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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...

  2. Cholesteryl esters in human malignant neoplasms.

    Science.gov (United States)

    Tosi, M R; Bottura, G; Lucchi, P; Reggiani, A; Trinchero, A; Tugnoli, V

    2003-01-01

    Cholesteryl esters (CholE) were detected in human malignant neoplasms by means of in vitro nuclear magnetic resonance spectroscopy. Spectroscopic analysis of the total lipid extracts obtained from cerebral tumors revealed appreciable amount of esterified cholesterol in high grade gliomas such as glioblastomas and anaplastic oligodendrogliomas, characterized by prominent neovascularity. The finding that no CholE were detected in the healthy brain and in low grade and benign tumors supports a possible correlation between this class of lipids and histological vascular proliferation. Compared with high grade gliomas, renal cell carcinomas show higher levels of CholE, absent in the healthy renal parenchyma and in benign oncocytomas. In nefro-carcinomas, cytoplasmic lipid inclusions and prominent vascularization contribute to the increased levels of CholE present mainly as oleate. CholE are discussed as potential biochemical markers of cancer and as a target for new therapeutic strategies.

  3. THE ACTIVITY OF CHOLESTERYL ESTER TRANSFER PROTEIN IS DECREASED IN HYPOTHYROIDISM - A POSSIBLE CONTRIBUTION TO ALTERATIONS IN HIGH-DENSITY-LIPOPROTEINS

    NARCIS (Netherlands)

    DULLAART, RPF; HOOGENBERG, K; GROENER, JEM; DIKKESCHEI, LD; ERKELENS, DW; DOORENBOS, H

    1990-01-01

    The activity of cholesteryl ester transfer protein is instrumental in the distribution of cholesteryl ester between lipoproteins in plasma. We measured the activity of cholesteryl ester transfer protein in plasma, designated cholesteryl ester transfer activity, as the rate of cholesteryl ester trans

  4. Effects of ethanol, acetaldehyde and cholesteryl esters on pancreatic lysosomes.

    OpenAIRE

    Wilson, J S; Apte, M V; Thomas, M. C.; Haber, P S; Pirola, R C

    1992-01-01

    Recent studies indicate that altered lysosomal function may be involved in the early stages of pancreatic injury. Chronic consumption of ethanol increases rat pancreatic lysosomal fragility. The aim of this study is to determine whether the lysosomal fragility observed after chronic ethanol consumption is mediated by ethanol per se, its oxidative metabolite acetaldehyde or cholesteryl esters (substances which accumulate in the pancreas after ethanol consumption). Pancreatic lysosomes from cho...

  5. The micromethod for determination of cholesterol, cholesteryl esters and phospholipids

    Directory of Open Access Journals (Sweden)

    Okabe,Akinobu

    1974-12-01

    Full Text Available We examined the method for determining microquantities of lipids, including cholesterol, cholesteryl esters and phospholipids. A standard colorimetric procedure of cholesteryl esters was modified to accommodate a quantitative thin-layer chromatography. This method involved the following steps. (1 Separation of lipids by a thin-layer chromatography: Lipids were applied to Silica gel G plates. Plates were developed with petroleum ether-diethyl etheracetic acid (82: 18: 2, vIvIv. (2 Elution of cholesterol and its esters from scraped silica gel: After scraping the silica gel with adhered cholesterol and its esters, they were eluted with chloroform-methanol (4: 1, v,tv. In the case of phspholipids, the silica gel was calcified. (3 Colorimetric determination of the lipids: Cholesterol and its esters eluted from the silica gel were determined by the method of ZAK with ROSENTHAL'S color reagent directly and after saponification, respectively. Phospholipids were calculated from the phosphorous content determined by the method of KATES. On the basis of examination of recovery and analyses of lipids extracted from tissue, it was concluded that this method permitted a reliable estimation of microquantities of cholesterol, its esters and phospholipids from small amounts of biological materials.

  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.

    2015-01-01

    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. 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...... 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...

  8. Elevated plasma cholesteryl ester transfer in NIDDM : relationships with apolipoprotein B-containing lipoproteins and phospholipid transfer protein

    NARCIS (Netherlands)

    Riemens, S; van Tol, A; Sluiter, W; Dullaart, R

    1998-01-01

    Lecithin:cholesteryl acyl transferase (LCAT) and cholesteryl ester transfer protein (CETP) are key factors in the esterification of cholesterol and the subsequent transfer of cholesteryl ester from high density lipoproteins (HDL) towards very low and low density lipoproteins (VLDL + LDL). Phospholip

  9. Exploring unsaturated fatty acid cholesteryl esters as transdermal permeation enhancers.

    Science.gov (United States)

    Rambharose, Sanjeev; Kalhapure, Rahul S; Jadhav, Mahantesh; Govender, Thirumala

    2017-04-01

    The intrinsic protective barrier property of skin, one of the major challenges in the design of transdermal drug delivery systems, can be overcome through the use of chemical permeation enhancers (CPEs). Herein, we explore the potential of unsaturated fatty acid (UFA) esters of cholesterol (Chol) viz., oleate, linoleate and linolenate, as transdermal CPEs using tenofovir (TNF) as a model drug. All Chol UFA esters at 1% w/w were found to be more effective enhancers when compared to their respective parent fatty acids (FAs) and saturated FA counterparts. Cholesteryl linolenate (Chol-LLA) showed the most superior performance (enhancement ratio (ER) = 3.71). The greatest ER for Chol-LLA (5.93) was achieved at a concentration of 2% w/w. The histomorphological and transepithelial electrical resistance (TEER) evaluations supported the results of the permeability studies. These findings showed no significant loss in the integrity of the epidermis, with drug and enhancer treatment having temporary effects on the barrier property of the epidermis. Chol UFA esters can therefore be considered as new CPEs for exploitation in topical formulations for various classes of drugs.

  10. Evolving neural network optimization of cholesteryl ester separation by reversed-phase HPLC

    OpenAIRE

    Jansen, Michael A.; Kiwata, Jacqueline; Arceo, Jennifer; Faull, Kym F.; Hanrahan, Grady; Porter, Edith

    2010-01-01

    Cholesteryl esters have antimicrobial activity and likely contribute to the innate immunity system. Improved separation techniques are needed to characterize these compounds. In this study, optimization of the reversed-phase high-performance liquid chromatography separation of six analyte standards (four cholesteryl esters plus cholesterol and tri-palmitin) was accomplished by modeling with an artificial neural network–genetic algorithm (ANN-GA) approach. A fractional factorial design was emp...

  11. 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

    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...... change of helix X of CETP to an open state, in which we found the accessibility of cholesteryl esters to the C-terminal tunnel opening of CETP to increase. Furthermore, in the absence of helix X, cholesteryl esters rapidly diffused into CETP through the C-terminal opening. The results provide compelling...

  12. Critical role of neutral cholesteryl ester hydrolase 1 in cholesteryl ester hydrolysis in murine macrophages[S

    Science.gov (United States)

    Sakai, Kent; Igarashi, Masaki; Yamamuro, Daisuke; Ohshiro, Taichi; Nagashima, Shuichi; Takahashi, Manabu; Enkhtuvshin, Bolormaa; Sekiya, Motohiro; Okazaki, Hiroaki; Osuga, Jun-ichi; Ishibashi, Shun

    2014-01-01

    Hydrolysis of intracellular cholesteryl ester (CE) is the rate-limiting step in the efflux of cholesterol from macrophage foam cells. In mouse peritoneal macrophages (MPMs), this process is thought to involve several enzymes: hormone-sensitive lipase (Lipe), carboxylesterase 3 (Ces3), neutral CE hydrolase 1 (Nceh1). However, there is some disagreement over the relative contributions of these enzymes. To solve this problem, we first compared the abilities of several compounds to inhibit the hydrolysis of CE in cells overexpressing Lipe, Ces3, or Nceh1. Cells overexpressing Ces3 had negligible neutral CE hydrolase activity. We next examined the effects of these inhibitors on the hydrolysis of CE and subsequent cholesterol trafficking in MPMs. CE accumulation was increased by a selective inhibitor of Nceh1, paraoxon, and two nonselective inhibitors of Nceh1, (+)-AS115 and (−)-AS115, but not by two Lipe-selective inhibitors, orlistat and 76-0079. Paraoxon inhibited cholesterol efflux to apoA-I or HDL, while 76-0079 did not. These results suggest that Nceh1 plays a dominant role over Lipe in the hydrolysis of CE and subsequent cholesterol efflux in MPMs. PMID:24868095

  13. Phase behavior and crystalline structures of cholesteryl ester mixtures: a C-13 MASNMR study.

    Science.gov (United States)

    Guo, W; Hamilton, J A

    1995-06-01

    Cholesteryl esters are a transport and storage form of cholesterol in normal physiology but also a significant lipid in atherosclerotic plaques. To understand better the molecular properties of cholesteryl esters in tissues and plaques, we have studied the polymorphic and mesomorphic features of pure and mixed cholesteryl esters by solid state C-13 NMR with magic angle sample spinning (MASNMR). The temperature-dependent properties of two single components (cholesteryl linoleate (CL, C18:2) and cholesteryl linolenate (CLL, C18:3)), four binary systems (cholesteryl palmitate (CP, C16:0) with CL, CLL or cholesteryl oleate (CO, C18:1), and CO/CL), one ternary system (CO/CP/CL), and one quaternary system (CO/CP/CL/CLL) were studied. The mixing ratios were based on the composition of an atherosclerosis plaque dissected from a cholesterol-fed New Zealand white rabbit. C-13 MASNMR determined the phase transition temperatures, identified the phases present in all systems, and provided novel information about molecular structures. For example, solid CL exhibited a disordered structure with multiple molecular conformations, whereas pure CLL had a crystalline structure different from the three most commonly characterized forms (MLII, MLI, BL). In binary mixtures, the crystalline structure of each cholesteryl ester species was identified by its own characteristic resonances. It was found that CP always existed in its native BL form, but CL and CO were influenced by the composition of the mixture. CL was induced to form MLII crystals by the coexisting CP (55 wt%). When CO was cooled from the isotropic phase, it existed as a mixture of MLII and an amorphous form. The presence of CP significantly accelerated the conversion of the amorphous form to the MLII form. For the ternary mixture co-dried from chloroform, CL cocrystallized with CO in the MLII form and CP existed in BL form. Addition of a small amount of CLL slightly increased the heterogeneity of the solid mixture, but had

  14. Plasma cholesteryl ester transfer protein is predominantly derived from Kupffer cells

    NARCIS (Netherlands)

    Wang, Y.; Tuin, S. van der; Tjeerdema, N.; Dam, A.D. van; Rensen, S.S.; Hendrikx, T.; Berbee, J.F.; Atanasovska, B.; Fu, J.; Hoekstra, M.; Bekkering, S.; Riksen, N.P.; Buurman, W.A.; Greve, J.W.; Hofker, M.H.; Shiri-Sverdlov, R.; Meijer, O.C.; Smit, J.W.A.; Havekes, L.M.; Dijk, K.W. van; Rensen, P.C.

    2015-01-01

    The role of Kupffer cells (KCs) in the pathophysiology of the liver has been firmly established. Nevertheless, KCs have been underexplored as a target for diagnosis and treatment of liver diseases owing to the lack of noninvasive diagnostic tests. We addressed the hypothesis that cholesteryl ester t

  15. Plasma Cholesteryl Ester Transfer Protein Is Predominantly Derived From Kupffer Cells

    NARCIS (Netherlands)

    Wang, Yanan; van der Tuin, Sam; Tjeerdema, Nathanja; van Dam, Andrea D.; Rensen, Sander S.; Hendrikx, Tim; Berbee, Jimmy F. P.; Atanasovska, Biljana; Fu, Jingyuan; Hoekstra, Menno; Bekkering, Siroon; Riksen, Niels P.; Buurman, Wim A.; Greve, Jan Willem; Hofker, Marten H.; Shiri-Sverdlov, Ronit; Meijer, Onno C.; Smit, Johannes W. A.; Havekes, Louis M.; van Dijk, Ko Willems; Rensen, Patrick C. N.

    2015-01-01

    The role of Kupffer cells (KCs) in the pathophysiology of the liver has been firmly established. Nevertheless, KCs have been underexplored as a target for diagnosis and treatment of liver diseases owing to the lack of noninvasive diagnostic tests. We addressed the hypothesis that cholesteryl ester t

  16. Self-assembled monolayers of cholesterol and cholesteryl esters on graphite.

    Science.gov (United States)

    Hibino, Masahiro; Tsuchiya, Hiroshi

    2014-06-17

    The molecular arrangements of self-assembled monolayers (SAMs) of cholesterol, cholesteryl laurate, and cholesteryl stearate adsorbed on a graphite surface were studied using scanning tunneling microscopy (STM) at the liquid-solid interface. The STM images of the SAMs showed two-dimensional periodic arrays of bright regions that corresponded to the sterol rings. However, individual sterol rings could not be observed in the bright regions in the STM images of the cholesterol monolayers. Nevertheless, by comparing the STM images and the crystallographic data, it is concluded that the cholesterol molecules are arranged in pairs oriented head-to-head owing to the hydrogen bonds between the hydroxyl groups. These dimers, in turn, are oriented parallel to each other, owing to the interactions between the sterol rings. The STM images of cholesteryl ester monolayers had molecular resolution and showed pairs of cholesteryl ester molecules oriented in an antiparallel manner, with their fatty acid chains located in the central regions. Furthermore, the fatty acid chains of cholesteryl stearate were observed to be oriented in the (1120) zigzag direction of the graphite lattice, whereas those of cholesteryl laurate were oriented in the (1010) armchair direction. These observations reveal that the interactions between the fatty acid chains affect the structure of the SAMs. The molecular arrangements also depend on the lengths of the fatty acid chains of the cholesterol esters and hence on the interactions between the alkyl chains and the graphite surface. The self-assembly at the liquid-solid interface is therefore controlled by the interactions between sterol rings, between alkyl chains, and between alkyl chains and the substrate.

  17. Fatty acid composition in major depression: decreased omega 3 fractions in cholesteryl esters and increased C20: 4 omega 6/C20:5 omega 3 ratio in cholesteryl esters and phospholipids.

    Science.gov (United States)

    Maes, M; Smith, R; Christophe, A; Cosyns, P; Desnyder, R; Meltzer, H

    1996-04-26

    Recently, there were some reports that major depression may be accompanied by alterations in serum total cholesterol, cholesterol ester and omega 3 essential fatty acid levels and by an increased C20: 4 omega 6/C20: 5 omega 3, i.e., arachidonic acid/eicosapentaenoic, ratio. The present study aimed to examine fatty acid composition of serum cholesteryl esters and phospholipids in 36 major depressed, 14 minor depressed and 24 normal subjects. Individual saturated (e.g., C14:0; C16:0, C18:0) and unsaturated (e.g., C18:1, C18:2, C20:4) fatty acids in phospholipid and cholesteryl ester fractions were assayed and the sums of the percentages of omega 6 and omega 3, saturated, branched chain and odd chain fatty acids, monoenes as well as the ratios omega 6/omega 3 and C20:4 omega 6/C20:5 omega 3 were calculated. Major depressed subjects had significantly higher C20:4 omega 6/C20:5 omega 3 ratio in both serum cholesteryl esters and phospholipids and a significantly increased omega 6/omega 3 ratio in cholesteryl ester fraction than healthy volunteers and minor depressed subjects. Major depressed subjects had significantly lower C18:3 omega 3 in cholesteryl esters than normal controls. Major depressed subjects showed significantly lower total omega 3 polyunsaturated fatty acids in cholesteryl esters and significantly lower C20:5 omega 3 in serum cholesteryl esters and phospholipids than minor depressed subjects and healthy controls. These findings suggest an abnormal intake or metabolism of essential fatty acids in conjunction with decreased formation of cholesteryl esters in major depression.

  18. The relationship between cholesteryl ester transfer protein levels and risk factor profile in patients with familial hypercholesterolemia

    NARCIS (Netherlands)

    de Grooth, Greetje J; Smilde, Tineke J; Van Wissen, Sanne; Klerkx, Anke H E M; Zwinderman, Aeilko H; Fruchart, Jean-Charles; Kastelein, John J P; Stalenhoef, Anton F H; Kuivenhoven, Jan Albert

    2004-01-01

    BACKGROUND: Cholesteryl ester transfer protein (CETP) mediates the transfer of neutral lipids between lipoproteins. The role of CETP in atherogenesis is controversial. To better understand the relationships between plasma CETP levels, lipoproteins and atherosclerosis, we assessed these parameters in

  19. Evolving neural network optimization of cholesteryl ester separation by reversed-phase HPLC.

    Science.gov (United States)

    Jansen, Michael A; Kiwata, Jacqueline; Arceo, Jennifer; Faull, Kym F; Hanrahan, Grady; Porter, Edith

    2010-07-01

    Cholesteryl esters have antimicrobial activity and likely contribute to the innate immunity system. Improved separation techniques are needed to characterize these compounds. In this study, optimization of the reversed-phase high-performance liquid chromatography separation of six analyte standards (four cholesteryl esters plus cholesterol and tri-palmitin) was accomplished by modeling with an artificial neural network-genetic algorithm (ANN-GA) approach. A fractional factorial design was employed to examine the significance of four experimental factors: organic component in the mobile phase (ethanol and methanol), column temperature, and flow rate. Three separation parameters were then merged into geometric means using Derringer's desirability function and used as input sources for model training and testing. The use of genetic operators proved valuable for the determination of an effective neural network structure. Implementation of the optimized method resulted in complete separation of all six analytes, including the resolution of two previously co-eluting peaks. Model validation was performed with experimental responses in good agreement with model-predicted responses. Improved separation was also realized in a complex biological fluid, human milk. Thus, the first known use of ANN-GA modeling for improving the chromatographic separation of cholesteryl esters in biological fluids is presented and will likely prove valuable for future investigators involved in studying complex biological samples.

  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. Kinetics of Non-Isothermal Crystallization of Coconut-based Cholesteryl Ester: Avrami and Ozawa Approache

    Directory of Open Access Journals (Sweden)

    J. F. Joson

    2003-06-01

    Full Text Available Kinetics of non-isothermal crystallization of coconut-based cholesteryl ester was performed by differentialscanning calorimetry under various heating rates. Different analysis methods were used to describe theprocess of non-isothermal crystallization. The results showed that the Avrami equation could describe thesystem very well. However, the Ozawa analysis failed. A probable reason is the difference in the crystallizationkinetics at high and low relative crystallization. The phase transitions of the coconut-based cholesterylester were also observed through optical polarizing microscopy

  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, 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,

  3. The association of HDL cholesterol concentration with the-629C > A CETP promoter polymorphism is not fully explained by its relationship with plasma cholesteryl ester transfer

    NARCIS (Netherlands)

    Dullaart, R. P. F.; Borggreve, S. E.; Hillege, H. L.; Dallinga-Thie, G. M.

    2008-01-01

    Objective . HDL cholesterol is associated with the -629C>A cholesteryl ester transfer protein (CETP) promoter polymorphism. This relationship may in part be explained via effects on plasma cholesteryl ester transfer (CET), which reflects the activity of CETP in the context of endogenous lipoproteins

  4. Effects of oxidation on the hydrolysis by cholesterol esterase of sitosteryl esters as compared to a cholesteryl ester.

    Science.gov (United States)

    Julien-David, Diane; Ennahar, Saïd; Miesch, Michel; Geoffroy, Philippe; Raul, Francis; Aoude-Werner, Dalal; Lessinger, Jean-Marc; Marchioni, Eric

    2009-10-01

    Phytosteryl esters (PE) are used as ingredients in functional food to decrease plasma concentration of low density lipoprotein-cholesterol (LDL-C). Effective impairment of cholesterol absorption by PE suggests that these esters are hydrolyzed by the pancreatic cholesterol esterase (CEase, EC 3.1.1.13) and the liberated sterol may interfere with cholesterol reducing its intestinal absorption. PE-enriched foods are marketed for cooking purposes, and temperature is one of the most important factors leading to the formation of oxidation products. Very little is known about the outcome of PE oxides during the digestive process. A new analytical method based on mass spectrometric detection directly after enzymatic reaction was developed to determine in vitro the activity of CEase on PE and their oxides present in functional food. Using this method, we identified a new inhibitor of CEase: sitosteryl 9,10-dihydroxystearate, which behaves as a non-competitive inhibitor of the hydrolysis of cholesteryl oleate and sitosteryl oleate.

  5. 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

    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 re

  6. Association of cholesteryl ester transfer protein genotypes with CETP mass and activity, lipid levels, and coronary risk

    NARCIS (Netherlands)

    Thompson, Alexander; Di Angelantonio, Emanuele; Sarwar, Nadeem; Erqou, Sebhat; Saleheen, Danish; Dullaart, Robin P. F.; Keavney, Bernard; Ye, Zheng; Danesh, John

    2008-01-01

    Context The importance of the cholesteryl ester transfer protein (CETP) pathway in coronary disease is uncertain. Study of CETP genotypes can help better understand the relevance of this pathway to lipid metabolism and disease risk. Objective To assess associations of CETP genotypes with CETP phenot

  7. 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

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

    NARCIS (Netherlands)

    R. Sofat (Reecha); A. Hingorani (Aroon); L. Smeeth (Liam); S.E. Humphries (Steve); P.J. Talmud; J. Cooper (Jim); T. Shah (Tina); M.S. Sandhu (Manjinder); S.L. Ricketts (Sally); S.M. Boekholdt (Matthijs); N.J. Wareham (Nick); K-T. Khaw (Kay-Tee); M. Kumari (Meena); M. Kivimaki (Mika); M. Marmot (Michael); F.W. Asselbergs (Folkert); P. van der Harst (Pim); R.P.F. Dullaart (Robin); G. Navis (Gerjan); D.J. van Veldhuisen (Dirk); W.H. van Gilst (Wiek); J.F. Thompson (John); P. McCaskie (Pamela); C. Palmer (Cameron); M. Arca (Marcello); F. Quagliarini (Fabiana); C. Gaudio (Carlo); F. Cambien (François); V. Nicaud; O. Poirer (Odette); V. Gudnason (Vilmundur); A.J. Isaacs (Aaron); J.C.M. Witteman (Jacqueline); P. Tikka-Kleemola (Päivi); M. Pencina (Michael); R.S. Vasan (Ramachandran Srini); R.B. D'Agostino (Ralph); J.M. Ordovas (Jose); T.Y. Li (Tricia); S. Kakko (Sakari); H. Kauma (Heikki); M.J. Savolainen (Markku); Y.A. Kesäniemi (Antero); A. Sandhofer (Anton); B. Paulweber (Bernhard); J.V. Sorli (Jose); A. Goto (Akimoto); S. Yokoyama (Shinji); K. Okumura (Kenji); B.D. Horne (Benjamin); C. Packard (Chris); D. Freeman (Dilys); I. Ford (Ian); N. Sattar (Naveed); V. McCormack (Valerie); D.A. Lawlor (Debbie); S. Ebrahim (Shanil); G.D. Smith; J.J.P. Kastelein (John); J. Deanfield (John); J.P. Casas (Juan)

    2010-01-01

    textabstractBackground: 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

  9. Lipid exchange mechanism of the cholesteryl ester transfer protein clarified by atomistic and coarse-grained simulations.

    Directory of Open Access Journals (Sweden)

    Artturi Koivuniemi

    2012-01-01

    Full Text Available 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 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 through its charged and tryptophan residues. Upon binding, CETP rapidly (in about 10 ns induced the formation of a small hydrophobic patch to the phospholipid surface of the droplet, opening a route from the core of the lipid droplet to the binding pocket of CETP. This was followed by a conformational change of helix X of CETP to an open state, in which we found the accessibility of cholesteryl esters to the C-terminal tunnel opening of CETP to increase. Furthermore, in the absence of helix X, cholesteryl esters rapidly diffused into CETP through the C-terminal opening. The results provide compelling 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.

  10. Lowered omega3 polyunsaturated fatty acids in serum phospholipids and cholesteryl esters of depressed patients.

    Science.gov (United States)

    Maes, M; Christophe, A; Delanghe, J; Altamura, C; Neels, H; Meltzer, H Y

    1999-03-22

    Depression is associated with a lowered degree of esterification of serum cholesterol, an increased C20:4omega6/C20:5omega3 ratio and decreases in omega3 fractions in fatty acids (FAs) or in the red blood cell membrane. The aims of the present study were to examine: (i) serum phospholipid and cholesteryl ester compositions of individual saturated fatty acids (SFAs), monounsaturated FAs (MUFAs) and polyunsaturated FAs (PUFAs) in major depressed patients vs. healthy volunteers; (ii) the relationships between the above FAs and lowered serum zinc (Zn), a marker of the inflammatory response in depression; and (iii) the effects of subchronic treatment with antidepressants on FAs in depression. The composition of the FAs was determined by means of thin layer chromatography in conjunction with gas chromatography. Lipid concentrations were assayed by enzymatic colorimetric methods. The oxidative potential index (OPI) of FAs was computed in 34 major depressed inpatients and 14 normal volunteers. Major depression was associated with: increased MUFA and C22:5omega3 proportions and increased C20:4omega6/C20:5omega3 and C22:5omega6/C22:6omega3 ratios; lower C22:4omega6, C20:5omega3 and C22:5omega3 fractions in phospholipids; lower C18:3omega3, C20:5omega3 and total (sigma)omega3 FAs, and higher C20:4omega6/C20:5omega3 and sigmaomega6/sigmaomega3 ratios in cholesteryl esters; lower serum concentrations of phospholipids and cholesteryl esters; and a decreased OPI. In depression, there were significant and positive correlations between serum Zn and C20:5omega3 and C22:6omega3 fractions in phospholipids; and significant inverse correlations between serum Zn and the sigmaomega6/sigmaomega3, C20:4omega6/C20:5omega3, and C22:5omega6/C22:6omega3 ratios in phospholipids. There was no significant effect of antidepressive treatment on any of the FAs. The results show that, in major depression, there is a deficiency of omega3 PUFAs and a compensatory increase in MUFAs and C22:5omega6 in

  11. Expression of the human apolipoprotein A-I gene in transgenic mice alters high density lipoprotein (HDL) particle size distribution and diminishes selective uptake of HDL cholesteryl esters

    Energy Technology Data Exchange (ETDEWEB)

    Chajekshaul, T.; Hayek, T.; Walsh, A.; Breslow, J.L. (Rockefeller University, New York, NY (USA))

    1991-08-01

    Transgenic mice carrying the human apolipoprotein (apo) A-I gene (HuAITg mice) were used to examine the effects of overexpression of the human gene on high density lipoprotein (HDL) particle size distribution and metabolism. On a chow diet, control mice had HDL cholesterol and apo A-I levels of 49 {plus minus} 2 and 137 {plus minus} 12 mg/dl of plasma, respectively. HuAITg mice had HDL cholesterol, human apo A-I, and mouse apo A-I levels of 88 {plus minus} 2, 255 {plus minus} 19, and 16 {plus minus} 2 mg/dl, respectively. Nondenaturing gradient gel electrophoresis revealed control mouse plasma HDL to be primarily monodisperse with a particle diameter of 10.2 nm, whereas HuAITg mouse plasma HDL was polydisperse with particles of diameter 11.4, 10.2, and 8.7 nm, which correspond in size to human HDL1, HDL2, and HDL3, respectively. In vivo turnover studies of HDL labeled with (3H)cholesteryl linoleyl ether and 125I-apo A-I were performed. In control animals, the fractional catabolic rate (FCR) for HDL cholesteryl ester was significantly more than the apo A-I FCR. In the HuAITg mice, the HDL cholesteryl ester FCR was the same as the apo A-I FCR. There were no significant differences between control and HuAITg animals in the sites of tissue removal of HDL cholesteryl ester, with the liver extracting most of the injected radioactivity. Control and HuAITg animals had comparable liver and intestinal cholesterol synthesis and LDL FCR. In conclusion, HuAITg mice have principally human and not mouse apo A-I in their plasma. This apparently causes a change in HDL particle size distribution in the transgenic mice to one resembling the human pattern. The replacement of mouse by human apo A-I also apparently causes the loss of the selective uptake pathway of HDL cholesteryl esters present in control mice.

