be an emulsifier. The glycerol-coconut oil fatty acid ester produced higher stability emulsion compare with glycerol decanoic ester. The antimicrobial activity assay using disc diffusion method showed that both glycerol-coconut oil fatty acid ester and glycerol-decanoic ester had the ability inhibiting the growth of Propionibacterium acnes and Staphylococcus epidermidis. Glycerol-decanoic ester shows higher antimicrobial activity than glycerol-coconut oil fatty acid ester.

  17. Potential Grape-Derived Contributions to Volatile Ester Concentrations in Wine

    OpenAIRE

    Boss, Paul; Pearce, Anthony; Zhao, Yanjia; Nicholson, Emily; Dennis, Eric; Jeffery, David

    2015-01-01

    Grape composition affects wine flavour and aroma not only through varietal compounds, but also by influencing the production of volatile compounds by yeast. C9 and C12 compounds that potentially influence ethyl ester synthesis during fermentation were studied using a model grape juice medium. It was shown that the addition of free fatty acids, their methyl esters or acyl-carnitine and acyl-amino acid conjugates can increase ethyl ester production in fermentations. The stimulation of ethyl est...

  18. A New Initiator Cholesteryl Chloroformate for Cupper-Based Atom Transfer Radical Polymerization of Methyl Methacrylate

    Institute of Scientific and Technical Information of China (English)

    曹健; 楚娟; 张可达

    2004-01-01

    The polymerization of metyl methacrylate (MMA) was studied in detail by use of CuCl/L as a catalyst and cholesteryl chloroformate (CC) as an initiator. It was found that the atom transfer radical polymerization of MMA could proceed when L equals to a multidentate aliphatic amine ligand, N,N,N',N",N"-penta(methyl acrylate)diethylenetriamine (MA5-DETA), and no polymerization was occurred while L=2,2'-bipyridine and 1,10-phenanthroline. The linear proportionality of the molecular weights to the conversions and straight lines observed in ln[M]0/[M] versus time plots indicated that the present polymerization system had the typical controlled polymerization characteristics.

  19. Are Polyphosphates or Phosphate Esters Prebiotic Reagents?

    Science.gov (United States)

    Keefe, Anthony D.; Miller, Stanley L.

    1995-01-01

    It is widely held that there was a phosphate compound in prebiotic chemistry that played the role of adenosine triphosphate and that the first living organisms had ribose-phosphate in the backbone of their genetic material. However, there are no known efficient prebiotic synthesis of high-energy phosphates or phosphate esters. We review the occurrence of phosphates in nature, the efficiency of the volcanic synthesis of P4O10, the efficiency of polyphosphate synthesis by heating phosphate minerals under geological conditions, and the use of high-energy organic compounds such as cyanamide or hydrogen cyanide. These are shown to be inefficient processes especially when the hydrolysis of the polyphosphates is taken into account. For example, if a whole atmosphere of methane or carbon monoxide were converted to cyanide which somehow synthesized polyphosphates quantitatively, the polyphosphate concentration in the ocean would still have been insignificant. We also attempted to find more efficient high-energy polymerizing agents by spark discharge syntheses, but without success. There may still be undiscovered robust prebiotic syntheses of polyphosphates, or mechanisms for concentrating them, but we conclude that phosphate esters may not have been constituents of the first genetic material. Phosphoanhydrides are also unlikely as prebiotic energy sources.

  20. Valyl benzyl ester chloride

    Directory of Open Access Journals (Sweden)

    Grzegorz Dutkiewicz

    2010-02-01

    Full Text Available In the title compound (systematic name: 1-benzyloxy-3-methyl-1-oxobutan-2-aminium chloride, C12H18NO2+·Cl−, the ester group is approximately planar, with a maximum deviation of 0.040 (2 Å from the least-squares plane, and makes a dihedral angle of 28.92 (16° with the phenyl ring. The crystal structure is organized by N—H...Cl hydrogen bonds which join the two components into a chain along the b axis. Pairs of chains arranged antiparallel are interconnected by further N—H...Cl hydrogen bonds, forming eight-membered rings. Similar packing modes have been observed in a number of amino acid ester halides with a short unit-cell parameter of ca 5.5 Å along the direction in which the chains run.

  1. Cholesteryl-coated carbonyl iron particles with improved anti-corrosion stability and their viscoelastic behaviour under magnetic field

    Czech Academy of Sciences Publication Activity Database

    Mrlik, M.; Ilčíková, M.; Sedlačík, M.; Mosnáček, J.; Peer, Petra; Filip, Petr

    2014-01-01

    Roč. 292, č. 9 (2014), s. 2137-2143 ISSN 0303-402X R&D Projects: GA ČR(CZ) GP14-32114P Grant - others:GA MŠk(CZ) ED2.1.00/03.0111 Institutional support: RVO:67985874 Keywords : carbonyl iron * cholesteryl chloroformate * silicone oil suspensions * viscoelasticity * magnetorheology Subject RIV: BK - Fluid Dynamics Impact factor: 1.865, year: 2014

  2. Improved thermooxidation and sedimentation stability of covalently-coated carbonyl iron particles with cholesteryl groups and their influence on magnetorheology

    Czech Academy of Sciences Publication Activity Database

    Mrlík, M.; Ilčíková, M.; Pavlínek, V.; Mosnáček, J.; Peer, Petra; Filip, Petr

    2013-01-01

    Roč. 396, april (2013), s. 146-151 ISSN 0021-9797 R&D Projects: GA ČR GA202/09/1626 Grant - others:GA MŠk(CZ) ED2.1.00/03.0111 Institutional support: RVO:67985874 Keywords : covalent coating * carbonyl iron * cholesteryl chloroformate * thermooxidation * Magnetorheology Subject RIV: BK - Fluid Dynamics Impact factor: 3.552, year: 2013

  3. Effect of apolipoprotein E-free high density lipoproteins on cholesterol metabolism in cultured pig hepatocytes

    International Nuclear Information System (INIS)

    Bachorik, P.S.; Virgil, D.G.; Kwiterovich, P.O. Jr.

    1987-01-01

    We studied cholesterol synthesis from [ 14 C]acetate, cholesterol esterification from [ 14 C]oleate, and cellular cholesterol and cholesteryl ester levels after incubating cells with apoE-free high density lipoproteins (HDL) or low density lipoproteins (LDL). LDL suppressed synthesis by up to 60%, stimulated esterification by up to 280%, and increased cell cholesteryl ester content about 4-fold. Esterification increased within 2 h, but synthesis was not suppressed until after 6 h. ApoE-free HDL suppressed esterification by about 50% within 2 h. Cholesterol synthesis was changed very little within 6 h, unless esterification was maximally suppressed; synthesis was then stimulated about 4-fold. HDL lowered cellular unesterified cholesterol by 13-20% within 2 h and promoted the removal of newly synthesized cholesterol and cholesteryl esters. These changes were transient; by 24 h, both esterification and cellular unesterified cholesterol returned to control levels, and cholesteryl esters increased 2-3-fold. HDL core lipid was taken up selectively from 125 I-labeled [ 3 H]cholesteryl ester- and ether-labeled HDL. LDL core lipid uptake was proportional to LDL apoprotein uptake. The findings suggest that 1) the cells respond initially to HDL or LDL with changes in esterification, and 2) HDL mediates both the removal of free cholesterol from the cell and the delivery of HDL cholesteryl esters to the cell

  4. Apomorphine and its esters

    DEFF Research Database (Denmark)

    Borkar, Nrupa; Chen, Zhizhong; Saaby, Lasse

    2016-01-01

    Oral delivery of apomorphine via prodrug principle may be a potential treatment for Parkinson's disease. The purpose of this study was to investigate the transport and stability of apomorphine and its esters across Caco-2 cell monolayer and their affinity towards chylomicrons. Apomorphine......, monolauroyl apomorphine (MLA) and dilauroyl apomorphine (DLA) were subjected to apical to basolateral (A-B) and basolateral to apical (B-A) transport across Caco-2 cell monolayer. The stability of these compounds was also assessed by incubation at intestinal pH and physiological pH with and without Caco-2...

  5. Esters with water esters 2-c to 6-c

    CERN Document Server

    Getzen, F W; Hefter, G T; Maczynski, Andrzej

    1992-01-01

    This volume is the first of two devoted to esters and water. It includes solubility data for binary systems containing an ester and water up to the end of 1988. The critical evaluations were all prepared by one author and an introductory section has been included to elaborate the philosophy and methodology followed in the evaluations.

  6. Synthesis, Characterization and Biocompatibility of Biodegradable Elastomeric Poly(ether-ester urethane)s Based on Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) and Poly(ethylene glycol) via Melting Polymerization

    DEFF Research Database (Denmark)

    Li, Zibiao; Yang, Xiaodi; Wu, Linping

    2009-01-01

    Poly(ether-ester urethane)s (PUs) multiblock co-polymers were synthesized from telechelic hydroxylated poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) and poly(ethylene glycol) (PEG) via a melting polymerization (MP) process using 1,6-hexamethylene diisocyanate (HDI) as a non-toxic couplin...

  7. Effects of protein kinase C activators on phorbol ester-sensitive and -resistant EL4 thymoma cells.

    Science.gov (United States)

    Sansbury, H M; Wisehart-Johnson, A E; Qi, C; Fulwood, S; Meier, K E

    1997-09-01

    Phorbol ester-sensitive EL4 murine thymoma cells respond to phorbol 12-myristate 13-acetate with activation of ERK mitogen-activated protein kinases, synthesis of interleukin-2, and death, whereas phorbol ester-resistant variants of this cell line do not exhibit these responses. Additional aspects of the resistant phenotype were examined, using a newly-established resistant cell line. Phorbol ester induced morphological changes, ERK activation, calcium-dependent activation of the c-Jun N-terminal kinase (JNK), interleukin-2 synthesis, and growth inhibition in sensitive but not resistant cells. A series of protein kinase C activators caused membrane translocation of protein kinase C's (PKCs) alpha, eta, and theta in both cell lines. While PKC eta was expressed at higher levels in sensitive than in resistant cells, overexpression of PKC eta did not restore phorbol ester-induced ERK activation to resistant cells. In sensitive cells, PKC activators had similar effects on cell viability and ERK activation, but differed in their abilities to induce JNK activation and interleukin-2 synthesis. PD 098059, an inhibitor of the mitogen activated protein (MAP)/ERK kinase kinase MEK, partially inhibited ERK activation and completely blocked phorbol ester-induced cell death in sensitive cells. Thus MEK and/or ERK activation, but not JNK activation or interleukin-2 synthesis, appears to be required for phorbol ester-induced toxicity. Alterations in phorbol ester response pathways, rather than altered expression of PKC isoforms, appear to confer phorbol ester resistance to EL4 cells.

  8. Phthalate esters in marine algae

    OpenAIRE

    Gezgin, Tuncay; Güven, Kasim Cemal; Akçin, Göksel

    2001-01-01

    Abstract o-Phthalate esters as diethyl phthalate, dibutyl phthalate, di-isobutyl phthalate and diethylhexyl phthalate were identified at surface and inner part of algae collected in the Bosphorus, as Ulva lactuca, Enteromorpha linza, Cystoseria barbata, Pterocladia capillaceaeand Ceramium rubrum. The same esters were also detected in seawater samples taken from the same area. Thus parallelism in pollution was noted between the algae and the surrounding seawater,

  9. Increased plant sterol and stanol levels in brain of Watanabe rabbits fed rapeseed oil derived plant sterol or stanol esters

    DEFF Research Database (Denmark)

    Fricke, Christiane B.; Schrøder, Malene; Poulsen, Morten

    2007-01-01

    . Cholesterol synthesis in brain, indicated by lathosterol, a local surrogate cholesterol synthesis marker, does not seem to be affected by plant sterol or stanol ester feeding. We conclude that high dose intake of plant sterol and stanol esters in Watanabe rabbits results in elevated concentrations...... of these components not only in the periphery but also in the central nervous system....... of these components in brain tissue of homozygous and heterozygous Watanabe rabbits, an animal model for familial hypercholesterolemia. Homozygous animals received either a standard diet, RSO stanol or RSO sterol ester while heterozygous animals were additionally fed with 2 g cholesterol/kg to the respective diet...

  10. Potential Grape-Derived Contributions to Volatile Ester Concentrations in Wine

    Directory of Open Access Journals (Sweden)

    Paul K. Boss

    2015-04-01

    Full Text Available Grape composition affects wine flavour and aroma not only through varietal compounds, but also by influencing the production of volatile compounds by yeast. C9 and C12 compounds that potentially influence ethyl ester synthesis during fermentation were studied using a model grape juice medium. It was shown that the addition of free fatty acids, their methyl esters or acyl-carnitine and acyl-amino acid conjugates can increase ethyl ester production in fermentations. The stimulation of ethyl ester production above that of the control was apparent when lower concentrations of the C9 compounds were added to the model musts compared to the C12 compounds. Four amino acids, which are involved in CoA biosynthesis, were also added to model grape juice medium in the absence of pantothenate to test their ability to influence ethyl and acetate ester production. β-Alanine was the only one shown to increase the production of ethyl esters, free fatty acids and acetate esters. The addition of 1 mg∙L−1 β-alanine was enough to stimulate production of these compounds and addition of up to 100 mg∙L−1 β-alanine had no greater effect. The endogenous concentrations of β-alanine in fifty Cabernet Sauvignon grape samples exceeded the 1 mg∙L−1 required for the stimulatory effect on ethyl and acetate ester production observed in this study.

  11. Potential grape-derived contributions to volatile ester concentrations in wine.

    Science.gov (United States)

    Boss, Paul K; Pearce, Anthony D; Zhao, Yanjia; Nicholson, Emily L; Dennis, Eric G; Jeffery, David W

    2015-04-29

    Grape composition affects wine flavour and aroma not only through varietal compounds, but also by influencing the production of volatile compounds by yeast. C9 and C12 compounds that potentially influence ethyl ester synthesis during fermentation were studied using a model grape juice medium. It was shown that the addition of free fatty acids, their methyl esters or acyl-carnitine and acyl-amino acid conjugates can increase ethyl ester production in fermentations. The stimulation of ethyl ester production above that of the control was apparent when lower concentrations of the C9 compounds were added to the model musts compared to the C12 compounds. Four amino acids, which are involved in CoA biosynthesis, were also added to model grape juice medium in the absence of pantothenate to test their ability to influence ethyl and acetate ester production. β-Alanine was the only one shown to increase the production of ethyl esters, free fatty acids and acetate esters. The addition of 1 mg∙L(-1) β-alanine was enough to stimulate production of these compounds and addition of up to 100 mg∙L(-1) β-alanine had no greater effect. The endogenous concentrations of β-alanine in fifty Cabernet Sauvignon grape samples exceeded the 1 mg∙L(-1) required for the stimulatory effect on ethyl and acetate ester production observed in this study.

  12. One-pot synthesis of hybrid gel by use of tributylstannyl ester of polymeric silicic acid, chlorosilane and organic monomer; Keisan no toribuchiru sutanniru esuteru kobuntai, kuroroshiran oyobi yuki monoma wo mochiita haiburiddo geru no ichidankai gosei

    Energy Technology Data Exchange (ETDEWEB)

    Moriya, O. [National Defense Academy, Kanagawa (Japan). Dept. of Chemistry; Sugisaki, T. [Lintec Co. Ltd., Saitama (Japan); Tomono, M.; Oikawa, M.; Kageyama, T. [Kanto-Gakuin Univ., Kanagawa (Japan)

    1999-12-10

    Organic-inorganic hybrid gels were obtained efficiently by one-pot procedure from tributylstannyl ester of polymeric silicic acid (PTBS), chloro (3-methacryloyloxypropyl) dimethylsilane (1a), and common monomers such as styrene, acrylonitrile, and methyl methacrylate. In the reaction system, substitution of tributylstannyl groups of PTBS by silyl groups of 1a and copolymerization of methacryloyloxy group of 1a with a monomer proceeded simultaneously under UV irradiation at room temperature. The resulting gel should be consisted of covalently bonded three components an regarded as a nanocomposite material The use of another chlorosilane 1b, which had cyanopropyl group, with 1a led to formation of a multifunctional hybrid gel. (author)

  13. Rigid Dipeptide Mimics: Synthesis of Enantiopure 5- and 7-Benzyl and 5,7-Dibenzyl Indolizidinone Amino Acids via Enolization and Alkylation of delta-Oxo alpha,omega-Di-[N-(9-(9-phenylfluorenyl))amino]azelate Esters.

    Science.gov (United States)

    Polyak, Felix; Lubell, William D.