  12. Severe chronic diarrhea and weight loss in cholesteryl ester storage disease: A case report

    Institute of Scientific and Technical Information of China (English)

    Uta Drebber; Matthias Andersen; Hans U Kasper; Peter Lohse; Manfred Stolte; Hans P Dienes

    2005-01-01

    AIM: An inherited deficiency of human lysosomal acid lipase (LAL)results in the rare conditions of Wolman disease and cholesteryl ester storage disease (CESD). We want to present the rare case of CESD in an adult.METHODS: We report about an adult female patient with severe chronic diarrhea and weight loss as a consequence of CESD. Clinical examination revealed signs of malabsorption and slightly elevated liver enzymes.RESULTS: Histopathologic changes in the liver tissue and DNA sequence analysis confirmed the diagnosis of CESD due to homozygosity for the most common CESD mutation,a G934A splice site defect encoded by exon 8 of the lysosomal acid lipase (LIPA) gene.CONCLUSION: It is the first case in the literature with diarrhea as a putative symptom of CESD in adult patients.

  13. Macrophage cholesterol homeostasis and metabolic diseases: critical role of cholesteryl ester mobilization.

    Science.gov (United States)

    Ghosh, Shobha

    2011-03-01

    Atherogenic dyslipidemia, including low HDL levels, is the major contributor of residual risk of cardiovascular disease that remains even after aggressive statin therapy to reduce LDL-cholesterol. Currently, distinction is not made between HDL-cholesterol and HDL, which is a lipoprotein consisting of several proteins and a core containing cholesteryl esters (CEs). The importance of assessing HDL functionality, specifically its role in facilitating cholesterol efflux from foam cells, is relevant to atherogenesis. Since HDLs can only remove unesterified cholesterol from macrophages while cholesterol is stored as CEs within foam cells, intracellular CE hydrolysis by CE hydrolase is vital. Reduction in macrophage lipid burden not only attenuates atherosclerosis but also reduces inflammation and linked pathologies such as Type 2 diabetes and chronic kidney disease. Targeting reduction in macrophage CE levels and focusing on enhancing cholesterol flux from peripheral tissues to liver for final elimination is proposed.

  14. Xanthohumol, a prenylated chalcone from Humulus lupulus L., inhibits cholesteryl ester transfer protein.

    Science.gov (United States)

    Hirata, Hiroshi; Takazumi, Koji; Segawa, Shuichi; Okada, Yukio; Kobayashi, Naoyuki; Shigyo, Tatsuro; Chiba, Hitoshi

    2012-10-01

    High density lipoprotein (HDL)-cholesterol levels are correlated with a low risk of atherosclerosis. The inhibition of cholesteryl ester transfer protein (CETP), which catalyses cholesterol transfer between lipoproteins, leads to an increase in HDL-cholesterol and is expected to be the next anti-atherogenic target. This study revealed that xanthohumol, a prenylated chalcone, showed the highest inhibition against CETP from screening of natural products in various plants. We investigated the inhibitory activity of some chalcones and flavanones. Naringenin chalcone showed weak CETP inhibition compared with xanthohumol. In addition, isoxanthohumol and naringenin drastically decreased the inhibitory activity. These results suggest that the prenyl group and chalcone structure of xanthohumol were responsible for the CETP inhibitory activity.

  15. Cloning and characterization of cholesteryl ester transfer protein isolated from the tree shrew

    Institute of Scientific and Technical Information of China (English)

    曾武威; 张坚; 陈保生; 吴钢; 薛红

    2003-01-01

    ObjectiveTo obtain the nucleotide sequence and deduced amino acid sequence of cholesterylester transfer protein (CETP) cDNA from the tree shrew (Tupaia glis). MethodsThe cDNA sequence of the tree shrew CETP was obtained by utilizing the techniqueof switching mechanism at 5' end of RNA transcript (SMART) and rapid amplification of cDNA end (RACE) from the first strand of the cDNA. The amino acidsequence of CETP was deduced from the cDNA sequence and its primary and secondary structures were predicted. ResultsThe sequence of CETP cDNA from tree shrew (GenBank accession number AF334033) covers 1636 bp, including 178 bp at the 3' end of the untranslated region anda 1458 bp fragment in a coding region, which provides the complete sequence of mature tree shrew CETP, although not the initiator methionine. The first 24 bp encodes a partial signal peptide. The mature protein consists of 477 amino acids and is longer than the human version by one amino acid (Gly318). Comparing this amino acid sequence with those of other animals' CETPs, the identity between tree shrew and human and rabbit CETP is 88% and 82%, respectively. The protein is extremely hydrophobic as it contains many hydrophobic residues, especially at the C-terminal, consistent with its function in the transfer of neutral lipids. The amino acid residues concerning with binding and transferringneutral lipids are highly conserved. There is a deletion of an N-linked glycosylation site at Asn342 in the tree shrew CETP protein that may participate in the removal of peripheral cholesterol and cholesteryl ester by increasing its activity of transferring cholesteryl ester. ConclusionThe possible glycosylation in the tree shrew CETP may be involved in the molecular mechanism of its insusceptibility to atherosclerosis.

  16. Lysosomal lipase deficiency: molecular characterization of eleven patients with Wolman or cholesteryl ester storage disease.

    Science.gov (United States)

    Fasano, Tommaso; Pisciotta, Livia; Bocchi, Letizia; Guardamagna, Ornella; Assandro, Paola; Rabacchi, Claudio; Zanoni, Paolo; Filocamo, Mirella; Bertolini, Stefano; Calandra, Sebastiano

    2012-03-01

    Wolman Disease (WD) and cholesteryl ester storage disease (CESD) represent two distinct phenotypes of the same recessive disorder caused by the complete or partial deficiency of lysosomal acidic lipase (LAL), respectively. LAL, encoded by the LIPA gene, hydrolyzes cholesteryl esters derived from cell internalization of plasma lipoproteins. WD is a rapidly progressive and lethal disease characterized by intestinal malabsorption, hepatic and adrenal failure. CESD is characterized by hepatic fibrosis, hyperlipidemia and accelerated atherosclerosis. Aim of the study was the identification of LIPA mutations in three WD and eight CESD patients. The WD patients, all deceased before the first year of age, were homozygous for two novel mutations (c.299+1G>A and c.419G>A) or a mutation (c.796G>T) previously reported as compound heterozygosity in a CESD patient. The two mutations (c.419G>A and c.796G>T) resulting in truncated proteins (p.W140* and p.G266*) and the splicing mutation (c.229+1G>A) were associated with undetectable levels of LIPA mRNA in fibroblasts. All eight CESD patients carried the common mutation c.894G>A known to result not only in a major non-functional transcript with the skipping of exon 8 (p.S275_Q298del), but also in a minor normally spliced transcript producing 5-10% residual LAL activity. The c.894G>A mutation was found in homozygosity in four patients and, as compound heterozygosity, in association with a known (p.H295Y and p.G342R) or a novel (p.W140*) mutation in four other CESD patients. Segregation analysis performed in all patients harboring c.895G>A showed its occurrence on the same haplotype suggesting a common founder ancestor. The other WD and CESD mutations were associated with different haplotypes.

  17. Insulin decreases plasma cholesteryl ester transfer but not cholesterol esterification in healthy subjects as well as in normotriglyceridaemic patients with type 2 diabetes

    NARCIS (Netherlands)

    Dullaart, RPF; Riemens, SC; Scheek, LM; van Tol, A

    1999-01-01

    Background Plasma cholesterol esterification (EST) and subsequent cholesteryl ester transfer (CET) from high-density lipoproteins (HDLs) towards apolipoprotein (apo) B-containing lipoproteins are key steps in HDL metabolism. Materials and methods The effects of exogenous hyperinsulinaemia on plasma

  18. Cholesteryl Ester Hydroperoxides Are Biologically Active Components of Minimally Oxidized Low Density Lipoprotein*S⃞

    Science.gov (United States)

    Harkewicz, Richard; Hartvigsen, Karsten; Almazan, Felicidad; Dennis, Edward A.; Witztum, Joseph L.; Miller, Yury I.

    2008-01-01

    Oxidation of low density lipoprotein (LDL) occurs in vivo and significantly contributes to the development of atherosclerosis. An important mechanism of LDL oxidation in vivo is its modification with 12/15-lipoxygenase (LO). We have developed a model of minimally oxidized LDL (mmLDL) in which native LDL is modified by cells expressing 12/15LO. This mmLDL activates macrophages inducing membrane ruffling and cell spreading, activation of ERK1/2 and Akt signaling, and secretion of proinflammatory cytokines. In this study, we found that many of the biological activities of mmLDL were associated with cholesteryl ester (CE) hydroperoxides and were diminished by ebselen, a reducing agent. Liquid chromatography coupled with mass spectroscopy demonstrated the presence of many mono- and polyoxygenated CE species in mmLDL but not in native LDL. Nonpolar lipid extracts of mmLDL activated macrophages, although to a lesser degree than intact mmLDL. The macrophage responses were also induced by LDL directly modified with immobilized 12/15LO, and the nonpolar lipids extracted from 12/15LO-modified LDL contained a similar set of oxidized CE. Cholesteryl arachidonate modified with 12/15LO also activated macrophages and contained a similar collection of oxidized CE molecules. Remarkably, many of these oxidized CE were found in the extracts of atherosclerotic lesions isolated from hyperlipidemic apoE–/– mice. These results suggest that CE hydroperoxides constitute a class of biologically active components of mmLDL that may be relevant to proinflammatory activation of macrophages in atherosclerotic lesions. PMID:18263582

  19. 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.

  20. Cholesteryl ester transfer protein levels and gene deficiency in Chinese patients with cardio-cerebrovascular diseases

    Institute of Scientific and Technical Information of China (English)

    庄一义; 汪俊军; 张宏娟; 李勇; 刘小传; 李露言; 陈光辉

    2002-01-01

    Objective To detect cholesteryl ester transfer protein (CETP) levels, frequencies of CETP D442G and Ⅰ14A mutations and characteristics of abnormal lipids in patients with cardio-cerebro vascular diseases. Methods Ninety-four myocardial infarction (MI) patients,110 stroke patients and 335 healthy controls were selected. The CETP concentration was determined using ELISA. The CETP activity was measured using a substrate of 14 C-radiolabeled discoidal bilayer particles. The CETP gene mutations were detected by PCR-RFLP. Results The CETP concentrations in the MI and stroke group, were higher than those in the controls. The gene mutation frequencies of D442G in the MI, stroke and control group were 3.5%, 3.6% and 5%, respectively, and the frequencies of Ⅰ14A were 1.05%, 0.91% and 1%, respectively. One case of D442G homozygote was detected in the healthy group. The frequency of two CETP gene mutations showed no significant difference among the patients and controls. The CETP concentration and activity in subjects with CETP mutations were one-third of those in the control group. The level of HDL-C, apo-A1 increased in the mutation subjects, while the TG level decreased. Conclusions The CETP level increased significantly in patients with cardio-cerebrovascular diseases. The carriers of CETP deficiency had CETP and lipid abnormalities.

  1. Cholesteryl ester hydrolase activity is abolished in HSL-/- macrophages but unchanged in macrophages lacking KIAA1363.

    Science.gov (United States)

    Buchebner, Marlene; Pfeifer, Thomas; Rathke, Nora; Chandak, Prakash G; Lass, Achim; Schreiber, Renate; Kratzer, Adelheid; Zimmermann, Robert; Sattler, Wolfgang; Koefeler, Harald; Fröhlich, Eleonore; Kostner, Gerhard M; Birner-Gruenberger, Ruth; Chiang, Kyle P; Haemmerle, Guenter; Zechner, Rudolf; Levak-Frank, Sanja; Cravatt, Benjamin; Kratky, Dagmar

    2010-10-01

    Cholesteryl ester (CE) accumulation in macrophages represents a crucial event during foam cell formation, a hallmark of atherogenesis. Here we investigated the role of two previously described CE hydrolases, hormone-sensitive lipase (HSL) and KIAA1363, in macrophage CE hydrolysis. HSL and KIAA1363 exhibited marked differences in their abilities to hydrolyze CE, triacylglycerol (TG), diacylglycerol (DG), and 2-acetyl monoalkylglycerol ether (AcMAGE), a precursor for biosynthesis of platelet-activating factor (PAF). HSL efficiently cleaved all four substrates, whereas KIAA1363 hydrolyzed only AcMAGE. This contradicts previous studies suggesting that KIAA1363 is a neutral CE hydrolase. Macrophages of KIAA1363(-/-) and wild-type mice exhibited identical neutral CE hydrolase activity, which was almost abolished in tissues and macrophages of HSL(-/-) mice. Conversely, AcMAGE hydrolase activity was diminished in macrophages and some tissues of KIAA1363(-/-) but unchanged in HSL(-/-) mice. CE turnover was unaffected in macrophages lacking KIAA1363 and HSL, whereas cAMP-dependent cholesterol efflux was influenced by HSL but not by KIAA1363. Despite decreased CE hydrolase activities, HSL(-/-) macrophages exhibited CE accumulation similar to wild-type (WT) macrophages. We conclude that additional enzymes must exist that cooperate with HSL to regulate CE levels in macrophages. KIAA1363 affects AcMAGE hydrolase activity but is of minor importance as a direct CE hydrolase in macrophages.

  2. Oxidized Cholesteryl Esters and Phospholipids in Zebrafish Larvae Fed a High Cholesterol Diet

    Science.gov (United States)

    Fang, Longhou; Harkewicz, Richard; Hartvigsen, Karsten; Wiesner, Philipp; Choi, Soo-Ho; Almazan, Felicidad; Pattison, Jennifer; Deer, Elena; Sayaphupha, Tiffany; Dennis, Edward A.; Witztum, Joseph L.; Tsimikas, Sotirios; Miller, Yury I.

    2010-01-01

    A novel hypercholesterolemic zebrafish model has been developed to study early events of atherogenesis. This model utilizes optically transparent zebrafish larvae, fed a high cholesterol diet (HCD), to monitor processes of vascular inflammation in live animals. Because lipoprotein oxidation is an important factor in the development of atherosclerosis, in this study, we characterized the oxidized lipid milieu in HCD-fed zebrafish larvae. Using liquid chromatography-mass spectrometry, we show that feeding an HCD for only 2 weeks resulted in up to 70-fold increases in specific oxidized cholesteryl esters, identical to those present in human minimally oxidized LDL and in murine atherosclerotic lesions. The levels of oxidized phospholipids, such as 1-palmitoyl-2-oxovaleroyl-sn-glycero-3-phosphocholine, and of various lysophosphatidylcholines were also significantly elevated. Moreover, lipoproteins isolated from homogenates of HCD-fed larvae induced cell spreading as well as ERK1/2, Akt, and JNK phosphorylation in murine macrophages. Removal of apoB-containing lipoproteins from the zebrafish homogenates with an anti-human LDL antibody, as well as reducing lipid hydroperoxides with ebselen, resulted in inhibition of macrophage activation. The TLR4 deficiency in murine macrophages prevented their activation with zebrafish lipoproteins. Using biotinylated homogenates of HCD-fed larvae, we demonstrated that their components bound to murine macrophages, and this binding was effectively competed by minimally oxidized LDL but not by native LDL. These data provide evidence that molecular lipid determinants of proatherogenic macrophage phenotypes are present in large quantities in hypercholesterolemic zebrafish larvae and support the use of the HCD-fed zebrafish as a valuable model to study early events of atherogenesis. PMID:20710028

  3. 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

    with obesity; e.g., low levels of high-density lipoproteins (HDL) are high risk factors of cardiovascular events. A number of genetic, lifestyle, and environmental factors have been shown to contribute to the lowering of HDL-cholesterol. One of these factors is cholesteryl ester transfer protein (CETP......) 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...

  4. Insights into the Tunnel Mechanism of Cholesteryl Ester Transfer Protein through All-atom Molecular Dynamics Simulations.

    Science.gov (United States)

    Lei, Dongsheng; Rames, Matthew; Zhang, Xing; Zhang, Lei; Zhang, Shengli; Ren, Gang

    2016-07-01

    Cholesteryl ester transfer protein (CETP) mediates cholesteryl ester (CE) transfer from the atheroprotective high density lipoprotein (HDL) cholesterol to the atherogenic low density lipoprotein cholesterol. In the past decade, this property has driven the development of CETP inhibitors, which have been evaluated in large scale clinical trials for treating cardiovascular diseases. Despite the pharmacological interest, little is known about the fundamental mechanism of CETP in CE transfer. Recent electron microscopy (EM) experiments have suggested a tunnel mechanism, and molecular dynamics simulations have shown that the flexible N-terminal distal end of CETP penetrates into the HDL surface and takes up a CE molecule through an open pore. However, it is not known whether a CE molecule can completely transfer through an entire CETP molecule. Here, we used all-atom molecular dynamics simulations to evaluate this possibility. The results showed that a hydrophobic tunnel inside CETP is sufficient to allow a CE molecule to completely transfer through the entire CETP within a predicted transfer time and at a rate comparable with those obtained through physiological measurements. Analyses of the detailed interactions revealed several residues that might be critical for CETP function, which may provide important clues for the effective development of CETP inhibitors and treatment of cardiovascular diseases.

  5. Detection and characterization of cholesteryl ester hydroperoxides in oxidized LDL and oxidized HDL by use of an Orbitrap mass spectrometer.

    Science.gov (United States)

    Hui, Shu-Ping; Sakurai, Toshihiro; Ohkawa, Futaba; Furumaki, Hiroaki; Jin, Shigeki; Fuda, Hirotoshi; Takeda, Seiji; Kurosawa, Takao; Chiba, Hitoshi

    2012-07-01

    Oxidation of cholesteryl esters in lipoproteins by reactive oxygen species yields cholesteryl ester hydroperoxides (CEOOH). In this study, we developed a novel method for identification and characterization of CEOOH molecules in human lipoproteins by use of reversed-phase liquid chromatography with an hybrid linear ion trap-Orbitrap mass spectrometer (LC-LTQ Orbitrap). Electrospray ionization tandem mass spectrometric analysis was performed in both positive-ion and negative-ion modes. Identification of CEOOH molecules was completed by use of high-mass-accuracy (MA) mass spectrometric data obtained by using the spectrometer in Fourier-transform (FT) mode. Native low-density lipoproteins (nLDL) and native high-density lipoproteins (nHDL) from a healthy donor were oxidized by CuSO(4), furnishing oxidized LDL (oxLDL) and oxidized HDL (oxHDL). No CEOOH molecules were detected in the nLDL and the nHDL, whereas six CEOOH molecules were detected in the oxLDL and the oxHDL. In positive-ion mode, CEOOH was detected as [M + NH(4)](+) and [M + Na](+) ions. In negative-ion mode, CEOOH was detected as [M + CH(3)COO](-) ions. CEOOH were more easily ionized in positive-ion mode than in negative-ion mode. The LC-LTQ Orbitrap method was applied to human plasma and six species of CEOOH were detected. The limit of detection was 0.1 pmol (S/N = 5:1) for synthesized CEOOH.

  6. 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

    2004-01-01

    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 1

  7. Renin-angiotensin-aldosterone responsiveness to low sodium and blood pressure reactivity to angiotensin-II are unrelated to cholesteryl ester transfer protein mass in healthy subjects

    NARCIS (Netherlands)

    Krikken, Jan A.; Dallinga-Thie, Geesje M.; Navis, Gerjan; Dullaart, Robin P. F.

    2008-01-01

    Background: The blood pressure increase associated with the cholesteryl ester transfer protein (CETP) inhibitor, torcetrapib is probably attributable to an off-target effect but it is unknown whether activation of the renin-angiotensin-aldosterone system (RAAS) may be related to variation in the pla

  8. The effect of cholesteryl ester transfer protein-629C -> A promoter polymorphism on high-density lipoprotein cholesterol is dependent on serum triglycerides

    NARCIS (Netherlands)

    Borggreve, SE; Hillege, HL; Wolffenbuttel, BHR; de Jong, PE; Bakker, SJL; van der Steege, G; van Tol, A; Dullaart, RPF

    2005-01-01

    Context: The -629C -> A cholesteryl ester transfer protein (CETP) promoter polymorphism is a determinant of HDL cholesterol (HDL-C). The effect of the closely linked CETP TaqIB polymorphism on HDL-C has been suggested to be modified by obesity and hyperinsulinemia. Objective: Because the CETP-mediat

  9. Efficacy and safety of a novel cholesteryl ester transfer protein inhibitor, JTT-705, in humans : a randomized phase II dose-response study

    NARCIS (Netherlands)

    de Grooth, Greetje J.; Kuivenhoven, Jan Albert; Stalenhoef, Anton F.H.; de Graaf, Jacqueline; Zwinderman, Aeilko H.; Posma, Jan L.; van Tol, Arie; Kastelein, John J.P.

    2002-01-01

    BACKGROUND: Cholesteryl ester transfer protein (CETP) mediates the transfer of neutral lipids between lipoproteins. High plasma levels of CETP are correlated with low HDL cholesterol levels, a strong risk factor for coronary artery disease. In earlier studies, JTT-705, a novel CETP inhibitor, was sh

  10. Antiproteinuric therapy decreases LDL-cholesterol as well as HDL-cholesterol in non-diabetic proteinuric patients: relationships with cholesteryl ester transfer protein mass and adiponectin

    NARCIS (Netherlands)

    J.A. Krikken; F. Waanders; G.M. Dallinga-Thie; L.D. Dikkeschei; L. Vogt; G.J. Navis; R.P.F. Dullaart

    2009-01-01

    Objective: Dyslipidemia contributes to increased cardiovascular risk in nephrotic syndrome. We questioned whether reduction in proteinuria not only lowers low-density lipoprotein cholesterol (LDL-C), but also high-density lipoprotein cholesterol (HDL-C) and cholesteryl ester transfer protein (CETP)

  11. Antiproteinuric therapy decreases LDL-cholesterol as well as HDL-cholesterol in non-diabetic proteinuric patients : relationships with cholesteryl ester transfer protein mass and adiponectin

    NARCIS (Netherlands)

    Krikken, J. A.; Waanders, F.; Dallinga-Thie, G. M.; Dikkeschei, L. D.; Vogt, L.; Navis, G. J.; Dullaart, R. P. F.

    2009-01-01

    Objective: Dyslipidemia contributes to increased cardiovascular risk in nephrotic syndrome. We questioned whether reduction in proteinuria not only lowers low-density lipoprotein cholesterol (LDL-C), but also high-density lipoprotein cholesterol (HDL-C) and cholesteryl ester transfer protein (CETP)

  12. Kinetics of the incorporation of dietary fatty acids into serum cholesteryl esters, erythrocyte membranes, and adipose tissue: an 18-month controlled study.

    NARCIS (Netherlands)

    Katan, M.B.; Deslypere, J.P.; Birgelen, van A.P.J.M.; Wennekes-Penders, M.M.H.; Zegwaard, M.J.

    1997-01-01

    Tissue levels of n-3 fatty acids reflect dietary intake, but quantitative data about rate of incorporation and levels as a function of intake are scarce. We fed 58 men 0, 3, 6, or 9 g/d of fish oil for 12 months and monitored fatty acids in serum cholesteryl esters, erythrocytes, and subcutaneous fa

  13. The effect of cholesteryl ester transfer protein -629C→A promoter polymorphism on high-density lipoprotein cholesterol is dependent on serum triglycerides

    NARCIS (Netherlands)

    S.E. Borggreve (Susanna); H.L. Hillege (Hans); B.H.R. Wolffenbuttel (Bruce); P. de Jong (Paul); S.J.L. Bakker (Stephan); G. van der Steege (Gerrit); A. van Tol (Arie); R.P.F. Dullaart (Robin)

    2005-01-01

    textabstractContext: The -629C→A cholesteryl ester transfer protein (CETP) promoter polymorphism is a determinant of HDL cholesterol (HDL-C). The effect of the closely linked CETP TaqIB polymorphism on HDL-C has been suggested to be modified by obesity and hyperinsulinemia. Objective: Because the CE

  14. 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, Andre P.

    2010-01-01

    Objective: 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

  15. Elevated cholesteryl ester transfer protein concentration is associated with an increased risk for cardiovascular disease in women, but not in men, with Type 2 diabetes : the Hoorn Study

    NARCIS (Netherlands)

    Alssema, M; Dekker, J M; Kuivenhoven, J A; Nijpels, G; Teerlink, T; Scheffer, P G; Diamant, M; Stehouwer, C D A; Bouter, L M; Heine, R J

    2007-01-01

    AIMS: Cholesteryl ester transfer protein (CETP) exchanges neutral lipids between lipoproteins. As the role of CETP in the atherogenic process is still not fully clarified, we studied the association of CETP concentration with the prevalence of cardiovascular disease (CVD) and with intima-media thick

  16. Cholesteryl ester transfer protein inhibitors in the treatment of dyslipidemia: a systematic review and meta-analysis.

    Directory of Open Access Journals (Sweden)

    Chuanwei Li

    Full Text Available Cholesteryl ester transfer protein (CETP inhibitors are gaining substantial research interest for raising high density lipoprotein cholesterol levels. The aim of the research was to estimate the efficacy and safety of cholesteryl ester transfer protein inhibitors as novel lipid modifying drugs. Systematic searches of English literature for randomized controlled trials (RCT were collected from MEDLINE, EBASE, CENTRAL and references listed in eligible studies. Two independent authors assessed the search results and only included the double-blind RCTs by using cholesteryl ester transfer protein inhibitors as exclusively or co-administrated with statin therapy irrespective of gender in enrolled adult subjects. Two independent authors extracted the data by using predefined data fields. Of 503 studies identified, 14 studies met the inclusion criteria, and 12 studies were included into the final meta-analysis. Our meta-analysis revealed that CETP inhibitors increased the HDL-c levels (n = 2826, p<0.00001, mean difference (MD = 20.47, 95% CI [19.80 to 21.15] and total cholesterol (n = 3423, p = 0.0002, MD = 3.57, 95%CI [1.69 to 5.44] to some extent combined with a reduction in triglyceride (n = 3739, p<0.00001, MD = -10.47, 95% CI [-11.91 to -9.03] and LDL-c (n = 3159, p<0.00001, MD = -17.12, 95% CI [-18.87 to -15.36] irrespective of mono-therapy or co-administration with statins. Subgroup analysis suggested that the lipid modifying effects varied according to the four currently available CETP inhibitors. CETP inhibitor therapy did not increase the adverse events when compared with control. However, we observed a slight increase in blood pressure (SBP, n = 2384, p<0.00001, MD = 2.73, 95% CI [2.14 to 3.31], DBP, n = 2384, p<0.00001, MD = 1.16, 95% CI [0.73 to 1.60] after CETP inhibitor treatment, which were mainly ascribed to the torcetrapib treatment subgroup. CETP inhibitors therapy is associated with significant increase in HDL-c and decrease in

  17. Modification of composition of a nanoemulsion with different cholesteryl ester molecular species: Effects on stability, peroxidation, and cell uptake

    Directory of Open Access Journals (Sweden)

    Cristina P Almeida

    2010-09-01

    Full Text Available Cristina P Almeida1, Carolina G Vital1, Thais C Contente1, Durvanei A Maria2, Raul C Maranhão1,31Lipid Metabolism Laboratory, Heart Institute (InCor, Medical School Hospital, 2Biochemistry and Biophysics Laboratories, Butantan Institute, 3Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, BrazilPurpose: Use of lipid nanoemulsions as carriers of drugs for therapeutic or diagnostic purposes has been increasingly studied. Here, it was tested whether modifications of core particle constitution could affect the characteristics and biologic properties of lipid nanoemulsions. Methods: Three nanoemulsions were prepared using cholesteryl oleate, cholesteryl stearate, or cholesteryl linoleate as main core constituents. Particle size, stability, pH, peroxidation of the nanoemulsions, and cell survival and uptake by different cell lines were evaluated.Results: It was shown that cholesteryl stearate nanoemulsions had the greatest particle size and all three nanoemulsions were stable during the 237-day observation period. The pH of the three nanoemulsion preparations tended to decrease over time, but the decrease in pH of cholesteryl stearate was smaller than that of cholesteryl oleate and cholesteryl linoleate. Lipoperoxidation was greater in cholesteryl linoleate than in cholesteryl oleate and cholesteryl stearate. After four hours’ incubation of human umbilical vein endothelial cells (HUVEC with nanoemulsions, peroxidation was minimal in the presence of cholesteryl oleate and more pronounced with cholesteryl linoleate and cholesteryl stearate. In contrast, macrophage incubates showed the highest peroxidation rates with cholesteryl oleate. Cholesteryl linoleate induced the highest cell peroxidation rates, except in macrophages. Uptake of cholesteryl oleate nanoemulsion by HUVEC and fibroblasts was greater than that of cholesteryl linoleate and cholesteryl stearate. Uptake of the three nanoemulsions by monocytes was equal. Uptake of

  18. 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.