    1998-08-21

    Azabicyclo[X.Y.0]alkane amino acids are tools for constructing mimics of peptide structure and templates for generating combinatorial libraries for drug discovery. Our methodology for synthesizing these conformationally rigid dipeptides has been elaborated such that alkyl groups can be appended onto the heterocycle to generate mimics of peptide backbone and side-chain structure. Inexpensive glutamic acid was employed as chiral educt in a Claisen condensation/ketone alkylation/reductive amination/lactam cyclization sequence that furnished alkyl-branched azabicyclo[4.3.0]alkane amino acid. Enantiopure 5-benzyl-, 7-benzyl-, and 5,7-dibenzylindolizidinone amino acids 2-4 were stereoselectively synthesized via efficient reaction sequences featuring the alkylation of di-tert-butyl alpha,omega-di-[N-(PhF)amino]azelate delta-ketone 5. A variety of alkyl halides were readily added to the enolate of ketone 5 to provide mono- and dialkylated ketones 6 and 7. Hydride additions to 6 and 7, methanesulfonations, and intramolecular S(N)2 displacements by the PhF amine gave 5-alkylprolines that were converted by lactam cyclizations into 7- and 5-benzyl-, as well as 5,7-dibenzyl-2-oxo-3-N-(BOC)amino-1-azabicyclo[4.3.0]nonane-9-carboxylate methyl esters 10, 11, and 14. Epimerization of the alkyl-branched stereocenter via an iminium-enaminium equilibrium proved effective for controlling diastereoselectivity in reductive aminations with 6 and 7 in order to furnish 5-alkylprolines that were similarly converted to 7- benzyl- and 5,7-dibenzylindolizidinone N-(BOC)amino esters 10 and 14. Ester hydrolysis with hydroxide ion and potassium trimethylsilanolate then gave enantiopure indolizidinone amino acids 2-4. Epimerization at C-9 of benzylindolizidinone amino esters was also used to provide alternative diastereomers of 10, 11, and 14. This practical methodology for introducing side-chain groups onto the heterocycle with regioselective and diastereoselective control is designed to enhance

  14. Inhibition of Mevalonate Pathway and Synthesis of the Storage Lipids in Human Liver-Derived and Non-liver Cell Lines by Lippia alba Essential Oils.

    Science.gov (United States)

    Montero-Villegas, Sandra; Polo, Mónica; Galle, Marianela; Rodenak-Kladniew, Boris; Castro, María; Ves-Losada, Ana; Crespo, Rosana; García de Bravo, Margarita

    2017-01-01

    The essential oils (EOs) of Lippia alba, an herb extensively used as a folk medicine in Latin America, are today promoted as an effective means of eliminating problems caused by hyperlipemia. We hypothesized that L.alba EOs inhibited cholesterol and triacylglycerols synthesis and decreased the intracellular depots of those lipids (lipid droplets), mechanisms involving the induction of a hypolipidemic response. Our aim was, therefore, to evaluate the hypolipogenic capability of the EOs of four L. alba chemotypes on liver-derived (HepG2) and non-liver (A549) human cell lines and to identify the potential biochemical targets of those chemotypes, particularly within the mevalonate pathway (MP). [ 14 C]Acetate was used as radioactive precursor for assays. Lipid analyses were performed by thin-layer and capillary gas chromatography, lipid droplets analyzed by fluorescence microscopy, and HMGCR levels determined by Western blot. In both cell lines, all four chemotypes exerted hypocholesterogenic effects within a concentration range of 3.2-32 µg/mL. Nonsaponifiable lipids manifested a decrease in incorporation of [ 14 C]acetate into squalene, lanosterol, lathosterol, and cholesterol, but not into ubiquinone, thus suggesting an inhibition of enzymes in the MP downstream from farnesyl pyrophosphate. The tagetenone chemotype, the most efficacious hypocholesterogenic L. alba EO, lowered HMGCR protein levels; inhibited triacylglycerols, cholesteryl esters, and phospholipids synthesis; and diminished lipid droplets in size and volume. These results revealed that L. alba EOs inhibited different lipogenic pathways and such lipid-lowering effects could prove essential to prevent cardiovascular diseases.

  15. Environmental effect of rapeseed oil ethyl ester

    International Nuclear Information System (INIS)

    Makareviciene, V.; Janulis, P.

    2003-01-01

    Exhaust emission tests were conducted on rapeseed oil methyl ester (RME), rapeseed oil ethyl ester (REE) and fossil diesel fuel as well as on their mixtures. Results showed that when considering emissions of nitrogen oxides (NO x ), carbon monoxide (CO) and smoke density, rapeseed oil ethyl ester had less negative effect on the environment in comparison with that of rapeseed oil methyl ester. When fuelled with rapeseed oil ethyl ester, the emissions of NO x showed an increase of 8.3% over those of fossil diesel fuel. When operated on 25-50% bio-ester mixed with fossil diesel fuel, NO x emissions marginally decreased. When fuelled with pure rapeseed oil ethyl ester, HC emissions decreased by 53%, CO emissions by 7.2% and smoke density 72.6% when compared with emissions when fossil diesel fuel was used. Carbon dioxide (CO 2 ) emissions, which cause greenhouse effect, decreased by 782.87 g/kWh when rapeseed oil ethyl ester was used and by 782.26 g/kWh when rapeseed oil methyl ester was used instead of fossil diesel fuel. Rapeseed oil ethyl ester was more rapidly biodegradable in aqua environment when compared with rapeseed oil methyl ester and especially with fossil diesel fuel. During a standard 21 day period, 97.7% of rapeseed oil methyl ester, 98% of rapeseed oil ethyl ester and only 61.3% of fossil diesel fuel were biologically decomposed. (author)

  16. Avocado and olive oil methyl esters

    International Nuclear Information System (INIS)

    Knothe, Gerhard

    2013-01-01

    Biodiesel, the mono-alkyl esters of vegetable oils, animal fats or other triacylglycerol-containing materials and an alternative to conventional petroleum-based diesel fuel, has been derived from a variety of feedstocks. Numerous feedstocks have been investigated as potential biodiesel sources, including commodity oils, however, the methyl esters of avocado and olive oil would likely be suitable as biodiesel fuel. In order to expand the database and comprehensive evaluation of the properties of vegetable oil esters, in this work the fuel-related properties of avocado and olive oil methyl esters, which exhibit similar fatty acid profiles including high oleic acid content, are determined. The cetane numbers of avocado oil methyl esters and olive oil methyl esters are relatively high, determined as 59.2 and 62.5, respectively, due to their elevated content of methyl oleate. Other properties are well within the ranges specified in biodiesel standards. The cloud points of both esters are slightly above 0 °C due to their content of saturated esters, especially methyl palmitate. Overall, avocado and olive oil yield methyl esters with fuel properties comparable to methyl esters from other commodity vegetable oils. The 1 H and 13 C NMR spectra of avocado and olive oil methyl esters are reported. -- Highlights: • Methyl esters of avocado and olive oil meet biodiesel fuel standards. • Provides comparison for methyl esters of other vegetable oils with high oleic content. • Discusses and compares present results with prior literature

  17. Liquid Crystalline Thermosets from Ester, Ester-imide, and Ester-amide Oligomers

    Science.gov (United States)

    Dingemans, Theodorus J. (Inventor); Weiser, Erik S. (Inventor); St. Clair, Terry L. (Inventor)

    2009-01-01

    Main chain thermotropic liquid crystal esters, ester-imides, and ester-amides were prepared from AA, BB, and AB type monomeric materials and end-capped with phenylacetylene, phenylmaleimide, or nadimide reactive end-groups. The end-capped liquid crystal oligomers are thermotropic and have, preferably, molecular weights in the range of approximately 1000-15,000 grams per mole. The end-capped liquid crystaloligomers have broad liquid crystalline melting ranges and exhibit high melt stability and very low melt viscosities at accessible temperatures. The end-capped liquid crystal oli-gomers are stable forup to an hour in the melt phase. They are highly processable by a variety of melt process shape forming and blending techniques. Once processed and shaped, the end-capped liquid crystal oigomers were heated to further polymerize and form liquid crystalline thermosets (LCT). The fully cured products are rubbers above their glass transition temperatures.

  18. Mechanical properties and chemical stability of pivalolactone-based poly(ether ester)s

    NARCIS (Netherlands)

    Tijsma, E.J.; Tijsma, E.J.; van der Does, L.; Bantjes, A.; Bantjes, A.; Vulic, I.

    1994-01-01

    The processing, mechanical and chemical properties of poly(ether ester)s, prepared from pivalolactone (PVL), 1,4-butanediol (4G) and dimethyl terephthalate (DMT), were studied. The poly(ether ester)s could easily be processed by injection moulding, owing to their favourable rheological and thermal

  19. REPRODUCTIVE TOXICITY OF PHTHALATE ESTERS

    Science.gov (United States)

    Phthalate esters display several modes of toxicity in mammalian species. In the rat, in utero exposure at relatively low dosage levels disrupts development of the reproductive system of the male rat by altering fetal testis hormone production. This presentation is a review of t...

  20. First total synthesis of Boehmenan

    Indian Academy of Sciences (India)

    The first total synthesis of dilignan Boehmenan has been achieved. A biomimetic oxidative coupling of the ferulic acid methyl ester in the presence of silver oxide is the crucial step in the synthesis sequence, generating the dihydrobenzofuran skeleton. Hydroxyl group was protected with DHP and reducted with LiAlH4 to ...

  1. Microwave-assisted cyclizations promoted by polyphosphoric acid esters: a general method for 1-aryl-2-iminoazacycloalkanes

    Directory of Open Access Journals (Sweden)

    Jimena E. Díaz

    2016-09-01

    Full Text Available The first general procedure for the synthesis of 5 to 7-membered 1-aryl-2-iminoazacycloalkanes is presented, by microwave-assisted ring closure of ω-arylaminonitriles promoted by polyphosphoric acid (PPA esters. 1-Aryl-2-iminopyrrolidines were easily prepared from the acyclic precursors employing a chloroformic solution of ethyl polyphosphate (PPE. The use of trimethylsilyl polyphosphate (PPSE in solvent-free conditions allowed for the synthesis of 1-aryl-2-iminopiperidines and hitherto unreported 1-aryl-2-iminoazepanes. The cyclization reaction involves good to high yields and short reaction times, and represents a novel application of PPA esters in heterocyclic synthesis.

  2. Unsaturated Fatty Acid Esters Metathesis Catalyzed by Silica Supported WMe5

    KAUST Repository

    Riache, Nassima

    2015-11-14

    Metathesis of unsaturated fatty acid esters (FAEs) by silica supported multifunctional W-based catalyst is disclosed. This transformation represents a novel route towards unsaturated di-esters. Especially, the self-metathesis of ethyl undecylenate results almost exclusively on the homo-coupling product whereas with such catalyst, 1-decene gives ISOMET (isomerization and metathesis olefin) products. The olefin metathesis in the presence of esters is very selective without any secondary cross-metathesis products demonstrating that a high selective olefin metathesis could operate at 150 °C. Additionally, a cross-metathesis of unsaturated FAEs and α-olefins allowed the synthesis of the corresponding ester with longer hydrocarbon skeleton without isomerisation.

  3. N-Acetyl-D- and L-esters of 5'-AMP hydrolyze at different rates

    Science.gov (United States)

    Wickramasinghe, N. S.; Lacey, J. C. Jr; Lacey JC, J. r. (Principal Investigator)

    1993-01-01

    Studies of the properties of aminoacyl derivatives of 5'-AMP are aimed at understanding the origin of the process of protein synthesis. Aminoacyl (2',3') esters of 5'-AMP can serve as models of the 3'-terminus of aminoacyl tRNA. We report here on the relative rates of hydrolysis of Ac-D- and L-Phe AMP esters as a function of pH. At all pHs above 3, the rate constant of hydrolysis of the Ac-L-Phe ester is 1.7 to 2.1 times that of Ac-D-Phe ester. The D-isomer seems partially protected from hydrolysis by a stronger association with the adenine ring of the 5'-AMP.

  4. Catalytic Ester to Stannane Functional Group Interconversion via Decarbonylative Cross-Coupling of Methyl Esters

    KAUST Repository

    Yue, Huifeng

    2018-01-03

    An unprecedented conversion of methyl esters to stannanes was realized, providing access to a series of arylstannanes via nickel catalysis. Various common esters including ethyl, cyclohexyl, benzyl, and phenyl esters can undergo the newly developed decarbonylative stannylation reaction. The reaction shows broad substrate scope, can differentiate between different types of esters, and if applied in consecutive fashion, allows the transformation of methyl esters into aryl fluorides or biaryls via fluororination or arylation.

  5. Catalytic Ester to Stannane Functional Group Interconversion via Decarbonylative Cross-Coupling of Methyl Esters

    KAUST Repository

    Yue, Huifeng; Zhu, Chen; Rueping, Magnus

    2018-01-01

    An unprecedented conversion of methyl esters to stannanes was realized, providing access to a series of arylstannanes via nickel catalysis. Various common esters including ethyl, cyclohexyl, benzyl, and phenyl esters can undergo the newly developed decarbonylative stannylation reaction. The reaction shows broad substrate scope, can differentiate between different types of esters, and if applied in consecutive fashion, allows the transformation of methyl esters into aryl fluorides or biaryls via fluororination or arylation.

  6. Synthesis, Characterization, and Cytotoxicity of a Novel Gold(III Complex with O,O′-Diethyl Ester of Ethylenediamine-N,N′-Di-2-(4-MethylPentanoic Acid

    Directory of Open Access Journals (Sweden)

    Nebojša Pantelić

    2016-09-01

    Full Text Available A novel gold(III complex, [AuCl2{(S,S-Et2eddl}]PF6, ((S,S-Et2eddl = O,O′-diethyl ester of ethylenediamine-N,N′-di-2-(4-methylpentanoic acid was synthesized and characterized by IR, 1D (1H and 13C, and 2D (H,H-COSY and H,H-NOESY NMR spectroscopy, mass spectrometry, and elemental analysis. Density functional theory calculations confirmed that (R,R-N,N′ diastereoisomer was energetically the most stable isomer. In vitro antitumor action of ligand precursor [(S,S-H2Et2eddl]Cl2 and corresponding gold(III complex was determined against tumor cell lines: human adenocarcinoma (HeLa, human colon carcinoma (LS174, human breast cancer (MCF7, non-small cell lung carcinoma cell line (A549, and non-cancerous cell line human embryonic lung fibroblast (MRC-5 using microculture tetrazolium test (MTT assay. The results indicate that both ligand precursor and gold(III complex have showed very good to moderate cytotoxic activity against all tested malignant cell lines. The highest activity was expressed by [AuCl2{(S,S-Et2eddl}]PF6 against the LS174 cells, with IC50 value of 7.4 ± 1.2 µM.

  7. Lupeol and its esters: NMR, powder XRD data and in vitro evaluation of cancer cell growth

    Directory of Open Access Journals (Sweden)

    Aline Teixeira Maciel e Silva

    2018-02-01

    Full Text Available ABSTRACT The triterpene lupeol (1 and some of its esters are secondary metabolites produced by species of Celastraceae family, which have being associated with cytotoxic activity. We report herein the isolation of 1, the semi-synthesis of eight lupeol esters and the evaluation of their in vitro activity against nine strains of cancer cells. The reaction of carboxylic acids with 1 and DIC/DMAP was used to obtain lupeol stearate (2, lupeol palmitate (3 lupeol miristate (4, and the new esters lupeol laurate (5, lupeol caprate (6, lupeol caprilate (7, lupeol caproate (8 and lupeol 3’,4’-dimethoxybenzoate (9, with high yields. Compounds 1-9 were identified using FT-IR, 1H, 13C-NMR, CHN analysis and XRD data and were tested in vitro for proliferation of human cancer cell activity. In these assays, lupeol was inactive (GI50> 250µg/mL while lupeol esters 2 -4 and 7 - 9 showed a cytostatic effect. The XRD method was a suitable tool to determine the structure of lupeol and its esters in solid state. Compound 3 showed a selective growth inhibition effect on erythromyeloblastoid leukemia (K-562 cells in a concentration-dependent way. Lupeol esters 4 and 9 showed a selective cytostatic effect with low GI50 values representing promising prototypes for the development of new anticancer drugs.

  8. Ester Tuiksoo. Proua Suhkru kibedad päevad / Ester Tuiksoo ; interv. Piret Tali

    Index Scriptorium Estoniae

    Tuiksoo, Ester, 1965-

    2005-01-01

    Põllumajandusminister Ester Tuiksoo, kellel peagi täitub ministri ametis aasta Euroopa Liidu suhkrutrahvist, maaettevõtlusest, põllumajandusest, Euroopa Liidu toetustest, ministri elu- ja teenistuskäigust. Lisa: Ester Tuiksoo

  9. Partial Reduction of Esters to Aldehydes Using a Novel Modified Red-Al Reducing Agent

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Won Kyu; Kang, Daehoon; An, Duk Keun [Kangwon National Univ., Chunchon (Korea, Republic of)

    2014-07-15

    We have developed a convenient alternative method for the synthesis of aldehydes from both aromatic and aliphatic esters in very good to excellent yields in the absence of any additives using a modified Red-Al that was easily prepared by reacting commercially available Red-Al with cis-2,6-dimethyl morpholine. The advantages of the present methodology are as follows: simple preparation procedure of the reducing agent, improved product yields, convenient reaction temperature, and short reaction times. Therefore, the new reagent has great potential to be a useful alternative partial reducing agent for the synthesis of aldehydes from esters in organic synthesis. Aldehydes are valuable building blocks and reactive intermediates in organic synthesis. The general and classical syntheses of aldehydes from esters involve reduction-oxidation and partial reduction using efficient partial reducing agents. Obviously, one-step partial reduction methods are more useful than two-step reduction-oxidation methods owing to their simplicity, and generality in organic synthesis.