  19. The role of cholesteryl ester transfer protein and phospholipid transfer protein in the remodeling of plasma high-density lipoproteins.

    Science.gov (United States)

    Lagrost, L

    1997-08-01

    Recent studies demonstrated that alterations in the size distribution of high-density lipoproteins (HDLs) constitute reliable markers for the risk of coronary artery disease. These observations suggested that the determination of the size distribution of HDL subpopulations by using polyacrylamide gradient gel electrophoresis might constitute an effective tool in clinical practice for the detection of patients with elevated risk. During the last decade, concordant observations revealed that all the HDL subpopulations are metabolically interrelated, and their relative abundances are dependent on the activity of several plasma factors, among them the cholesteryl ester transfer protein (CETP) and the phospholipid transfer protein (PLTP). As reviewed in the present article, although both CETP and PLTP can promote the size redistribution or conversion of HDL, the two plasma lipid transfer proteins can alter differently the plasma HDL distribution profile through distinct mechanisms. (Trends Cardiovasc Med 1997;7:218-224). © 1997, Elsevier Science Inc.

  20. Enhanced removal from the plasma of LDL-like nanoemulsion cholesteryl ester in trained men compared with sedentary healthy men.

    Science.gov (United States)

    Vinagre, Carmen G C; Ficker, Elisabeth S; Finazzo, Claudia; Alves, Maria J N; de Angelis, Katia; Irigoyen, Maria Claudia; Negrão, Carlos E; Maranhão, Raul C

    2007-10-01

    The objective of this study was to evaluate the effects of exercise training on plasma removal of a cholesterol-rich nanoemulsion (LDE) that mimics low-density lipoprotein (LDL) lipid structure and binds to LDL receptors. LDE-derived cholesteryl ester plasma kinetics was studied in 24 exercise-trained and 20 sedentary male subjects. LDE labeled with [(14)C]cholesteryl ester was injected intravenously, and plasma samples were collected over a 24-h period to determine radioisotope decay curves. LDL cholesterol concentration was similar in both groups. Fractional clearance rate (FCR) of the nanoemulsion label was greater in the exercise-trained group compared with the sedentary group (0.138 +/- 0.152 and 0.0261 +/- 0.023 h(-1), respectively). A positive correlation was found (r = 0.60, P < 0.01) between FCR and peak O(2) consumption in trained subjects. Circulating oxidized LDL levels were lower in trained subjects compared with the sedentary group (9.0 +/- 2.0 and 16.0 +/- 3.0 mU/l). LDE was also injected into control and LDL receptor gene knockout mice submitted and not submitted to training. Muscle LDE uptake percentage was increased in the trained mice compared with the untrained mice (1.1 +/- 0.8 and 0.2 +/- 0.1, respectively, P < 0.0001) in the control group but not in the knockout animals, indicating that the LDL receptor is involved in the increased uptake elicited by exercise. These results show that exercise training increases LDE plasma removal, which in turn suggests that it also increases LDL receptors or LDL receptor activity.

  1. Hyperspectral-stimulated Raman scattering imaging of cholesteryl ester accumulation: new avenue to diagnosis of human prostate cancer

    Science.gov (United States)

    Du, Jun; Wang, Ping; Yue, Shuhua

    2016-10-01

    Most prostate cancers (PCa) are slowly growing, and only the aggressive ones require early diagnosis and effective treatment. The current standard for PCa diagnosis remains histopathology. Nonetheless, for the differentiation between Gleason score 6 (low-risk PCa), which can be left without treatment, and Gleason score 7 (high-risk PCa), which requires active treatment, the inter-observer discordance can be up to 40%. Our previous study reveals that cholesteryl ester (CE) accumulation induced by PI3K/AKT activation underlies human PCa aggressiveness. However, Raman spectromicroscopy used in this study could only provide compositional information of certain lipid droplets (LDs) selected by the observer, which overlooked cell-to-cell variation and hindered translation to accurate automated diagnosis. Here, we demonstrated quantitative mapping of CE level in human prostate tissues using hyperspectral stimulated Raman scattering (SRS) microscopy that renders compositional information for every pixel in the image. Specifically, hundreds of SRS images at Raman shift between 1620-1800 cm-1 were taken, and multivariate curve resolution algorism was used to retrieve concentration images of acyl C=C bond, sterol C=C bond, and ester C=O bond. Given that the ratio between images of sterol C=C and ester C=O (sterol C=C/C=O) is nonlinearly proportional to CE percentage out of total lipid, we were able to quantitatively map CE level. Our data showed that CE level was significantly greater in high Gleason grade compared to low Gleason grade, and could be a factor that significantly contributed to cancer recurrence. Our study provides an opportunity towards more accurate PCa diagnosis and prediction of aggressiveness.

  2. 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

  3. Synthesis of substituted 2-cyanoarylboronic esters

    DEFF Research Database (Denmark)

    Lysén, Morten; Hansen, Henriette M; Begtrup, Mikael

    2006-01-01

    The synthesis of substituted 2-cyanoarylboronic esters is described via lithiation/in situ trapping of the corresponding methoxy-, trifluoromethyl-, fluoro-, chloro-, and bromobenzonitriles. The crude arylboronic esters were obtained in high yields and purities and with good regioselectivities....

  4. 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.

    2012-01-01

    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

  5. Reduced leucocyte cholesteryl ester transfer protein expression in acute coronary syndromes

    NARCIS (Netherlands)

    Ye, D; Kraaijeveld, A O; Grauss, R W; Willems, S M; van Vark-van der Zee, L C; de Jager, S C A; Jauhiainen, M; Kuivenhoven, J A; Dallinga-Thie, G M; Atsma, D E; Hogendoorn, P C W; Biessen, E A L; Van Berkel, T J C; Jukema, J W; van Eck, M

    2008-01-01

    OBJECTIVE: Cholesterol ester transfer protein (CETP) plays an important role in HDL cholesterol metabolism. Leucocytes, including monocyte-derived macrophages in the arterial wall synthesize and secrete CETP, but its role in atherosclerosis is unclear. The aim of the current study was to investigate

  6. 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.

  7. 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.

  8. High level of serum cholesteryl ester transfer protein inactive hepatitis C virus infection

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    AIM To determine the significance of cholesteryl estertransfer protein (CETP) in lipoprotein abnormalities inchronic hepatitis C virus (HCV) infection.METHODS: We evaluated the significance of the serumconcentration of CETP in 110 Japanese patients withchronic HCV infection. Fifty-five patients had active HCVinfection, and HCV eradication had been achieved in55. The role of CETP in serum lipoprotein abnormalities,specifically, in triglyceride (TG) concentrations in thefour major classes of lipoproteins, was investigatedusing Pearson correlations in conjunction with multipleregression analysis and compared them between thosewith active HCV infection and those in whom eradicationhad been achieved.RESULTS: The serum CETP levels of patients withactive HCV infection were significantly higher than thoseof patients in whom HCV eradication was achieved(mean ± SD, 2.84 ± 0.69 μg/mL vs 2.40 ± 1.00 μg/mL, P = 0.008). In multiple regression analysis, HCVinfection status (active or eradicated) was an independentfactor significantly associated with the serumCETP level. TG concentrations in low-density lipoprotein(mean ± SD, 36.25 ± 15.28 μg/mL vs 28.14 ± 9.94μg/mL, P = 0.001) and high-density lipoprotein (HDL)(mean ± SD, 25.9 ± 7.34 μg/mL vs 17.17 ± 4.82μg/mL, P 〈 0.001) were significantly higher in patients with active HCV infection than in those in whom HCVeradication was achieved. The CETP level was stronglycorrelated with HDL-TG in patients with active HCVinfection (R = 0.557, P 〈 0.001), whereas CETP wasnot correlated with HDL-TG in patients in whom HCVeradication was achieved (R = -0.079, P = 0.56).CONCLUSION: Our results indicate that CETP playsa role in abnormalities of lipoprotein metabolism inpatients with chronic HCV infection.

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

    Science.gov (United States)

    Guo, Shu-xia; Yao, Ming-hong; Ding, Yu-song; Zhang, Jing-yu; Yan, Yi-zhong; Liu, Jia-ming; Zhang, Mei; Rui, Dong-sheng; Niu, Qiang; He, Jia; Guo, Heng; Ma, Ru-lin

    2016-01-01

    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. PMID:27608031

  10. 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.

  11. A Novel Missense Mutation (L296Q) in Cholesteryl Ester Transfer Protein Gene Related to Coronary Heart Disease

    Institute of Scientific and Technical Information of China (English)

    Ke-Qin ZHENG; Si-Zhong ZHANG; Li ZHANG; De-Jia HUANG; Lin-Chuan LIAO; Yi-Ping HOU

    2004-01-01

    Cholesteryl ester transfer protein (CETP) is a key participant in the reverse transport ofcholesterol from the peripheral tissues to the liver. To understand the role that CETP gene plays in thepathogenesis of coronary heart disease (CHD), the promoter region, all 16 exons and adjacent intronicregions of CETP gene were screened for single nucleotide polymorphisms (SNPs) in 203 CHD patients and209 controls by a combination of PCR, denaturing high performance liquid chromatography (DHPLC),molecular cloning, and DNA sequencing. A novel missense mutation in the CETP gene was identified. Thismutation (L296Q) was a T-to-A conversion at codon 296 of exon 10 which replaced the codon for leucine(CTG) with the codon for glutamine (CAG). Association study revealed that L296Q mutation was associatedwith CHD with a significantly higher mutant allele frequency in the CHD patients than that in the controls (0.160 vs. 0.091,x2= 9.014, P = 0.003), and that the odds ratio for the development of CHD was 1.83 for the296Q allele carriers relative to 296LL homozygotes. Statistical analyses demonstrated that the mutant 296Q allelecarrier patients displayed significantly higher total cholesterol (TC) and low density lipoprotein cholesterol(LDL-C) concentrations than non-carrier patients. The results of the present study suggest that the L296Qmutation is related to CHD, and the identification of new mutations in the CETP gene will afford the oppor-tunity to investigate the relationship between CETP gene and CHD.

  12. Cholesteryl ester transfer protein, low density lipoprotein particle size and intima media thickness in patients with coronary heart disease.

    Science.gov (United States)

    Tosheska, Katerina; Labudovic, Danica; Jovanova, Silvana; Jaglikovski, Branko; Alabakovska, Sonja

    2011-08-01

    Cholesteryl ester transfer protein (CETP) plays a key role in reverse cholesterol transport and high density lipoprotein (HDL) metabolism. Predominance of small, dense LDL particles is associated with an increased risk of atherosclerosis and coronary heart disease (CHD).The aim of the study was to determine the potential relationship between the CETP concentration and low density lipoprotein (LDL) particle size and their association with intima media thickness (IMT) in patients with CHD. Lipid parameters, CETP concentration and LDL particle size were determined in 100 healthy subjects (control group) and in 100 patients with CHD, aged 43 to 77 years. Plasma CETP concentrations were measured by an enzyme-linked immuno-sorbent assay with two different monoclonal antibodies. LDL subclasses were separated by nondenaturing polyacrilamide 3-31% gradient gel electrophoresis. CETP concentration was higher in patients compared to controls (2.02 ± 0.75 mg/ml vs. 1.74 ± 0.63 mg/ml, p<0.01). Mean LDL particle size (nm) was significantly smaller in patients than in controls (24.5 ± 1.1 vs. 26.1 ± 0.9; p<0.001). There was no relation between LDL particle size and CETP concentration (r=-0.1807, p=0.072). Age, diastolic blood pressure, CETP concentration and LDL particle size were independent factors for determing IMT by multiple linear regression analysis. They accounted for 35.2 % of the observed variability in IMT. CETP is not an independent contributor of LDL particle size. CETP might play a role in determining lipoprotein distributions, but did not seem to be the sole factor in the formation of small LDL particles.

  13. A Novel Missense Mutation (L296Q) in Cholesteryl Ester Transfer Protein Gene Related to Coronary Heart Disease

    Institute of Scientific and Technical Information of China (English)

    Ke-QinZHENG; Si-ZhongZHANG; LiZHANG; De-JiaHUANG; Lin-ChuanLIAO; Yi-PingHOU

    2004-01-01

    Cholesteryl ester transfer protein (CETP) is a key participant in the, reverse transport of cholesterol from the peripheral tissues to the liver. To understand the role that CETP gene plays in the pathogenesis of coronary heart disease (CHD), the promoter region, all 16 exons and adjacent intronic regions of CETP gene were screened for single nucleotide polymorphisms (SNPs) in 203 CHD patients and 209 controls by a combination of PCR, denaturing high performance liquid chromatography (DHPLC),molecular cloning, and DNA sequencing. A novel missense mutation in the CETP geve was identified. This mutation (L296Q) was a T-to-A conversion at codon 296 of exon 10 which replaced the codon for leucine (CTG) with the codon for glutamine (CAG). Association study revealed that L296Q mutation was associated with CHD with a significantly higher mutant allele frequency in the CHD patients than that in the controls (0.160 vs. 0.091,x2=9.014, P=0.003), and that the odds ratio for the development of CHD was 1.83 for the 296Q allele carriers relative to 296LL homozygotes. Statistical analyses demonstrated thai the mutant 296Q allele carrier patients displayed significantly higher total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) concentrations than non-carrier patients. The results of the present study suggest that the L296Q mutation is related to CHD, and the identification of new mutations in the CETP gene will afford the opportunity to investigate the relationship between CETP gene and CHD.

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

    Science.gov (United States)

    Miyares, Marta A; Davis, Kyle

    2012-01-01

    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 only test the hypothesis if CETP inhibition lowers residual CV risk but will also provide insight as to which patient

  15. 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

  16. The cholesteryl ester transfer protein (CETP) TaqIB polymorphism in the cholesterol and recurrent events study : no interaction with the response to pravastatin therapy and no effects on cardiovascular outcome: a prospective analysis of the CETP TaqIB polymorphism on cardiovascular outcome and interaction with cholesterol-lowering therapy

    NARCIS (Netherlands)

    de Grooth, Greetje J; Zerba, Kim E; Huang, Shu-Pang; Tsuchihashi, Zenta; Kirchgessner, Todd; Belder, René; Vishnupad, Priya; Hu, Beihong; Klerkx, Anke H E M; Zwinderman, Aeilko H; Jukema, J Wouter; Sacks, Frank M; Kastelein, John J P; Kuivenhoven, Jan Albert

    2004-01-01

    OBJECTIVES: On the basis of quantitative coronary angiography data, the cholesteryl ester transfer protein (CETP) TaqIB gene polymorphism has been postulated to predict the progression of coronary atherosclerosis and response to cholesterol-lowering therapy. BACKGROUND: Cholesteryl ester transfer pr

  17. Association between cholesteryl ester transfer protein gene polymorphisms and variations in lipid levels in patients with coronary heart disease

    Institute of Scientific and Technical Information of China (English)

    郑克勤; 张思仲; 贺勇; 张立; 张克兰; 黄德嘉; 孙岩

    2004-01-01

    Background The TaqⅠB, MspⅠ and I405V polymorphisms of cholesteryl ester transfer protein (CETP), an important regulatory factor of lipid metabolism, have been attracted much more attention by the researchers. In this study, we investigated the associations between these 3 polymorphisms of CETP gene and variations in plasma lipid and lipoprotein levels in patients with coronary heart disease (CHD).Methods Genomic DNA was extracted from leukocytes of 203 CHD patients and 100 control subjects using the salting out method. Genotyping of the CETP gene was performed using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) techniques. Statistical analysis was conducted using the SPSS 10.0 software package.Results The distribution of allele and genotype frequencies of the TaqⅠB, MspⅠ, and I405V polymorphisms was similar in the CHD patient group and the control group. The B1B1 genotype of the TaqⅠB polymorphism was associated with significantly higher TC (P=0.039) and LDL-C (P=0.044) levels than the B2B2 genotype in CHD patients, and with significantly higher LDL-C (P=0.034) levels than the B2B2 genotype in controls. Homozygotes of the I405V polymorphism exhibited significantly higher HDL-C levels than VV homozygotes among control subjects (P=0.023). In male CHD patients with unambiguously assigned haplotypes, B2-M2-V/B2-M2-I patients demonstrated significantly higher HDL-C concentrations than B1-M2-V/B1-M2-I (P=0.023) and B1-M2-V/B1-M2-V patients (P=0.047). Conclusions Genetic variations in the CETP gene may account for a significant proportion of the differences in plasma lipid and lipoprotein concentrations among the general population. The B1B1 genotype of the TaqⅠB polymorphism is probably a genetic risk factor for CHD in the study population.

  18. Cholesteryl ester transfer protein TaqIB variant, high-density lipoprotein cholesterol levels, cardiovascular risk, and efficacy of pravastatin treatment : individual patient meta-analysis of 13,677 subjects

    NARCIS (Netherlands)

    Boekholdt, S M; Sacks, F M; Jukema, J W; Shepherd, J; Freeman, D J; McMahon, A D; Cambien, F; Nicaud, V; de Grooth, G J; Talmud, P J; Humphries, S E; Miller, G J; Eiriksdottir, G; Gudnason, V; Kauma, H; Kakko, S; Savolainen, M J; Arca, M; Montali, A; Liu, S; Lanz, H J; Zwinderman, A H; Kuivenhoven, J A; Kastelein, J J P

    2005-01-01

    BACKGROUND: Several studies have reported that the cholesteryl ester transfer protein (CETP) TaqIB gene polymorphism is associated with HDL cholesterol (HDL-C) levels and the risk of coronary artery disease (CAD), but the results are inconsistent. In addition, an interaction has been implicated betw

  19. High-density lipoprotein cholesterol is related to the TaqIB cholesteryl ester transfer protein gene polymorphism and smoking, but not to moderate alcohol consumption in insulin-dependent diabetic men

    NARCIS (Netherlands)

    Dullaart, RPF; Beusekamp, BJ; Riemens, SC; Hoogenberg, K; Stulp, BK; Van Tol, A; Sluiter, WJ

    1998-01-01

    In non-diabetic subjects, the high-density lipoprotein (HDL) cholesterol level is increased by alcohol and decreased by smoking. The biallelic B1B2 polymorphism of the cholesteryl ester transfer protein (CETP) gene is a genetic determinant of HDL cholesterol. We evaluated the effect of moderate alco

  20. Plasma cholesteryl ester transfer and hepatic lipase activity are related to high-density lipoprotein cholesterol in association with insulin resistance in type 2 diabetic and non-diabetic subjects

    NARCIS (Netherlands)

    Riemens, SC; Van Tol, A; Scheek, LM; Dullaart, RPF

    2001-01-01

    We evaluated the: hypothesis that plasma cholesteryl ester transfer (CET) and lipase activities are influenced by insulin sensitivity and contribute to the low high-density lipoprotein (HDL) cholesterol observed in type 2 diabetic patients and insulin-resistant non-diabetic subjects. Sixteen type 2

  1. An increased coronary risk is paradoxically associated with common cholesteryl ester transfer protein gene variations that relate to higher high-density lipoprotein cholesterol: A population-based study

    NARCIS (Netherlands)

    S.E. Borggreve (Susanna); H.L. Hillege (Hans); B.H.R. Wolffenbuttel (Bruce); P. de Jong (Paul); M.W. Zuurman (Mike); G. van der Steege (Gerrit); A. van Tol (Arie); R.P.F. Dullaart (Robin)

    2006-01-01

    textabstractBackground: Several cholesteryl ester transfer protein (CETP) polymorphisms affect high-density lipoprotein (HDL) cholesterol, but the impact of CETP gene variants on incident coronary disease in the general population is uncertain after correction for their effect on HDL cholesterol. De

  2. Alcohol consumption, TaqIB polymorphism of cholesteryl ester transfer protein, high-density lipoprotein cholesterol, and risk of coronary heart disease in men and women

    DEFF Research Database (Denmark)

    Jensen, Majken K; Mukamal, Kenneth J; Overvad, Kim;

    2008-01-01

    AIMS: To investigate whether a common polymorphism in the cholesteryl ester transfer protein (CETP) gene modifies the relationship of alcohol intake with high-density lipoprotein cholesterol (HDL-C) and risk of coronary heart disease (CHD). METHODS AND RESULTS: Parallel nested case-control studies...... among women [Nurses' Health Study (NHS)] and men [Health Professionals Follow-up Study (HPFS)] where 246 women and 259 men who developed incident CHD were matched to controls (1:2) on age and smoking. The TaqIB variant and alcohol consumption were associated with higher HDL-C, with the most pronounced...... effects of alcohol among B2 carriers. In the NHS we did not find an inverse association between alcohol and CHD in B2 non-carriers (P trend: 0.5), but did among B2 carriers (P trend

  3. Amyloidogenic Properties of a D/N Mutated 12 Amino Acid Fragment of the C-Terminal Domain of the Cholesteryl-Ester Transfer Protein (CETP

    Directory of Open Access Journals (Sweden)

    Victor García-González

    2011-03-01

    Full Text Available The cholesteryl-ester transfer protein (CETP facilitates the transfer of cholesterol esters and triglycerides between lipoproteins in plasma where the critical site for its function is situated in the C-terminal domain. Our group has previously shown that this domain presents conformational changes in a non-lipid environment when the mutation D470N is introduced. Using a series of peptides derived from this C-terminal domain, the present study shows that these changes favor the induction of a secondary β-structure as characterized by spectroscopic analysis and fluorescence techniques. From this type of secondary structure, the formation of peptide aggregates and fibrillar structures with amyloid characteristics induced cytotoxicity in microglial cells in culture. These supramolecular structures promote cell cytotoxicity through the formation of reactive oxygen species (ROS and change the balance of a series of proteins that control the process of endocytosis, similar to that observed when β-amyloid fibrils are employed. Therefore, a fine balance between the highly dynamic secondary structure of the C-terminal domain of CETP, the net charge, and the physicochemical characteristics of the surrounding microenvironment define the type of secondary structure acquired. Changes in this balance might favor misfolding in this region, which would alter the lipid transfer capacity conducted by CETP, favoring its propensity to substitute its physiological function.

  4. Selective removal of cholesteryl ester in atherosclerotic plaque by nanosecond pulsed laser at 5.75 μm for less-invasive laser angioplasty

    Science.gov (United States)

    Ishii, Katsunori; Tsukimoto, Hideki; Hazama, Hisanao; Awazu, Kunio

    2009-02-01

    Laser angioplasty, for example XeCl excimer laser coronary angioplasty (ELCA), has gained more attention for the treatment of serious stenosis blocked by plaque. Low degrees of thermal damage after ablation of atherosclerotic plaques have been achieved by ELCA. However, the large number of risks associated with the procedure, for example, dissections or perforations of the coronary arteries limits its application. A laser treatment technique with high ablation efficiency but low arterial wall injury is desirable. Mid-infrared laser with a wavelength of 5.75 µm is selectively well absorbed in C=O stretching vibration mode of ester bonds in cholesteryl ester. The purpose of this study is to determine the effectiveness of nanosecond pulsed laser at 5.75 µm irradiation for atherosclerotic plaques. We made a study on the irradiation effect to atherosclerotic plaques in tunica intima in a wet condition. In this study, we used a mid-infrared tunable solid-state laser which is operated by difference-frequency generation, with a wavelength of 5.75 µm, a pulse width of 5 ns and a pulse duration of 10 Hz as a treatment light source, and a thoracic aorta of WHHLMI rabbit as an atherosclerosis model. As a result, less-invasive interaction parameters for removing atherosclerotic plaques were confirmed. This study shows that the nanosecond pulsed laser irradiation at 5.75 µm is a powerful tool for selective and less-invasive treatment of atherosclerotic plaques.

  5. Taq1B Polymorphism of Cholesteryl Ester Transfer Protein (CETP) and Its Effects on the Serum Lipid Levels in Metabolic Syndrome Patients.

    Science.gov (United States)

    Maroufi, Nazila Fathi; Farzaneh, Khadijeh; Alibabrdel, Mahdi; Zarei, Leila; Cheraghi, Omid; Soltani, Sina; Montazersaheb, Soheila; Akbarzadeh, Maryam; Nouri, Mohammad

    2016-12-01

    The metabolic syndrome (MetS) is one of the most important risk factors for type 2 diabetes and cardiovascular disease. This syndrome is characterized by abdominal obesity, hypertension, insulin resistance, and dyslipidemia. The plasma origin of Cholesteryl ester transfer protein (CETP) is responsible for transferring cholesterol esters from high-density lipoprotein particles to apolipoprotein B containing lipoproteins compartment. We conducted this study to investigate the association between CETP gene Taq1B (rs708272) polymorphism in the metabolic syndrome among Iranian subjects. A sample size of 200 patients diagnosed with MetS together with 200 healthy donors as control were enrolled in this study. The investigation of polymorphism was performed by the use of polymerase chain reaction and restriction fragment length polymorphism analysis. To determine the relationship between polymorphism and lipid profile, we measured lipids and CETP concentration in metabolic syndrome and control subjects. Genotype distribution and allelic frequencies of polymorphism were determined and compared in both groups. Our findings showed that all clinical and biochemical characteristics in patients differed from the control group. The results showed that genotype and allele frequency of the Taq1B polymorphism was not significantly different between two groups. Instinctively, CETP was significantly higher in metabolic syndrome (1.64 ± 0.32 µg/ml) than in control (1.53 ± 0.34 µg/ml). A low level of CETP was found in blood of B2B2 typified genotype. In spite of Taq1B polymorphism on ester transfer protein concentration, no direct correlation was found between this polymorphism and metabolic syndrome.

  6. 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.

  7. Synthesis of insecticidal sucrose esters

    Institute of Scientific and Technical Information of China (English)

    Song Zi-juan; Li Shu-jun; Chen Xi; Liu Li-mei; Song Zhan-qian

    2006-01-01

    Some synthetic sucrose esters (SE) are a relatively new class of insecticidal compounds produced by reacting sugars with fatty acids, which are safe for the environment. Especially, sucrose esters composed of C6-C12 fatty acids have desirable insecticidal properties against many soft-bodied arthropod pests. In our study, sucrose octanoate which has the highest activity against a range of arthropod species was synthesized by a trans-esterification method and proved its insecticidal property. Under the condition of a homogeneous liquid, sucrose octanoate was prepared by reacting ethyl octanoate with sucrose at reduced pressure; the yield was 79.11%. Sucrose octanoate synthesized was identified and its property analyzed by IR, TLC and spectrophotometric analysis. It was shown that the ratio of monoester to polyester in sucrose octanoate was 1.48:1. The insecticidal activity of the synthetic sucrose octanoate was evaluated at a concentration of 4 and 8 mg·mL-1. The mortality of first-instar larvae ofLymantria dispar from its contact toxicity was 72.5% after 36 hours, the revision insect reduced rate of Aphis glycines reached above 80% at 4 and 8 mg·mL-1 after being treated for 5 days. Since the SE products are nontoxic to humans and higher animals, fully biodegradable and hydrolyzed to readily metabolizable sucrose and fatty acid, they are not harmful to crops and appear to be good insecticide candidates.

  8. 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.

  9. The influence of dietary fish oil vs. sunflower oil on the fatty acid composition of plasma cholesteryl-esters in healthy, adult cats.

    Science.gov (United States)

    Plantinga, E A; Beynen, A C

    2003-12-01

    The question addressed was whether the fatty acid composition of plasma cholesteryl esters (CEs) in cats reflects the intake of fatty acids. Diets containing either fish oil or sunflower oil were fed to six healthy, adult cats in a cross-over trial. The dry cat foods contained approximately 18.5% crude fat, of which two-third was in the form of the variable oil. Blood samples were collected at the end of each 4-week feeding period, and the fatty acid composition of plasma CEs and plasma concentrations of lipoproteins were determined. Consumption of the diet with fish oil was associated with significantly greater proportions of eicosapentaenoic acid, arachidonic acid, alpha-linolenic acid, oleic acid, palmitic acid and myristic acid in plasma CEs. The intake of fish oil instead of sunflower oil reduced the percentage of linoleic acid in CEs. The plasma concentrations of total cholesterol, high-density lipoprotein cholesterol, phospholipids and triglycerides were not affected by fish oil vs. sunflower oil feeding.

  10. Entamoeba mitosomes play an important role in encystation by association with cholesteryl sulfate synthesis.

    Science.gov (United States)

    Mi-ichi, Fumika; Miyamoto, Tomofumi; Takao, Shouko; Jeelani, Ghulam; Hashimoto, Tetsuo; Hara, Hiromitsu; Nozaki, Tomoyoshi; Yoshida, Hiroki

    2015-06-01

    Hydrogenosomes and mitosomes are mitochondrion-related organelles (MROs) that have highly reduced and divergent functions in anaerobic/microaerophilic eukaryotes. Entamoeba histolytica, a microaerophilic, parasitic amoebozoan species, which causes intestinal and extraintestinal amoebiasis in humans, possesses mitosomes, the existence and biological functions of which have been a longstanding enigma in the evolution of mitochondria. We previously demonstrated that sulfate activation, which is not generally compartmentalized to mitochondria, is a major function of E. histolytica mitosomes. However, because the final metabolites of sulfate activation remain unknown, the overall scheme of this metabolism and the role of mitosomes in Entamoeba have not been elucidated. In this study we purified and identified cholesteryl sulfate (CS) as a final metabolite of sulfate activation. We then identified the gene encoding the cholesteryl sulfotransferase responsible for synthesizing CS. Addition of CS to culture media increased the number of cysts, the dormant form that differentiates from proliferative trophozoites. Conversely, chlorate, a selective inhibitor of the first enzyme in the sulfate-activation pathway, inhibited cyst formation in a dose-dependent manner. These results indicate that CS plays an important role in differentiation, an essential process for the transmission of Entamoeba between hosts. Furthermore, we show that Mastigamoeba balamuthi, an anaerobic, free-living amoebozoan species, which is a close relative of E. histolytica, also has the sulfate-activation pathway in MROs but does not possess the capacity for CS production. Hence, we propose that a unique function of MROs in Entamoeba contributes to its adaptation to its parasitic life cycle.

  11. Single nucleotide polymorphisms in cholesteryl ester transfer protein gene and recurrent coronary heart disease or mortality in patients with established atherosclerosis.

    Science.gov (United States)

    Virani, Salim S; Lee, Vei-Vei; Brautbar, Ariel; Grove, Megan L; Nambi, Vijay; Alam, Mahboob; Elayda, MacArthur; Wilson, James M; Willerson, James T; Boerwinkle, Eric; Ballantyne, Christie M

    2013-11-01

    It is not known whether genetic variants in the cholesteryl ester transfer protein (CETP) gene are associated with recurrent coronary heart disease events or mortality in secondary prevention patients. Among 3,717 patients with acute coronary syndrome or coronary artery bypass grafting (CABG) enrolled in a prospective genetic registry, we evaluated whether CETP gene variants previously shown to be associated with reduced CETP activity and high-density lipoprotein cholesterol increase ("A" allele for both TaqIB [rs708272] and rs12149545) are associated with a reduction in recurrent myocardial infarction (MI), recurrent revascularization, or death. At 4.5 years of follow-up, 439 recurrent MI, 698 recurrent revascularizations, and 756 deaths occurred. Using an additive model of inheritance, the "A" allele for rs708272 was not associated with recurrent MI (hazard ratio [HR] 0.95, 95% confidence interval [CI] 0.78 to 1.17 for AG; HR 0.89, 95% CI 0.67 to 1.19 for AA; compared with GG genotype), recurrent revascularization (HR 1.13, 95% CI 0.95 to 1.33 for AG; HR 1.05, 95% CI 0.84 to 1.32 for AA), or mortality (HR 1.02, 95% CI 0.86 to 1.19 for AG; HR 1.11, 95% CI 0.91 to 1.37 for AA) in the overall cohort. Similar results were seen for the "A" allele for rs12149545. In the CABG subgroup, AG genotype for rs708272 was associated with an increased mortality (HR 1.38, 95% CI 1.06 to 1.79) compared with GG genotype. Results remained consistent using dominant model of inheritance. In conclusion, genetic CETP variants were not associated with recurrent MI or recurrent revascularization in overall cohort with a possible mortality increase in patients who underwent CABG.

  12. Cholesteryl ester transfer protein inhibitors in coronary heart disease: Validated comparative QSAR modeling of N, N-disubstituted trifluoro-3-amino-2-propanols.

    Science.gov (United States)

    Mondal, Chanchal; Halder, Amit Kumar; Adhikari, Nilanjan; Jha, Tarun

    2013-10-01

    Cholesteryl ester transfer protein (CETP) converts high density lipoprotein cholesterol to low density lipoproteins. It is a promising target for treatment of coronary heart disease. Two dimensional quantitative structure activity relationship (2D-QSAR), hologram QSAR (HQSAR) studies and comparative molecular field analysis (CoMFA) as well as comparative molecular similarity analysis (CoMSIA) were performed on 104 CETP inhibitors. The statistical qualities of generated models were justified by internal and external validation, i.e., q(2) and R(2)pred respectively. The best 2D-QSAR model was obtained with q(2) and R(2)pred values of 0.794 and 0.796 respectively. The 2D-QSAR study suggests that unsaturation, branching and van der Waals volumes may play important roles. The HQSAR model showed q(2) and R(2)pred values of 0.628 and 0.550 respectively. Similarly, CoMFA model showed q(2) and R(2)pred values of 0.707 and 0.755 respectively whereas CoMSIA model was obtained with q(2) and R(2)pred values of 0.696 and 0.703 respectively. CoMFA and CoMSIA studies indicate that steric factors are important at substituted phenoxy and tetrafluoroethoxy groups whereas electropositive factors play important role at difluoromethyl group. The results of 3D-QSAR studies validate those of 2D-QSAR and HQSAR studies as well as the earlier observed SAR data. Current work may help to develop better CETP inhibitors.

  13. Synthesis of Trimethylolpropane Esters of Calophyllum Methyl Esters : Effect of Temperature and Molar Ratio

    Directory of Open Access Journals (Sweden)

    Yeti Widyawati

    2014-12-01

    Full Text Available Trimethylolpropane esters were synthesized by transesterification of calophyllum methyl esters and trimethylolpropane using a calcium oxide as the catalyst. The results showed that the optimal reaction conditions (temperature: 130 0C, reaction time: 5 h, reactant molar ratio: 3.9:1, catalyst amount 3%w/w, and formed  trimethylolpropane ester of 79.0% were obtained. The basic physicochemical properties of the trimethylolpropane esters were the following : kinematic viscosities of 56.40 cSt and 8.8 cSt at 40 0C and 100 0C,  viscosity index 193, flash point 218 0C and pour point -3 0C. So Methyl esters of fatty acids of would callophylum  methyl ester is good raw material for the synthesis of lubricating oils.

  14. Comparison of fatty acid proportions in serum cholesteryl esters among people with different glucose tolerance status: The CoDAM study

    NARCIS (Netherlands)

    Woudenbergh, van G.J.; Kuijsten, A.; Kallen, C.J.; Greevenbroek, M.M.; Stehouwer, C.D.; Blaak, E.E.; Feskens, E.J.M.

    2012-01-01

    Background and aim - Altered fatty acid patterns in blood may be associated with insulin resistance and related disorders. We investigated whether serum proportions of cholesteryl fatty acids and desaturase activity are associated with glucose tolerance status and insulin resistance. Methods and res

  15. Facile synthesis and characterization of novel thermo-chromism cholesteryl-containing hydrogen-bonded liquid crystals

    Institute of Scientific and Technical Information of China (English)

    Wan Li He; Tao Liu; Zhou Yang; Dong Yu Zhao; Wei Huang; Hui Cao; Guo Jie Wang; Huai Yang

    2009-01-01

    Two series of novel cholesteryl-containing H-bonded liquid crystals were prepared through facile self-assembly between cholesteryl isonicotinate (proton acceptor) exhibiting a monotropic cholesteric phase, and the 4-alkoxy-benzoic acid or 4-alkoxy cinnamic acid (proton donor). It was found that the increase of the conjugate length as well as the terminal length can contribute to enhance the interaction of molecules and thus significantly influenced the thermal behaviors of H-bonded LCs. The cholesteric reflection spectra of the induced mesogenic complexes were located in the visible region with the color tuneable thermo-sensitivity, which could be used for display application.

  16. Short-chain aliphatic ester synthesis using Thermobifida fusca cutinase.

    Science.gov (United States)

    Su, Lingqia; Hong, Ruoyu; Guo, Xiaojie; Wu, Jing; Xia, Yongmei

    2016-09-01

    Short-chain aliphatic esters are commonly used as fruit flavorings in the food industry. In this study, Thermobifida fusca (T. fusca) cutinase was used for the synthesis of aliphatic esters, and the maximum yield of ethyl caproate reached 99.2% at a cutinase concentration of 50U/ml, 40°C, and water content of 0.5%, representing the highest ester yield to date. The cutinase-catalyzed esterification displayed strong tolerance for water content (up to 8%) and acid concentration (up to 0.8M). At substrate concentrations ⩽0.8M, the ester yield remained above 80%. Moreover, ester yields of more than 98% and 95% were achieved for acids of C3-C8 and alcohols of C1-C6, respectively, indicating extensive chain length selectivity of the cutinase. These results demonstrate the superior ability of T. fusca cutinase to catalyze the synthesis of short-chain esters. This study provides the basis for industrial production of short-chain esters using T. fusca cutinase.

  17. Curdlan ester derivatives: synthesis, structure, and properties.

    Science.gov (United States)

    Marubayashi, Hironori; Yukinaka, Kazuyori; Enomoto-Rogers, Yukiko; Takemura, Akio; Iwata, Tadahisa

    2014-03-15

    A series of ester derivatives of curdlan, which is a β-(1 → 3)-D-glucan extracellularly produced by microorganism, with varying alkyl chain lengths (C2-C12) were synthesized by the heterogeneous reaction using trifluoroacetic anhydride. As a result, high-molecular-weight (Mw ≥ 6 × 10(5)) and fully-acylated curdlan was obtained with relatively high yield (>70%). Thermal stability of curdlan was greatly improved by esterification. Crystallization was observed for curdlan esters with C2-C6 side chains. Both Tg (170 → 50 °C) and Tm (290 → 170 °C) of curdlan esters decreased with increasing the side-chain length. By the increase in the side-chain carbon number, curdlan esters showed lower Young's modulus and tensile strength, and larger elongation at break. Thus, material properties of curdlan esters can be controlled by changing the side-chain length. It was found that the increase of the side-chain length resulted in the decrease of crystallinity and the change of crystal structures.

  18. Fatty acid phytyl ester synthesis in chloroplasts of Arabidopsis.

    Science.gov (United States)

    Lippold, Felix; vom Dorp, Katharina; Abraham, Marion; Hölzl, Georg; Wewer, Vera; Yilmaz, Jenny Lindberg; Lager, Ida; Montandon, Cyrille; Besagni, Céline; Kessler, Felix; Stymne, Sten; Dörmann, Peter

    2012-05-01

    During stress or senescence, thylakoid membranes in chloroplasts are disintegrated, and chlorophyll and galactolipid are broken down, resulting in the accumulation of toxic intermediates, i.e., tetrapyrroles, free phytol, and free fatty acids. Chlorophyll degradation has been studied in detail, but the catabolic pathways for phytol and fatty acids remain unclear. A large proportion of phytol and fatty acids is converted into fatty acid phytyl esters and triacylglycerol during stress or senescence in chloroplasts. We isolated two genes (PHYTYL ESTER SYNTHASE1 [PES1] and PES2) of the esterase/lipase/thioesterase family of acyltransferases from Arabidopsis thaliana that are involved in fatty acid phytyl ester synthesis in chloroplasts. The two proteins are highly expressed during senescence and nitrogen deprivation. Heterologous expression in yeast revealed that PES1 and PES2 have phytyl ester synthesis and diacylglycerol acyltransferase activities. The enzymes show broad substrate specificities and can employ acyl-CoAs, acyl carrier proteins, and galactolipids as acyl donors. Double mutant plants (pes1 pes2) grow normally but show reduced phytyl ester and triacylglycerol accumulation. These results demonstrate that PES1 and PES2 are involved in the deposition of free phytol and free fatty acids in the form of phytyl esters in chloroplasts, a process involved in maintaining the integrity of the photosynthetic membrane during abiotic stress and senescence.

  19. Triphenylethanamine Derivatives as Cholesteryl Ester Transfer Protein Inhibitors: Discovery of N-[(1R)-1-(3-Cyclopropoxy-4-fluorophenyl)-1-[3-fluoro-5-(1,1,2,2-tetrafluoroethoxy)phenyl]-2-phenylethyl]-4-fluoro-3-(trifluoromethyl)benzamide (BMS-795311).

    Science.gov (United States)

    Qiao, Jennifer X; Wang, Tammy C; Adam, Leonard P; Chen, Alice Ye A; Taylor, David S; Yang, Richard Z; Zhuang, Shaobin; Sleph, Paul G; Li, Julia P; Li, Danshi; Yin, Xiaohong; Chang, Ming; Chen, Xue-Qing; Shen, Hong; Li, Jianqing; Smith, Daniel; Wu, Dauh-Rurng; Leith, Leslie; Harikrishnan, Lalgudi S; Kamau, Muthoni G; Miller, Michael M; Bilder, Donna; Rampulla, Richard; Li, Yi-Xin; Xu, Carrie; Lawrence, R Michael; Poss, Michael A; Levesque, Paul; Gordon, David A; Huang, Christine S; Finlay, Heather J; Wexler, Ruth R; Salvati, Mark E

    2015-11-25

    Cholesteryl ester transfer protein (CETP) inhibitors raise HDL-C in animals and humans and may be antiatherosclerotic by enhancing reverse cholesterol transport (RCT). In this article, we describe the lead optimization efforts resulting in the discovery of a series of triphenylethanamine (TPE) ureas and amides as potent and orally available CETP inhibitors. Compound 10g is a potent CETP inhibitor that maximally inhibited cholesteryl ester (CE) transfer activity at an oral dose of 1 mg/kg in human CETP/apoB-100 dual transgenic mice and increased HDL cholesterol content and size comparable to torcetrapib (1) in moderately-fat fed hamsters. In contrast to the off-target liabilities with 1, no blood pressure increase was observed with 10g in rat telemetry studies and no increase of aldosterone synthase (CYP11B2) was detected in H295R cells. On the basis of its preclinical profile, compound 10g was advanced into preclinical safety studies.

  20. Synthesis of fatty acid starch esters in supercritical carbon dioxide

    NARCIS (Netherlands)

    Muljana, Henky; van der Knoop, Sjoerd; Keijzer, Danielle; Picchioni, Francesco; Janssen, Leon P. B. M.; Heeres, Hero J.

    2010-01-01

    This manuscript describes an exploratory study on the synthesis of fatty acid/potato starch esters using supercritical carbon dioxide (scCO(2)) as the solvent. The effects of process variables such as pressure (6-25 MPa), temperature (120-150 degrees C) and various basic catalysts and fatty acid der

  1. Microwave-Assisted Synthesis of Cinnamyl Long Chain Aroma Esters.

    Science.gov (United States)

    Worzakowska, Marta

    2015-06-08

    Cinnamyl long chain aroma esters were prepared by using the conventional and microwave-assisted methods. The esterification reaction of naturally occurring 3-phenyl-prop-2-en-1-ol and different chain lengths acidic and diol reagents was carried out at the temperature of 140 °C under solvent free conditions. As acidic reagents, oxolane-2,5-dione, oxane-2,6-dione, hexanedioic acid and decanedioic acid were applied. Ethane-1,2-diol and 2,2'-[oxybis(2,1-ethandiyloxy)]diethanol were used as diol reagents. The synthesis of high molecular mass cinnamyl esters under conventional method conditions requires a long time to obtain high yields. The studies confirm that by using microwave irradiation, it is possible to reduce the reaction times to only 10-20 min. The structures of prepared esters were confirmed on the basis of FTIR, 1H-NMR and 13C-NMR. In addition, the newly obtained cinnamyl long chain esters were tested for their thermal properties. The TG studies proved the high thermal resistance of the obtained esters under inert and oxidative conditions.

  2. Synthesis and properties of differently charged chemiluminescent acridinium ester labels.

    Science.gov (United States)

    Natrajan, Anand; Sharpe, David

    2013-02-14

    Chemiluminescent acridinium dimethylphenyl esters containing N-sulfopropyl groups in the acridinium ring are highly sensitive, hydrophilic labels that are used in automated immunoassays for clinical diagnostics. Light emission from these labels is triggered with alkaline peroxide in the presence of a cationic surfactant. At physiological pH, N-sulfopropyl acridinium esters exist as water adducts that are commonly referred to as pseudobases. Pseudobase formation, which results from addition of water to the zwitterionic N-sulfopropyl acridinium ring, neutralizes the positive charge on the acridinium nitrogen and imparts a net negative charge to the label due to the sulfonate moiety. As a consequence, N-sulfopropyl acridinium ester conjugates of small molecule haptens as well as large molecules such as proteins gain negative charges at neutral pH. In the current study, we describe the synthesis and properties of two new hydrophilic acridinium dimethylphenyl ester labels where the net charge in the labels was altered. In one label, the structure of the hydrophilic N-alkyl group attached to the acridinium ring was changed so that the pseudobase of the label contains no net charge. In the second acridinium ester, two additional negative charges in the form of sulfopropyl groups were added to the acridinium ring to make this label's pseudobase strongly anionic. Chemiluminescence measurements of these labels, as well as their conjugates of an antibody with a neutral pI, indicate that acridinium ester charge while having a modest effect on emission kinetics has little influence on light output. However, our results demonstrate that acridinium ester charge can affect protein pI, apparent chemiluminescence stability and non-specific binding of protein conjugates to microparticles. These results emphasize the need for careful consideration of acridinium ester charge in order to optimize reagent stability and performance in immunoassays. In the current study, we observed that

  3. 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

  4. 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.

  5. Unique cellular events occurring during the initial interaction of macrophages with matrix-retained or methylated aggregated low density lipoprotein (LDL). Prolonged cell-surface contact during which ldl-cholesteryl ester hydrolysis exceeds ldl protein degradation.

    Science.gov (United States)

    Buton, X; Mamdouh, Z; Ghosh, R; Du, H; Kuriakose, G; Beatini, N; Grabowski, G A; Maxfield, F R; Tabas, I

    1999-11-05

    A critical event in atherogenesis is the interaction of arterial wall macrophages with subendothelial lipoproteins. Although most studies have investigated this interaction by incubating cultured macrophages with monomeric lipoproteins dissolved in media, arterial wall macrophages encounter lipoproteins that are mostly bound to subendothelial extracellular matrix, and these lipoproteins are often aggregated or fused. Herein, we utilize a specialized cell-culture system to study the initial interaction of macrophages with aggregated low density lipoprotein (LDL) bound to extracellular matrix. The aggregated LDL remains extracellular for a relatively prolonged period of time and becomes lodged in invaginations in the surface of the macrophages. As expected, the degradation of the protein moiety of the LDL was very slow. Remarkably, however, hydrolysis of the cholesteryl ester (CE) moiety of the LDL was 3-7-fold higher than that of the protein moiety, in stark contrast to the situation with receptor-mediated endocytosis of acetyl-LDL. Similar results were obtained using another experimental system in which the degradation of aggregated LDL protein was delayed by LDL methylation rather than by retention on matrix. Additional experiments indicated the following properties of this interaction: (a) LDL-CE hydrolysis is catalyzed by lysosomal acid lipase; (b) neither scavenger receptors nor the LDL receptor appear necessary for the excess LDL-CE hydrolysis; and (c) LDL-CE hydrolysis in this system is resistant to cellular potassium depletion, which further distinguishes this process from receptor-mediated endocytosis. In summary, experimental systems specifically designed to mimic the in vivo interaction of arterial wall macrophages with subendothelial lipoproteins have demonstrated an initial period of prolonged cell-surface contact in which CE hydrolysis exceeds protein degradation.

  6. 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.

  7. Evaluation of lipids, drug concentration, and safety parameters following cessation of treatment with the cholesteryl ester transfer protein inhibitor anacetrapib in patients with or at high risk for coronary heart disease.

    Science.gov (United States)

    Gotto, Antonio M; Cannon, Christopher P; Li, Xiujiang Susie; Vaidya, Sanskruti; Kher, Uma; Brinton, Eliot A; Davidson, Michael; Moon, Jennifer E; Shah, Sukrut; Dansky, Hayes M; Mitchel, Yale; Barter, Philip

    2014-01-01

    The aim of this study was to assess the effects on lipids and safety during a 12-week reversal period after 18 months of treatment with anacetrapib. The cholesteryl ester transfer protein inhibitor anacetrapib was previously shown to reduce low-density lipoprotein cholesterol by 39.8% (estimated using the Friedewald equation) and increase high-density lipoprotein (HDL) cholesterol by 138.1%, with an acceptable side-effect profile, in patients with or at high risk for coronary heart disease in the Determining the Efficacy and Tolerability of CETP Inhibition With Anacetrapib (DEFINE) trial. A total of 1,398 patients entered the 12-week reversal-phase study, either after completion of the active-treatment phase or after early discontinuation of the study medication. In patients allocated to anacetrapib, placebo-adjusted mean percentage decreases from baseline were observed at 12 weeks off the study drug for Friedewald-calculated low-density lipoprotein cholesterol (18.6%), non-HDL cholesterol (17.6%), and apolipoprotein B (10.2%); placebo-adjusted mean percentage increases were observed for HDL cholesterol (73.0%) and apolipoprotein A-I (24.5%). Residual plasma anacetrapib levels (about 40% of on-treatment apparent steady-state trough levels) were also detected 12 weeks after cessation of anacetrapib. No clinically important elevations in liver enzymes, blood pressure, electrolytes, or adverse experiences were observed during the reversal phase. Preliminary data from a small cohort (n = 30) revealed the presence of low concentrations of anacetrapib in plasma 2.5 to 4 years after the last anacetrapib dose. In conclusion, after the cessation of active treatment, anacetrapib plasma lipid changes and drug levels decreased to approximately 40% of on-treatment trough levels at 12 weeks after dosing, but modest HDL cholesterol elevations and low drug concentrations were still detectable 2 to 4 years after the last dosing.

  8. Gold-catalyzed reactions of propargylic esters with vinylazides for the synthesis of Z- or E-configured buta-1,3-dien-2-yl esters.

    Science.gov (United States)

    Wagh, Sachin Bhausaheb; Liu, Rai-Shung

    2015-10-28

    Gold-catalyzed synthesis of buta-1,3-dien-2-yl esters by the reaction of propargyl esters with vinylazides is described; the reaction mechanism is postulated to involve a vinyl attack of vinylazides at alkenyl gold carbenes.

  9. Diastereoselective Ugi reaction for the synthesis of unnatural amino esters

    Directory of Open Access Journals (Sweden)

    Rafael Oliveira Rocha

    2012-06-01

    Full Text Available Multicomponent Reactions (MCR are useful reactions to obtain complex products by the simple mixture of 3 or more reactants. The classic Ugi reaction (4-UCR involves a mixture of an amine, aldehyde, isocyanide and a carboxylic acid, giving peptoides as products. Some modifications of this reaction have been reported, among which the use of amino acids and Lewis acids, such as titanium (IV chloride, to induce stereoselectivity in good ratio. In this work we demonstrate the efficiency of different Lewis acids in the modified Ugi reaction and good levels of diastereoselectivity and yields in the synthesis of unnatural secondary amino esters.

  10. 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.

  11. Lipase-catalysed ester synthesis in solvent-free oil system: is it esterification or transesterification?

    Science.gov (United States)

    Sun, Jingcan; Yu, Bin; Curran, Philip; Liu, Shao-Quan

    2013-12-01

    Ester synthesis was carried out in a solvent-free system of lipase, coconut oil and ethanol or fusel alcohols to ascertain the reaction mechanism. During ester formation, octanoic and decanoic acids increased initially and then decreased gradually, indicating that ester production was a two-step reaction consisting of hydrolysis and esterification, rather than alcoholysis. With ethanol as the alcohol substrate, added butyric acid inhibited ester synthesis. However, when fusel alcohols were used as the alcohol substrate, no significant inhibitory effect by butyric acid was observed. Added octanoic acid did not show any adverse effect on the synthesis of corresponding esters. The results suggest that polarity of the reactants determines lipase activity. This study provides the first evidence on the mechanism of immobilised lipase-catalysed ester synthesis in a solvent-free system involving both hydrolysis and esterification.

  12. Enzymatic synthesis and application of fatty acid ascorbyl esters

    Directory of Open Access Journals (Sweden)

    Stojanović Marija M.

    2013-01-01

    Full Text Available Fatty acid ascorbyl esters are liposoluble substances that possess good antioxidative properties. These compounds could be synthesized by using various acyl donors for acylation of vitamin C in reaction catalyzed by chemical means or lipases. Enzymatic process is preferred since it is regioselective, performed under mild reaction conditions, with the obtained product being environmentally friendly. Polar organic solvents, ionic liquids, and supercritical fluids has been successfully used as a reaction medium, since commonly used solvents with high Log P values are inapplicable due to ascorbic acid high polarity. Acylation of vitamin C using fatty acids, their methyl-, ethyl-, and vinyl esters, as well as triglycerides has been performed, whereas application of the activated acyl donors enabled higher molar conversions. In each case, majority of authors reported that using excessive amount of the acyl donor had positive effect on yield of product. Furthermore, several strategies have been employed for shifting the equilibrium towards the product by water content control. These include adjusting the initial water activity by pre-equilibration of reaction mixture, enzyme preparation with water vapor of saturated salt solutions, and the removal of formed water by the addition of molecular sieves or salt hydrate pairs. The aim of this article is to provide a brief overview of the procedures described so far for the lipase-catalyzed synthesis of fatty acid ascorbyl esters with emphasis on the potential application in food, cosmetics, and pharmaceutics. Furthermore, it has been pointed out that the main obstacles for process commercialization are long reaction times, lack of adequate purification methods, and high costs of lipases. Thus, future challenges in this area are testing new catalysts, developing continuous processes for esters production, finding cheaper acyl donors and reaction mediums, as well as identifying standard procedures for

  13. Synthesis of α-amino-β-keto-esters (β-oxodipeptides)

    Institute of Scientific and Technical Information of China (English)

    Yanjie XU; Ligong CHEN

    2008-01-01

    The synthesis of α-amino-β-keto-esters (β-oxo dipeptides) was studied. Corresponding α-amino-β-keto-esters were prepared from BOC-(L)-Valine and BOC-(L)-isoleucine by coupling with (D,L)-threonine hydro-chloride and oxidation with Dess-Martin periodinane (DMP) with a total yield of 48% and 38%, respectively.

  14. Synthesis and Stability Studies of α,α‐Difluoro Ester Phospholipids

    DEFF Research Database (Denmark)

    Pedersen, Palle Jacob; Andresen, Thomas Lars; Clausen, Mads Hartvig

    2012-01-01

    The synthesis of two new α,α‐difluoro ester phospholipid conjugates is described and the stability of their liposomal formulations in three different aqueous buffers (pH 4.5, 7.5 and 8.5) has been investigated. The studies confirmed that α,α‐difluoro esters are much more prone to hydrolysis when...

  15. Synthesis of Higher Fatty Acid Starch Esters using Vinyl Laurate and Stearate as Reactants

    NARCIS (Netherlands)

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

    2008-01-01

    This paper describes the synthesis of long-chain fatty esters of corn starch (starch laurate and starch stearate) with a broad range in degree of substitution (DS = 0.24-2.96). The fatty esters were prepared by reacting the starch with vinyl laurate or vinyl stearate in the presence of basic catalys

  16. Ultrasound-assisted synthesis of aliphatic acid esters at room temperature.

    Science.gov (United States)

    Hobuss, Cristiane B; Venzke, Dalila; Pacheco, Bruna S; Souza, Alexander O; Santos, Marco A Z; Moura, Sidnei; Quina, Frank H; Fiametti, Karina G; Vladimir Oliveira, J; Pereira, Claudio M P

    2012-05-01

    This work describes the ultrasound-assisted synthesis of saturated aliphatic esters from synthetic aliphatic acids and either methanol or ethanol. The products were isolated in good yields after short reaction times under mild conditions.

  17. Stereocontrolled synthesis of 1,5-stereogenic centers through three-carbon homologation of boronic esters.

    Science.gov (United States)

    Unsworth, Phillip J; Leonori, Daniele; Aggarwal, Varinder K

    2014-09-08

    Allylic pinacol boronic esters are stable toward 1,3-borotropic rearrangement. We developed a Pd(II)-mediated isomerization process that gives di- or trisubstituted allylic boronic esters with high E selectivity. The combination of this method with lithiation-borylation enables the synthesis of carbon chains that bear 1,5-stereogenic centers. The utility of this method has been demonstrated in a formal synthesis of (+)-jasplakinolide.