  10. Method of making a cyanate ester foam

    Science.gov (United States)

    Celina, Mathias C.; Giron, Nicholas Henry

    2014-08-05

    A cyanate ester resin mixture with at least one cyanate ester resin, an isocyanate foaming resin, other co-curatives such as polyol or epoxy compounds, a surfactant, and a catalyst/water can react to form a foaming resin that can be cured at a temperature greater than 50.degree. C. to form a cyanate ester foam. The cyanate ester foam can be heated to a temperature greater than 400.degree. C. in a non-oxidative atmosphere to provide a carbonaceous char foam.

  11. Yeast: the soul of beer's aroma--a review of flavour-active esters and higher alcohols produced by the brewing yeast.

    Science.gov (United States)

    Pires, Eduardo J; Teixeira, José A; Brányik, Tomás; Vicente, António A

    2014-03-01

    Among the most important factors influencing beer quality is the presence of well-adjusted amounts of higher alcohols and esters. Thus, a heavy body of literature focuses on these substances and on the parameters influencing their production by the brewing yeast. Additionally, the complex metabolic pathways involved in their synthesis require special attention. More than a century of data, mainly in genetic and proteomic fields, has built up enough information to describe in detail each step in the pathway for the synthesis of higher alcohols and their esters, but there is still place for more. Higher alcohols are formed either by anabolism or catabolism (Ehrlich pathway) of amino acids. Esters are formed by enzymatic condensation of organic acids and alcohols. The current paper reviews the up-to-date knowledge in the pathways involving the synthesis of higher alcohols and esters by brewing yeasts. Fermentation parameters affecting yeast response during biosynthesis of these aromatic substances are also fully reviewed.

  12. Preparation and study of novel poly(sulfone-ester-amide)s

    Energy Technology Data Exchange (ETDEWEB)

    Bruma, M. [Institute of Macromolecular Chemistry, Isai (Romania)], Mercer, F. [Raychem Corporation, Menlo Park, CA (United States); Gronewald, S. [Southwest Texas State Univ., San Marcos, TX (United States)] [and others

    1995-12-31

    A series of novel poly(ester-amide)s containing sulfone groups in the main chain have been prepared and compared with related polymers which do not have sulfone bridges. Incorporation of sulfone moieties into the polymer backbone improved the solubility of these polymers without significant loss of their high thermal stability, and provided a large {open_quotes}window{close_quotes} between T{sub g} and decomposition temperature. Solutions of poly(sulfone-ester-amide)s in NMP have been cast into flexible films, having low dielectric constant. The synthesis and characterization of these new polymers will be presented.

  13. Palladium-mediated conversion of para-aminoarylboronic esters into para-aminoaryl- 11C-methanes

    DEFF Research Database (Denmark)

    Andersen, Valdemar Lykke; Herth, Matthias Manfred; Lehel, Szabolcs

    2013-01-01

    of free amines. Aryl boronic esters containing primary, secondary, and tertiary amines were successfully converted into corresponding labeled methyl derivatives in suf¿cient radiochemical yield to apply this method for tracer development. This procedure was applied to the labeling of CIMBI-712......Cross-couplings are an alternative to conventional 11C-methylations which are generally employed in PET tracer synthesis. Therefore, we set out to develop a general procedure for the synthesis of para-11CH3 labeled aromatic amines from the corresponding para-aminoarylboronic esters in the presence...

  14. Triphenyltin derivatives of sulfanylcarboxylic esters.

    Science.gov (United States)

    Casas, José S; Couce, María D; Sánchez, Agustín; Seoane, Rafael; Sordo, José; Perez-Estévez, Antonio; Vázquez-López, Ezequiel

    2018-03-01

    The reaction of 3-(aryl)-2-sulfanylpropenoic acids [H 2 xspa; x: p=3-phenyl-, f=3-(2-furyl)-, t=3-(2-thienyl)-] with methanol or ethanol gave the corresponding methyl (Hxspme) or ethyl (Hxspee) esters. The reaction of these esters (HL) with triphenyltin(IV) hydroxide gave compounds of the type [SnPh 3 L], which were isolated and characterized as solids by elemental analysis, IR spectroscopy and mass spectrometry and in solution by multinuclear ( 1 H, 13 C and 119 Sn) NMR spectroscopy. The structures of [SnPh 3 (pspme)], [SnPh 3 (fspme)] and [SnPh 3 (fspee)] were determined by X-ray diffractometry and the antimicrobial activity against E. coli, S. aureus, B. subtilis, P. aeruginosa, Resistant P. aeruginosa (a strain resistant to 'carbapenem'), and C. albicans was tested and the in vitro cytotoxic activity against the HeLa-229, A2780 and A2780cis cell lines was determined for all compounds. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Síntese de esteres terpenóides por via enzimática: influência do tamanho da cadeia alifática do ácido graxo e da estrutura do álcool de terpeno Synthesis of terpen esters by enzymatic route: influence of the fatty acid size chain and alcohol structure

    Directory of Open Access Journals (Sweden)

    Heizir F. CASTRO

    1997-12-01

    Full Text Available A especificidade de uma preparação comercial de lipase imobilizada, com relação a molécula ácida e alcoólica do substrato, foi estudada através da síntese de diversos ésteres de terpenóides. Na série de reações do citronelol e ácidos graxos com diferentes tamanho de cadeia alifática (C2 a C18, altas taxas de esterificação (95 a 98% foram alcançadas para ácidos contendo 4 ou mais carbonos. Numa segunda série de experimentos, diferentes álcoois terpenos foram esterificados com ácido butírico, sendo constatado uma influência marcante da estrutura do álcool de terpeno no desempenho desta preparação enzimática. Graus de esterificação maiores que 95% somente foram obtidos para os álcoois primários como citronelol, geraniol e nerol. Álcoois secundários (mentol e terciários (linalol não foram esterificados, sob as condições testadas.The selectivity of a commercial immobilized lipase preparation was tested in two set of esterification reactions. In the first group, synthesis were carried out with citronellol and different organic acids (C2 to C18. For this case, with the exception of acetic acid, the size of the carbon chain showed no significant alteration in the esterification rates. Acids containing four or more carbons, were considered to be excellent acyl donors, resulting in the esterification rates in the range of 95% to 98%. Alternatively, the esterification reactions were carried out with different terpen alcohols and butyric acid. The alcohol structure showed to have great influence on the performance of this enzyme preparation. Esterification degree over 95% were attained for primary alcohols such as citronellol, geraniol and nerol. Secondary (menthol and tertiary (linallol were not esterified under the tested conditions.

  16. Preparation of Spirocyclic β-Proline Esters

    DEFF Research Database (Denmark)

    Fjelbye, Kasper; Marigo, Mauro; Clausen, Rasmus Prætorius

    2017-01-01

    A series of novel N-Bn-protected spirocyclic β-proline esters were prepared using [3+2] cycloaddition and subsequently converted into their corresponding aldehydes. In addition, two novel N-Cbz-protected spirocyclic β-proline esters were prepared using intramolecular cyclization starting from...

  17. Anticholinesterase activity of fluorochloronitroacetic acid esters

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, Yu.Ya.; Brel, V.K. Martynov, I.V.

    1984-11-01

    Results are presented from pharmacologic and biochemical experiments leading to the conclusion that fluorochloronitroacetic acid esters have anticholinesterase activity. Since the esters caused muscular weakness in mice, experiments were performed on isolated tissue preparation. The biochemical experiments consisted of finding the biomolecular constants of irreversible inhibition of acetylcholinesterase by the esters, using acetylcholinesterase from human erythrocytes, as well as horse serum cholinesterase. The ethyl and n-propyl esters of halogen nitroacetic acid were used in all experiments. It was found that the propyl ester caused an increase in the force of individual contractions in the isolated muscle specimens, plus an inability of the muscle to retain tetanus. The substances were determined to have an anticholinesterase effect. The mechanism of cholinesterase inhibition is not yet known. It is probable that the substances acylate the serine hydroxyl of the esterase center of the cholinestersase. 7 references, 1 figure.

  18. Thermoresponsive Membrane Based on Thermotropic Liquid Crystalline Cholesteryl - (L-lacticacidn System: Study of Its Drug Permeability

    Directory of Open Access Journals (Sweden)

    Massoumeh Bagheri

    2013-01-01

    Full Text Available The rapidly increasing interest in functional materials with reversibly switchable physico- chemical properties has led to significant work on the development of stimuli responsive membranes. Thermotropic liquid crystals with their exceptional properties have potentials for drug-delivery applications. Thermoresponsive liquid-crystal-embedded membranes were investigated for the purpose of developing the drug delivery systems with thermal stimuli response. Drug release occurs at temperatures above the phase transition temperature of thermotropic liquid crystals. Therefore, they can control drug release in response to small temperature changes. In this work, the biocompatible and thermotropic liquid crystalline polymer cholesteryl-(L-lactic acidn ,CLAn (n=30, was synthesized with accurate control of molecular weight via ring opening polymerization method. Polymerization of L-lactide was carried out in the presence of cholesterol as an initiator and catalytic amount of tin (II octoate (Sn(Oct2 at 150°C in 5 h. The number-average degree of polymerization of CLA 30 was obtained from 1H NMR spectroscopy. The phase transition behavior of liquid crystalline CLA30 was established by differential scanning calorimetry and polarizing optical microscopy. The resulting liquid crystalline CLA30 was subsequently utilized to prepare CLA30 -embedded cellulose nitrate membrane by adsorption method. The CLA30-embedded cellulose nitrate membrane was used by an in-vitro drug penetration studies. Acetaminophen was used as a model drug. The permeation study was carried out at different temperatures around glass transition temperature of polymer CLA30 (37, 45 and 40°C, respectively. The results show that the CLA30 -embedded cellulose nitrate membranes exhibit thermo-responsive sensitivity with controlled drug permeation.

  19. Complexation of c6-ceramide with cholesteryl phosphocholine - a potent solvent-free ceramide delivery formulation for cells in culture.

    Directory of Open Access Journals (Sweden)

    Pramod Sukumaran

    Full Text Available Ceramides are potent bioactive molecules in cells. However, they are very hydrophobic molecules, and difficult to deliver efficiently to cells. We have made fluid bilayers from a short-chain D-erythro-ceramide (C6-Cer and cholesteryl phosphocholine (CholPC, and have used this as a formulation to deliver ceramide to cells. C6-Cer complexed with CholPC led to much larger biological effects in cultured cells (rat thyroid FRTL-5 and human HeLa cells in culture compared to C6-Cer dissolved in dimethyl sulfoxide (DMSO. Inhibition of cell proliferation and induction of apoptosis was significantly more efficient by C6-Cer/CholPC compared to C6-Cer dissolved in DMSO. C6-Cer/CholPC also permeated cell membranes and caused mitochondrial Ca(2+ influx more efficiently than C6-Cer in DMSO. Even though CholPC was taken up by cells to some extent (from C6-Cer/CholPC bilayers, and was partially hydrolyzed to free cholesterol (about 9%, none of the antiproliferative effects were due to CholPC or excess cholesterol. The ceramide effect was not limited to D-erythro-C6-Cer, since L-erythro-C6-Cer and D-erythro-C6-dihydroCer also inhibited cell priolifereation and affected Ca(2+ homeostasis. We conclude that C6-Cer complexed to CholPC increased the bioavailability of the short-chain ceramide for cells, and potentiated its effects in comparison to solvent-dissolved C6-Cer. This new ceramide formulation appears to be superior to previous solvent delivery approaches, and may even be useful with longer-chain ceramides.

  20. Synthesis & Characterization of New bis-Symmetrical Adipoyl ...

    African Journals Online (AJOL)

    Full Title: Synthesis and Characterization of New bis-Symmetrical Adipoyl, Terepthaloyl, Chiral Diimido-di-L-alanine Diesters and Chiral Phthaloyl-L-alanine Ester of Tripropoxy p-tert-Butyl Calix[4]arene and Study of Their Hosting Ability for Alanine and Na+. Bis-symmetrical tripropoxy p-tert-butyl calix[4]arene esters were ...

  1. Gamma radiolysis and vinyl esters

    International Nuclear Information System (INIS)

    De Bruyn, H.; Balic, R.; Gilbert, R.G.

    1998-01-01

    The principle behind γ relaxation of free-radical polymerizations is that the source of initiating radicals can be switched off 'instantaneously'. In the absence of initiating radicals the only kinetic events remaining are propagation, transfer and termination. For monomers whose propagation rate coefficients have been determined, relaxation behaviour can be interpreted to determine radical-loss rate coefficients and test models of loss mechanisms. This technique has been employed successfully on styrene and MMA emulsion polymerizations. In the present study, vinyl acetate and vinyl neo-decanoate (a ten-carbon-branched homologue of vinyl acetate) were studied, with the propagation rate coefficients for both monomers being established by pulsed-laser polymerization. Both were found to exhibit rapid γ relaxation rates in emulsion polymerization. This is a surprising result because mechanisms for rapid relaxation in emulsion polymerizations require that chain transfer to monomer (which is rapid for both monomers) is followed by exit from the particle into the aqueous phase with subsequent re-entry into a radical-containing particle leading to bimolecular termination. It is not unreasonable to suppose that this may be possible for vinyl acetate which is fairly water soluble (∼0.3 M). However, vinyl neo-decanoate is virtually insoluble (∼0.00004 M) and hence desorption is extremely unlikely. The most likely explanation for the observed rapid relaxations is that some of the radicals produced by γ radiolysis are slow to initiate vinyl esters and hence act as radical traps. As vinyl esters are known to be particularly unreactive monomers. it is feasible that this experimental artifact affects them to a much greater extent than some of the monomers studied successfully with this technique in the past

  2. Clicked Cinnamic/Caffeic Esters and Amides as Radical Scavengers and 5-Lipoxygenase Inhibitors

    Directory of Open Access Journals (Sweden)

    Jérémie A. Doiron

    2014-01-01

    Full Text Available 5-Lipoxygenase (5-LO is the key enzyme responsible for the conversion of arachidonic acid to leukotrienes, a class of lipid mediators implicated in inflammatory disorders. In this paper, we describe the design, synthesis, and preliminary activity studies of novel clicked caffeic esters and amides as radical scavengers and 5-LO inhibitors. From known 5-LO inhibitor 3 as a lead, cinnamic esters 8a–h and amides 9a–h as well as caffeic esters 15a–h and amides 16a–h were synthesized by Cu(I-catalyzed [1,3]-dipolar cycloaddition with the appropriate azide precursors and terminal alkynes. All caffeic analogs are proved to be good radical scavengers (IC50: 10–20 μM. Esters 15g and 15f possessed excellent 5-LO inhibition activity in HEK293 cells and were equipotent with the known 5-LO inhibitor CAPE and more potent than Zileuton. Several synthesized esters possess activities rivaling Zileuton in stimulated human polymorphonuclear leukocytes.

  3. The 4-pyridylmethyl ester as a protecting group for glutamic and aspartic acids: 'flipping' peptide charge states for characterization by positive ion mode ESI-MS.

    Science.gov (United States)

    Garapati, Sriramya; Burns, Colin S

    2014-03-01

    Use of the 4-pyridylmethyl ester group for side-chain protection of glutamic acid residues in solid-phase peptide synthesis enables switching of the charge state of a peptide from negative to positive, thus making detection by positive ion mode ESI-MS possible. The pyridylmethyl ester moiety is readily removed from peptides in high yield by hydrogenation. Combining the 4-pyridylmethyl ester protecting group with benzyl ester protection reduces the number of the former needed to produce a net positive charge and allows for purification by RP HPLC. This protecting group is useful in the synthesis of highly acidic peptide sequences, which are often beset by problems with purification by standard RP HPLC and characterization by ESI-MS. Copyright © 2014 European Peptide Society and John Wiley & Sons, Ltd.

  4. Acetobacter turbidans α-Amino Acid Ester Hydrolase. How a Single Mutation Improves an Antibiotic-Producing Enzyme

    NARCIS (Netherlands)

    Barends, Thomas R.M.; Polderman-Tijmes, Jolanda J.; Jekel, Peter A.; Williams, Christopher; Wybenga, Gjalt; Janssen, Dick B.; Dijkstra, Bauke W.

    2006-01-01

    The α-amino acid ester hydrolase (AEH) from Acetobacter turbidans is a bacterial enzyme catalyzing the hydrolysis and synthesis of β-lactam antibiotics. The crystal structures of the native enzyme, both unliganded and in complex with the hydrolysis product D-phenylglycine are reported, as well as

  5. Total synthesis of nepetoidin B

    Science.gov (United States)

    The total synthesis of nepetoidin B (the 2-(3,4-dihydroxyphenyl)ethenyl ester of 3-(3,4-dihydroxy¬phenyl)-2-propenoic acid) has been achieved in two steps from commercially available 1,5-bis(3,4-dimethoxyphenyl)-1,4-pentadien-3-one. Tetramethylated nepetoidin B was prepared directly by Baeyer-Villig...

  6. 21 CFR 172.854 - Polyglycerol esters of fatty acids.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyglycerol esters of fatty acids. 172.854 Section... HUMAN CONSUMPTION Multipurpose Additives § 172.854 Polyglycerol esters of fatty acids. Polyglycerol esters of fatty acids, up to and including the decaglycerol esters, may be safely used in food in...

  7. Cobalt-catalyzed hydrogenation of esters to alcohols: unexpected reactivity trend indicates ester enolate intermediacy.

    Science.gov (United States)

    Srimani, Dipankar; Mukherjee, Arup; Goldberg, Alexander F G; Leitus, Gregory; Diskin-Posner, Yael; Shimon, Linda J W; Ben David, Yehoshoa; Milstein, David

    2015-10-12

    The atom-efficient and environmentally benign catalytic hydrogenation of carboxylic acid esters to alcohols has been accomplished in recent years mainly with precious-metal-based catalysts, with few exceptions. Presented here is the first cobalt-catalyzed hydrogenation of esters to the corresponding alcohols. Unexpectedly, the evidence indicates the unprecedented involvement of ester enolate intermediates. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Free cholesterol and cholesterol esters in bovine oocytes: Implications in survival and membrane raft organization after cryopreservation.

    Directory of Open Access Journals (Sweden)

    Jorgelina Buschiazzo

    Full Text Available Part of the damage caused by cryopreservation of mammalian oocytes occurs at the plasma membrane. The addition of cholesterol to cell membranes as a strategy to make it more tolerant to cryopreservation has been little addressed in oocytes. In order to increase the survival of bovine oocytes after cryopreservation, we proposed not only to increase cholesterol level of oocyte membranes before vitrification but also to remove the added cholesterol after warming, thus recovering its original level. Results from our study showed that modulation of membrane cholesterol by methyl-β-cyclodextrin (MβCD did not affect the apoptotic status of oocytes and improved viability after vitrification yielding levels of apoptosis closer to those of fresh oocytes. Fluorometric measurements based on an enzyme-coupled reaction that detects both free cholesterol (membrane and cholesteryl esters (stored in lipid droplets, revealed that oocytes and cumulus cells present different levels of cholesterol depending on the seasonal period. Variations at membrane cholesterol level of oocytes were enough to account for the differences found in total cholesterol. Differences found in total cholesterol of cumulus cells were explained by the differences found in both the content of membrane cholesterol and of cholesterol esters. Cholesterol was incorporated into the oocyte plasma membrane as evidenced by comparative labeling of a fluorescent cholesterol. Oocytes and cumulus cells increased membrane cholesterol after incubation with MβCD/cholesterol and recovered their original level after cholesterol removal, regardless of the season. Finally, we evaluated the effect of vitrification on the putative raft molecule GM1. Cholesterol modulation also preserved membrane organization by maintaining ganglioside level at the plasma membrane. Results suggest a distinctive cholesterol metabolic status of cumulus-oocyte complexes (COCs among seasons and a dynamic organizational structure

  9. Noncovalent PEGylation: different effects of dansyl-, L-tryptophan-, phenylbutylamino-, benzyl- and cholesteryl-PEGs on the aggregation of salmon calcitonin and lysozyme.

    Science.gov (United States)

    Mueller, Claudia; Capelle, Martinus A H; Seyrek, Emek; Martel, Sophie; Carrupt, Pierre-Alain; Arvinte, Tudor; Borchard, Gerrit

    2012-06-01

    Protein aggregation is a major instability that can occur during all stages of protein drug production and development. Protein aggregates may compromise the safety and efficacy of the final protein formulation. In this paper, various new excipients [phenylbutylamino-, benzyl-, and cholesteryl-polyethylene glycols (PEGs)] and their use for the reduction of aggregation of salmon calcitonin (sCT) and hen egg-white lysozyme (HEWL) by noncovalent PEGylation are presented. The ability to suppress aggregation of sCT in various buffer systems at a 1:1 molar ratio was assessed by following changes in protein conformation and aggregation state over time. The results are compared with that of dansyl- and L-tryptophan (Trp)-PEGs described in earlier publications. Furthermore, the influence of the different PEG-based excipients on the aggregation of HEWL was measured. HEWL aggregation was completely suppressed in the presence of cholesteryl-PEGs (2 and 5 kDa), whereas deterioration was observed using benzyl-methoxy polyethylene glycols (mPEGs; 2 and 5 kDa). Phenylbutylamino- and Trp-mPEG (2 kDa), as well as dansyl-PEGs of different molecular weight prolonged the lag phase of aggregation and reduced the aggregation velocity of HEWL. Copyright © 2012 Wiley Periodicals, Inc.

  10. Thermal Properties of Methyl Ester-Containing Poly(2-oxazolines

    Directory of Open Access Journals (Sweden)

    Petra J. M. Bouten

    2015-10-01

    Full Text Available This paper describes the synthesis and thermal properties in solution and bulk of poly(2-alkyl-oxazolines (PAOx containing a methyl ester side chain. Homopolymers of 2-methoxycarbonylethyl-2-oxazoline (MestOx and 2-methoxycarbonylpropyl-2-oxazoline (C3MestOx, as well as copolymers with 2-ethyl-2-oxazoline (EtOx and 2-n-propyl-2-oxazoline (nPropOx, with systematic variations in composition were prepared. The investigation of the solution properties of these polymers revealed that the cloud point temperatures (TCPs could be tuned in between 24 °C and 108 °C by variation of the PAOx composition. To the best of our knowledge, the TCPs of PMestOx and PC3MestOx are reported for the first time and they closely resemble the TCPs of PEtOx and PnPropOx, respectively, indicating similar hydrophilicity of the methyl ester and alkyl side chains. Furthermore, the thermal transitions and thermal stability of these polymers were investigated by DSC and TGA measurements, respectively, revealing amorphous polymers with glass transition temperatures between -1 °C and 54 °C that are thermally stable up to >300 °C.

  11. Microreactors—A Powerful Tool to Synthesize Peroxycarboxylic Esters

    Directory of Open Access Journals (Sweden)

    Tobias Illg

    2015-12-01

    Full Text Available The synthesis of peroxycarboxylic esters, as one subgroup of organic peroxides, is characterized by a high thermal hazard potential regarding process safety. In case of failure in the production process, e.g., if the heat of reaction cannot be removed sufficiently fast, decomposition reactions can be triggered, and as a result, remarkable amounts of heat and gas can be released and can cause a high extent of damage. Multifarious technical and organizational measures are necessary to ensure the safe industrial production of peroxides. With the introduction of microreaction technology plenty of possibilities have been opened to carry out highly exothermic reactions in smaller volumes and with more efficient heat removal. In this paper we report the application of three different microstructured reactors, representing different mixing strategies, to synthesize two peroxymonocarboxylic esters, namely tert-butyl peroxypivalate and tert-butyl peroxy-2-ethylhexanoate. The following reactor types were considered: an orifice microreactor, a split and recombine microreactor and a capillary tube reactor in combination with ultrasonication. The efficiency of the two phase liquid/liquid reaction is expressed in comparison of conversion and selectivity. With microreaction technology a remarkable increase in space-time-yield, ranging from 12,500 kg·m−3·h−1 to 414,000 kg·m−3·h−1, is achieved.

  12. Novel fatty acid methyl esters from the actinomycete Micromonospora aurantiaca

    Science.gov (United States)

    Bruns, Hilke; Riclea, Ramona

    2011-01-01

    Summary The volatiles released by Micromonospora aurantiaca were collected by means of a closed-loop stripping apparatus (CLSA) and analysed by GC–MS. The headspace extracts contained more than 90 compounds from different classes. Fatty acid methyl esters (FAMEs) comprised the major compound class including saturated unbranched, monomethyl and dimethyl branched FAMEs in diverse structural variants: Unbranched, α-branched, γ-branched, (ω−1)-branched, (ω−2)-branched, α- and (ω−1)-branched, γ- and (ω−1)-branched, γ- and (ω−2)-branched, and γ- and (ω−3)-branched FAMEs. FAMEs of the last three types have not been described from natural sources before. The structures for all FAMEs have been suggested based on their mass spectra and on a retention index increment system and verified by the synthesis of key reference compounds. In addition, the structures of two FAMEs, methyl 4,8-dimethyldodecanoate and the ethyl-branched compound methyl 8-ethyl-4-methyldodecanoate were deduced from their mass spectra. Feeding experiments with isotopically labelled [2H10]leucine, [2H10]isoleucine, [2H8]valine, [2H5]sodium propionate, and [methyl-2H3]methionine demonstrated that the responsible fatty acid synthase (FAS) can use different branched and unbranched starter units and is able to incorporate methylmalonyl-CoA elongation units for internal methyl branches in various chain positions, while the methyl ester function is derived from S-adenosyl methionine (SAM). PMID:22238549

  13. N-hydroxysuccinimide-hippuran ester: application for radiolabeling of macromolecules

    International Nuclear Information System (INIS)

    Chervu, L.R.; Chun, S.B.; Bhargava, K.K.

    1987-01-01

    A method for synthesis of N-hydroxysuccinimide ester of radioactive orthoiodohippurric acid (OIH-OSU) is developed in order to label macromolecules including antibodies. The OIH-OSU is prepared in 87% yield by reacting molar equivalents of o-iodohippuric acid, N:N-di-succinimidyl carbonate and pyridine in DMF overnight. The active labeled ester is obtained using high specific activity OIH in a similar synthetic protocol. Conjugation of OIH-OSU to human serum albumin is effected by incubating the reactants for half an hour at room temperature followed by purification of the labeled protein on a Sephadex G-100 column with activity yield of 44.3%. Organ distribution for the labeled albumin preparation and the commercial iodinated human serum albumin (RISA) in mice and rats is similar. As expected urinary excretion of radioactivity for the labeled preparation is greater than that of RISA reflecting the rapid urinary clearance of the OIH moiety released into the bloodstream. Hippuran labeling method offers a mild and rapid protocol for radioiodine labeling of proteins and antibodies for application in diagnostic nuclear medicine procedures

  14. Allied, MGC link on cyanate esters

    International Nuclear Information System (INIS)

    Wood, A.

    1993-01-01

    In the latest of a line of joint ventures in its plastics business, Allied Signal has reached agreement with Mitsubishi Gas Chemical (MGC) to jointly develop thermoset cyanate ester resins and blends. The deal will involve further development of Allied Signal's Primaset phenol-formaldehyde cyanate ester resins, a new entrant in the thermoset arena. Although the Primaset resins were discovered in the 1960s, this would be the first time they are available commercially. The deal will marry Primaset technology with MGC's Skylex bisphenol A cyanate ester resins, says Fred DiAntonis, director/advanced materials at Allied Signal. The two firms are looking at marketing blends of the two materials. The potential market for these resins, used commercially by the electronics industry in printed circuit boards and by the aerospace industry in composites, is significant, says Robert P. Viarengo, Allied Signal president/performance materials. By aligning ourselves with MGC, the world leader in cyanate ester resin, we anticipate moving forward aggressively. The main competitor is Ciba, which acquired bisphenol A cyanate ester resins with its purchase of Rhone-Poulenc's high temperature resins business. DiAntonis estimates the market for cyanate ester resins could be worth $150 million by the end of the decade, although development costs have been in the tens of millions of dollars range

  15. A brief review on synthesis & applications of β-enamino carbonyl compounds

    Directory of Open Access Journals (Sweden)

    yellajyosula L N Murthy

    2012-01-01

    Full Text Available Owing to the wide range applications of β-enamino esters (enamines of β–dicarbonyl compounds in pharmaceuticals and as building blocks for the synthesis of a variety of heterocyclic compounds, β-amino esters, β-amino acids, γ-amino alcohols, peptides and alkaloids a number of methods have been developed so far for the synthesis of these compounds. Due to the importance of these compounds as intermediates in organic synthesis, a concised review is presented.

  16. Antiwear and antioxidant studies of cardanol phosphate ester additives

    Energy Technology Data Exchange (ETDEWEB)

    Mazzetto, S.E.; Oliveira, L.D.M.; Lomonaco, D.; Veloso, P.A., E-mail: selma@ufc.br [Lab. de Produtos e Tecnologia em Processos (LPT), Dept. de Quimica Organica e Inorganica, Universidade Federal do Ceara, Fortaleza, CE (Brazil)

    2012-07-15

    In the search for new applications and products derived from Cashew Nut Shell Liquid (CNSL), we report herein the synthesis and characterization (GC/MS and {sup 1}H, {sup 13}C, and {sup 31}P NMR) of four phosphate esters derived from hydrogenated cardanol, including their applications as antiwear additives for diesel (S500) and as antioxidant additives for mineral oils, evaluated through the HFRR test and oxidative stability analyses, respectively. The results obtained showed very good to excellent performances promoted by the bioadditives evaluated, especially for the thiophosphorylated derivative, which notably reduced the sludge residue and the acidity index of the oxidized oil (0.52 mg NaOH/g sample) and also improved the diesel lubricity, reducing the wear of metal parts by more than 50% (330 {Mu}m). Keywords: Cardanol; Antiwear; Antioxidant; Diesel; Mineral oil. (author)

  17. Methyl esters from vegetable oils with hydroxy fatty acids: Comparison of lesquerella and castor methyl esters

    Science.gov (United States)

    The search for alternative feedstocks for biodiesel as partial replacement for petrodiesel has recently extended to castor oil. In this work, the castor oil methyl esters were prepared and their properties determined in comparison to the methyl esters of lesquerella oil, which in turn is seen as alt...

  18. Screening of adjunct cultures and their application in ester formation in Camembert-type cheese.

    Science.gov (United States)

    Hong, Q; Liu, X M; Hang, F; Zhao, J X; Zhang, H; Chen, W

    2018-04-01

    The ethanol content and esterase and alcohol acyltransferase activities are the limiting factors in the synthesis of ethyl esters in Camembert-type cheeses. This study aimed to investigate the effects of alcohol, esterase and alcohol acyltransferase activities on ethyl ester formation in Camembert-type cheeses. Five experimental cheeses were prepared with three adjunct cultures with different enzyme activities and two levels of ethanol content (400 or 800 μg/g). The cheeses were aged for 4 weeks and analysed weekly for basic physicochemical, textural, volatile and sensory properties. The results showed that both the enzyme activity and ethanol content were limiting factors in the synthesis of ethyl esters in the Camembert-type cheeses. Variation in the esterase synthesis activity was observed among lactic acid bacteria, and the starter culture Lactococcus lactis MA 14 LYO distinguished itself through its high acidifying and esterase hydrolysis abilities. The addition of CCFM 12, a lactic acid bacteria strain with high esterase and alcohol acyltransferase activity, along with 400 or 800 μg/g of ethanol, notably enhanced the generation of ethyl esters and the corresponding fruity flavour, without causing dramatic changes in the basic physicochemical indices and microbial profile. In addition, cohesiveness was influenced by the addition of 400 and 800 μg/g of ethanol, and more resilience with 800 μg/g of ethanol had been found. The results showed that the addition of CCFM12 with 400 and 800 μg/g of ethanol may be applied in the production of Camembert cheese to enhance its fruity flavour. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Disruption of Retinol (Vitamin A Signaling by Phthalate Esters: SAR and Mechanism Studies.

    Directory of Open Access Journals (Sweden)

    Yanling Chen

    Full Text Available A spectrum of reproductive system anomalies (cryptorchidism, hypospadias, dysgenesis of Wolffian duct-derived tissues and prostate, and reduced sperm production in male rats exposed in utero to phthalate esters (PEs are thought to be caused by PE inhibition of fetal testosterone production. Recently, dibutyl and dipentyl phthalate (DBuP, DPnP were shown to disrupt the retinol signaling pathway (RSP in mouse pluripotent P19 embryonal carcinoma cells in vitro. The RSP regulates the synthesis and cellular levels of retinoic acid (RA, the active metabolite of retinol (vitamin A. In this new study, a total of 26 di- and mono-esters were screened to identify additional phthalate structures that disrupt the RSP and explore their mechanisms of action. The most potent PEs, those causing > 50% inhibition, contained aryl and cycloalkane groups or C4-C6 alkyl ester chains and were the same PEs reported to cause malformations in utero. They shared similar lipid solubility; logP values were between 4 and 6 and, except for PEs with butyl and phenyl groups, were stable for prolonged periods in culture. Mono- and cognate di-esters varied in ability to disrupt the RSP; e.g., DEHP was inactive but its monoester was active while DBuP was active yet its monoester was inactive. DBuP and dibenzyl phthalate both disrupted the synthesis of RA from retinol but not the ability of RA to activate gene transcription. Both PEs also disrupted the RSP in C3H10T1/2 multipotent mesenchymal stem cells. Based on this in vitro study showing that some PEs disrupt retinol signaling and previous in vivo studies that vitamin A/RA deficiency and PEs both cause strikingly similar anomalies in the male rat reproductive system, we propose that PE-mediated inhibition of testosterone and RA synthesis in utero are both causes of malformations in male rat offspring.