  18. Synthesis of a high-grade lubricant from sunflower oil methyl esters

    Directory of Open Access Journals (Sweden)

    Hillion Gérard

    2003-09-01

    Full Text Available This paper presents the synthesis of saturated branched fatty acid methyl esters by codimerization of ethylene with conjugated linoleic methyl esters from sunflower oil. The catalytic system used is composed of iron, diimine and a reducing agent. This four-step synthesis will be discussed. After a last step of transesterification with TMP (trimethylolpropane a lubricant with interesting characteristics (in particular a high thermal stability and a good cold behavior is obtained

  19. A Study on Correlation between Cholesteryl Ester Transfer Protein and Coronary Heart Disease%胆固醇酯转运蛋白水平与冠心病患者血脂指标的相关性

    Institute of Scientific and Technical Information of China (English)

    刘祎; 刘寅; 高静

    2013-01-01

    Objective To investigate the effect of cholesteryl ester transfer protein (CETP) on lipid parameters in patients with coronary heart disease (CHD). Methods Five hundred and fifty-five cases were divided into CHD group (n= 430) and control group (n=120) according to the result of coronary angiography (CAG). The plasma levels of CETP, total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), apolipoprotein A1(ApoA1), apolipoprotein B (ApoB) and ApoA1/ApoB were measured and analyzed respectively in two groups. Results The values of HDL-C, ApoA1 and ApoAl/ApoB were significantly lower in CHD group compared with those of control group (P < 0.01). There was no significant difference in the level of CETP hetween two groups, hut the level of CETP was negatively correlated with the levels of HDL-C and ApoAl (r,= -0.141 and r,= -0.165 ,P < 0.05). The multivari-ate logistic regression analysis showed that CETP level was not independent risk factors of CHD.Conclusion Although CETP was not influencing factors of coronary heart disease, this study provided clinical data for regulating hlood lipids and treatment of coronary heart disease hy the intervention of CETP.%目的 探讨血浆胆固醇酯转运蛋白(CETP)对冠心病(CHD)患者相关血脂指标的影响.方法 行冠状动脉造影的患者550例,根据冠状动脉造影结果分为CHD组(n=430)和正常组(n=120).测定2组血浆CETP、总胆固醇(TC)、三酰甘油(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)、载脂蛋白A1(ApoA1)、载脂蛋白B(ApoB)及ApoA1/ApoB水平.结果 CHD组患者血浆中HDL-C、ApoA1及ApoA1/ApoB的水平显著低于正常组(P < 0.01);CETP水平在CHD组与正常组间差异无统计学意义,CETP水平与HDL-C和ApoA1值呈负相关(rs分别为-0.141和-0.165,P < 0.05);多因素Logistic回归分析显示,CETP不是CHD的独立影响因素.结论 CETP虽然不是冠心病的

  20. Fmoc solid-phase synthesis of peptide thioesters by masking as trithioortho esters

    DEFF Research Database (Denmark)

    Brask, Jesper; Albericio, F.; Jensen, Knud Jørgen

    2003-01-01

    Total chemical synthesis of proteins by chemoselective ligation relies on C-terminal peptide thioesters as building blocks. Their preparation by standard Fmoc solid-phase peptide synthesis is made difficult by the lability of thioesters to aminolysis by the secondary amines used for removal of th...... of the Fmoc group. Here we present a novel backbone amide linker (BAL) strategy for their synthesis in which the thioester functionality is masked as a trithioortho ester throughout the synthesis....

  1. Synthesis and properties of chemiluminescent acridinium ester labels with fluorous tags.

    Science.gov (United States)

    Natrajan, Anand; Wen, David; Sharpe, David

    2014-06-21

    Acridinium dimethylphenyl esters are highly sensitive chemiluminescent labels that are used in clinical diagnostics. Light emission from these labels is triggered with alkaline peroxide in the presence of the cationic surfactant cetyltrimethylammonium chloride (CTAC). CTAC compresses emission times of these labels to ester chemiluminescence (light yield) is quite sensitive to the polarity of the micellar interface. In the current study, we report the synthesis of new acridinium ester labels with fluorous tags of varying fluorine content and their chemiluminescence in the presence of cationic micelles of CTAC, anionic micelles of sodium perfluorooctanoate (SPFO) as well as mixed micelles of CTAC and SPFO. These studies indicate that in the presence of the mixed micelle system of CTAC and SPFO and at low mole fractions of SPFO, polarity of the mixed micelle interface is lower than that of CTAC leading to a greater enhancement of chemiluminescence for both fluorinated acridinium esters as well as a structurally analogous but non-fluorinated acridinium ester. Chemiluminescence stability of the fluorinated acridinium esters was either comparable to or better than the stability of the non-fluorinated acridinium ester. Non-specific binding to paramagnetic microparticles was higher for fluorinated acridinium esters requiring a surfactant wash to reduce their non-specific binding to the same extent as that observed for the non-fluorinated acridinium ester.

  2. Synthesis and anti-tumor activity of alkenyl camptothecin esters

    Institute of Scientific and Technical Information of China (English)

    Zhi-song CAO; John MENDOZA; Albert DEJESUS; Beppino GIOVANELLA

    2005-01-01

    Aim: To study the degrees of influence of changing side ester chains at position C20 of camptothecin on the anti-tumor activity of the molecules. Methods: The esterification reaction of camptothecin 1 and 9-nitrocamptothecin 2 with crotonic anhydride in pyridine gave the corresponding esters 3 and 4, respectively. The acylation of 1 and 2 with cinnamoyl chloride gave products 7 and 8. Epoxidation reaction of 3 and 4 with m-chloroperoxybenzoic acid in benzene solvent gave the products 5 and 6. Esters 3, 4, and 5 were tested for anti-tumor activity against 14 human cancer cell lines. Results: Both in vitro and in vivo anti-tumor activity studies for these esters were conducted and the data demonstrated positive results, that is, these esters were active against the tested tumor lines. Conclusion: Alkenyl esters 3 and 4 showed strong anti-tumor activity in vitro against 14 different cancer cell lines. Ester 3 was active against human breast carcinoma in mice and the toxicity of the agent was not observed in mice during the treatment, implying that this agent is effective for treatment with low toxicity.

  3. 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.

  4. Enzymatic synthesis of polyol esters in aqueous-organic two-phase systems.

    OpenAIRE

    Janssen, A.E.M.

    1993-01-01

    The last decade increasingly attention is paid to lipases as catalysts for synthesis of components, such as fatty acid-based surfactants, flavors, edible oil equivalents, monomers and polymers, and amides. In this thesis, the lipase-catalyzed esterification of polyols and fatty acids is described. These esters consist of a nonpolar part (fatty acid) and a polar part (polyol). Therefore, polyol esters have surface-active properties and are used as emulsifier in food, pharmaceutics; and cosmeti...

  5. Biochemical Characterization of a First Fungal Esterase from Rhizomucor miehei Showing High Efficiency of Ester Synthesis

    OpenAIRE

    Yu Liu; Haibo Xu; Qiaojuan Yan; Shaoqing Yang; Xiaojie Duan; Zhengqiang Jiang

    2013-01-01

    BACKGROUND: Esterases with excellent merits suitable for commercial use in ester production field are still insufficient. The aim of this research is to advance our understanding by seeking for more unusual esterases and revealing their characterizations for ester synthesis. METHODOLOGY/PRINCIPAL FINDINGS: A novel esterase-encoding gene from Rhizomucor miehei (RmEstA) was cloned and expressed in Escherichia coli. Sequence analysis revealed a 975-bp ORF encoding a 324-amino-acid polypeptide be...

  6. Synthesis of Optically Active trans-2-Aminocyclopropane-carboxylic Esters

    Institute of Scientific and Technical Information of China (English)

    Jiang Chun ZHONG; Shang Zhong LIU; Qing Hua BIAN; Ming Ming YIN; Min WANG

    2006-01-01

    Two new optically active trans-2-aminocyclopropanecarboxylic esters (β-ACCs) of optical purity 91%-96% were concisely synthesized via ozonization, oxidation, Curtius rearrangement from commercial available optically active trans-chrysanthemate in total yield 36%.

  7. Chemoenzymatic Synthesis and Chemical Recycling of Poly(ester-urethanes

    Directory of Open Access Journals (Sweden)

    Hiroto Hayashi

    2011-08-01

    Full Text Available Novel poly(ester-urethanes were prepared by a synthetic route using a lipase that avoids the use of hazardous diisocyanate. The urethane linkage was formed by the reaction of phenyl carbonate with amino acids and amino alcohols that produced urethane-containing diacids and hydroxy acids, respectively. The urethane diacid underwent polymerization with polyethylene glycol and a,w-alkanediols and also the urethane-containing hydroxy acid monomer was polymerized by the lipase to produce high-molecular-weight poly(ester-urethanes. The periodic introduction of ester linkages into the polyurethane chain by the lipase-catalyzed polymerization afforded chemically recyclable points. They were readily depolymerized in the presence of lipase into cyclic oligomers, which were readily repolymerized in the presence of the same enzyme. Due to the symmetrical structure of the polymers, poly(ester-urethanes synthesized in this study showed higher Tm, Young’s modulus and tensile strength values.

  8. 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......-opening polymerization of E-caprolactone initiated by 5-hexyn-1-ol and Mitsunobu coupling with 4-pentenoic acid provide hetero-telechelic poly(epsilon-caprolactone) bearing terminal alkyne and alkene groups. It is then employed in the sequential "click" reactions with the azide-functionalized dendritic wedge...

  9. Synthesis and physical properties of pennycress estolides and esters

    Science.gov (United States)

    A new series of pennycress (Thlasphi arvense L.) based free-acid estolides was synthesized by an acid-catalyzed condensation reaction, followed by an esterification reaction to produce the 2-ethylhexyl (2-EH) esters of the initial estolides. The physical properties of the estolides are highly affect...

  10. RAFT Polymerization of Vinyl Esters: Synthesis and Applications

    Directory of Open Access Journals (Sweden)

    Simon Harrisson

    2014-05-01

    Full Text Available This article is the first comprehensive review on the study and use of vinyl ester monomers in reversible addition fragmentation chain transfer (RAFT polymerization. It covers all the synthetic aspects associated with the definition of precision polymers comprising poly(vinyl ester building blocks, such as the choice of RAFT agent and reaction conditions in order to progress from simple to complex macromolecular architectures. Although vinyl acetate was by far the most studied monomer of the range, many vinyl esters have been considered in order to tune various polymer properties, in particular, solubility in supercritical carbon dioxide (scCO2. A special emphasis is given to novel poly(vinyl alkylates with enhanced solubilities in scCO2, with applications as reactive stabilizers for dispersion polymerization and macromolecular surfactants for CO2 media. Other miscellaneous uses of poly(vinyl esters synthesized by RAFT, for instance as a means to produce poly(vinyl alcohol with controlled characteristics for use in the biomedical area, are also covered.

  11. A Convenient Synthesis of Amino Acid Methyl Esters

    Directory of Open Access Journals (Sweden)

    Yaowu Sha

    2008-05-01

    Full Text Available A series of amino acid methyl ester hydrochlorides were prepared in good toexcellent yields by the room temperature reaction of amino acids with methanol in thepresence of trimethylchlorosilane. This method is not only compatible with natural aminoacids, but also with other aromatic and aliphatic amino acids.

  12. Lipase catalyzed synthesis of aromatic esters of sugar alcohols

    NARCIS (Netherlands)

    Croitoru, R.; Broek, van den L.A.M.; Frissen, A.E.; Davidescu, C.M.; Peter, F.; Boeriu, C.G.

    2011-01-01

    Commercially available lipases (Candida antarctica lipase B, Novozyme 435, Thermomyces lanuginosus lipase, and Lipozyme TL IM), as well as sol-gel immobilized lipases, have been screened for their ability to acylate regioselectively xylitol, sorbitol, and mannitol with a phenolic ester in a binary m

  13. Synthesis and physical properties of petroselinic based estolide esters

    Science.gov (United States)

    A new series of petroselinic (Coriandrum sativum L.)-based estolide 2-ethylhexyl (2-EH) esters were synthesized, as the capping material varied in length and in degrees of unsaturation, in a perchloric acid catalyzed one-pot process with the esterification process incorporated into an in situ second...

  14. Serum cholesteryl ester n-3 fatty acid analysis by high performance liquid chromatography%高效液相色谱测定血清胆固醇酯n-3脂肪酸指数方法的建立

    Institute of Scientific and Technical Information of China (English)

    崔瑞芳; 董军; 周伟燕; 国汉邦; 李红霞; 满永; 王抒; 陈文祥

    2010-01-01

    Objective To develop an HPLC method for the measurement of n-3 fatty acid index of serum cholesteryl esters.Methods Serum triglycerides were hydrolyzed with ethanolic sodium hydroxide and cholesteryl esters (CEs) were extracted with hexane.The extracted CEs were analyzed by reversed phase HPLC with a UV detection at 205 nm.Cholesteryl eicosapentaenoate and docosahexaenoate ( major n-3 fatty acid cholesteryl esters) were identified by liquid chromatography-tandem mass spectrometry and cholesterol in each CE fraction was measured.Peak areas of CEs were corrected for cholesterol and CE n-3 index was calculated using the corrected peak area and expressed as the percentage of n-3 fatty acid CEs in total CEs.Results The HPLC analysis can be finished in 6 minutes.Triglycerides which interfere with the determination of n-3 fatty acid index, were hydrolyzed with ethanolic sodium hydroxide (4 mol/L) in 30 seconds.The within-run and total CVs for CE n-3 index averaged 0.66% and 0.90%, respectively.CE n-3 indexes of 70 volunteers and 36 coronary heart disease patients apparently healthy subjects and patients with coronary heart disease in Beijing Hospital appeared to be positively skewed and leptokurtic distribution ( skewness = 1.25, kurtosis = 1.70 ).The median of n-3 indices were 0.98% ( 0.37% - 2.40% ).The logarithm of n-3 index appeared to be normal distribution and the average is 0.003 7% with standard deviations of 0.15.The distribution of n-3 indices of gender groups was similar with the total.The medians of females and males were 1.08% (0.60% -2.40%) and 0.95% (0.37% -2.11%) respectively, and the former were significantly higher than the latter( t = - 3.021, P = 0.003 ).Conclusion A new method for the measurement of n-3 index of serum cholesteryl esters by HPLC has been established.It is simple and precise and can be used in predicting cardiovascular diseases risks and monitoring dietary intake of n-3 fatty acids.%目的 建立一种HPLC测定血清胆固醇酯n-3

  15. Papain-specific activating esters in aqueous dipeptide synthesis.

    NARCIS (Netherlands)

    Beer, R.J. de; Zarzycka, B.; Mariman, M.; Amatdjais-Groenen, H.; Mulders, M.J.; Quaedflieg, P.J.L.M.; Delft, F.L. van; Nabuurs, S.B.; Rutjes, F.P.J.T.

    2012-01-01

    Enzymatic peptide synthesis has the potential to be a viable alternative for chemical peptide synthesis. Because of the increasing commercial interest in peptides, new and improved enzymatic synthesis methods are desirable. In recently developed enzymatic strategies such as substrate mimetic approac

  16. Synthesis of some glucose-fatty acid esters by lipase from Candida antarctica and their emulsion functions.

    Science.gov (United States)

    Ren, Kangzi; Lamsal, Buddhi P

    2017-01-01

    The synthesis of glucose esters with palmitic acid, lauric acid and hexanoic acid using lipase enzyme was studied and their emulsion functionality in oil-in-water system were compared. Reactions at 3:1M ratio of fatty acids-to-glucose had the highest conversion percentages (over 90% for each of the fatty acid). Initial conversion rate increased as substrate solubility increased. Ester bond formation was confirmed by nuclear magnetic resonance technique that the chemical shifts of glucose H-6 and α-carbon protons of fatty acids in the ester molecules shifted to the higher fields. Contact angle of water on esters' pelleted surface increased as the hydrophobicity increased. Glucose esters' and commercial sucrose esters' functionality as emulsifiers were compared. Glucose esters delayed, but did not prevent coalescence, because the oil droplets diameter doubled during 7days. Sucrose esters prevented coalescence during 7days since the droplets diameter did not have significant change.

  17. Rhodium(I)-Catalyzed Benzannulation of Heteroaryl Propargylic Esters: Synthesis of Indoles and Related Heterocycles.

    Science.gov (United States)

    Li, Xiaoxun; Xie, Haibo; Fu, Xiaoning; Liu, Ji-Tian; Wang, Hao-Yuan; Xi, Bao-Min; Liu, Peng; Xu, Xiufang; Tang, Weiping

    2016-07-18

    A de novo synthesis of a benzene ring allows for the preparation of a diverse range of heterocycles including indoles, benzofurans, benzothiophenes, carbazoles, and dibenzofurans from simple heteroaryl propargylic esters using a unified carbonylative benzannulation strategy. Multiple substituents can be easily introduced to the C4-C7 positions of indoles and related heterocycles.

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

    OpenAIRE

    Díaz-Coutiño, Francisco D.; Jaime Escalante

    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.

  19. APPLICATION OF THE SULFONATE ESTER GROUP AS A LINKER FOR SOLID PHASE ORGANIC SYNTHESIS

    Institute of Scientific and Technical Information of China (English)

    SUN Weimin; LUO Juntao; HUANG Wenqiang; ZHU Xiaoxia

    2001-01-01

    A use of Sulfonate ester as a linker in synthesis of ω-aminoalkanols was reported. Diols were tethered onto polystyryl sulfonyl chloride resin, yielding sulfonate resins (2). After cleaved by diethyl amine, diisopropylamine and propylamine respectively, three ω-aminoalkanols were obtained.

  20. APPLICATION OF THE SULFONATE ESTER GROUP AS A LINKER FOR SOLID PHASE ORGANIC SYNTHESIS

    Institute of Scientific and Technical Information of China (English)

    SUNWeimin; ZHUXiaoxia; 等

    2001-01-01

    A use of sulfonate ester as a linker in synthesis of w-aminoalkanols was reporte.Diols were tethered onto polystyryl sulfonyl chloride resin,yielding sulfonate resins(2).After cleaved by diethyl amine,diisopropylamine and propylamine respectively,three w-aminoalkanlos were obtained.

  1. 氧化低密度脂蛋白诱导主动脉平滑肌细胞胆固醇酯聚集和凋%Oxidized-LDL Leads to Cholesteryl Ester Accumulation and A poptosis in Porcine Aortic Smooth Muscle Cells

    Institute of Scientific and Technical Information of China (English)

    袁中华; 杨永宗; 杨小毅

    2002-01-01

    Both cellular cholesterol metabolism imbalance and apoptosis are related to th e development of atherosclerosis. To investigate the relationship between the ce llular cholesterol metabolism and apoptosis, the porcine aortic smooth muscle ce lls were cultured with medium 199 containing 15 mg/L oxidized low density lipo protein (Ox-LDL) for 72 h, the ratio of cellular cholesteryl ester to total cholesterol increased from 26.2% to 64.1%, and Ox-LDL induced accumulation o f cellular ch olesteryl ester in a concentration dependent manner in the cells. It indicated t hat the vascular smooth muscle cells had transformed to foam cells. In addition, cells incubated with oxidized low density lipoprotein had characteristic of apo ptosis, as determined by fluorescence microscope, laser scanning confocal micros cope and flow cytometry. From this findings, it was speculated that the inducti on of apoptosis may be related to the raise of the ratio of cellular cholesteryl este r to total cholesterol besides oxidation of low density lipoprotein in vascular smooth muscle cells.%细胞内胆固醇代谢的失衡和细胞凋亡都与动脉粥样硬化的发生有关.为了研究两者之间的关系,我们把猪的主动脉平滑肌细胞与15 mg/L氧化低密度脂蛋白共同孵育 72 h,发现细胞内胆固醇酯与总胆固醇的比值由26.2%增加到64.1%,并且细胞内胆固醇酯的积聚有剂量依赖关系,表明细胞已经转化为平滑肌源性的泡沫细胞.另外,使用荧光显微镜、激光共聚焦显微镜和流式细胞仪分别发现,与氧化低密度脂蛋白共孵育的细胞有典型的凋亡形态改变.从实验可以推测,由氧化低密度脂蛋白诱导的平滑肌细胞凋亡,除了低密度脂蛋白氧化的因素外,也可能与细胞内胆固醇酯与总胆固醇的比值升高有关.

  2. Synthesis and characterization of novel dipeptide ester prodrugs of acyclovir

    Science.gov (United States)

    Nashed, Yasser E.; Mitra, Ashim K.

    2003-07-01

    Four dipeptide (Gly-Gly, Gly-Val, Val-Val, Val-Gly) ester prodrugs of 9-[(2-hydroxyethoxy)methyl]guanine (acyclovir, ACV) were synthesized. LC/MS was used to characterize the new prodrugs. Both 1H NMR and 13C NMR spectra of the four prodrugs of ACV were measured and assigned based on spectral comparison with compounds of similar structures.

  3. Enzymatic synthesis of lipophilic rutin and vanillyl esters from fish byproducts.

    Science.gov (United States)

    Mbatia, Betty; Kaki, Shiva Shanker; Mattiasson, Bo; Mulaa, Francis; Adlercreutz, Patrick

    2011-07-13

    Lipase-catalyzed synthesis of lipophilic phenolic antioxidants was carried out with a concentrate of n-3 polyunsaturated fatty acids (PUFAs), recovered from oil extracted from salmon ( Salmon salar ) byproduct. Vanillyl alcohol and rutin were selected for the esterification reaction, and obtained esters yields were 60 and 30%, respectively. The antioxidant activities of the esters were compared with those of commercial butylated hydroxytoluene (BHT) and α-tocopherol using DPPH radical scavenging and thiobarbituric acid assays. In the DPPH assay, rutin esters showed better activity than vanillyl esters, and on the contrary in lipophilic medium, vanillyl esters were found to be superior to rutin esters. In bulk oil system, the antioxidant activities of rutin and vanillyl derivatives were lower than that of BHT and α-tocopherol, but in emulsion, they showed better activity than α-tocopherol. By attaching to natural phenolics, the PUFAs are protected against oxidation, and PUFA improves the hydrophobicity of the phenolic, which could enhance its function in lipid systems.

  4. Synthesis of new fatty acids amides from aminolysis of fatty acid methyl esters (FAMEs); Sintese de novas amidas graxas a partir da aminolise de esteres metilicos

    Energy Technology Data Exchange (ETDEWEB)

    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., E-mail: dqmdoca@furg.b [Universidade Federal do Rio Grande, RS (Brazil). Escola de Quimica e Alimentos

    2010-07-01

    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)

  5. Linear and cyclic ester Oligomers of succinic acid and 1,4-butanediol: Biocatalytic synthesis and characterization

    NARCIS (Netherlands)

    Habeych Narvaez, D.I.; Eggink, G.; Boeriu, C.G.

    2011-01-01

    The lipase-catalyzed synthesis of cyclic ester oligomers from non-activated succinic acid (A) and 1,4-butanediol (B) in the presence of immobilized Candida antarctica lipase B was investigated. Batch and pulse fed-batch systems were implemented to increase the formation of cyclic ester products. The

  6. 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.

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

    Science.gov (United States)

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

    2013-06-01

    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.

  8. Enzymatic Synthesis of Palm Alkyl Ester Using Dialkyl Carbonate as an Alkyl Donors

    Directory of Open Access Journals (Sweden)

    Roila Awang

    2010-01-01

    Full Text Available Problem statement: Though efficient in terms of reaction yield and time, the chemical approach to synthesizing alkyl ester has drawback such as difficulties in the recovery of glycerol and the need for removal of salt residue. On the other hand, biocatalyst allow for synthesis of specific alkyl esters and easy recovery of glycerol. However, the solvent-free alcoholysis, does not give high conversion. The same problem was also found when ethyl or methyl acetate was used as acyl acceptors. Approach: Lipase catalyzed transesterification of oil and dialkyl carbonate was predicted to give higher conversion in solvent free reaction system. Results: Alkyl esters were synthesized enzymatically to overcome the problems associated with chemical processes. In this study, dialkyl carbonates were used as an alkyl donor for the production of alkyl ester. Nine commercial lipases were tested for their suitability for the reaction system. Among the lipase tested, Novozym 435 was chosen for optimization study because of their higher activity. In a solvent-free reaction system, the ester formation using dialkyl carbonate was 6 times higher than using ethanol and methanol. The effect of various reaction parameters such as temperature, amount of enzyme, organic solvent and structure of substrates were studied to determine optimal condition. The optimal conditions of ester formation were reaction temperature at 60°C, reaction time at 8 h, enzyme amount of 10% (w/w of oil and 0.2% wt added water. Conclusion: Solvent-free lipase catalyzed transesterification of palm kernel oil and dialkyl carbonates gave higher conversion of ester compared to the reaction using short chain alcohol as an alkyl donors.

  9. Monoacryloyl esters of carbohydrates: synthesis, polymerization and application in ceramic technology.

    Science.gov (United States)

    Wiecinska, Paulina; Mizerski, Tadeusz; Szafran, Mikolaj

    2014-10-13

    The article presents the interdisciplinary research among organic synthesis, chemistry of polymers and ceramic technology. It presents the synthesis of monoacryloyl esters of fructose and glucose that is 1-O-acryloyl-D-fructose and 3-O-acryloyl-D-glucose, conditions of their polymerization and application in shaping of advanced ceramic powders by the so called gelcasting method. The paper presents the influence of carbohydrate esters on the viscosity of Al2O3 suspensions and microstructure of final ceramic samples. The results showed that synthesized esters of saccharides can play the role of organic monomers able to polymerize in situ and self-cross-linking compounds in gelcasting. The paper presents the proposed structure of polymeric network which is formed from acryloyl ester of glucose during gelcasting process. The paper describes rheological behaviour of slurries composed of synthesized substances and A2O3 powders, wetting angles of alumina substrate by synthesized compounds, differences in glass transition temperatures of polymers and the microstructure of obtained final ceramic samples.

  10. Ionic liquids as novel solvents for the synthesis of sugar fatty acid ester.

    Science.gov (United States)

    Mai, Ngoc Lan; Ahn, Kihun; Bae, Sang Woo; Shin, Dong Woo; Morya, Vivek Kumar; Koo, Yoon-Mo

    2014-12-01

    Sugar fatty acid esters are bio-surfactants known for their non-toxic, non-ionic, and high biodegradability . With great emulsifying and conditioning effects, sugar fatty acids are widely used in the food, pharmaceutical, and cosmetic industries. Biosynthesis of sugar fatty acid esters has attracted growing attention in recent decades. In this study, the enzymatic synthesis of sugar fatty acid esters in ionic liquids was developed, optimized, and scaled up. Reaction parameters affecting the conversion yield of lipase-catalyzed synthesis of glucose laurate from glucose and vinyl laurate (i.e. temperature, vinyl laurate/glucose molar ratio, and enzyme loads) were optimized by response surface methodology (RSM). In addition, production was scaled up to 2.5 L, and recycling of enzyme and ionic liquids was investigated. The results showed that under optimal reaction conditions (66.86 °C, vinyl laurate/glucose molar ratio of 7.63, enzyme load of 73.33 g/L), an experimental conversion yield of 96.4% was obtained which is close to the optimal value predicted by RSM (97.16%). A similar conversion yield was maintained when the reaction was carried out at 2.5 L. Moreover, the enzymes and ionic liquids could be recycled and reused effectively for up to 10 cycles. The results indicate the feasibility of ionic liquids as novel solvents for the biosynthesis of sugar fatty acid esters.

  11. 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.

  12. Synthesis and antimicrobial properties of 4-acylaminobenzenethiosulfoacid S-esters

    Directory of Open Access Journals (Sweden)

    Vira Lubenets

    2017-02-01

    Full Text Available A series of esters of 4-acetyl, 4-trifluoroacetyl- and 4-(3-chloropropionylaminobenzenethiosulfoacids (twenty-four compounds were synthesized and characterized by elemental analysis, 1H NMR and IR spectroscopy. The antibacterial activity of the novel candidates has been screened using the agar diffusion or serial dilution methods against representative Gram-positive (Staphylococcus aureus, Bacillus subtilis, Bacillus mesentericus, Mycobacterium sp., Mycobacterium luteum, Gram-negative (Aeromonas sp., Burkholderia cepacia, Alcaligenes faecalis, Pseudomonas aeruginosa, Escherichia coli, Proteus vulgaris bacteria and fungi (Candida albicans, Candida tenuis, Candida glabrata, Verticillium dahliae, Trichophyton gypseum, Aspergillus niger, Aspergillus fumigatus, Penicillium chrysogenum. Particular potency has been discovered against all tested pathogenic bacteria and fungi by compounds 1l and 3l at nanomolar concentrations. Some appropriate effect of thiosulfoesters structure upon their antimicrobial activity was determined.