  20. Synthesis and Antiangiogenic Activity of New Silybin Galloyl Esters

    Czech Academy of Sciences Publication Activity Database

    Gažák, Radek; Valentová, K.; Fuksová, Kateřina; Marhol, Petr; Kuzma, Marek; Medina, M. A.; Oborná, I.; Ulrichová, J.; Křen, Vladimír

    2011-01-01

    Roč. 54, č. 20 (2011), s. 7397-7407 ISSN 0022-2623 R&D Projects: GA ČR GAP207/10/0288; GA ČR(CZ) GAP301/11/0767; GA MŠk OC08049 Institutional research plan: CEZ:AV0Z50200510 Keywords : Silybin * gallates * HUVEC Subject RIV: CC - Organic Chemistry Impact factor: 5.248, year: 2011

  1. Benzofuranyl Esters: Synthesis, Crystal Structure Determination, Antimicrobial and Antioxidant Activities

    Directory of Open Access Journals (Sweden)

    C. S. Chidan Kumar

    2015-09-01

    Full Text Available A series of five new 2‐(1‐benzofuran‐2‐yl‐2‐oxoethyl 4-(un/substitutedbenzoates 4(a–e, with the general formula of C8H5O(C=OCH2O(C=OC6H4X, X = H, Cl, CH3, OCH3 or NO2, was synthesized in high purity and good yield under mild conditions. The synthesized products 4(a–e were characterized by FTIR, 1H-, 13C- and 1H-13C HMQC NMR spectroscopic analysis and their 3D structures were confirmed by single-crystal X-ray diffraction studies. These compounds were screened for their antimicrobial and antioxidant activities. The tested compounds showed antimicrobial ability in the order of 4b < 4a < 4c < 4d < 4e and the highest potency with minimum inhibition concentration (MIC value of 125 µg/mL was observed for 4e. The results of antioxidant activities revealed the highest activity for compound 4e (32.62% ± 1.34% in diphenyl-2-picrylhydrazyl (DPPH radical scavenging, 4d (31.01% ± 4.35% in ferric reducing antioxidant power (FRAP assay and 4a (27.11% ± 1.06% in metal chelating (MC activity.

  2. One-pot synthesis of well-defined polyether/polyester block copolymers and terpolymers by a highly efficient catalyst switch approach

    KAUST Repository

    Alamri, Haleema

    2016-04-20

    A highly efficient methodology, based on a novel catalyst switch approach with rapid crossover characteristics, was developed for the one-pot synthesis of block co/terpolymers of cyclic ethers and esters. This new approach, which takes advantage of one of the best catalysts for epoxide (t-BuP4) and cyclic ester (t-BuP2) polymerization, opens new horizons toward the synthesis of cyclic ether/ester complex macromolecular architectures. © The Royal Society of Chemistry 2016.

  3. One-pot synthesis of well-defined polyether/polyester block copolymers and terpolymers by a highly efficient catalyst switch approach

    KAUST Repository

    Alamri, Haleema; Hadjichristidis, Nikolaos

    2016-01-01

    A highly efficient methodology, based on a novel catalyst switch approach with rapid crossover characteristics, was developed for the one-pot synthesis of block co/terpolymers of cyclic ethers and esters. This new approach, which takes advantage of one of the best catalysts for epoxide (t-BuP4) and cyclic ester (t-BuP2) polymerization, opens new horizons toward the synthesis of cyclic ether/ester complex macromolecular architectures. © The Royal Society of Chemistry 2016.

  4. The European source term code ESTER - basic ideas and tools for coupling of ATHLET and ESTER

    International Nuclear Information System (INIS)

    Schmidt, F.; Schuch, A.; Hinkelmann, M.

    1993-04-01

    The French software house CISI and IKE of the University of Stuttgart have developed during 1990 and 1991 in the frame of the Shared Cost Action Reactor Safety the informatic structure of the European Source TERm Evaluation System (ESTER). Due to this work tools became available which allow to unify on an European basis both code development and code application in the area of severe core accident research. The behaviour of reactor cores is determined by thermal hydraulic conditions. Therefore for the development of ESTER it was important to investigate how to integrate thermal hydraulic code systems with ESTER applications. This report describes the basic ideas of ESTER and improvements of ESTER tools in view of a possible coupling of the thermal hydraulic code system ATHLET and ESTER. Due to the work performed during this project the ESTER tools became the most modern informatic tools presently available in the area of severe accident research. A sample application is given which demonstrates the use of the new tools. (orig.) [de

  5. Application conditions for ester cured alkaline phenolic resin sand

    Directory of Open Access Journals (Sweden)

    Ren-he Huang

    2016-07-01

    Full Text Available Five organic esters with different curing speeds: propylene carbonate (i.e. high-speed ester A; 1, 4-butyrolactone; glycerol triacetate (i.e. medium-speed ester B; glycerol diacetate; dibasic ester (DBE (i.e. low-speed ester C, were chosen to react with alkaline phenolic resin to analyze the application conditions of ester cured alkaline phenolic resin. The relationships between the curing performances of the resin (including pH value, gel pH value, gel time of resin solution, heat release rate of the curing reaction and tensile strength of the resin sand and the amount of added organic ester and curing temperature were investigated. The results indicated the following: (1 The optimal added amount of organic ester should be 25wt.%-30wt.% of alkaline phenolic resin and it must be above 20wt.%-50 wt.% of the organic ester hydrolysis amount. (2 High-speed ester A (propylene carbonate has a higher curing speed than 1, 4-butyrolactone, and they were both used as high-speed esters. Glycerol diacetate is not a high-speed ester in alkaline phenolic resin although it was used as a high-speed ester in ester cured sodium silicate sand; glycerol diacetate and glycerol triacetate can be used as medium-speed esters in alkaline phenolic resin. (3 High-speed ester A, medium-speed ester B (glycerol triacetate and low-speed ester C (dibasic ester, i.e., DBE should be used below 15 ìC, 35 ìC and 50 ìC, respectively. High-speed ester A or low-speed ester C should not be used alone but mixed with medium-speed ester B to improve the strength of the resin sand. (4 There should be a suitable solid content (generally 45wt.%-65wt.% of resin, alkali content (generally 10wt.%-15wt.% of resin and viscosity of alkaline phenolic resin (generally 50-300 mPa≤s in the preparation of alkaline phenolic resin. Finally, the technique conditions of alkaline phenolic resin preparation and the application principles of organic ester were discussed.

  6. Organocatalytic Asymmetric Michael Addition of 4-Hydroxycoumarin to β,γ-Unsaturated α-Keto Esters

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Chang Won; Han, Tae Hyun; Kim, Dae Young [Soonchunhyang Univ., Asan (Korea, Republic of)

    2013-06-15

    In conclusion, we have developed organocatalytic enantioselective conjugate addition reaction of 4-hydroxycoumarin (1) to β,γ-unsaturated α-keto esters 2 to afford biologically valuable warfarin derivatives 3. The process is efficiently catalyzed by a binaphthyl-modified thiourea organocatalyst. The coumarin core is present as a characteristic structural motif in a large number of natural products and biologically active molecules.1 Particularly, many of these naturally occurring 4-hydroxycoumarin and their synthetic analogues are important precursors for the synthesis of natural products and pharmaceuticals. Enantioselective organocatalytic conjugate addition of 4-hydroxycoumarin to α,β-unsaturated ketones is a straightforward method to access warfarin which is an effective anticoagulants. Although a number of reactions of α,β-unsaturated ketones as Michael acceptors have been reported, the corresponding β,γ-unsaturated α-keto esters have received relatively little attention as Michael acceptors. Recently, several groups have reported the asymmetric Michael addition of 4-hydroxycoumarin to β,γ-unsaturated α-keto esters catalyzed by Cu(II)-bisoxazoline, N,N'-dioxide-Ni(II) complexes, thiourea catalysts. Although several efficient methods have been achieved by these systems, an effective method for the synthesis of warfarin analogues is still a challenge.

  7. Organocatalytic Asymmetric Michael Addition of 4-Hydroxycoumarin to β,γ-Unsaturated α-Keto Esters

    International Nuclear Information System (INIS)

    Suh, Chang Won; Han, Tae Hyun; Kim, Dae Young

    2013-01-01

    In conclusion, we have developed organocatalytic enantioselective conjugate addition reaction of 4-hydroxycoumarin (1) to β,γ-unsaturated α-keto esters 2 to afford biologically valuable warfarin derivatives 3. The process is efficiently catalyzed by a binaphthyl-modified thiourea organocatalyst. The coumarin core is present as a characteristic structural motif in a large number of natural products and biologically active molecules.1 Particularly, many of these naturally occurring 4-hydroxycoumarin and their synthetic analogues are important precursors for the synthesis of natural products and pharmaceuticals. Enantioselective organocatalytic conjugate addition of 4-hydroxycoumarin to α,β-unsaturated ketones is a straightforward method to access warfarin which is an effective anticoagulants. Although a number of reactions of α,β-unsaturated ketones as Michael acceptors have been reported, the corresponding β,γ-unsaturated α-keto esters have received relatively little attention as Michael acceptors. Recently, several groups have reported the asymmetric Michael addition of 4-hydroxycoumarin to β,γ-unsaturated α-keto esters catalyzed by Cu(II)-bisoxazoline, N,N'-dioxide-Ni(II) complexes, thiourea catalysts. Although several efficient methods have been achieved by these systems, an effective method for the synthesis of warfarin analogues is still a challenge

  8. Palladium-catalysed arylation of acetoacetate esters to yield 2-arylacetic acid esters

    CSIR Research Space (South Africa)

    Zeevaart, JG

    2004-05-24

    Full Text Available , was developed simultaneously by Hart- wig and Buchwald.5 Typically the tert-butyl ester of propionic acid is treated with an aryl halide (bromide or chloride) in the presence of a strong base, palladium and a bulky phosphine ligand or a bulky imidazolinium CO2t... novel palladium- catalysed conditions for the arylation of acetoacetate esters resulting in the formation of 2-arylacetic acid esters. When we attempted the arylation of tert-butyl aceto- acetate 1a with bromobenzene 2a using mild reaction conditions (K3...

  9. Segmented poly(ether ester)s and poly(ether ester amide)s for use in tissue engineering

    OpenAIRE

    Deschamps, A.A.

    2002-01-01

    The objective of the studies described in this thesis is to investigate the applicability of these slowly degradable thermoplastic elastomers as scaffolds for tissue engineering, with emphasis on their phase separation and degradation properties. A second thermoplastic elastomer in which the terephthalic moieties have been replaced by ester-amide segments, is also investigated for use in scaffolding.

  10. Correlation and prediction of mixing thermodynamic properties of ester-containing systems: Ester + alkane and ester + ester binary systems and the ternary dodecane + ethyl pentanoate + ethyl ethanoate

    International Nuclear Information System (INIS)

    Pérez, Noelia; Fernández, Luís; Ortega, Juan; Toledo, Francisco J.; Wisniak, Jaime

    2012-01-01

    Highlights: ► Excess enthalpies and volumes were measured for ester–ester–alkane. ► Mixing behaviour for ester–ester, ester–alkane and ester–ester–alkane are analyzed. ► Correlations with a new polynomial model reproduce well the mixing properties. ► UNIFAC predictions for h E result acceptable excluding the ester–ester mixtures. - Abstract: Excess thermodynamic properties V m E and H m E , have been measured for the ternary mixture dodecane + ethyl pentanoate + ethyl ethanoate and for the corresponding binaries dodecane + ethyl pentanoate, dodecane + ethyl ethanoate, ethyl pentanoate + ethyl ethanoate at 298.15 K. All mixtures show endothermic and expansive effects. Experimental results are correlated with a suitable equation whose final form for the excess ternary quantity M E contains the particular contributions of the three binaries (i–j) and a last term corresponding to the ternary, all of them obtained considering fourth-order interactions. The fit goodness for all mixtures is good and comparable to others equations taken from the literature. In this work the dissolution model for the binaries and ternary is analyzed with a special attention to ester–ester binaries whose behaviour is discussed. The application of the UNIFAC group contribution model to estimate the H m E yields acceptable results for the binaries (with the exception of ester–ester) and for the ternary mixture.

  11. Naturally Occurring Cinnamic Acid Sugar Ester Derivatives

    Directory of Open Access Journals (Sweden)

    Yuxin Tian

    2016-10-01

    Full Text Available Cinnamic acid sugar ester derivatives (CASEDs are a class of natural product with one or several phenylacrylic moieties linked with the non-anomeric carbon of a glycosyl skeleton part through ester bonds. Their notable anti-depressant and brains protective activities have made them a topic of great interest over the past several decades. In particular the compound 3′,6-disinapoylsucrose, the index component of Yuanzhi (a well-known Traditional Chinese Medicine or TCM, presents antidepressant effects at a molecular level, and has become a hotspot of research on new lead drug compounds. Several other similar cinnamic acid sugar ester derivatives are reported in traditional medicine as compounds to calm the nerves and display anti-depression and neuroprotective activity. Interestingly, more than one third of CASEDs are distributed in the family Polygalaceae. This overview discusses the isolation of cinnamic acid sugar ester derivatives from plants, together with a systematic discussion of their distribution, chemical structures and properties and pharmacological activities, with the hope of providing references for natural product researchers and draw attention to these interesting compounds.

  12. Ester Tuiksoo - Eesti esimene naissoost põllumajandusminister / Ester Tuiksoo ; interv. Toomas Verrev

    Index Scriptorium Estoniae

    Tuiksoo, Ester, 1965-

    2007-01-01

    Ametist lahkuv põllumajandusminister Ester Tuiksoo räägib saadud juhtimiskogemusest, Euroopa Liidu ühise põllumajanduspoliitika juurutamisest, rahvuskala valimisest, Rahvaliidu käekäigust parlamendivalimistel

  13. QSAR for cholinesterase inhibition by organophosphorus esters and CNDO/2 calculations for organophosphorus ester hydrolysis

    Science.gov (United States)

    Johnson, H.; Kenley, R. A.; Rynard, C.; Golub, M. A.

    1985-01-01

    Quantitative structure-activity relationships were derived for acetyl- and butyrylcholinesterase inhibition by various organophosphorus esters. Bimolecular inhibition rate constants correlate well with hydrophobic substituent constants, and with the presence or absence of catonic groups on the inhibitor, but not with steric substituent constants. CNDO/2 calculations were performed on a separate set of organophosphorus esters, RR'P(O)X, where R and R' are alkyl and/or alkoxy groups and X is fluorine, chlorine or a phenoxy group. For each subset with the same X, the CNDO-derived net atomic charge at the central phosphorus atom in the ester correlates well with the alkaline hydrolysis rate constant. For the whole set of esters with different X, two equations were derived that relate either charge and leaving group steric bulk, or orbital energy and bond order to the hydrogen hydrolysis rate constant.

  14. Technetium and rhenium tracers with metabolizable ester functions

    International Nuclear Information System (INIS)

    Syhre, R.; Seifert, S.; Schneider, F.; Pietzsch, H.J.; Spies, H.; Johannsen, B.

    1993-01-01

    Re-DMSA (dimercaptosuccinic acid) ester complexes were prepored by ligand exchange reactions. To determine whether the ester band in Re-DMSA ester complexes is susceptible to cleavage by esterases, incubation experiments with tissue homogenates and plasma were carried out. (BBR)

  15. 21 CFR 172.848 - Lactylic esters of fatty acids.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Lactylic esters of fatty acids. 172.848 Section 172... CONSUMPTION Multipurpose Additives § 172.848 Lactylic esters of fatty acids. Lactylic esters of fatty acids... prepared from lactic acid and fatty acids meeting the requirements of § 172.860(b) and/or oleic acid...

  16. Celorbicol, isocelorbicol, and their esters: new sesquiterpenoids from Celastrus orbiculatus

    Energy Technology Data Exchange (ETDEWEB)

    Smith, C.R. Jr. (Dept. of Agriculture, Peoria, IL); Miller, R.W.; Weisleder, D.; Rohwedder, W.K.; Eickman, N.; Clardy, J.

    1976-10-01

    Esters of two new sesquiterpenoid polyalcohols - celorbicol and isocelorbicol - have been isolated from Celastrus orbiculatus. Structures of the parent alcohols have been established by x-ray crystallography, and those of the derived esters have been assigned by NMR spectroscopy. These compounds are structurally related to other polyesters and ester alkaloids from the Celastraceae, all of which are based on the dihydroagarofuran ring system.

  17. Synthesis and properties of highly branched Jatropha curcas L. oil derivatives

    NARCIS (Netherlands)

    Daniel, Louis; Ardiyanti, Agnes R.; Schuur, Boelo; Manurung, Robert; Broekhuis, Antonius A.; Heeres, Hero J.

    The synthesis and properties of a number of novel branched Jatropha curcas L. oil (JO) derivatives containing vicinal di-ester units in the fatty acid chains are reported. Both the length (acetyl vs. hexanoyl) and the stereochemistry of the vicinal di-ester units (cis vs. trans) were varied. The

  18. Synthesis of hydrophobic peptides : An Fmoc “Solubilising Tail” method

    NARCIS (Netherlands)

    Choma, Christin T.; Robillard, George T.; Englebretsen, Darren R.

    1998-01-01

    The development of an Fmoc method for synthesis and purification of hydrophobic peptides using a “solubihsing tail” strategy is described. Peptide-constructs of the form hydrophobic peptide-[CHmb ester]-solubilising peptide were synthesised. Procedures for forming the 4-Hmb ester linkage, and

  19. Toxicity of phosphor esters: Willy Lange (1900-1976) and Gerda von Krueger (1907-after 1970).

    Science.gov (United States)

    Petroianu, G A

    2010-10-01

    In 1851 Williamson serendipitously discovered a new and efficient way to produce ethers using ethyl iodide and potassium salts. Based on this new synthetic approach, the Frenchman Philippe de Clermont and the Muscovite Wladimir Moschnin, both élèves of Adolphe Wurtz in his Paris School of Chemistry, achieved the synthesis of the first ester of pyrophosphoric acid (TEPP). de Clermont "tasted" the new compound and although TEPP is a potent cholinesterase inhibitor he failed to recognize its toxicity. Almost a century later, in 1932, Willy Lange (1900-1976) and his graduate student Gerda v. Krueger (1907-after 1970) described the toxicity of organophosphonates. While the classic paper of the two "Uber Ester der Monofluorphosphorsäure." is cited by almost everybody working in the field, little is known about Lange and almost nothing about v. Krueger. This brief communication attempts to shed some light on the life of both.

  20. Transcription profile data of phorbol esters biosynthetic genes during developmental stages in Jatropha curcas.

    Science.gov (United States)

    Jadid, Nurul; Mardika, Rizal Kharisma; Purwani, Kristanti Indah; Permatasari, Erlyta Vivi; Prasetyowati, Indah; Irawan, Mohammad Isa

    2018-06-01

    Jatropha curcas is currently known as an alternative source for biodiesel production. Beside its high free fatty acid content, J. curcas also contains typical diterpenoid-toxic compounds of Euphorbiaceae plant namely phorbol esters. This article present the transcription profile data of genes involved in the biosynthesis of phorbol esters at different developmental stages of leaves, fruit, and seed in Jatropha curcas . Transcriptional profiles were analyzed using reverse transcription-polymerase chain reaction (RT-PCR). We used two genes including GGPPS (Geranylgeranyl diphospate synthase), which is responsible for the formation of common diterpenoid precursor (GGPP) and CS (Casbene Synthase), which functions in the synthesis of casbene. Meanwhile, J. curcas Actin ( ACT ) was used as internal standard. We demonstrated dynamic of GGPPS and CS expression among different stage of development of leaves, fruit and seed in Jatropha .

  1. Synthesis of derivatives of tetronic acid and pulvinic acid. Total synthesis of norbadione A

    International Nuclear Information System (INIS)

    Mallinger, A.

    2008-11-01

    When vegetables like mushrooms are contaminated by radioactive caesium 137, this radioactive caesium is associated to norbadione A, a natural pigment present in two mushroom species and which can be used as a caesium decorporation agent or maybe as protection agent against ionizing radiations. Within this perspective, this research report describes the biosynthesis and the structure and properties of the norbadione A and of pulvinic acids (physicochemical properties, anti-oxidizing properties). Then, it presents the various tetronic acids (3-acyl-, 3-alkyl-, 3-alkoxy-, 3-aryl-tetronic acids and non 3-substituted tetronic acids), their synthesis path as they are described in the literature, and presents a new synthesis approach using a tandem reaction (with different esters or hydroxy esters) and the synthesis of tetronic acids. The author also proposes a new synthesis way for methyl pulvinates, and finally reports the work on the development of a total synthesis of the norbadione A

  2. Poly(ester-anhydride):poly(beta-amino ester) micro- and nanospheres: DNA encapsulation and cellular transfection.

    Science.gov (United States)

    Pfeifer, Blaine A; Burdick, Jason A; Little, Steve R; Langer, Robert

    2005-11-04

    Poly(ester-anhydride) delivery devices allow flexibility regarding carrier dimensions (micro- versus nanospheres), degradation rate (anhydride versus ester hydrolysis), and surface labeling (through the anhydride functional unit), and were therefore tested for DNA encapsulation and transfection of a macrophage P388D1 cell line. Poly(l-lactic acid-co-sebacic anhydride) and poly(l-lactic acid-co-adipic anhydride) were synthesized through melt condensation, mixed with 25 wt.% poly(beta-amino ester), and formulated with plasmid DNA (encoding firefly luciferase) into micro- and nanospheres using a double emulsion/solvent evaporation technique. The micro- and nanospheres were then characterized (size, morphology, zeta potential, DNA release) and assayed for DNA encapsulation and cellular transfection over a range of poly(ester-anhydride) copolymer ratios. Poly(ester-anhydride):poly(beta-amino ester) composite microspheres (6-12 microm) and nanospheres (449-1031 nm), generated with copolymers containing between 0 and 25% total polyanhydride content, encapsulated plasmid DNA (>or=20% encapsulation efficiency). Within this polyanhydride range, poly(adipic anhydride) copolymers provided DNA encapsulation at an increased anhydride content (10%, microspheres; 10-25%, nanospheres) compared to poly(sebacic anhydride) copolymers (1%, microspheres and nanospheres) with cellular transfection correlating with the observed DNA encapsulation.

  3. Active Ester Containing Surfmer for One-Stage Polymer Nanoparticle Surface Functionalization in Mini-Emulsion Polymerization

    Directory of Open Access Journals (Sweden)

    Vanessa L. Albernaz

    2018-04-01

    Full Text Available Functional surface active monomers (surfmers are molecules that combine the functionalities of surface activity, polymerizability, and reactive groups. This study presents an improved pathway for the synthesis of the active ester containing surfmer p-(11-acrylamidoundecanoyloxyphenyl dimethylsulfonium methyl sulfate (AUPDS. Further, the preparation of poly(methyl methacrylate and polystyrene nanoparticles (NPs by mini-emulsion polymerization using AUPDS is investigated, leading to NPs with active ester groups on their surface. By systematically varying reaction parameters and reagent concentrations, it was found that AUPDS feed concentrations between 2–4 mol% yielded narrowly distributed and stable spherical particles with average sizes between 83 and 134 nm for non-cross-linked NPs, and up to 163 nm for cross-linked NPs. By basic hydrolysis of the active ester groups in aqueous dispersion, the positive ζ-potential (ZP was converted into a negative ZP and charge quantities determined by polyelectrolyte titrations before and after hydrolysis were in the same range, indicating that the active ester groups were indeed accessible in aqueous suspension. Increasing cross-linker amounts over 10 mol% also led to a decrease of ZP of NPs, probably due to internalization of the AUPDS during polymerization. In conclusion, by using optimized reaction conditions, it is possible to prepare active ester functionalized NPs in one stage using AUPDS as a surfmer in mini-emulsion polymerization.

  4. Nickel-Catalyzed C-S Bond Formation via Decarbonylative Thioetherification of Esters, Amides and Intramolecular Recombination Fragment Coupling of Thioesters

    KAUST Repository

    Lee, Shao-Chi

    2018-01-15

    A nickel catalyzed cross-coupling protocol for the straightforward C-S bond formation has been developed. Various mercaptans and a wide range of ester and amide substrates bearing various substituents were tolerated in this process which afforded products in good to excellent yields. Furthermore, an intramolecular protocol for the synthesis of thioethers starting from thioesters has been developed. The utility of this protocol has been demonstrated in the synthesis of benzothiophene on the bench top.

  5. Nickel-Catalyzed C-S Bond Formation via Decarbonylative Thioetherification of Esters, Amides and Intramolecular Recombination Fragment Coupling of Thioesters

    KAUST Repository

    Lee, Shao-Chi; Liao, Hsuan-Hung; Chatupheeraphat, Adisak; Rueping, Magnus

    2018-01-01

    A nickel catalyzed cross-coupling protocol for the straightforward C-S bond formation has been developed. Various mercaptans and a wide range of ester and amide substrates bearing various substituents were tolerated in this process which afforded products in good to excellent yields. Furthermore, an intramolecular protocol for the synthesis of thioethers starting from thioesters has been developed. The utility of this protocol has been demonstrated in the synthesis of benzothiophene on the bench top.

  6. Total synthesis and stereochemical assignment of the salicylate antitumor macrolide lobatamide C(1).

    Science.gov (United States)

    Shen, Ruichao; Lin, Cheng Ting; Porco, John A

    2002-05-22

    The total synthesis and stereochemical assignment of the potent antitumor macrolide lobatamide C is reported. The synthesis involves Cu(I)-mediated enamide formation and Na(2)CO(3)-mediated esterification of a beta-hydroxy acid and a salicylate cyanomethyl ester. Macrolactonization was accomplished using a Mitsunobu protocol. The stereochemical assignment of lobatamide C was achieved by Mosher ester analysis and comparison with prepared stereoisomers.

  7. Synthesis of azaphenanthridines via anionic ring closure

    DEFF Research Database (Denmark)

    Hansen, Henriette Møller; Lysén, M.; Begtrup, M.

    2005-01-01

    A new and convergent synthesis of azaphenanthridines via an anionic ring closure is reported. Ortho-lithiation/in situ borylation of cyanopyridines produces the corresponding cyanopyridylboronic esters, which undergo a Suzuki-Miyaura cross-coupling to give the key intermediates. Addition of lithium...

  8. Atorvastatin affects low density lipoprotein and non-high density lipoprotein cholesterol relations with apolipoprotein B in type 2 diabetes mellitus : modification by triglycerides and cholesteryl ester transfer protein

    NARCIS (Netherlands)

    Kappelle, Paul J.W.H.; Zwang, Louwerens; Huisman, Menno V.; Banga, Jan Dirk; Sluiter, Wim. J.; Dallinga-Thie, Geesje M.; Dullaart, Robin P. F.

    Objectives: Non-HDL-cholesterol (non-HDL-C) and apolipoprotein (apo) B are proposed as treatment targets. The extent to which statin therapy affects relationships of LDL-C and non-HDL-C with apoB was examined in type 2 diabetes. Methods: Analyses were performed in 217 hypertriglyceridaemic type 2

  9. Enzymatic synthesizing of phytosterol oleic esters.

    Science.gov (United States)

    Pan, Xinxin; Chen, Biqiang; Wang, Juan; Zhang, Xinzhi; Zhul, Biyun; Tan, Tianwei

    2012-09-01

    A method of synthesizing the phytosterol esters from oleic acid and sterols was studied, using immobilized lipase Candida sp. 99-125 as catalyst. Molar ratio (oleic acid/phytosterols), temperature, reaction period, organic solvents, catalyst, and silica-gel drier were optimized, and the result showed that 93.4% of the sterols had been esterified under the optimal synthetic condition: the molar ratio of oleic acid/phytosterol is 1:1 in 10 mL iso-octane, immobilized lipase (w, 140% of the sterols), incubated in an orbital shaker (200 rpm) at a temperature of 45 °C for 24 h. The immobilized lipase could be reused for at least 13 times with limited loss of esterification activity. The conversion still maintained up to 86.6%. Hence, this developed process for synthesizing phytosterol esters could be considered as simple and low-energy consumption compared to existing chemical processes.

  10. Naturally occurring antifungal aromatic esters and amides

    International Nuclear Information System (INIS)

    Ali, M.S.; Shahnaz; Tabassum, S.; Ogunwande, I.A.; Pervez, M.K.

    2010-01-01

    During the search of antifungal natural products from terrestrial plants, a new long chained aromatic ester named grandiflorate along with spatazoate from Portulaca grandiflora and N-[2-methoxy-2-(4-methoxyphenyl) ethyl]-trans-cinnamide and aegeline from Solanum erianthum of Nigeria were isolated and tested against six fungal species. The known constituents have not been reported so far from mentioned investigated plants. Structures of the isolated compounds were elucidated with the aid of spectroscopic techniques including two dimensional NMR experiments. Among the compounds, the esters found more potent than amides against Candida albicans and Aspergillus flavus. The new compound grandiflorate gave response against all tested fungal species while aegeline was found to give lowest inhibition during this study. (author)

  11. Naturally occurring antifungal aromatic esters and amides

    Energy Technology Data Exchange (ETDEWEB)

    Ali, M S; Shahnaz,; Tabassum, S; Ogunwande, I A; Pervez, M K [University of Karachi (Pakistan). HEJ Research Inst. of Chemistry, International Centre for Chemical and Biological Sciences

    2010-08-15

    During the search of antifungal natural products from terrestrial plants, a new long chained aromatic ester named grandiflorate along with spatazoate from Portulaca grandiflora and N-[2-methoxy-2-(4-methoxyphenyl) ethyl]-trans-cinnamide and aegeline from Solanum erianthum of Nigeria were isolated and tested against six fungal species. The known constituents have not been reported so far from mentioned investigated plants. Structures of the isolated compounds were elucidated with the aid of spectroscopic techniques including two dimensional NMR experiments. Among the compounds, the esters found more potent than amides against Candida albicans and Aspergillus flavus. The new compound grandiflorate gave response against all tested fungal species while aegeline was found to give lowest inhibition during this study. (author)

  12. Atmospheric oxidation of selected alcohols and esters

    Energy Technology Data Exchange (ETDEWEB)

    Becker, K H; Cavalli, F

    2001-03-01

    The decision whether it is appropriate and beneficial for the environment to deploy specific oxygenated organic compounds as replacements for traditional solvent types requires a quantitative assessment of their potential atmospheric impacts including tropospheric ozone and other photooxidant formation. This involves developing chemical mechanisms for the gasphase atmospheric oxidation of the compounds which can be reliably used in models to predict their atmospheric reactivity under a variety of environmental conditions. Until this study, there was very little information available concerning the atmospheric fate of alcohols and esters. The objectives of this study were to measure the atmospheric reaction rates and to define atmospheric reaction mechanisms for the following selected oxygenated volatile organic compounds: the alcohols, 1-butanol and 1-pentanol, and the esters, methyl propionate and dimethyl succinate. The study has successfully addressed these objectives. (orig.)

  13. N-Heterocyclic Carbene-Catalyzed Vinylogous Mukaiyama Aldol Reaction of α-Keto Esters and α-Trifluoromethyl Ketones

    KAUST Repository

    Du, Guang-Fen; Wang, Ying; Xing, Fen; Xue, Mei; Guo, Xu-Hong; Huang, Kuo-Wei; Dai, Bin

    2015-01-01

    © Georg Thieme Verlag Stuttgart · New York · Synthesis 2016. N-Heterocyclic carbene (NHC)-catalyzed vinylogous Mukaiyama aldol reaction of ketones was developed. Under the catalysis of 5 mol% NHC, α-keto esters and α-trifluoromethyl ketones reacted with 2-(trimethysilyloxy)furan efficiently to produce γ-substituted butenolides containing adjacent quaternary and tertiary carbon centers in high yields with good diastereoselectivities.

  14. Arylboronate ester based diazeniumdiolates (BORO/NO), a class of hydrogen peroxide inducible nitric oxide (NO) donors.

    Science.gov (United States)

    Dharmaraja, Allimuthu T; Ravikumar, Govindan; Chakrapani, Harinath

    2014-05-16

    Here, we report the design, synthesis, and evaluation of arylboronate ester based diazeniumdiolates (BORO/NO), a class of nitric oxide (NO) donors activated by hydrogen peroxide (H2O2), a reactive oxygen species (ROS), to generate NO. We provide evidence for the NO donors' ability to permeate bacteria to produce NO when exposed to H2O2 supporting possible applications for BORO/NO to study molecular mechanisms of NO generation in response to elevated ROS.

  15. Cytosolic cholesterol ester hydrolase in adrenal cortex

    OpenAIRE

    Tocher, Douglas R.

    1983-01-01

    Cholesterol ester hydrolase (CEH) in adrenocortical cytosol was known to be phosphorylated and activated, in response to ACTH in a cAMPdependent protein kinase mediated process. The purification of CEH from bovine adrenocortical cytosol was attempted. The use of detergents to solubilise the enzyme from lipid-rich aggregates was investigated and sodium cholate was found to be effective. A purification procedure using cholate solubilised enzyme was developed. The detergent int...

  16. Antimicrobial polyurethane thermosets based on undecylenic acid: synthesis and evaluation

    OpenAIRE

    Cádiz, V.; Galià, M.; Ronda, J.C.; Lligadas, G.; Bordons, A.; Esteve-Zarzoso, B.; Lluch, C.

    2014-01-01

    10.1002/mabi.201400017 In the present study, plant oil-derived surface-modifiable polyurethane thermosets are presented. Polyol synthesis is carried out taking advantage of thiol-yne photopolymerization of undecylenic acid derivatives containing methyl ester or hydroxyl moieties. The prepared methyl ester-containing polyurethanes allow surface modification treatment to enhance their hydrophilicity and impart antimicrobial activity through the following two steps: i) grafting poly(propylen...

  17. Fluorous Parallel Synthesis of A Hydantoin/Thiohydantoin Library

    OpenAIRE

    Lu, Yimin; Zhang, Wei

    2005-01-01

    Fluorous tagging strategy is applied to solution-phase parallel synthesis of a library containing hydantoin and thiohydantoin analogs. Two perfluoroalkyl (Rf)-tagged α-amino esters each react with 6 aromatic aldehydes under reductive amination conditions. Twelve amino esters then each react with 10 isocyanates and isothiocyanates in parallel. The resulting 120 ureas and thioureas undergo spontaneous cyclization to form the corresponding hydantoins and thiohydantoins. The intermediate and fina...