  13. Synthesis of alkyl esters by cutinase in miniemulsion and organic solvent media.

    Science.gov (United States)

    de Barros, Dragana P C; Fonseca, Luís P; Cabral, Joaquim M S; Weiss, Clemens K; Landfester, Katharina

    2009-05-01

    The main objective of this work was studying and testing the nature and influence of reaction media (organic solvent vs. miniemulsion system) on the synthesis of alkyl esters catalyzed by Fusarium solani pisi cutinase. Ester synthesis and cutinase selectivity for different chain length of acids and alcohols (ethyl and hexyl) were evaluated. In iso-octane, after 1 h of reaction, cutinase exhibits rates of esterification between 0.24 micromol x mg(-)1 x min(-1) for ethyl oleate and 1.15 micromol x mg(-)1 x min(-1) for ethyl butyrate, while in a miniemulsion system the rates were from 0.05 for ethyl heptanoate to 0.76 micromol x mg(-1) x min(-1) for ethyl decanoate. The reaction rate for the synthesis of hexyl esters in a miniemulsion system was from 0.19 for hexyl heptanoate to 1.07 micromol x mg(-)1 x min(-1) for hexyl decanoate. High conversion yields of 95% at equilibrium after 8 h of reaction in iso-octane for pentanoic acid (C(5)) with ethanol at equimolar concentration (0.1 M) was achieved. Additionally, this work showed that a significant and unexpected shift in cutinase selectivity occurred towards longer chain length carboxylic acids (C(8)-C(10)) in miniemulsion system as compared to organic solvent (iso-octane) and previous studies in reverse micellar systems. The possibility of working with higher concentration of substrates, without inhibitory effect on the enzyme, was another advantage of the miniemulsion system.

  14. Effect of Alcohol Structure on the Optimum Condition for Novozym 435-Catalyzed Synthesis of Adipate Esters

    Directory of Open Access Journals (Sweden)

    Mohd Basyaruddin Abdul Rahman

    2011-01-01

    Full Text Available Immobilized Candida antarctica lipase B, Novozym 435, was used as the biocatalyst in the esterification of adipic acid with four different isomers of butanol (n-butanol, sec-butanol, iso-butanol, and tert-butanol. Optimum conditions for the synthesis of adipate esters were obtained using response surface methodology approach with a four-factor-five-level central composite design concerning important reaction parameters which include time, temperature, substrate molar ratio, and amount of enzyme. Reactions under optimized conditions has yielded a high percentage of esterification (>96% for n-butanol, iso-butanol, and sec-butanol, indicating that extent of esterification is independent of the alcohol structure for primary and secondary alcohols at the optimum conditions. Minimum reaction time (135 min for achieving maximum ester yield was obtained for iso-butanol. The required time for attaining maximum yield and also the initial rates in the synthesis of di-n-butyl and di-sec-butyl adipate were nearly the same. Immobilized Candida antarctica lipase B was also capable of esterifying tert-butanol with a maximum yield of 39.1%. The enzyme is highly efficient biocatalyst for the synthesis of adipate esters by offering a simple production process and a high esterification yield.

  15. Green Synthesis of Wax Ester by Immobilized Lipase

    Institute of Scientific and Technical Information of China (English)

    Salina; Mat; Radzi; Noob; Mona; Mohd.Yunus; Siti; Salhah; othman; Mahiran; Basri; Mohd.Basyaruddin; Abdul; Rahman

    2007-01-01

    1 Results Enzyme catalysis is most attractive for the synthesis and modification of biologically relevant classes of fine organic compounds, which are difficult to prepare and to handle by conventional means[1]. In this study, commercial immobilized lipase from Candida antarctica (Novozym 435) was used in the preparation of fine organic compound with excellent properties and application as raw material for cosmetic formulation - oleyl palmitate. The effect of various reaction parameters were optimized c...

  16. Synthesis of calixarenes and their extraction performance for ester catechins

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A series of extractants (tert-butylcalix[6]arene, tert-butylcalix[8]arene and octeacetate of tert-butylcalix[8]arene) were synthesized, and their structures were identified by IR and 1H-NMR. The distribution behavior of ester catechins monomer in the aqueous and chloroform two-phase system containing one of calixarene was studied. The influences of different extractants,concentration of tert-butylcalix[8]arene and extraction temperature on the partition coefficients and the separation factors were investigated. The experiment results show that tert-butylcalix[8]arene is the best extractant that forms a more stable supramolecular compound with gallocatechin gallate (GCG) than with epigallocathechin gallate (EGCG) or epicatechin gallate (ECG). When the concentration ofp-tert-butylcalix[8]arene is 3.79 mmol/L, the extraction temperature is 4 ℃C, the partition coefficients of KGG cG, KECG,KEGG cG are 0.987, 0.629, 0.449, the separation factors ofα1 and α2 are 1.450 and 1.596, respectively. The important factors influencing the extraction properties of calixarene are discovered to be its cavity size and hydrogen bonding.

  17. Synthesis and Characterization of Branched Poly(ester urea)s with Different Branch Density

    Science.gov (United States)

    Yu, Jiayi; Becker, Matthew

    2015-03-01

    A new class of L-phenylalanine-based poly(ester urea)s (PEU) was developed that possess tunable mechanical properties, water uptake ability and degradation rates. Our preliminary data has shown that 1,6-hexanediol L - phenylalanine-based poly(ester urea)s possesses an elastic modulus nearly double that of poly(lactic acid). My work details the synthesis of a series of L - phenylalanine-based poly(ester urea)s possessing a variation in diol chain length and in branch density and shows how these subtle structural differences influence the mechanical properties and in vitro biodegradation rates. The elastic moduli span a range of values that overlap with several currently clinically available degradable polymers. Increasingly the diol chain lengths increases the amount of flexible segment in the chemical structure, which results in reduced elastic modulus values and increased values of elongation at break. Increasing the amount of branch monomer incorporated into the system reduces the molecular entanglement, which also results in decreased elastic modulus values and increased values of elongation at break. The L - phenylalanine-based poly(ester urea)s also exhibited a diol length dependent degradation process that varied between 1-5 % over 16 weeks. Compared with PLLA, PEUs degrade more quickly and the rate can be tuned by changing the diol chain length. PEUs absorb more water and the water uptake ability can be tuned by changing the branch density. This work was supported by Akron Functional Materials Center.

  18. SYNTHESIS OF ACRYLIC ESTERS IN PHASE TRANSFER CATALYSIS: KINETICS AND ECOLOGICAL ASPECTS

    Directory of Open Access Journals (Sweden)

    GAGIK TOROSYAN

    2012-06-01

    Full Text Available Phase-Transfer Catalysis (PTC technology is used in the commercial manufacture and also in pollution mitigation treatment processes. In the paper is demonstrated the synthesis of esters of acrylic and metacrylic acids, which have wide applications in the industry for the synthesis of unique polymeric materials, by phase transfer catalysis method. It is necessary to notice that the synthesis of acrylic acids in PTC medium is more important because that compounds are more sensitive at acidic and basic conditions. Here is shown that the offered method has more advantages in comparison with the traditional methods. PTC is characterized by a higher degree of conversion of raw materials into useful products, smaller material and power resources consumption. The offered method for acrylic ester synthesis in comparison with the traditional methods has more advantages: higher process rates, mild reaction conditions, allowing lower energy costs, the complete elimination of hazardous and dangerous organic solvents, all leading to a sharp reduction of air pollution, and volume of generated wastewaters.

  19. 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.

  20. Parallel Synthesis of an Imidazole-4,5-dicarboxamide Library Bearing Amino Acid Esters and Alkanamines

    Directory of Open Access Journals (Sweden)

    Rosanna Solinas

    2008-12-01

    Full Text Available The imidazole-4,5-dicarboxylic acid scaffold is readily derivatized with amino acid esters and alkanamines to afford compounds with intramolecularly hydrogen bonded conformations that mimic substituted purines and therefore are hypothesized to be potential inhibitors of kinases through competitive binding to the ATP site. In this work, a total of 126 dissymmetrically disubstituted imidazole-4,5-dicarboxamides with amino acid ester and alkanamide substituents 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.

  1. Formation of isoprostane bicyclic endoperoxides from the autoxidation of cholesteryl arachidonate.

    Science.gov (United States)

    Yin, Huiyong; Havrilla, Christine M; Morrow, Jason D; Porter, Ned A

    2002-07-03

    Autoxidation of polyunsaturated fatty acids and esters leads to a complex mixture containing hydroperoxides and cyclic peroxides. Prostaglandin bicyclic endoperoxides have been detected from the autoxidation of cholesteryl arachidonate by LC-MS and GC-MS techniques. All four possible types (I-IV) of bicyclic endoperoxides have been found starting from different regioisomeric hydroperoxides of cholesteryl arachidonate. Furthermore, the stereochemistry of Type IV bicyclic endoperoxides has been determined by conversion to pentafluorobenzyl (PFB) ester, trimethylsilyl (TMS) derivatives, and comparison with synthetic standards by the use of GC-MS. All eight possible diastereomers of the derivatized isoprostanes were observed and were separated by gas chromatography. The bicyclic endoperoxides with the two alkyl chains syn on the cyclopentane ring were formed preferentially to those with anti configuration, a result anticipated from earlier work. Substantial amounts of the anti-substituted isoprostanes, including PGF(2)(alpha), were, however, observed in the product mixture.

  2. Solid Phase Synthesis of 2-Substituted 1,3-Oxazin-6-ones Using Resin-bound Cyclic Malonic Acid Ester

    Institute of Scientific and Technical Information of China (English)

    LIU, Zhan-Xiang(刘占祥); RUAN, Xiu-Xiu(阮秀秀); HUANG, Xian(黄宪)

    2004-01-01

    A facile solid phase synthesis of 2-substituted 1,3-oxazin-6-ones using polymer-supported Meldrum's acid has been reported. Reaction of the resin-bound cyclic malonic acid ester with triethyl orthoformate and subsequent double substitution with amide, afforded the corresponding polymer-supported acylaminomethylene cyclic malonic acid ester, which upon thermal treatment led to 1, 3-oxazin-6-ones in good yields and with high purity.

  3. 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...

  4. Integrated process of distillation with side reactors for synthesis of organic acid esters

    Science.gov (United States)

    Panchal, Chandrakant B; Prindle, John C; Kolah, Aspri; Miller, Dennis J; Lira, Carl T

    2015-11-04

    An integrated process and system for synthesis of organic-acid esters is provided. The method of synthesizing combines reaction and distillation where an organic acid and alcohol composition are passed through a distillation chamber having a plurality of zones. Side reactors are used for drawing off portions of the composition and then recycling them to the distillation column for further purification. Water is removed from a pre-reactor prior to insertion into the distillation column. An integrated heat integration system is contained within the distillation column for further purification and optimizing efficiency in the obtaining of the final product.

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

    OpenAIRE

    N. M. Huang

    2011-01-01

    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). Formatio...

  6. Biochemical characterization of a first fungal esterase from Rhizomucor miehei showing high efficiency of ester synthesis.

    Directory of Open Access Journals (Sweden)

    Yu Liu

    Full Text Available BACKGROUND: Esterases with excellent merits suitable for commercial use in ester production field are still insufficient. The aim of this research is to advance our understanding by seeking for more unusual esterases and revealing their characterizations for ester synthesis. METHODOLOGY/PRINCIPAL FINDINGS: A novel esterase-encoding gene from Rhizomucor miehei (RmEstA was cloned and expressed in Escherichia coli. Sequence analysis revealed a 975-bp ORF encoding a 324-amino-acid polypeptide belonging to the hormone-sensitive lipase (HSL family IV and showing highest similarity (44% to the Paenibacillus mucilaginosus esterase/lipase. Recombinant RmEstA was purified to homogeneity: it was 34 kDa by SDS-PAGE and showed optimal pH and temperature of 6.5 and 45°C, respectively. The enzyme was stable to 50°C, under a broad pH range (5.0-10.6. RmEstA exhibited broad substrate specificity toward p-nitrophenol esters and short-acyl-chain triglycerols, with highest activities (1,480 U mg(-1 and 228 U mg(-1 for p-nitrophenyl hexanoate and tributyrin, respectively. RmEstA efficiently synthesized butyl butyrate (92% conversion yield when immobilized on AOT-based organogel. CONCLUSION: RmEstA has great potential for industrial applications. RmEstA is the first reported esterase from Rhizomucor miehei.

  7. Synthesis and enzymatic hydrolysis of esters, constituting simple models of soft drugs.

    Science.gov (United States)

    Graffner-Nordberg, M; Sjödin, K; Tunek, A; Hallberg, A

    1998-04-01

    One way to minimise systemic side effects of drugs is to design molecules, soft drugs, in such a way that they are metabolically inactivated rapidly after having acted on their pharmacological target. Hydrolases (esterases, peptidases, lipases, glycosidases, etc.) are enzymes well suited to use for drug inactivation since they are ubiquitously distributed. Insertion of ester bonds susceptible to enzymatic cleavage may represent one approach to make the action of a drug more restricted to the site of application. The present study describes the chemical synthesis of fourteen model compounds comprising a bicyclic aromatic unit connected by an ester-containing bridge to another aromatic ring. Initial attempts to define a) the tissue selectivity of the hydrolytic metabolism and b) the molecular structural factors affecting the rate of enzymatic ester cleavage are presented. The data show that human and rat liver fractions were more active than human duodenal mucosa and human blood leukocytes at hydrolysing the compounds. The rank order of the compounds was, however, very similar in the different biological systems. Commercially available pig liver carboxyl esterase and cholesterol esterase both reasonably well predict the rank order in the tissue fractions.

  8. 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).

  9. On the nature of ionic liquids and their effects on lipases that catalyze ester synthesis.

    Science.gov (United States)

    De Diego, Teresa; Lozano, Pedro; Abad, Miguel A; Steffensky, Katharina; Vaultier, Michel; Iborra, José L

    2009-03-25

    Free and immobilized lipases from Candida antarctica (CALA and CALB), Thermomyces lanuginosus (TLL) and Rhizomucor miehei (RML) were used as catalysts in the synthesis of butyl propionate by transesterification in reaction media consisting in nine different ionic liquids. Enzyme activities were clearly dependent on the nature of the ions, the results being improving as the alkyl chain length of the imidazolium cation increased, and as a function of the type of anion ([PF(6)], [BF(4)] or [ethylsulphate]). The best synthetic activity (655.5U/mg protein at 40 degrees C) was obtained when free CALB were assayed in the water-miscible IL cocosalkyl pentaethoxy methyl ammonium methosulfate ([CPMA][MS]), and was clearly related with the water content of the medium. The synthetic activity of free CALB in [CPMA][MS] was enhanced with the increase in temperature, while practically no effect was obtained for TLL. The ability of free CALB to synthesize aliphatic esters of different alkyl chain lengths, using different alkyl vinyl esters and 1-alkanols as substrates, was also studied in [CPMA][MS], the best results (4500U/mg protein) being obtained for the synthesis of hexyl butyrate.

  10. Inhibition of insect juvenile hormone epoxide hydrolase: asymmetric synthesis and assay of glycidol-ester and epoxy-ester inhibitors of trichoplusia ni epoxide hydrolase.

    Science.gov (United States)

    Linderman, R J; Roe, R M; Harris, S V; Thompson, D M

    2000-01-01

    Juvenile hormone (JH) undergoes metabolic degradation by two major pathways involving JH esterase and JH epoxide hydrolase (EH). While considerable effort has been focussed on the study of JH esterase and the development of inhibitors for this enzyme, much less has been reported on the study of JH-EH. In this work, the asymmetric synthesis of two classes of inhibitors of recombinant JH-EH from Trichoplusia ni, a glycidol-ester series and an epoxy-ester series is reported. The most effective glycidol-ester inhibitor, compound 1, exhibited an I(50) of 1.2x10(-8) M, and the most effective epoxy-ester inhibitor, compound 11, exhibited an I(50) of 9.4x10(-8) M. The potency of the inhibitors was found to be dependent on the absolute configuration of the epoxide. In both series of inhibitors, the C-10 R-configuration was found to be significantly more potent that the corresponding C-10 S-configuration. A mechanism for epoxide hydration catalyzed by insect EH is also presented.

  11. Scope and Limitations of Fmoc Chemistry SPPS-Based Approaches to the Total Synthesis of Insulin Lispro via Ester Insulin.

    Science.gov (United States)

    Dhayalan, Balamurugan; Mandal, Kalyaneswar; Rege, Nischay; Weiss, Michael A; Eitel, Simon H; Meier, Thomas; Schoenleber, Ralph O; Kent, Stephen B H

    2017-01-31

    We have systematically explored three approaches based on 9-fluorenylmethoxycarbonyl (Fmoc) chemistry solid phase peptide synthesis (SPPS) for the total chemical synthesis of the key depsipeptide intermediate for the efficient total chemical synthesis of insulin. The approaches used were: stepwise Fmoc chemistry SPPS; the "hybrid method", in which maximally protected peptide segments made by Fmoc chemistry SPPS are condensed in solution; and, native chemical ligation using peptide-thioester segments generated by Fmoc chemistry SPPS. A key building block in all three approaches was a Glu[O-β-(Thr)] ester-linked dipeptide equipped with a set of orthogonal protecting groups compatible with Fmoc chemistry SPPS. The most effective method for the preparation of the 51 residue ester-linked polypeptide chain of ester insulin was the use of unprotected peptide-thioester segments, prepared from peptide-hydrazides synthesized by Fmoc chemistry SPPS, and condensed by native chemical ligation. High-resolution X-ray crystallography confirmed the disulfide pairings and three-dimensional structure of synthetic insulin lispro prepared from ester insulin lispro by this route. Further optimization of these pilot studies could yield an efficient total chemical synthesis of insulin lispro (Humalog) based on peptide synthesis by Fmoc chemistry SPPS.

  12. TaqI B1/B2 and -629A/C cholesteryl ester transfer protein (CETP gene polymorphisms and their association with CETP activity and high-density lipoprotein cholesterol levels in a Tehranian population. Part of the Tehran Lipid and Glucose Study (TLGS

    Directory of Open Access Journals (Sweden)

    Maryam S Daneshpour

    2007-01-01

    Full Text Available We examined the cholesteryl ester transfer protein (CETP gene TaqI intron 1 B1/B2 polymorphism and the -629A/C CETP promoter polymorphism in respect to high-density lipoprotein cholesterol (HDL-C in a healthy Iranian population taken from the Tehran Lipid and Glucose Study (TLGS. The relationship between CETP activity and HDL-C level was also determined along with body mass index, blood pressure and tobacco smoking status. PCR-RFLP used to amplify a segment of the CETP intron 1 TaqI (B2/B1 polymorphism from 1021 individuals and we selected 345 individuals from the lowest, middle and highest HDL-C deciles and investigated the -629A/C polymorphism. We also evaluated the CETP activity of 103 of these individuals, each with at least one homozygous allele. The presence of the TaqI B2 and -629A/C A alleles were significantly associated with increased HDL-C levels (B2B2 = 1.19 ± 0.31 mmolL-1 vs. B1B1 = 1.01 ± 0.2 mmol L-1 for p < 0.001; AA = 1.15 ± 0.41 mmol L-1 vs. CC = 0.95 ± 0.28 mmol L-1 for p < 0.001 and decreased the CETP activity (B1B1 = 67.8 ± 8.9 pmol L-1 vs. B2B2 = 62.6 ± 9.6 pmol L-1 for p < 0.01; CC = 68.6 ± 8.4 pmol L-1 vs. AA = 62.7 ± 9.7 pmol L-1 for p < 0.002. The frequencies were 0.382 for the TaqI B2 allele and 0.462 for the -629A/C A allele, with linkage disequilibrium analysis giving D = 0.0965 and D' = 0.4695. We demonstrated that the TaqI B1 and B2 alleles and the -629A/C A and C alleles were in linkage disequilibrium in our population and that there was a significant association between the B2 and A alleles and high HDL-C levels and low CETP activity. Linkage disequilibrium between the TaqI A and B2 alleles also detected.

  13. Kinetically controlled synthesis of monoglyceryl esters from chiral and prochiral acids methyl esters catalyzed by immobilized Rhizomucor miehei lipase.

    Science.gov (United States)

    Acosta, Andreina; Filice, Marco; Fernandez-Lorente, Gloria; Palomo, Jose M; Guisan, Jose M

    2011-01-01

    Partial acylation of only one primary hydroxyl group of glycerol generates a chiral center at position 2. Rhizomucor miehei lipase (RML) catalyzes the kinetically controlled transesterification of different aromatic carboxylic acids methyl esters with glycerol. High synthetic yields of glyceryl esters (around 70-80%) were obtained even in the presence of significant concentrations of water (from 5% to 20%). After a long incubation of the reaction mixture in the presence of the biocatalyst only pure free acid was obtained. Other lipases (from Geobacillus thermocatenulatus and from Thermomyces lanuginose) also catalyzed similar kinetically controlled transesterifications although less efficiently. RML immobilized on Sepharose-Q showed a high activity and specificity, compared to the immobilization by other techniques, only producing monoglyceryl esters with all substrates. In particular, monoglyceryl-phenylmalonate product was synthesized in 82% overall yield and >99% diastereomeric excess at pH 7.0 and 37°C and 90% glycerol.

  14. Synthesis, stereochemical determination and biochemical characterization of the enantiomeric phosphate esters of the novel immunosuppressive agent FTY720.

    Science.gov (United States)

    Hale, Jeffrey J; Yan, Lin; Neway, William E; Hajdu, Richard; Bergstrom, James D; Milligan, James A; Shei, Gan-Ju; Chrebet, Gary L; Thornton, Rosemary A; Card, Deborah; Rosenbach, Mark; HughRosen; Mandala, Suzanne

    2004-09-15

    The novel immunosuppressive agent FTY720 (1) is phosphorylated in vivo in a variety of species yielding an active metabolite that is an agonist of four of the five known G-protein-coupled sphingosine-1-phosphate (S1P) receptors. A synthesis amenable to producing gram quantities of the stereoisomeric phosphate esters, a determination of their absolute stereochemistry via an enantioselective synthesis and their characterization as S1P receptor agonists and antagonists is reported.

  15. 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

    or with a minimum amount of solvent assisted by magnetic stirring, ultrasound irradiation and microwave irradiation. Ultrasound irradiation has good effects on the synthesis of sterically hindered thiosulfonate S-esters in solvent-free media as well as in a minimum amount of anhydrous diethyl ether....

  16. Lipase catalyzed synthesis of organic acid esters of lactic acid in non-aqueous media.

    Science.gov (United States)

    Kiran, K R; Divakar, S

    2001-05-04

    Lipases from Rhizomucor miehei (Lipozyme IM20) and porcine pancreas (PPL) were employed as catalysts for the esterification reaction between the hydroxyl group of lactic acid and the carboxyl group of organic acids. Reactions were carried out at both shake-flask and bench-scale levels. Various parameters, such as solvent, temperature, substrate and enzyme concentrations, effect of buffer volume, buffer pH and water volume, were investigated for optimization of yields. While ethylmethyl ketone (EMK) was found to be the best solvent for shake-flask reactions, chloroform gave higher yields at bench-scale level. Detailed studies were carried out with respect to the synthesis of palmitoyl and stearoyl lactic acids. At shake-flask level, maximum yields of 37.5 and 40% were observed in case of palmitoyl and stearoyl lactic acids, respectively, with Lipozyme IM20; at bench-scale level, the maximum yields were 85.1 and 99% respectively, when PPL was employed. Of all the organic acids employed (C(2)--C(18)), only lauric, palmitic and stearic acids gave yields above 50%. At bench-scale level, PPL could be reused for up to three cycles with yields above 40%. Esters prepared were found to conform to Food Chemical Codex (FCC) specifications in terms of acid value, ester value, sodium and lactic acid contents.

  17. Biomass Production and Ester Synthesis by In Situ Transesterification/Esterification Using the Microalga Spirulina platensis

    Directory of Open Access Journals (Sweden)

    Tatiana Rodrigues da Silva Baumgartner

    2013-01-01

    Full Text Available The increasing energy demand and reduction in the availability of nonrenewable energy sources, allied with an increase in public environmental awareness, have stimulated a search for alternative energy sources. The present study was aimed at producing biomass from the microalga Spirulina platensis and at assessing in situ synthesis of alkyl esters via acid transesterification/esterification of biomass to produce biodiesel. Two alcohols (ethanol and methanol and two cosolvents (hexane and chloroform were tested, at different temperatures (30, 45, 60, 75, and 90°C and reaction times (10, 20, 30, 60, and 120 min. The factorial analysis of variance detected an interaction between the factors (: temperature, reaction time, alcohol, and cosolvent. The best yields were obtained with the combination ethanol and chloroform at 60°C, after 30 min of reaction, and with hexane at 45°C, after 10 min of reaction. In situ transesterification/esterification of alga biomass to form esters for biodiesel production adds unconventional dynamics to the use of this feedstock.

  18. 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.

  19. Synthesis and fungicidal activity of aryl carbamic acid-5-aryl-2-furanmethyl ester.

    Science.gov (United States)

    Li, Ying; Li, Bao-Ju; Ling, Yun; Miao, Hong-Jian; Shi, Yan-Xia; Yang, Xin-Ling

    2010-03-10

    Chitin, a major structural component of insect cuticle and fungus cell wall but absent in plants and vertebrates, is regarded as a safe and selective target for pest control agents. Chitin synthesis inhibitors (CSIs) have been well-known as insect growth regulators (IGRs) but rarely found as fungicides in agriculture. To find novel CSIs with good activity, benzoylphenylurea, a typical kind of CSIs, was chosen as the lead compound and 26 novel aryl carbamic acid-5-aryl-2-furanmethyl esters were designed by converting the urea linkages of benzoylphenylureas to carbamic acid esters and changing the aniline parts into furanmethyl groups. The title compounds were synthesized and their structures confirmed by IR, (1)H NMR, and elemental analysis. Preliminary insecticidal and fungicidal bioassays were carried out. The results indicated that the title compounds had no insecticidal effect on Culex pipiens pallens and Plutella xylostella Linnaeus , but most compounds exhibited good fungicidal activities against Corynespora cassiicola , Thanatephorus cucumeris , Botrytis cinerea , and Fusarium oxysporum . In particular, compounds V-4, V-6, V-7, and V-8 showed better activities against the four strains than those of the commercialized fungicides. The morphologic result suggested that compound V-21 had disturbed the cell wall formation of C. cassiicola. The results indicated that modification on the urea linkage of benzoylphenylurea was an effective way to discover new candidates for fungicides.

  20. Synthesis and insecticidal activities of new pyrethroid acid oxime ester derivatives

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A series of compounds containing oxime-ester linkage in place of the ester linkage in pyrethroid ester are designed and prepared. Bioassay data of insecticidal activities of these compounds on Ostrinia nubilalis (H.) and Culex pipines (L.) are presented. Among them 4-dimethyaminobenzaldehyde oxime ester of 2,2,3,3-tetramethylcyclopropanecarboxylic acid and 4-dimethyamino benzaldehyde oxime ester of cyclopropanecarboxylic acid are found to be potent insecticide against Ostrinia nubilalis (H.). Structure-activity relationship of the compounds is discussed.

  1. 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.

  2. Synthesis, antioxidant and antimicrobial activity of novel vanillin derived piperidin-4-one oxime esters: preponderant role of the phenyl ester substituents on the piperidin-4-one oxime core.

    Science.gov (United States)

    Harini, Salakatte Thammaiah; Kumar, Honnaiah Vijay; Rangaswamy, Javarappa; Naik, Nagaraja

    2012-12-15

    The study has been achieved the efficient synthesis of vanillin derived piperidin-4-one oxime esters (5a-m) via four step reaction involved Mannich reaction of vanillin, acetone and ammonium acetate to obtain 2,6-bis(4-hydroxy-3-methoxyphenyl)-piperidin-4-one 2 followed by N-methylation and oximation. Further, to enhance the biological activity of vanillin derived piperidin-4-one oxime core, esterification of 4 with substituted benzoyl chlorides in the presence of strong organic base t-BuOK accomplished a series of vanillin derived piperidin-4-one oxime esters (5a-m). The synthesized analogues are screened for their antioxidant and antimicrobial studies and the preponderant effect of the phenyl ester substituents on the biological activity of piperidin-4-one oxime core was demonstrated. Among the tested compounds, 5i and 5j are emerged as outperformed antioxidants than standard Butylated hydroxy anisole (BHA) whereas, compounds 5b and 5d manifested potent antibacterial and antifungal activity than standard streptomycin and fluconazole respectively.

  3. Synthesis, properties and applications of interacting blends of acrylated novalac epoxy resin based poly(ester-amides and vinyl ester

    Directory of Open Access Journals (Sweden)

    Pragnesh N. Dave

    2016-09-01

    Full Text Available Epoxy resin based unsaturated poly(ester-amide resins (UPEAs were prepared by the reported method. These UPEAs were then treated with acryloyl chloride to afford acrylated UPEAs resin (i.e. AUPEAs. Interacting blends of equal proportional AUPEAs and vinyl ester epoxy (VE resin were prepared. APEAs and AUPEAs were characterized by elemental analysis, molecular weight determined by vapor pressure osmometer and by IR spectral study and by thermogravimetry. The curing of interacting blends was monitored on differential scanning calorimeter (DSC. Based on DSC data in situ glass reinforced composites of the resultant blends have been prepared and characterized for mechanical, electrical and chemical properties. Unreinforced blends were characterized by thermogravimetry (TGA.

  4. Crystallization behavior of supercooled smectic cholesteryl myristate nanoparticles containing phospholipids as stabilizers

    DEFF Research Database (Denmark)

    Kuntsche, Judith; Koch, Michel; Drechsler, M;

    2005-01-01

    Supercooled smectic nanoparticles based on physiological cholesterol esters are under investigation as a potential novel carrier system for lipophilic drugs. The present study investigates the very complex crystallization behavior of such nanoparticles stabilized with the aid of phospholipids....... Phospholipid and phospholipid/bile salt stabilized cholesteryl myristate dispersions were prepared by high-pressure melt homogenization and characterized by particle size measurements, differential scanning calorimetry, X-ray diffraction and electron microscopy. To obtain fractions with very small smectic...... nanoparticles, selected dispersions were ultracentrifuged. A mixture of cholesteryl myristate and the phospholipid used for the stabilization of the dispersions was also investigated by light microscopy. The nanoparticles usually display a bimodal crystallization event which depends on the thermal treatment...

  5. 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.

  6. A Novel Method for the Synthesis of Bioactive Benzimidazolyl-Phenoxyacetic Acid O-Acetylglucosyl Saccharide Esters

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A novel method of synthesis of nitro or trifluoromethyl substituted benzimidazolyl-phenoxyacetic acid O-acetylglucosyl saccharide esters by the reaction of O-acetylglucosyl bromide with substituted benzimidazolyl -phenoxyacetic acid at room temperature was developed. 4-dimethylaminopyridine (DMAP) was used as catalyst, triethylamine (Et3N) was used as deacid reagent, three saccharide esters were synthesized in the system of DMAP/ Et3N. The catalytic mechanism of DMAP/Et3N was discussed. The results show that DMAP is an effective catalyst, the yields can reach 50%. The test indicates that the title compounds show better antiplantviral activity.

  7. 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.

  8. Synthesis of Polysubstituted Benzoic Esters from 1,2-Dihydropyridines and Its Application to the Synthesis of Fluorenones.

    Science.gov (United States)

    Tejedor, David; Prieto-Ramírez, Mary Cruz; Ingold, Mariana; Chicón, Margot; García-Tellado, Fernando

    2016-06-03

    A convenient, instrumentally simple, and efficient methodology to transform 1,2-dihydropyridines into benzoic esters is described. The generated multisubstituted benzoic esters feature different topologies spanning from simple aromatic rings to fused benzocycloalkane systems. As an extension of this methodology, these benzoic esters are efficiently transformed into an array of fluorenone frameworks featuring interesting and novel topological patterns.

  9. A Convenient, General Synthesis of 1,1-Dimethylallyl Esters as Protecting Groups for Carboxylic Acids

    Science.gov (United States)

    Sedighi, Minoo; Lipton, Mark A.

    2006-01-01

    Carboxylic acids were converted in high yield to their 1,1-dimethylallyl (DMA) esters in two steps. Palladium-catalyzed deprotection of DMA esters was shown to be compatible with tert-butyl, benzyl and Fmoc protecting groups, and Fmoc deprotection could be carried out selectively in the presence of DMA esters. DMA esters were also shown to be resistant to nucleophilic attack, suggesting that they will serve as alternatives to tert-butyl esters when acidic deprotection conditions need to be avoided. PMID:15816730

  10. A convenient, general synthesis of 1,1-dimethylallyl esters as protecting groups for carboxylic acids.

    Science.gov (United States)

    Sedighi, Minoo; Lipton, Mark A

    2005-04-14

    [reaction: see text] Carboxylic acids were converted in high yield to their 1,1-dimethylallyl (DMA) esters in two steps. Palladium-catalyzed deprotection of DMA esters was shown to be compatible with tert-butyl, benzyl, and Fmoc protecting groups, and Fmoc deprotection could be carried out selectively in the presence of DMA esters. DMA esters were also shown to be resistant to nucleophilic attack, suggesting that they will serve as alternatives to tert-butyl esters when acidic deprotection conditions need to be avoided.

  11. Synthesis and characterization of novel polysiloxanes. I. Telechelic cyanate esters. II. Hindered alkyl siloxanes

    Science.gov (United States)

    Fu, Zhidong

    Two aspects of novel polysiloxane chemistry have been explored in this work: (1) the synthesis and characterization of polysiloxanes functionalized with terminal cyanate ester groups for use as low flammability impact modifiers for commercial phenolic cyanate ester resins (CERs) and (2) the synthesis and characterization of polydiethylsiloxane and polycyclotetramethylenesiloxane. CERs have been proposed as a potentially useful matrix material for commercial aircraft manufacture. However, commercial CERs do not currently have the appropriate fracture toughness for practical applications. Prior studies have shown that siloxanes offer excellent flame suppression and can improve the CERs impact properties. In this work, a series of new siloxanes terminated with cyanate-reactive groups, including bis[1,3-(4--cyanatophenyl)]-1,1,3,3-tetramethyldisiloxane (11), alpha,o-(4-cyanatophenyl) oligodimethylsiloxane (12), and alpha,o-(4-cyanatophenyl) oligo(dimethyl- co-diphenylsiloxane) (13), have been synthesized from corresponding diphenols. The intermediates and products were characterized by 1H NMR, 13C NMR, FTIR, GC-MS, and GPC. To synthesize the diphenols, a new route to synthesize disiloxane terminated with THP protected diphenols (dimer) was established. The synthesized dimer was used to equilibrate with D4 and/or D4'' to make desired siloxane oligomers. The mechanism of the equilibration of the dimer with D4 were studied. The synthesized CER monomers were polymerized by a cyclotrimerization reaction. The cured compound 11 is a brittle solid with Tg of 274°C. The cured 12 (oligodimethyl-siloxane) and 13 (oligodimethylsiloxane- co-diphenylsiloxane) are elastomers with Tg of -110°C and -8°C, respectively. The curing processes and intermediates were studied by dynamic and isothermal differential scanning calorimetry, GPC, IR and 13C NMR. The synthesized CER monomers were used as impact modifiers to blend and co-cure with the commercial CERs, Primaset PT-30. SEM shows

  12. Mechanism of the cobalt oxazoline palladacycle (COP)-catalyzed asymmetric synthesis of allylic esters.

    Science.gov (United States)

    Cannon, Jeffrey S; Kirsch, Stefan F; Overman, Larry E; Sneddon, Helen F

    2010-11-03

    The catalytic enantioselective S(N)2' displacement of (Z)-allylic trichloroacetimidates catalyzed by the palladium(II) complex [COP-OAc](2) is a broadly useful method for the asymmetric synthesis of chiral branched allylic esters. A variety of experiments aimed at elucidating the nature of the catalytic mechanism and its rate- and enantiodetermining steps are reported. Key findings include the following: (a) the demonstration that a variety of bridged-dipalladium complexes are present and constitute resting states of the COP catalyst (however, monomeric palladium(II) complexes are likely involved in the catalytic cycle); (b) labeling experiments establishing that the reaction proceeds in an overall antarafacial fashion; (c) secondary deuterium kinetic isotope effects that suggest substantial rehybridization at both C1 and C3 in the rate-limiting step; and (d) DFT computational studies (B3-LYP/def2-TZVP) that provide evidence for bidentate substrate-bound intermediates and an anti-oxypalladation/syn-deoxypalladation pathway. These results are consistent with a novel mechanism in which chelation of the imidate nitrogen to form a cationic palladium(II) intermediate activates the alkene for attack by external carboxylate in the enantiodetermining step. Computational modeling of the transition-state structure for the acyloxy palladation step provides a model for enantioinduction.

  13. Synthesis and insecticidal activity of some novel fraxinellone-based esters.

    Science.gov (United States)

    Guo, Yong; Yan, Yuanyuan; Yu, Xiang; Wang, Yi; Zhi, Xiao-Yan; Hu, Ying; Xu, Hui

    2012-07-18

    In continuation of a program aimed at the discovery and development of natural products-based insecticidal agents, two series of novel fraxinellone-based esters were synthesized by modification at the C-4 or C-10 position of fraxinellone and evaluated for their insecticidal activity against the pre-third-instar larvae of Mythimna separata in vivo. An efficient method for the stereoselective synthesis of 4α-hydroxyfraxinellone from fraxinellonone was developed, and the steric configuration of 6h was unambiguously confirmed by X-ray crystallography. Among 37 compounds, some derivatives displayed potent insecticidal activity; especially compounds 6h, 6q, 6t, and 7q showed more promising insecticidal activity than toosendanin, a commercial botanical insecticide derived from Melia azedarach . This suggested that introduction of the fluorine atom on the phenyl ring could lead to a more potent compound than one possessing chlorine or bromine. Meanwhile, introduction of the heterocyclic fragments at the C-4 or C-10 position of fraxinellone was essential for their insecticidal activity. This will pave the way for further design, structural modification, and development of fraxinellone as an insecticidal agent.

  14. Synthesis and Characteristics of an Aspartame Analogue, L-Asparaginyl L-3-Phenyllactic Acid Methyl Ester

    Institute of Scientific and Technical Information of China (English)

    Hu TAO; Da-Fu CUI; You-Shang ZHANG

    2004-01-01

    An aspartame analogue,L-asparaginyl L-3-phenyllactic acid methyl ester was synthesized with aspartic acid replaced by asparagine and peptide bond replaced by ester bond.The aspartic acid of aspartame could be replaced by asparagine as reported in the literature.In this analogue,the hydrogen ofamide group could still form a hydrogen bond with the oxygen of ester bond and the ester bond was isosteric with peptide bond.However,the product was not sweet,showing that the peptide bond could not be replaced by ester bond.The peptide C-N bond behaves as a double bond that is not free to rotate and the C,O,N and H atoms are in the same plane.The replacement of peptide bond by ester bond destroyed the unique conformation of peptide bond,resulting in the loss of sweet taste.

  15. Synthesis of N-(methoxycarbonyl or isopropylcarbamoyl- methoxyphosphonyl)-α-amino acid ester and their stereomers

    Institute of Scientific and Technical Information of China (English)

    陈茹玉; 李慧英

    1996-01-01

    N-(methoxycarbonyl-methoxyphosphonyl)-α-amino add esters (I) were synthesized via the reaction of the corresponding phosphonyl chloride with amino acid ester hydrochlorides in the presence of a base. Compound I was aminated to yield N-(isopropylcarbainoyl-methoxyphosphonyl)-α-amino acid esters (II). With l-amino acids as starting materials, the isomers of products I and II were separated and their configurations were confirmed by the single crystal X-ray diffraction of II.

  16. 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.

  17. 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.

  18. Synthesis of (2R, 4R)-2-N-tert-Butyloxycarbonyl Amino-4,5-epoxido-valeric Acid Methyl Ester

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The stereoselective synthesis of (2R, 4R)-2-N-tert-butyloxycarbonyl amino-4, 5-epoxido- valeric acid methyl ester 8, which is the key intermediate for the synthesis of (2'S, 2R) -3-trans-nitrocyclopropyl-alanine, was first accomplished.

  19. Synthesis of (2R,4R)—2—N—tert—Butyloxycarbonyl Amino—4,5—epoxido—valeric Acid Methyl Ester

    Institute of Scientific and Technical Information of China (English)

    XinRongQIN; YuLiXIE; 等

    2002-01-01

    The stereoselective synthesis of (2R,4R)-2-N-tert-butyloxycarbonyl amino-4,5-epoxido-valeric acid methyl ester 8,which is the key intermediate for the synthesis of (2′S,2R)-3-trans-nitrocyclopropyl-alanine,was first accomplished.

  20. The synthesis of astaxanthin esters,independent of the formation of cysts,highly correlates with the synthesis of fatty acids in Haematococcus pluvialis

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The compositions and contents of astaxanthin esters and fatty acids in four types of Haematococcus pluvialis cells were studied by HPLC and GC-MS. Results showed that the synthesis and accumulation of astaxanthin was independent of the formation of cysts, but was highly correlated with the synthesis and accumulation of fatty acids, though it is an well known phenomenon that the accumulation of astaxanthin is usually accompanied by the formation of cyst. The red cysts contain more than 30% of fatty acids, with 81% of the unsaturated fatty acids. Taken together, besides a resource of astaxanthin, H. pluvialis would be a good resource of valuable fatty acids.

  1. Synthesis of peptides containing C-terminal methyl esters using trityl side-chain anchoring: application to the synthesis of a-factor and a-factor analogs.

    Science.gov (United States)

    Diaz-Rodriguez, Veronica; Mullen, Daniel G; Ganusova, Elena; Becker, Jeffrey M; Distefano, Mark D

    2012-11-16

    A new cysteine anchoring method was developed for the synthesis of peptides containing C-terminal cysteine methyl esters. This method consists of attachment of Fmoc-Cys-OCH(3) to either 2-ClTrt-Cl or Trt-Cl resins (via the side-chain thiol) followed by preparation of the desired peptide using Fmoc-based SPPS. We applied this method to the synthesis of the mating pheromone a-factor and a 5-FAM labeled a-factor analog. The peptides were obtained with high yield and purity and were shown to be bioactive in a growth arrest assay.

  2. The synthesis of astaxanthin esters, independent of the formation of cysts, highly correlates with the synthesis of fatty acids in Haematococcus pluvialis

    Institute of Scientific and Technical Information of China (English)

    MIAO FengPing; LU DaYan; ZHANG ChengWu; ZUO JinCheng; GENG YaHong; HU HongJun; LI YeGuang

    2008-01-01

    The compositions and contents of astaxanthin esters and fatty acids in four types of Haematococcus pluvialis cells were studied by HPLC and GC-MS. Results showed that the synthesis and accumulation of astaxanthin was independent of the formation of cysts, but was highly correlated with the synthesis and accumulation of fatty acids, though it is an well known phenomenon that the accumulation of astaxanthin is usually accompanied by the formation of cyst. The red cysts contain more than 30% of fatty acids, with 81% of the unsaturated fatty acids. Taken together, besides a resource of astaxanthin, H. Pluvialis would be a good resource of valuable fatty acids.

  3. 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.

  4. Wax ester synthesis is required for Mycobacterium tuberculosis to enter in vitro dormancy.

    Directory of Open Access Journals (Sweden)

    Tatiana D Sirakova

    Full Text Available Mycobacterium tuberculosis (Mtb is known to produce wax esters (WE when subjected to stress. However, nothing is known about the enzymes involved in biosynthesis of WE and their role in mycobacterial dormancy. We report that two putative Mtb fatty acyl-CoA reductase genes (fcr expressed in E. coli display catalytic reduction of fatty acyl-CoA to fatty aldehyde and fatty alcohol. Both enzymes (FCR1/Rv3391 and FCR2/Rv1543 showed a requirement for NADPH as the reductant, a preference for oleoyl-CoA over saturated fatty acyl-CoA and were inhibited by thiol-directed reagents. We generated Mtb gene-knockout mutants for each reductase. Metabolic incorporation of( 14C-oleate into fatty alcohols and WE was severely diminished in the mutants under dormancy-inducing stress conditions that are thought to be encountered by the pathogen in the host. The fatty acyl-CoA reductase activity in cell lysates of the mutants under nitric oxide stress was significantly reduced when compared with the wild type. Complementation restored the lost activity completely in the Δfcr1 mutant and partially in the Δfcr2 mutant. WE synthesis was inhibited in both Δfcr mutants. The Δfcr mutants exhibited faster growth rates, an increased uptake of (14C-glycerol suggesting increased permeability of the cell wall, increased metabolic activity levels and impaired phenotypic antibiotic tolerance under dormancy-inducing combined multiple stress conditions. Complementation of the mutants did not restore the development of antibiotic tolerance to wild-type levels. Transcript analysis of Δfcr mutants showed upregulation of genes involved in energy generation and transcription, indicating the inability of the mutants to become dormant. Our results indicate that the fcr1 and fcr2 gene products are involved in WE synthesis under in vitro dormancy-inducing conditions and that WE play a critical role in reaching a dormant state. Drugs targeted against the Mtb reductases may inhibit its

  5. 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...... conditions allow the presence of functionalities such as ester or cyano groups or halogen substituents that are usually not compatible with the conditions used in directed ortho metalation of arenes. The arylboronic esters underwent Suzuki-type cross-coupling with a range of aryl halides, furnishing biaryls...

  6. Synthesis and Biological Activity of New Pyrethroid Acid Oxime-esters Containing Pyrazole Ring

    Institute of Scientific and Technical Information of China (English)

    MA Jun-an; HUANG Run-qiu; FENG Lei; SONG Jian; QIU De-wen

    2003-01-01

    A series of compounds containing oxime-ester linkage and pyrazole ring(in place of the ester linkage and the alcohol moiety in pyrethroid ester) was designed and synthesized. The structures of all the compounds prepared were confirmed by 1H NMR and MS spectroscopy as well as elemental analyses. The bioassay data of those compounds against tobacco mosaic virus(TMV), cucumber mosaic virus(CMV), potato virus X(PVX) and potato virus Y(PVY) were presented. Among them compound 6i was found to possess significant plant antiviral activities. But all the compounds showed low insecticidal and acaricidal activities.

  7. One-pot stereoselective synthesis of α,β-differentiated diamino esters via the sequence of aminochlorination, aziridination and intermolecular SN2 reaction.

    Science.gov (United States)

    Xiong, Yiwen; Qian, Ping; Cao, Chenhui; Mei, Haibo; Han, Jianlin; Li, Guigen; Pan, Yi

    2014-01-01

    We report here an efficient one-pot method for the synthesis of α,β-differentiated diamino esters directly from cinnamate esters using N,N-dichloro-p-toluenesulfonamide and benzylamine as nitrogen sources. The key transformations include a Cu-catalyzed aminohalogenation and aziridination, followed by an intermolecular SN2 nucleophilic ring opening by benzylamine. The reactions feature a wide scope of substrates and proceed with excellent stereo- and regioselectivity (anti:syn >99:1) .

  8. The base-free chemoselective ring opening of epoxides with carboxylic acids using [bmim]Br: a rapid entry into 1,2-diol mono-esters synthesis.

    Science.gov (United States)

    Rad, Mohammad Navid Soltani; Behrouz, Somayeh

    2013-02-01

    A facile and highly convenient base-free protocol for the chemoselective preparation of 1,2-diol mono-esters is described. In this method, the regioselective ring opening of epoxides with carboxylic acids in the presence of [bmim]Br furnishes the corresponding 1,2-diol mono-esters in excellent yields. This method is efficient for various structurally diverse epoxides and carboxylic acids and it can be efficiently applied for the scale up synthesis of 1,2-diol mono-esters in reasonable to good yields. [bmim]Br remarkably influences the reaction progress and acts as both solvent and catalyst in this protocol.

  9. Lipase catalyzed synthesis of L-alanyl, L-leucyl and L-phenylalanyl esters of D-glucose using unprotected amino acids.

    Science.gov (United States)

    Vijayakumar, Giriyapura R; Lohith, Kenchaiah; Somashekar, Bhandya R; Divakar, Soundar

    2004-09-01

    Enzymatic synthesis of l-alanyl, l-leucyl and l-phenylalanyl esters of D-glucose was carried out in a non-polar solvent using lipases from Rhizomucor miehei and porcine pancreas. The unprotected amino acids at millimolar concentrations were used in presence of 10 to 50% (w/w) glucose of the lipases to give ester yields up to >99%. The reaction mixture on analysis by 2-D NMR showed that the product is a mixture of 6-O-, 3-O- and 2-O-monoesters and 2,6-di-O- and 3,6- di-O-esters.

  10. SYNTHESIS AND CHARACTERIZATION OF HYPERBRANCHED POLY(ESTER-AMIDE)S BASED ON GALLIC ACID AND DL-2-AMINOBUTYRIC ACID

    Institute of Scientific and Technical Information of China (English)

    Ya-li Su; Xiu-ru Li; Yue-jin Tong; Yue-sheng Li

    2004-01-01

    A novel AB3-type monomer was prepared from gallic acid and DL-2-aminobutyric acid, and used for the synthesis of the biocompatible hyperbranched poly(ester-amide)s by self-polycondensation. The polymers were characterized via FTIR and NMR spectroscopy and thermal analysis, and the average degree of branching of the polymers was estimated to be 0.75.The polymers with abundant acetyl end groups were found to be amorphous with lower intrinsic viscosity, better thermal stability and excellent solubility.

  11. PENGGUNAAN GETAH PEPAYA DALAM SINTESIS ESTER XILITOL ASAM LEMAK (EXAL [The Use of Papaya Exudates for Fatty Acid Xilitol Synthesis

    Directory of Open Access Journals (Sweden)

    Suhardi

    2003-12-01

    Full Text Available Fatty acid xylitol-ester (FAXILE are xylitol esters of fatty acids with one to five DE (degree of esterification value. FAXILE with DE value of 3 or higher can be used as low calorie fat replacer since they have low digestive property; while the xylitol ester with DE of less than 3 can be used as emulsifier. The FAXILE synthesis experiments were carried out by esterification of xylitol with palm oil¡¦s fatty acid (POFA using papaya exudates as a lipase source. The objective of this experiment was to evaluate the potential of papaya exuadates for the synthesis of FAXILE. In this first experiment, test were carried out to determine hydrolytic activity of lipases obtained from different part of papaya plant. The test, were performed with the presence of CaO and under different pH value. The papaya exudates were used for FAXILE synthesis under an optimum condition obtained from the first experiment. Samples were drawn during incubation at 40„aC for 1,2,3, and 4 days and hydroxyl number was analyzed to confirm the ester formation. The results showed that the most active exudate was from papaya leaves, followed by exudates from fruit with hydrolytic activity of 653 and 296 ƒÝmol/g. minutes, respectively. The hydrolytic activity of the fruit exudate was optimum at pH 6.0, at 45-50„aC, with the addition of CaO 4% dry exudates. The FAXILE synthesis with acid of papaya exudates was optimum at pH 6.0, at 45„aC with molar ratio of xylitol: fatty acids was 1 to 6,3 days incubation. At this condition the conversion rate xylitol to FAXILE was 79%.

  12. 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.

  13. Helicobacter pylori Cholesteryl α-Glucosides Contribute to Its Pathogenicity and Immune Response by Natural Killer T Cells

    Science.gov (United States)

    Ito, Yuki; Vela, Jose Luis; Matsumura, Fumiko; Hoshino, Hitomi; Tyznik, Aaron; Lee, Heeseob; Girardi, Enrico; Zajonc, Dirk M.; Liddington, Robert; Kobayashi, Motohiro; Bao, Xingfeng; Bugaytsova, Jeanna; Borén, Thomas; Jin, Rongsheng; Zong, Yinong; Seeberger, Peter H.; Nakayama, Jun; Kronenberg, Mitchell; Fukuda, Minoru

    2013-01-01

    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. PMID:24312443

  14. Novel Catalytic Method for Synthesis of Glycosyl Esters by Combining PTC with DMAP

    Institute of Scientific and Technical Information of China (English)

    YANG Song-tao; ZHANG Suo-qin; ZHANG Guang-liang; WANG Xiao-ming; LI Yao-xian

    2007-01-01

    This article presents a novel catalytic method by combining phase-transfer catalyst, benzyltriethylammonium chloride, with 4-dimethylaminopyridine for the syntheses of glycosyl esters from substituted phenoxyacetic acids and the peracetate of α-D-l-bromosugars to produce eight novel β-glycosyl esters in high yields. The structures of the synthesized compounds were established by IR, MS, 1H NMR, and 13C NMR spectra and elemental analyses.

  15. 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.

  16. Synthesis and characterization of new biodegradable thermosensitive polyphosphazenes with lactic acid ester and methoxyethoxyethoxy side groups

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Two novel biodegradable thermosensitive polyphosphazenes with lactic acid ester and methoxyethoxyethoxy side groups were synthesized via the macromolecular substitution reactions of poly(dichlorophosphazene) with the sodium salt of lactic acid ester and sodium methoxyethoxyethoxide.Their structures were confirmed by ~(31)p NMR,~1H NMR,~(13)C NMR,IR,DSC,and elemental analysis.The lower critical solution temperature(LCST) behavior in water and in vitro degradation property of the polymers was investigated....

  17. 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.

  18. Synthesis and Pharmacological Properties of Novel Esters Based on Monocyclic Terpenes and GABA

    Directory of Open Access Journals (Sweden)

    Mariia Nesterkina

    2016-06-01

    Full Text Available Novel esters of γ-aminobutyric acid (GABA with monocyclic terpenes were synthesized via Steglich esterification and characterized by 1H-NMR, IR and mass spectral studies. Their anticonvulsant, analgesic and anti-inflammatory activities were evaluated by a PTZ-induced convulsion model, AITC-induced hyperalgesia and AITC-induced paw edema, respectively. All studied esters, as well as their parent terpenes, were found to produce antinociceptive effects in the AITC-induced model and attenuate acute pain more than the reference drug benzocaine after their topical application. GABA esters of l-menthol and thymol were also shown to exceed the reference drug ibuprofen in their ability to decrease the inflammatory state induced by intraplantar injection of the TRPA1 activator AITC. The present findings indicate that GABA esters of carvacrol and guaiacol are not a classical prodrug and possess their own pharmacological activity. Prolonged antiseizure action of the ester based on the amino acid and guaiacol (200 mg/kg was revealed at 24 h after oral administration. Furthermore, orally co-administered gidazepam (1 mg/kg and GABA esters of l-menthol, thymol and carvacrol produce synergistic seizure prevention effects.

  19. Kinetic investigation of a solvent-free, chemoenzymatic reaction sequence towards enantioselective synthesis of a β-amino acid ester.

    Science.gov (United States)

    Strompen, Simon; Weiss, Markus; Ingram, Thomas; Smirnova, Irina; Gröger, Harald; Hilterhaus, Lutz; Liese, Andreas

    2012-06-01

    A solvent-free, chemoenzymatic reaction sequence for the enantioselective synthesis of β-amino acid esters has been kinetically and thermodynamically characterized. The coupled sequence comprises a thermal aza-Michael addition of cheap starting materials and a lipase catalyzed aminolysis for the kinetic resolution of the racemic ester. Excellent ee values of >99% were obtained for the β-amino acid ester at 60% conversion. Kinetic constants for the aza-Michael addition were obtained by straightforward numerical integration of second-order rate equations and nonlinear fitting of the progress curves. A different strategy had to be devised for the biocatalytic reaction. Initially, a simplified Michaelis-Menten model including product inhibition was developed for the reaction running in THF as an organic solvent. Activity based parameters were used instead of concentrations in order to facilitate the transfer of the kinetic model to the solvent-free system. Observed solvent effects not accounted for by the use of thermodynamic activities were incorporated into the kinetic model. Enzyme deactivation was observed to depend on the ratio of the applied substrates and also included in the kinetic model. The developed simple model is in very good agreement with the experimental data and allows the simulation and optimization of the solvent-free process.

  20. Enhancing trimethylolpropane esters synthesis through lipase immobilized on surface hydrophobic modified support and appropriate substrate feeding methods.