  18. Methyl and ethyl soybean esters production

    Energy Technology Data Exchange (ETDEWEB)

    Pighinelli, Anna Leticia Montenegro Turtelli; Park, Kil Jin; Zorzeto, Thais Queiroz [Universidade Estadual de Campinas (FEAGRI/UNICAMP), SP (Brazil). Fac. de Engenharia Agricola], E-mail: annalets@feagri.unicamp.br; Bevilaqua, Gabriela [Universidade Estadual de Campinas (IQ/UNICAMP), SP (Brazil). Inst. de Quimica

    2008-07-01

    Biodiesel is a fuel obtained from triglycerides found in nature, like vegetable oils and animal fats. Nowadays it has been the subject of many researches impulses by the creation of the Brazilian law that determined the blend of 2% of biodiesel with petrodiesel. Basically, there are no limitations on the oilseed type for chemical reaction, but due to high cost of this major feedstock, it is important to use the grain that is available in the region of production. Soybean is the oilseed mostly produced in Brazil and its oil is the only one that is available in enough quantity to supply the current biodiesel demand. The objective of this work was to study the effects of reaction time and temperature on soybean oil transesterification reaction with ethanol and methanol. A central composite experimental design with five variation levels was used and response surface methodology applied for the data analysis. The statistical analysis of the results showed that none of the factors affected the ethyl esters production. However, the methyl esters production suffered the influence of temperature (linear effect), reaction time (linear and quadratic) and interaction of these two variables. None of the generated models showed significant regression consequently it was not possible to build the response surface. The experiments demonstrated that methanol is the best alcohol for transesterification reactions and the ester yield was up to 85%. (author)

  19. Stimulation of mast cells leads to cholesterol accumulation in macrophages in vitro by a mast cell granule-mediated uptake of low density lipoprotein

    International Nuclear Information System (INIS)

    Kokkonen, J.O.; Kovanen, P.T.

    1987-01-01

    The uptake of low density lipoprotein (LDL) by cultured mouse macrophages was markedly promoted by isolated rat mast cell granules present in the culture medium. The granule-mediated uptake of 125 I-LDL enhanced the rate of cholesteryl ester synthesis in the macrophages, the result being accumulation of cholesteryl esters in these cells. Binding of LDL to the granules was essential for the granule-mediated uptake of LDL by macrophages, for the uptake process was prevented by treating the granules with avidin or protamine chloride or by treating LDL with 1,2-cyclohexanedione, all of which inhibit the binding of LDL to the granules. Inhibition of granule phagocytosis by the macrophages with cytochalasin B also abolished the granule-mediated uptake of LDL. Finally, mouse macrophage monolayers and LDL were incubated in the presence of isolated rat serosal mast cells. Stimulation of the mast cells with compound 48/80, a degranulating agent, resulted in dose-dependent release of secretory granules from the mast cells and a parallel increase in 14 C cholesteryl ester synthesis in the macrophages. The results show that, in this in vitro model, the sequence of events leading to accumulation of cholesteryl esters in macrophages involves initial stimulation of mast cells, subsequent release of their secretory granules, binding of LDL to the exocytosed granules, and, finally, phagocytosis of the LDL-containing granules by macrophages

  20. A Short Synthesis of (+)-Cyclophellitol

    DEFF Research Database (Denmark)

    Hansen, Flemming Gundorph; Bundgaard, Eva; Madsen, Robert

    2005-01-01

    A new synthesis of (+)-cyclophellitol, a potent b-glucosidase inhibitor, has been completed in nine steps from D-xylose. The key transformations involve a zinc-mediated fragmentation of benzyl-protected methyl 5-deoxy-5-iodo-xylofuranoside followed by a highly diastereoselective indium-mediated c......-mediated coupling with ethyl 4-bromocrotonate. Subsequent ring-closing olefin metathesis, ester reduction, olefin epoxidation, and deprotection then afford the natural product. This constitutes the shortest synthesis of (+)-cyclophellitol reported to date....

  1. Photoreactive molecular layers containing aryl ester units: Preparation, UV patterning and post-exposure modification

    Energy Technology Data Exchange (ETDEWEB)

    Hoefler, Thomas [Institute for Chemistry and Technology of Materials, Graz University of Technology, Stremayrgasse 16, A-8010 Graz (Austria); Track, Anna M. [Institute of Solid State Physics, Graz University of Technology, Petersgasse 16/II, A-8010 Graz (Austria); Institute of Physics, University of Graz, Universitaetsplatz 5, A-8010 Graz (Austria); Pacher, Peter [Institute of Solid State Physics, Graz University of Technology, Petersgasse 16/II, A-8010 Graz (Austria); Shen, Quan [Institute of Physics, Montanuniversitaet Leoben, Franz-Josef-Strasse 18, A-8700 Leoben (Austria); Flesch, Heinz-Georg [Institute of Solid State Physics, Graz University of Technology, Petersgasse 16/II, A-8010 Graz (Austria); Hlawacek, Gregor [Institute of Physics, Montanuniversitaet Leoben, Franz-Josef-Strasse 18, A-8700 Leoben (Austria); Koller, Georg; Ramsey, Michael G. [Institute of Physics, University of Graz, Universitaetsplatz 5, A-8010 Graz (Austria); Schennach, Robert; Resel, Roland [Institute of Solid State Physics, Graz University of Technology, Petersgasse 16/II, A-8010 Graz (Austria); Teichert, Christian [Institute of Physics, Montanuniversitaet Leoben, Franz-Josef-Strasse 18, A-8700 Leoben (Austria); Kern, Wolfgang [Institute of Chemistry of Polymers, Montanuniversitaet Leoben, Franz-Josef-Strasse 18, A-8700 Leoben (Austria); Trimmel, Gregor [Institute for Chemistry and Technology of Materials, Graz University of Technology, Stremayrgasse 16, A-8010 Graz (Austria); Griesser, Thomas, E-mail: thomas.griesser@unileoben.ac.at [Institute for Chemistry and Technology of Materials, Graz University of Technology, Stremayrgasse 16, A-8010 Graz (Austria); Institute of Chemistry of Polymers, Montanuniversitaet Leoben, Franz-Josef-Strasse 18, A-8700 Leoben (Austria)

    2010-01-15

    The photolithographic modification of thin functional silane layers provides a versatile and powerful means of fabricating functionalized patterned surfaces which can be applied for tuning inorganic surface properties and for modern immobilisation techniques. In this contribution we present the synthesis of a new functional trichloro organosilane bearing photoreactive aryl ester groups and its application in thin silane layers on silicon oxide surfaces. Whereas the trichlorosilyl group acts as anchoring unit to the inorganic surface, the aryl ester group undergoes the photo-Fries rearrangement to yield hydroxyketones upon irradiation with UV-light of 254 nm which leads to a change in chemical reactivity of the surface. By a subsequent reaction with perfluorobutyryl chloride, the photogenerated hydroxy groups yield the corresponding perfluorinated ester compound, which allows further tuning of surface properties. The layer formation as well as the photoreaction and post-modification reaction was monitored by FTIR spectroscopy and X-ray photoelectron spectroscopy (XPS). The thickness of the obtained thin layers was determined by X-ray reflectivity (XRR). Photopatterned surfaces were produced using a contact mask during illumination followed by the post-modification reaction. Friction force microscopy (FFM) revealed the contrast between modified and unmodified regions of the patterned samples.

  2. Controlled release from aspirin based linear biodegradable poly(anhydride esters) for anti-inflammatory activity.

    Science.gov (United States)

    Dasgupta, Queeny; Movva, Sahitya; Chatterjee, Kaushik; Madras, Giridhar

    2017-08-07

    This work reports the synthesis of a novel, aspirin-loaded, linear poly (anhydride ester) and provides mechanistic insights into the release of aspirin from this polymer for anti-inflammatory activity. As compared to conventional drug delivery systems that rely on diffusion based release, incorporation of bioactives in the polymer backbone is challenging and high loading is difficult to achieve. In the present study, we exploit the pentafunctional sugar alcohol (xylitol) to provide sites for drug (aspirin) attachment at its non-terminal OH groups. The terminal OH groups are polymerized with a diacid anhydride. The hydrolysis of the anhydride and ester bonds under physiological conditions release aspirin from the matrix. The resulting poly(anhydride ester) has high drug loading (53%) and displays controlled release kinetics of aspirin. The polymer releases 8.5 % and 20%, of the loaded drug in one and four weeks, respectively and has a release rate constant of 0.0035h -0.61 . The release rate is suitable for its use as an anti-inflammatory agent without being cytotoxic. The polymer exhibits good cytocompatibility and anti-inflammatory properties and may find applications as injectable or as an implantable bioactive material. The physical insights into the release mechanism can provide development of other drug loaded polymers. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Environmentally friendly properties of vegetable oil methyl esters

    Directory of Open Access Journals (Sweden)

    Gateau Paul

    2005-07-01

    Full Text Available Measurements were carried out on Vegetable Oil Methyl Esters (VOME or FAME answering the most recent specifications. The products tested are RME (Rapeseed oil Methyl Ester, ERME (Erucic Rapeseed oil Methyl Esters, SME (Sunflower oil Methyl Esters, and HOSME (High Oleic Sunflower oil Methyl Esters. They contain more than 99.5% of fatty acid mono esters. The compositions are given. VOME are not volatile and they are not easily flammable. They are not soluble in water and they are biodegradable. According to the methods implemented for the determination of the German classification of substances hazardous to waters WGK, they are not toxic on mammals and unlike diesel fuel they are not toxic on fish, daphnia, algae and bacteria. The RME is not either toxic for shrimps. According to tests on rabbits, RME and SME are not irritating for the skin and the eyes. VOME display particularly attractive environmental properties.

  4. Isolation and identification of an ester from a crude oil

    Science.gov (United States)

    Phillips, H.F.; Breger, I.A.

    1958-01-01

    A dioctylphthalate has been isolated from a crude oil by means of adsorption column chromatography. The ester was identified by means of elemental analysis, refractive index, and its infra-red absorption spectrum. Saponification of the isolate and examination of the resultant alcohol by means of infrared absorption spectra led to the conclusion that the ester is a branched chain dioctylphthalate. This is the first reported occurrence of an ester in crude petroleum. ?? 1958.

  5. Mutagenic activity of phthalate esters in bacterial liquid suspension assays.

    OpenAIRE

    Seed, J L

    1982-01-01

    The mutagenic activities of several phthalate esters have been evaluated in an 8-azaguanine resistance assay in Salmonella typhimurium. Three phthalate esters were found to be mutagenic: dimethyl phthalate, diethyl phthalate and di-n-butyl phthalate. A number of other phthalate esters were not found to be mutagenic, including di(2-ethylhexyl) phthalate, di-n-octyl phthalate, diallyl phthalate, diisobutyl phthalate and diisodecyl phthalate. A metabolite of di(2-ethylhexyl) phthalate, 2-ethylhe...

  6. Lipase immobilization and production of fatty acid methyl esters from canola oil using immobilized lipase

    International Nuclear Information System (INIS)

    Yuecel, Yasin; Demir, Cevdet; Dizge, Nadir; Keskinler, Buelent

    2011-01-01

    Lipase enzyme from Aspergillus oryzae (EC 3.1.1.3) was immobilized onto a micro porous polymeric matrix which contains aldehyde functional groups and methyl esters of long chain fatty acids (biodiesel) were synthesized by transesterification of crude canola oil using immobilized lipase. Micro porous polymeric matrix was synthesized from styrene-divinylbenzene (STY-DVB) copolymers by using high internal phase emulsion technique and two different lipases, Lipozyme TL-100L ® and Novozym 388 ® , were used for immobilization by both physical adsorption and covalent attachment. Biodiesel production was carried out with semi-continuous operation. Methanol was added into the reactor by three successive additions of 1:4 M equivalent of methanol to avoid enzyme inhibition. The transesterification reaction conditions were as follows: oil/alcohol molar ratio 1:4; temperature 40 o C and total reaction time 6 h. Lipozyme TL-100L ® lipase provided the highest yield of fatty acid methyl esters as 92%. Operational stability was determined with immobilized lipase and it indicated that a small enzyme deactivation occurred after used repeatedly for 10 consecutive batches with each of 24 h. Since the process is yet effective and enzyme does not leak out from the polymer, the method can be proposed for industrial applications. -- Research highlights: → Lipozyme TL-100L and Novozym 388 were immobilized onto micro porous polymeric matrix by both physical adsorption and covalent linking. → Immobilized enzymes were used for synthesis of fatty acid methyl esters by transesterification of canola oil and methanol using semi-continuous operation system. → According to chromatographic analysis, Lipase Lipozyme TL-100L resulted in the highest yield of methyl ester as 92%.

  7. Investigation of bifunctional ester additives for methanol-gasoline system

    International Nuclear Information System (INIS)

    Zhang, J.; Yang, C.; Tang, Y.; Du, Q.; Song, N.; Zhang, Z.

    2014-01-01

    To explore new and multifunctional additives for methanol-gasoline, tartaric ester were synthesized and screened as phase stabilizer and saturation vapor pressure depressor for methanol-gasoline. The effect of the esters structure on the efficiency was discussed. The results show that the stabilities of the blends depend on the length of the glycolic esters alkoxy group. In addition, the tartaric esters also can depress the saturation vapor pressure of methanol-gasoline effectively in M15. Effect of the structure on the efficiency was also discussed. (author)

  8. Estereótipos e mulheres na cultura marroquina

    OpenAIRE

    Sadiqi,Fatima

    2008-01-01

    Estereótipos sobre as mulheres no Marrocos podem ser caracterizados como crenças culturais incompletas e inexatas mantidas por algumas pessoas e que se encontram inscritos em expressões lingüísticas ou em discursos subliminares. A cultura popular marroquina emprega representações poderosas para transmitir e sustentar tais estereótipos. Embora existam alguns estereótipos positivos, a maioria dos estereótipos sobre as mulheres no Marrocos é negativa e reflete ditames patriarcais subliminares qu...

  9. Emission and Mechanical Evaluations of Vinyl-Ester Resin Systems

    National Research Council Canada - National Science Library

    Sands, James

    2003-01-01

    Vinyl-ester resins (VE) are frequently used in liquid molding of composite materials for several applications including naval and army structures, commercial boat manufacturing, and building construction...

  10. Half esters and coating compositions comprising reactions products of half esters and polyepoxides

    NARCIS (Netherlands)

    Blaauw, R.; Mulder, W.J.; Koelewijn, R.; Boswinkel, G.

    2006-01-01

    The present invention relates to half esters based on dicarboxylic acid derivatives and dimer fatty diols, wherein the dimer fatty dio ls are based on dimerised and/or trimerised and/or oligomerised unsaturated fatty acids. The present invention further relates to resin compositions based on the

  11. Occurrence of 3-monochloropropanediol esters and glycidyl esters in commercial infant formulas in the United States.

    Science.gov (United States)

    Leigh, Jessica; MacMahon, Shaun

    2017-03-01

    This work presents occurrence data for fatty acid esters of 3-chloro-1,2-propanediol (3-MCPD) and glycidol in 98 infant formula samples purchased in the United States. These contaminants are considered potentially carcinogenic and/or genotoxic, making their presence in refined oils and foods a potential health risk. Recently, attention has focused on methodology to quantify MCPD and glycidyl esters in infant formula for risk-assessment purposes. Occurrence data for 3-MCPD and glycidyl esters were produced using a procedure for extracting fat from infant formula and an LC-MS/MS method for analysing fat extracts for intact esters. Infant formulas were produced by seven manufacturers, five of which use palm oil and/or palm olein in their formulations. In formulas containing palm/palm olein, concentrations for bound 3-MCPD and glycidol ranged from 0.021 to 0.92 mg kg - 1 (ppm) and from 3-MCPD and glycidol concentrations ranged from 0.072 to 0.16 mg kg - 1 (ppm) and from 0.005 to 0.15 mg kg - 1 (ppm), respectively. Although formulas from manufacturers A and G did not contain palm/palm olein, formulas from manufacturer E (containing palm olein) had the lowest concentrations of bound 3-MCPD and glycidol, demonstrating the effectiveness of industrial mitigation strategies.

  12. Role of low density lipoprotein-bound cholesterol esters in acute lymphoblastic leukemia cells

    International Nuclear Information System (INIS)

    Cutts, J.L.; Madden, E.A.; Melnykovych, G.

    1986-01-01

    The glucocorticoid sensitive CEM-C7 T-cell line was derived from human acute lymphoblastic leukemia cells by Norman and Thompson. Madden et al. have demonstrated that this growth inhibitory effect is due in part to a glucocorticoid-mediated inhibition of cholesterol synthesis and can be partially reversed by cholesterol dispersions. To further delineate the role of cholesterol in this growth inhibition, they have examined the ability of low density lipoprotein (LDL)-bound [ 3 H]cholesterol linoleate to reverse the growth inhibitory effect of 1 μM dexamethasone (Dex) on the CEM-C7 cells. LDL-bound cholesterol linoleate was unable to reverse the Dex-mediated growth inhibition, although incorporation of [ 14 C] acetate into free cholesterol was inhibited by 29%, following the Brown and Goldstein model. The presence of Dex further inhibited acetate incorporation into free cholesterol in the LDL-treated cells. Under all conditions, more than 99% of the acetate incorporated into cholesterol was present as free cholesterol, while over 87% of the LDL-bound cholesterol linoleate taken up remained in the ester compartment. These results indicate that CEM-C7 cells are unable to utilize LDL-bound cholesterol esters as a source of free cholesterol and rely on endogenous synthesis for their free cholesterol requirements

  13. Neutral Lipid Biosynthesis in Engineered Escherichia coli: Jojoba Oil-Like Wax Esters and Fatty Acid Butyl Esters

    OpenAIRE

    Kalscheuer, Rainer; Stöveken, Tim; Luftmann, Heinrich; Malkus, Ursula; Reichelt, Rudolf; Steinbüchel, Alexander

    2006-01-01

    Wax esters are esters of long-chain fatty acids and long-chain fatty alcohols which are of considerable commercial importance and are produced on a scale of 3 million tons per year. The oil from the jojoba plant (Simmondsia chinensis) is the main biological source of wax esters. Although it has a multitude of potential applications, the use of jojoba oil is restricted, due to its high price. In this study, we describe the establishment of heterologous wax ester biosynthesis in a recombinant E...

  14. Apple Aminoacid Profile and Yeast Strains in the Formation of Fusel Alcohols and Esters in Cider Production.

    Science.gov (United States)

    Eleutério Dos Santos, Caroline Mongruel; Pietrowski, Giovana de Arruda Moura; Braga, Cíntia Maia; Rossi, Márcio José; Ninow, Jorge; Machado Dos Santos, Tâmisa Pires; Wosiacki, Gilvan; Jorge, Regina Maria Matos; Nogueira, Alessandro

    2015-06-01

    The amino acid profile in dessert apple must and its effect on the synthesis of fusel alcohols and esters in cider were established by instrumental analysis. The amino acid profile was performed in nine apple musts. Two apple musts with high (>150 mg/L) and low (90%) during fermentation in all the ciders. Principal component analysis (PCA) explained 81.42% of data variability and the separation of three groups for the analyzed samples was verified. The ciders manufactured with low nitrogen content showed sluggish fermentation and around 50% less content of volatile compounds (independent of the yeast strain used), which were mainly 3-methyl-1-butanol (isoamyl alcohol) and esters. However, in the presence of amino acids (asparagine, aspartic acid, glutamic acid and alanine) there was a greater differentiation between the yeasts in the production of fusel alcohols and ethyl esters. High contents of these aminoacids in dessert apple musts are essential for the production of fusel alcohols and most of esters by aromatic yeasts during cider fermentation. © 2015 Institute of Food Technologists®

  15. Esterase- and pH-responsive poly(β-amino ester)-capped mesoporous silica nanoparticles for drug delivery

    Science.gov (United States)

    Fernando, Isurika R.; Ferris, Daniel P.; Frasconi, Marco; Malin, Dmitry; Strekalova, Elena; Yilmaz, M. Deniz; Ambrogio, Michael W.; Algaradah, Mohammed M.; Hong, Michael P.; Chen, Xinqi; Nassar, Majed S.; Botros, Youssry Y.; Cryns, Vincent L.; Stoddart, J. Fraser

    2015-04-01

    Gating of mesoporous silica nanoparticles (MSNs) with the stimuli-responsive poly(β-amino ester) has been achieved. This hybrid nanocarrier releases doxorubicin (DOX) under acidic conditions or in the presence of porcine liver esterase. The DOX loaded poly(β-amino ester)-capped MSNs reduce cell viability when tested on MDA-MB-231 human breast cancer cells.Gating of mesoporous silica nanoparticles (MSNs) with the stimuli-responsive poly(β-amino ester) has been achieved. This hybrid nanocarrier releases doxorubicin (DOX) under acidic conditions or in the presence of porcine liver esterase. The DOX loaded poly(β-amino ester)-capped MSNs reduce cell viability when tested on MDA-MB-231 human breast cancer cells. Electronic supplementary information (ESI) available: Experimental details relating to (i) the synthesis and characterisation of the surface-functionalised MSN and POL (ii) cargo-loading and release studies in solution, (iii) cellular internalisation of nanomaterials, and (iv) cell viability tests. See DOI: 10.1039/c4nr07443b

  16. SwissProt search result: AK107138 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK107138 002-124-C12 (P38571) Lysosomal acid lipase/cholesteryl ester hydrolase pre...cursor (EC 3.1.1.13) (LAL) (Acid cholesteryl ester hydrolase) (Sterol esterase) (Lipase A) (Cholesteryl esterase) LICH_HUMAN 4e-40 ...

  17. SwissProt search result: AK100511 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK100511 J023099N19 (P38571) Lysosomal acid lipase/cholesteryl ester hydrolase prec...ursor (EC 3.1.1.13) (LAL) (Acid cholesteryl ester hydrolase) (Sterol esterase) (Lipase A) (Cholesteryl esterase) LICH_HUMAN 2e-58 ...

  18. SwissProt search result: AK100511 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK100511 J023099N19 (Q64194) Lysosomal acid lipase/cholesteryl ester hydrolase prec...ursor (EC 3.1.1.13) (LAL) (Acid cholesteryl ester hydrolase) (Sterol esterase) (Lipase A) (Cholesteryl esterase) LICH_RAT 4e-51 ...

  19. SwissProt search result: AK064554 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK064554 002-112-C03 (P38571) Lysosomal acid lipase/cholesteryl ester hydrolase pre...cursor (EC 3.1.1.13) (LAL) (Acid cholesteryl ester hydrolase) (Sterol esterase) (Lipase A) (Cholesteryl esterase) LICH_HUMAN 6e-15 ...

  20. SwissProt search result: AK107138 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK107138 002-124-C12 (Q64194) Lysosomal acid lipase/cholesteryl ester hydrolase pre...cursor (EC 3.1.1.13) (LAL) (Acid cholesteryl ester hydrolase) (Sterol esterase) (Lipase A) (Cholesteryl esterase) LICH_RAT 7e-40 ...

  1. SwissProt search result: AK243532 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243532 J100077E15 (Q64194) Lysosomal acid lipase/cholesteryl ester hydrolase prec...ursor (EC 3.1.1.13) (LAL) (Acid cholesteryl ester hydrolase) (Sterol esterase) (Lipase A) (Cholesteryl esterase) LICH_RAT 2e-31 ...

  2. SwissProt search result: AK243532 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243532 J100077E15 (Q9Z0M5) Lysosomal acid lipase/cholesteryl ester hydrolase prec...ursor (EC 3.1.1.13) (LAL) (Acid cholesteryl ester hydrolase) (Sterol esterase) (Lipase A) (Cholesteryl esterase) LICH_MOUSE 6e-35 ...

  3. SwissProt search result: AK064554 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK064554 002-112-C03 (Q9Z0M5) Lysosomal acid lipase/cholesteryl ester hydrolase pre...cursor (EC 3.1.1.13) (LAL) (Acid cholesteryl ester hydrolase) (Sterol esterase) (Lipase A) (Cholesteryl esterase) LICH_MOUSE 6e-15 ...

  4. SwissProt search result: AK107138 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK107138 002-124-C12 (Q9Z0M5) Lysosomal acid lipase/cholesteryl ester hydrolase pre...cursor (EC 3.1.1.13) (LAL) (Acid cholesteryl ester hydrolase) (Sterol esterase) (Lipase A) (Cholesteryl esterase) LICH_MOUSE 2e-39 ...

  5. SwissProt search result: AK100511 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK100511 J023099N19 (Q9Z0M5) Lysosomal acid lipase/cholesteryl ester hydrolase prec...ursor (EC 3.1.1.13) (LAL) (Acid cholesteryl ester hydrolase) (Sterol esterase) (Lipase A) (Cholesteryl esterase) LICH_MOUSE 2e-52 ...

  6. SwissProt search result: AK064554 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK064554 002-112-C03 (Q64194) Lysosomal acid lipase/cholesteryl ester hydrolase pre...cursor (EC 3.1.1.13) (LAL) (Acid cholesteryl ester hydrolase) (Sterol esterase) (Lipase A) (Cholesteryl esterase) LICH_RAT 1e-11 ...

  7. SwissProt search result: AK243532 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK243532 J100077E15 (P38571) Lysosomal acid lipase/cholesteryl ester hydrolase prec...ursor (EC 3.1.1.13) (LAL) (Acid cholesteryl ester hydrolase) (Sterol esterase) (Lipase A) (Cholesteryl esterase) LICH_HUMAN 9e-36 ...

  8. Determination of Phthalate Esters in the Aquatic Environment ...

    African Journals Online (AJOL)

    The use of solid phase extraction and capillary GLC provides the basis for selective determination of phthalate ester plasticizers in rivers and marine water samples. Of the several solvent ratios (methanol in dichloromethane) that were tried for selective elution of phthalate esters from the C18 solid phase glass catridge, the ...

  9. Effect of Sucrose Esters on the Physicochemical Properties of Wheat ...

    African Journals Online (AJOL)

    HP

    Purpose: To investigate the effect of sucrose esters on the physicochemical properties of wheat starch. Methods: Sucrose ester was mixed with wheat starch extracted from normal soft wheat cultivars and heated. Change in starch properties arising from the interaction between were assessed for starch blue value, viscosity ...

  10. Alternative Production of Fatty Acid Methyl Esters from Triglycerides ...

    African Journals Online (AJOL)

    The catalysts activity was tested in thermocatalytic cracking of triglyceride; a direct conversion process for fatty acid methyl esters (biodiesel). The SZ1 not only exhibited higher conversion of triglycerides but higher fatty acid methyl esters (FAMEs) yields of approximately 59% after 3h as compared to SZ2 (32%). In addition ...

  11. 13-week oral toxicity study with stanol esters in rats

    NARCIS (Netherlands)

    Turnbull, D.; Whittaker, M.H.; Frankos, V.H.; Jonker, D.

    1999-01-01

    Plant sterols and their saturated derivatives, known as stanols, reduce serum cholesterol when consumed in amounts of approximately 2 g per day. Stanol fatty acid esters have been developed as a highly fat-soluble form that may lower cholesterol more effectively than stanols. Stanol esters occur

  12. Preparation of esters of gallic acid with higher primary alcohols

    NARCIS (Netherlands)

    Kerk, G.J.M. van der; Verbeek, J.H.; Cleton, J.C.F.

    1951-01-01

    The esters of gallic acid and higher primary alcohols, especially fatty alcohols, have recently gained considerable interest as possible antioxidants for fats. Two independent methods for the preparation of these esters are described. In the first method the hitherto unknown compound galloyl

  13. Distribution of phthalate esters in underground water from power ...

    African Journals Online (AJOL)

    This study investigates the distribution of phthalateacid esters (PAEs) in groundwater from some power stations in Delta State. Groundwater samples were collected from eight power transmission and distribution stations. Concentrations (μg/L) of six phthalate acid esters compounds in the groundwater ranged from ...

  14. Rapid NIR determination of alkyl esters in virgin olive oil

    International Nuclear Information System (INIS)

    Cayuela, J.A.

    2017-01-01

    The regulation of The European Union for olive oil and olive pomace established the limit of 35 mg·kg-1 for fatty acids ethyl ester contents in extra virgin olive oils, from grinding seasons after 2016. In this work, predictive models have been established for measuring fatty acid ethyl and methyl esters and to measure the total fatty acid alkyl esters based on near infrared spectroscopy (NIRS), and used successfully for this purpose. The correlation coefficients from the external validation exercises carried out with these predictive models ranged from 0.84 to 0.91. Different classification tests using the same models for the thresholds 35 mg·kg-1 for fatty acid ethyl esters and 75 mg·kg-1 for fatty acid alkyl esters provided success percentages from 75.0% to 95.2%. [es

  15. Access to Optically Pure β-Hydroxy Esters via Non-Enzymatic Kinetic Resolution by a Planar-Chiral DMAP Catalyst

    Directory of Open Access Journals (Sweden)

    Alba E. Díazlvarez

    2014-09-01

    Full Text Available The development of new approaches to obtain optically pure β-hydroxy esters is an important area in synthetic organic chemistry since they are precursors of other high value compounds. Herein, the kinetic resolution of racemic β-hydroxy esters using a planar-chiral DMAP derivative catalyst is presented. Following this procedure, a range of aromatic β-hydroxy esters was obtained in excellent selectivities (up to s = 107 and high enantiomeric excess (up to 99% ee. Furthermore, the utility of the present method was demonstrated in the synthesis of (S-3-hydroxy-N-methyl-3-phenylpropanamide, a key intermediate for bioactive molecules such as fluoxetine, tomoxetine or nisoxetine, in its enantiomerically pure form.

  16. Quantitative Profiling of Ester Compounds Using HS-SPME-GC-MS and Chemometrics for Assessing Volatile Markers of the Second Fermentation in Bottle.

    Science.gov (United States)

    Muñoz-Redondo, José Manuel; Cuevas, Francisco Julián; León, Juan Manuel; Ramírez, Pilar; Moreno-Rojas, José Manuel; Ruiz-Moreno, María José

    2017-04-05

    A quantitative approach using HS-SPME-GC-MS was performed to investigate the ester changes related to the second fermentation in bottle. The contribution of the type of base wine to the final wine style is detailed. Furthermore, a discriminant model was developed based on ester changes according to the second fermentation (with 100% sensitivity and specificity values). The application of a double-check criteria according to univariate and multivariate analyses allowed the identification of potential volatile markers related to the second fermentation. Some of them presented a synthesis-ratio around 3-fold higher after this period and they are known to play a key role in wine aroma. Up to date, this is the first study reporting the role of esters as markers of the second fermentation. The methodology described in this study confirmed its suitability for the wine aroma field. The results contribute to enhance our understanding of this fermentative step.

  17. Discrimination of processing grades of olive oil and other vegetable oils by monochloropropanediol esters and glycidyl esters

    NARCIS (Netherlands)

    Yan, Jing; Oey, Sergio B.; Leeuwen, van Stefan P.J.; Ruth, van Saskia M.

    2018-01-01

    In this study, the processing derived contaminants 2- and 3-monochloropropanediol (2- and 3-MCPD) esters and glycidyl esters (GEs) were analysed in 84 oil samples by GC–MS/MS for the discrimination of processing grades of olive oils as a potential authentication tool. Concentrations of 2- and 3-MCPD

  18. A "catalyst switch" Strategy for the sequential metal-free polymerization of epoxides and cyclic Esters/Carbonate

    KAUST Repository

    Zhao, Junpeng

    2014-06-24

    A "catalyst switch" strategy was used to synthesize well-defined polyether-polyester/polycarbonate block copolymers. Epoxides (ethylene oxide and/or 1,2-butylene oxide) were first polymerized from a monoalcohol in the presence of a strong phosphazene base promoter (t-BuP4). Then an excess of diphenyl phosphate (DPP) was introduced, followed by the addition and polymerization of a cyclic ester (ε-caprolactone or δ-valerolactone) or a cyclic carbonate (trimethylene carbonate), where DPP acted as both the neutralizer of phosphazenium alkoxide (polyether chain end) and the activator of cyclic ester/carbonate. This work has provided a one-pot sequential polymerization method for the metal-free synthesis of block copolymers from monomers which are suited for different types of organic catalysts. © 2014 American Chemical Society.

  19. A "catalyst switch" Strategy for the sequential metal-free polymerization of epoxides and cyclic Esters/Carbonate

    KAUST Repository

    Zhao, Junpeng; Pahovnik, David; Gnanou, Yves; Hadjichristidis, Nikolaos

    2014-01-01

    A "catalyst switch" strategy was used to synthesize well-defined polyether-polyester/polycarbonate block copolymers. Epoxides (ethylene oxide and/or 1,2-butylene oxide) were first polymerized from a monoalcohol in the presence of a strong phosphazene base promoter (t-BuP4). Then an excess of diphenyl phosphate (DPP) was introduced, followed by the addition and polymerization of a cyclic ester (ε-caprolactone or δ-valerolactone) or a cyclic carbonate (trimethylene carbonate), where DPP acted as both the neutralizer of phosphazenium alkoxide (polyether chain end) and the activator of cyclic ester/carbonate. This work has provided a one-pot sequential polymerization method for the metal-free synthesis of block copolymers from monomers which are suited for different types of organic catalysts. © 2014 American Chemical Society.

  20. Palladium(II) complexes with R(2)edda derived ligands. Part IV. O,O'-dialkyl esters of (S,S)-ethylenediamine-N,N'-di-2-(4-methyl)-pentanoic acid dihydrochloride and their palladium(II) complexes: synthesis, characterization and in vitro antitumoral activity against chronic lymphocytic leukemia (CLL) cells.

    Science.gov (United States)

    Vujić, Jelena M; Cvijović, Milica; Kaluderović, Goran N; Milovanović, Marija; Zmejkovski, Bojana B; Volarević, Vladislav; Arsenijević, Nebojsa; Sabo, Tibor J; Trifunović, Srećko R

    2010-09-01

    Four novel bidentate N,N'-ligand precursors, including O,O'-dialkyl esters (alkyl = ethyl, n-propyl, n-butyl and n-pentyl), L1 x 2 HCl-L4 x 2 HCl, of (S,S)-ethylenediamine-N,N'-di-2-(4-methyl)-pentanoic acid dihydrochloride [(S,S)-H(4)eddl]Cl(2) and the corresponding palladium(II) complexes 1-4, were prepared and characterized by IR, (1)H NMR and (13)C NMR spectroscopy and elemental analysis. In vitro cytotoxicity of all compounds was determined against chronic lymphocytic leukemia cells (CLL). The compounds were found to exhibit higher antitumoral activity than cisplatin. The most active compound 2, [PdCl(2){(S,S)-nPr(2)eddl}], was found to be 13.6 times more active than cisplatin on CLL cells. 2010 Elsevier Masson SAS. All rights reserved.