    Science.gov (United States)

    Tao, Yifeng; Cui, Caixia; Shen, Huaqing; Liu, Luo; Chen, Biqiang; Tan, Tianwei

    2014-05-10

    Candida sp. 99-125 lipase immobilized on surface hydrophobic modified support and appropriate substrate feeding methods were used to improve the synthesis of tri-substituted trimethylolpropane (TMP) esters, which can be used as raw materials for biodegradable lubricants. The proposed novel production method is environmentally friendly. Lipase was adsorbed on surface hydrophobic silk fibers that were pretreated by amino-modified polydimethylsiloxane. A 5-level-4-factors central composite model, including reaction time, temperature, enzyme amount, and molar ratio of fatty acid to TMP, was designed to evaluate the interaction of process variables in the enzymatic esterification. The water activity was kept constant using a LiCl-saturated salt solution. Under the optimum conditions with 30% enzyme amount and substrates molar ratio 8.4 at 45°C for 47h, the total conversion of caprylic acid is 97.3% and the yield of tri-substituted TMP esters is 95.5%. The surface hydrophobic treatment resulted in less cluster water accumulated on the surface immobilized lipase, which was demonstrated by near-infrared spectra. Consequently, the optimum temperature and water tolerance of immobilized lipase were increased. Two TMP-feeding methods were used to maintain high molar ratio of fatty acid to TMP, and increase the final tri-substituted TMP esters content exceeding 85% (w/w) in reactant.

  1. Enzymatic Synthesis of Glucose-Based Fatty Acid Esters in Bisolvent Systems Containing Ionic Liquids or Deep Eutectic Solvents

    Directory of Open Access Journals (Sweden)

    Kai-Hua Zhao

    2016-09-01

    Full Text Available Sugar fatty acid esters (SFAEs are biocompatible nonionic surfactants with broad applications in food, cosmetic, and pharmaceutical industries. They can be synthesized enzymatically with many advantages over their chemical synthesis. In this study, SFAE synthesis was investigated by using two reactions: (1 transesterification of glucose with fatty acid vinyl esters and (2 esterification of methyl glucoside with fatty acids, catalyzed by Lipozyme TLIM and Novozym 435 respectively. Fourteen ionic liquids (ILs and 14 deep eutectic solvents (DESs were screened as solvents, and the bisolvent system composed of 1-hexyl-3-methylimidazolium trifluoromethylsulfonate ([HMIm][TfO] and 2-methyl-2-butanol (2M2B was the best for both reactions, yielding optimal productivities (769.6 and 397.5 µmol/h/g, respectively which are superior to those reported in the literature. Impacts of different reaction conditions were studied for both reactions. Response surface methodology (RSM was employed to optimize the transesterification reaction. Results also demonstrated that as co-substrate, methyl glucoside yielded higher conversions than glucose, and that conversions increased with an increase in the chain length of the fatty acid moieties. DESs were poor solvents for the above reactions presumably due to their high viscosity and high polarity.

  2. In vitro synthesis of linear α-1,3-glucan and chemical modification to ester derivatives exhibiting outstanding thermal properties.

    Science.gov (United States)

    Puanglek, Sakarin; Kimura, Satoshi; Enomoto-Rogers, Yukiko; Kabe, Taizo; Yoshida, Makoto; Wada, Masahisa; Iwata, Tadahisa

    2016-07-29

    Bio-based polymer is considered as one of potentially renewable materials to reduce the consumption of petroleum resources. We report herein on the one-pot synthesis and development of unnatural-type bio-based polysaccharide, α-1,3-glucan. The synthesis can be achieved by in vitro enzymatic polymerization with GtfJ enzyme, one type of glucosyltransferase, cloned from Streptococcus salivarius ATCC 25975 utilizing sucrose, a renewable feedstock, as a glucose monomer source, via environmentally friendly one-pot water-based reaction. The structure of α-1,3-glucan is completely linear without branches with weight-average molecular weight (Mw) of 700 kDa. Furthermore, acetate and propionate esters of α-1,3-glucan were synthesized and characterized. Interestingly, α-1,3-glucan acetate showed a comparatively high melting temperature at 339 °C, higher than that of commercially available thermoplastics such as PET (265 °C) and Nylon 6 (220 °C). Thus, the discovery of crystalline α-1,3-glucan esters without branches with high thermal stability and melting temperature opens the gate for further researches in the application of thermoplastic materials.

  3. In vitro synthesis of linear α-1,3-glucan and chemical modification to ester derivatives exhibiting outstanding thermal properties

    Science.gov (United States)

    Puanglek, Sakarin; Kimura, Satoshi; Enomoto-Rogers, Yukiko; Kabe, Taizo; Yoshida, Makoto; Wada, Masahisa; Iwata, Tadahisa

    2016-07-01

    Bio-based polymer is considered as one of potentially renewable materials to reduce the consumption of petroleum resources. We report herein on the one-pot synthesis and development of unnatural-type bio-based polysaccharide, α-1,3-glucan. The synthesis can be achieved by in vitro enzymatic polymerization with GtfJ enzyme, one type of glucosyltransferase, cloned from Streptococcus salivarius ATCC 25975 utilizing sucrose, a renewable feedstock, as a glucose monomer source, via environmentally friendly one-pot water-based reaction. The structure of α-1,3-glucan is completely linear without branches with weight-average molecular weight (Mw) of 700 kDa. Furthermore, acetate and propionate esters of α-1,3-glucan were synthesized and characterized. Interestingly, α-1,3-glucan acetate showed a comparatively high melting temperature at 339 °C, higher than that of commercially available thermoplastics such as PET (265 °C) and Nylon 6 (220 °C). Thus, the discovery of crystalline α-1,3-glucan esters without branches with high thermal stability and melting temperature opens the gate for further researches in the application of thermoplastic materials.

  4. Synthesis and intrinsic blue fluorescence study of hyperbranched poly(ester-amide-ether)

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A series of hyperbranched poly(ester-amide-ether)s (H-PEAEs) were synthesized via the A2+CB3 approach by the self-transesterification of ethyl ester-amide-ethers end-capped with three hydroxyl groups and ethyl ester group at two terminals.The molecular structures were characterized with 1H NMR and FT-IR spectroscopy.The number average molecular weights were estimated by GPC analysis to possess bimodal wide distribution from 1.57 to 2.09.The strong inherent blue fluorescence was observed at 330 nm for excitation and 390 nm for emission.Moreover,the emission intensity and fluorescence quantum yield increased along with the incorporated ether chain length,as well as almost linearly with the H-PEAE concentration in an aqueous solution.For comparing the fluorescence performance,the linear poly(ester-amide-ether) (L-PEAE) and hyperbranched poly(ester-amide) (H-PEA) were synthesized.The results showed that the coexistence of ether bond and carboxyl group in the molecular chain was essential for generating the strong fluorescence.However,the compact backbone of H-PEAE would be propitious to the enhancement of fluorescence properties.

  5. 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.

  6. Synthesis and biological evaluation of nigranoic acid esters as novel human neutrophil elastase inhibitors.

    Science.gov (United States)

    Huang, Guoli; Feng, Li; Liu, Bo; He, Yi; Li, Yiming; Chen, Yegao

    2015-01-01

    Human neutrophil elastase (HNE) has been implicated as a major contributor in the pathogenesis of diseases, such as lung disorders and other inflammatory diseases. A series of 12 new nigranoic acid esters were regioselectively synthesised in good yields and evaluated for HNE inhibitory activity. Nigranoic acid exhibited significant inhibitory activity against HNE with the IC50 value of 3.77 μM, and six esters displayed considerable inhibitory effects on HNE with IC50 values in the range of 2.61-8.95 μM. The nigranoic acid esters having phenyls substituted with bromine and trimethoxyls (3h and 3b) showed stronger inhibitory activity on HNE than nigranoic acid.

  7. 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.

  8. Synthesis of esters of androgens with unsaturated fatty acids for androgen requiring therapy.

    Science.gov (United States)

    Aiello, F; Garofalo, A; Aloisi, A M; Lamponi, S; Magnani, A; Petroni, A

    2013-06-01

    Androgens' metabolism and activity are gaining a more and more important role in human physiology particularly referring to aging and to neurodegenerative diseases. Androgen treatment is often required for long-lasting disorders. In order to improve their duration and effects, androgens can be administered as esters of carboxylic acids. The novelty of our research is the use of esters of androgens with specific unsaturated fatty acids, in order to reduce possible side effects particularly related to chronic pathologies with altered lipid homeostasis such as X-linked adrenoleukodystrophy and cardiovascular disorders. Thus the esters of the main androgenic substances testosterone, dihydrotestosterone (DHT) and their metabolite 5α-androstan-3α,17β-diol were chemically obtained by coupling with different unsaturated fatty acids. To this aim, fatty acids with various degree of unsaturation and belonging to different series were selected. Specifically, oleic acid (18:1, n-9), linoleic acid (18:2, n-6), and the n-3 fatty acids, α-linolenic acid (18:3), eicosapentaenoic acid (EPA, 20:5), and docosahexaenoic acid (DHA, 22:6) were used obtaining corresponding esters with acceptable yields and good degree of purity. All the synthesized compounds were tested for their cytotoxic activities in mouse NIH3T3 and human astrocyte cell lines. The esters demonstrated good tolerability and no in vitro cytotoxic effect in both cell cultures. After these promising preliminary results, the esters will be suitable for in vivo studies in order to ascertain their pharmacokinetic characteristics and their biological effects.

  9. Synthesis of (S)-ricinoleic acid and its methyl ester with the participation of ionic liquid.

    Science.gov (United States)

    Kula, Józef; Bonikowski, Radoslaw; Szewczyk, Malgorzata; Ciolak, Kornelia

    2014-10-01

    (R)-ricinoleic acid methyl ester obtained from commercial castor oil was transformed in a three-step procedure into its S-enantiomer in overall 36% yield using ionic liquid (1-butyl-3-methylimidazolium acetate) in the key step process. The developed procedure provides easy access to (S)-ricinoleic acid and its methyl ester of over 95% enantiomeric excess. Optical rotations of the newly obtained compounds as well as their chromatographic and spectral characteristics are provided and discussed in the context of enantiopurity both of the substrate material and the final products.

  10. 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 bios...... following a two-step solvent purification procedure whereby excess fatty acid substrate was first removed in a heptane/water (4:1, v/v) system, followed by selective ester extraction using an ethyl acetate/water system (1:6, v/v) at elevated temperature....

  11. 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.

  12. Synthesis and evaluation of thalidomide and phthalimide esters as antitumor agents

    DEFF Research Database (Denmark)

    Zahran, Magdy A H; Abdin, Yasmin G.; Osman, Amany M A

    2014-01-01

    A series of thalidomide and phthalimide ester analogs were efficiently synthesized from N-chloromethylthalidomide, N-chloromethylphthalimide, and N-(2-bromoethyl)phthalimide derivatives with various biologically important carboxylic acids. The synthesized compounds were purified and characterized...... by various chromatographic and spectroscopic techniques. The antitumor activity of all the synthesized compounds was screened against human liver and breast cancer cells, which showed that phthalimide ester 6a was the best cytotoxic compound against MCF7 cells, while all of the tested compounds showed a non...

  13. 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......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...

  14. STUDY ON THE SYNTHESIS AND PROPERTIES OF POLY(ESTER-IMIDE-ETHER) MULTIBLOCK COPOLYMERS

    Institute of Scientific and Technical Information of China (English)

    Zu-yao Shan; Zhen-yi Li

    2000-01-01

    A new class of poly(ester-imide-ether) multiblock copolymers was synthesized by transes-terification and melt copolymerization of dimethyl terephthalate (DMT) and N-(4-carbomethoxyphenyl)-4-(carbomethoxy)-phthalimide with ethylene glycol (EG) and polytetramethylene glycol (PTMG). The structure of the above copolymers was characterized by 1H-NMR and IR spectroscopy. Some properties of the coplymers were also examined. It was found that their mechanical properties and heat stability, compared with poly(ether-ester) copolymers, were obviously improved.

  15. Novel Approach: Tungsten Oxide Nanoparticle as a Catalyst for Malonic Acid Ester Synthesis via Ozonolysis

    Directory of Open Access Journals (Sweden)

    Bilal A. Wasmi

    2014-01-01

    Full Text Available Malonic acid ester was synthesized via the one-step ozonolysis of palm olein. Malonic acid ester was spectroscopically characterized using gas chromatography mass spectroscopy (GC-MS. Tungsten oxide nanoparticles were used as the catalyst, which was characterized via X-ray powder diffraction (XRD and field emission scanning electron microscopy (FE-SEM. Tungsten oxide provided several advantages as a catalyst for the esterification malonic acid such as simple operation for a precise ozonation method, an excellent yield of approximately 10%, short reaction times of 2 h, and reusability due to its recyclability.

  16. Stereocontrolled Synthesis of (E)-β, γ-Unsaturated Esters via Palladium-Catalyzed Cross-Coupling of (E)-Alkenylboronic Acids with a-Bromoacetic Esters

    Institute of Scientific and Technical Information of China (English)

    DUAN Yazhen; ZHANG Jianshe; YANG Jun; DENG Minzhi

    2009-01-01

    The cross-coupling reaction of trans-alkenylboronic acids with α-bromoacetic esters was firstly studied. It was found that using Pd(OAc)2 as catalyst, a bulky electron-rich phospine, (2-dicyclohexylphospino-biphenyl) as ligand, the reaction can be readily accomplished to give specific (E)-β,γ-unsaturated esters in high yields.

  17. 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.

  18. Microwave-assisted ester formation using O-alkylisoureas: a convenient method for the synthesis of esters with inversion of configuration.

    Science.gov (United States)

    Chighine, Alessandra; Crosignani, Stefano; Arnal, Marie-Claire; Bradley, Mark; Linclau, Bruno

    2009-07-03

    The formation of carboxylic esters via reaction of carboxylic acids with O-alkylisoureas proceeds in excellent yields with very short reaction times when conducted in a monomode microwave synthesizer. Efficient processes were developed using preformed or commercially available isoureas derived from primary and secondary alcohols, with a reaction time of only 5 min or less. It was demonstrated that under these microwave conditions, ester formation proceeded in good yields with clean inversion of configuration where appropriate. The process was validated using menthol, a hindered substrate for S(N)2 reactions. In addition, starting from primary alcohols, ester formation was successfully accomplished using an in situ isourea formation procedure. A polymer-assisted solution-phase procedure was also developed by employing preformed solid-supported isoureas and by an efficient "catch and release" ester formation procedure whereby primary alcohols were caught on resin as isoureas by reaction with immobilized carbodiimide and released as esters by subsequent treatment with a carboxylic acids.

  19. Synthesis and characterization of estolide esters containing epoxy and cyclic carbonate groups

    Science.gov (United States)

    The unsaturated sites in oleic 2-ethylhexyl estolide esters (containing 35% monoenic fatty acids) were converted into epoxide and five-membered cyclic carbonate groups and the products characterized by Fourier transform infrared spectra (FTIR), 1H-, and 13C-nuclear magnetic resonance (NMR) spectrosc...

  20. 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 synthes

  1. Design, synthesis and cytotoxicity studies of dithiocarbamate ester derivatives of emetine in prostate cancer cell lines.

    Science.gov (United States)

    Akinboye, Emmanuel S; Bamji, Zebalda D; Kwabi-Addo, Bernard; Ejeh, David; Copeland, Robert L; Denmeade, Samuel R; Bakare, Oladapo

    2015-09-01

    A small library of emetine dithiocarbamate ester derivatives were synthesized in 25-86% yield via derivatization of the N2'- position of emetine. Anticancer evaluation of these compounds in androgen receptor positive LNCaP and androgen receptor negative PC3 and DU145 prostate cancer cell lines revealed time dependent and dose-dependent cytotoxicity. With the exception of compound 4c, all the dithiocarbamate ester analogs in this study showed appreciable potency in all the prostate cancer cell lines (regardless of whether it is androgen receptor positive or negative) with a cytotoxicity IC50 value ranging from 1.312 ± 0.032 μM to 5.201 ± 0.125 μM by day 7 of treatment. Compared to the sodium dithiocarbamate salt 1, all the dithiocarbamate ester analogs (2 and 4a-4 g) displayed lower cytotoxicity than compound 1 (PC3, IC50 = 0.087 ± 0.005 μM; DU145, IC50 = 0.079 ± 0.003 μM and LNCaP, IC50 = 0.079 ± 0.003 μM) on day 7 of treatment. Consequently, it appears that S-alkylation of compound 1 leads to a more stable dithiocarbamate ester derivative that resulted in lower anticancer activity in the prostate cancer cell lines.

  2. New mesogenic Schiff base esters comprising benzothiazole moiety:Synthesis and mesomorphic properties

    Institute of Scientific and Technical Information of China (English)

    Sie Tiong Ha; Teck Ming Koh; Guan Yeow Yeap; Hong Cheu Lin; Jun Kit Beh; Yip Foo Win; Peng Lim Boey

    2009-01-01

    A homologous series of Schiff base esters,6-methoxy-2-(2-hydroxy-4-alkanoyloxybenzylidenamino)benzothiazoles,comprising a benzothiazole moiety as the core was synthesized.All the members of this series exhibited an enantiotropic nematic phase.The azomethine linkage along with the lateral hydroxyl and terminal methoxyl groups were found to exert an effect on the mesomorphic properties.

  3. Regioselective Synthesis of Polymerizable Vinyl Guaifenesin Esters Catalyzed by an Alkaline Protease of Bacillus subtilis

    Institute of Scientific and Technical Information of China (English)

    Na WANG; Qi WU; Jian Ming XU; Xiu Ming JIANG; Xian Fu LIN

    2004-01-01

    Three polymerizable vinyl guaifenesin esters with different acyl donor carbon chain lengths (C4,C6,C10) were regioselectivly synthesized by an alkaline protease from Bacillus subtilis in pyridine at 50°C for 1, 3, 5 days respectively.

  4. Synthesis of allyl esters of fatty acids and their ovicidal effect on Cydia pomonella (L.).

    Science.gov (United States)

    Escribà, Marc; Barbut, Montserrat; Eras, Jordi; Canela, Ramon; Avilla, Jesús; Balcells, Mercè

    2009-06-10

    Eight allyl esters of fatty acids were synthesized in moderate to high yields with a novel two-step procedure using glycerol as a starting material. The two-step methodology avoids the use of allyl alcohol. The first step consisted of heating at 80 degrees C for 48 h a 2:1:5 mmol mixture of glycerol, a fatty acid, and chlorotrimethylsilane in a solvent-free medium. The crude compound was then dissolved in butanone and heated at 115 degrees C in the presence of NaI. A tandem Finkelstein rearrangement-elimination reaction occurs, producing the corresponding allyl ester. The activity of these esters against Cydia pomonella (L.) (Lepidoptera: Tortricidae) eggs was tested in the laboratory by topical application of one 0.1 microL drop. All of the compounds showed a concentration-mortality response and caused 100% mortality at the highest concentration tested (10 mg/mL). There was an inverse relationship between the alkyl chain length and the ovicidal activity of the allyl ester; the LC(50) and the LC(90) of the two compounds that have the longer alkyl chains were significantly higher than those of the rest of the compounds. The ovicidal and IGR activities of this kind of compound appear to be unprecedented.

  5. A direct and sustainable synthesis of tertiary butyl esters enabled by flow microreactors.

    Science.gov (United States)

    Degennaro, Leonardo; Maggiulli, Daniela; Carlucci, Claudia; Fanelli, Flavio; Romanazzi, Giuseppe; Luisi, Renzo

    2016-08-01

    Tertiary butyl esters find large applications in synthetic organic chemistry. A straightforward method for the direct introduction of the tert-butoxycarbonyl group into a variety of organic compounds has been developed using flow microreactor systems. The resultant flow process was more efficient, versatile and sustainable compared to the batch.

  6. Highly Efficient Diastereoselective Synthesis of Tetrahydro-isoquinoline-3- carboxylate Ester Analogs from L-DOPA

    Institute of Scientific and Technical Information of China (English)

    WANG Ye; LIU Zhan-Zhu; CHEN Shi-Zhi; LIANG Xiao-Tian

    2003-01-01

    @@ Tetrahydroisoquinoline-3-carboxylate esters are an important motif of naturally occurring bioactive alkaloids and pharmacophores. They are generally regarded as neurotoxic compounds and are putatively involved in a variety of pathologic conditions of central nervous system, including alcoholism, phenylketonuria, and neurodegenerative disorders such as Parkinson's disease.

  7. Synthesis and antituberculosis activity of novel mefloquine-isoxazole carboxylic esters as prodrugs.

    Science.gov (United States)

    Mao, Jialin; Yuan, Hai; Wang, Yuehong; Wan, Baojie; Pak, Dennis; He, Rong; Franzblau, Scott G

    2010-02-01

    5-(2,8-Bis(trifluoromethyl)quinolin-4-yloxymethyl)isoxazole-3-carboxylic acid ethyl ester (compound 3) was reported to have excellent antituberculosis activity against both replicating and non-replicating Mycobacterium tuberculosis, with a minimum inhibitory concentration (MIC) of 0.9 microM and 12.2 microM, respectively. In this study, the antituberculosis activity of compound 3 was further investigated. Its activity appeared to be very specific for organisms of the M. tuberculosis complex and it effected significant reductions of bacterial numbers in infected macrophages with an EC(90) of 4.1 microM. More importantly, the increased in vitro antituberculosis activity of the corresponding acid (compound 4) at pH 6.0 suggested that it may be active in vivo in an acidic environment produced as a consequence of inflammation in the lungs of TB patients. The fact that various ester bioisosteres of compound 3 lost anti-TB activity further suggested that the ester compound 3 may function as a prodrug. The detailed structure-activity relationships (SARs) from this study should facilitate our ultimate goal of improving the anti-TB potency of this isoxazole ester series.

  8. Synthesis and antiproliferative activity of new bioconjugates of Salinomycin with amino acid esters.

    Science.gov (United States)

    Antoszczak, Michał; Sobusiak, Maria; Maj, Ewa; Wietrzyk, Joanna; Huczyński, Adam

    2015-09-01

    New Salinomycin (SAL) bioconjugates with amino acid methyl esters were obtained and their antiproliferative activity against cancer cell lines including drug-resistant ones was studied. New compounds exhibit antiproliferative activity towards leukemia and doxorubicin-resistant colon adenocarcinoma cell line and are more effective and less toxic than the commonly currently used anticancer drugs.

  9. Selective synthesis of thiodiglycol dicarboxylic acid esters via -TsOH/C-catalysed direct esterification

    Indian Academy of Sciences (India)

    Dahong Jiang; Min Huang

    2012-09-01

    The esterification of thiodiglycol and long alkyl-chain carboxylic acids is reported. Reaction of thiodiglycol with carboxylic acid via -TsOH/C-catalysed direct esterification afforded thiodiglycol dicarboxylic acid esters in good yields and chemoselectivity. The use of immobilized -TsOH on activated carbon as catalyst is crucial for the transformation.

  10. A Facile One-Pot Synthesis of α-Bromo-α,β-unsaturated Esters from Alcohols

    Directory of Open Access Journals (Sweden)

    Usama Karama

    2010-05-01

    Full Text Available Treatment ofN-bromosuccinimide (NBS with (carboethoxymethylene triphenylphosphorane (1 in CH2Cl2 followed by the addition of an alcohol in the presence of manganese dioxide under ultrasonic irradiation constitutes a stereoselective one-pot procedure for the preparation of Z-configured α–bromo-α,β-unsaturated esters in good to excellent yield.

  11. Synthesis and enzymic hydrolysis of an o-alanyl ester of phosphatidyl glycerol

    NARCIS (Netherlands)

    Bonsen, P.P.M.; Haas, Gerard H. de; Deenen, L.L.M. van

    1965-01-01

    A racemic 0-alanyl ester of phosphatidyl glycerol, containing one saturated and one unsaturated fatty acid, was synthesized by a reaction between silver benzyl- (γ-oleoyl-β-palmitoyl)-Dl-[alpha]-glycerol phosphate and DL-[alpha]-iodo-B-tert.-butyl-y-(N-tert.-butoxycarbonyl)-m-alanyl glycerol. The sy

  12. Synthesis of the Fatty Esters of Solketal and Glycerol-Formal: Biobased Specialty Chemicals

    Directory of Open Access Journals (Sweden)

    Alvise Perosa

    2016-01-01

    Full Text Available The caprylic, lauric, palmitic and stearic esters of solketal and glycerol formal were synthesized with high selectivity and in good yields by a solvent-free acid catalyzed procedure. No acetal hydrolysis was observed, notwithstanding the acidic reaction conditions.

  13. Synthesis of Versatile Building Blocks through Asymmetric Hydrogenation of Functionalized Itaconic Acid Mono-Esters

    NARCIS (Netherlands)

    Hekking, Koen F.W.; Lefort, Laurent; Vries, André H.M. de; Delft, Floris L. van; Schoemaker, Hans E.; Vries, Johannes G. de; Rutjes, Floris P.J.T.

    2008-01-01

    The rhodium-catalyzed asymmetric hydrogenation of several β-substituted itaconic acid mono-esters, using a library of monodentate phosphoramidite and phosphite ligands is described. Two β-alkyl-substituted substrates were readily hydrogenated by the rhodium complex Rh(COD)2BF4 in combination with (S

  14. 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.

  15. 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.

  16. Novel Stereoselective Synthesis of (E)-α,β-Unsaturated Esters by the Tandem Reaction of Deprotonation-Oxidation-Wittig Reaction from Phosphonium and Arsonium Salt

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Phosphonium or arsonium salt 1 can undergo the tandem reaction of deprotonation -oxidation-Wittig reaction with alcohol 2 in the presence of sodium hydroxide and manganese dioxide, which affords a general simplified method for the stereoselective synthesis of (E)-α,β-unsaturated esters 3.

  17. Study on the Stereoselective Synthesis of Carbapenem Sidechain (2S,4S)-4-Acetylsulphanyl-2-[(S)-1-phenylethylcarbamoyl]-pyrrolidine-1-carboxylic Acid 4-Nitrobenzyl Ester

    Institute of Scientific and Technical Information of China (English)

    Qian LIU; Gang FANG; Li Ping WU; Jian Mei CUI; Xiao Tian LIANG; Song WU

    2004-01-01

    A stereoselective and economic synthesis of the carbapenem sidechain (2S, 4S)-4-ace-tylsulphanyl-2-[ (S)1-phenylethyl-carbamoyl] pyrrolidine-l-carboxylic acid 4-nitrobenzyl ester was developed. Due to the effect of spatial hindrance, only the (2S,4S) diastereomer 3 was obtained by coupling 1 and the inexpensive racemic 2 catalyzed by EEDQ.

  18. 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.

  19. Synthesis of biodegradable chiral poly(ester-imide)s derived from valine-, leucine- and tyrosine-containing monomers.

    Science.gov (United States)

    Mallakpour, Shadpour; Asadi, Parvin; Sabzalian, Mohammad R

    2011-11-01

    The present demand for a drastic reduction in environmental pollution is extended to qualitative change in the approach to development of biodegradable polymers. The aim of this article is to focus on the synthesis of biodegradable optically active poly(ester-imide)s (PEI)s, which compose of different amino acids in the main chain as well as in the side chain. These polymers were synthesized by polycondensation of diacid monomers such as 5-(2-phthalimidyl-3-methyl butanoylamino) isophthalic acid (1), 5-(4-methyl-2-phthalimidyl pentanoylamino)isophthalic acid (2) with N,N'-(pyromellitoyl)-bis-L: -tyrosine dimethyl ester (3) as a phenolic diol. The direct polycondensation reaction was carried out in a system of tosyl chloride, pyridine and N,N-dimethylformamide as a condensing agent under conventional heating conditions. The optically active PEIs were obtained in good yield and moderate inherent viscosity. The synthesized polymers were characterized by means of FT-IR, (1)H-NMR, elemental and thermo gravimetric analysis techniques. In addition, in vitro toxicity and soil burial test were employed for assessing the sensitivity of these compounds to microbial degradation. To this purpose, biodegradability behavior of the monomers and polymers were investigated in culture media and soil condition. The results of this study revealed that synthesized monomers and their derived polymers are biologically active and probably microbiologically biodegradable.

  20. Synthesis and evaluation of thalidomide and phthalimide esters as antitumor agents.

    Science.gov (United States)

    Zahran, Magdy A H; Abdin, Yasmin G; Osman, Amany M A; Gamal-Eldeen, Amira M; Talaat, Roba M; Pedersen, Erik B

    2014-09-01

    A series of thalidomide and phthalimide ester analogs were efficiently synthesized from N-chloromethylthalidomide, N-chloromethylphthalimide, and N-(2-bromoethyl)phthalimide derivatives with various biologically important carboxylic acids. The synthesized compounds were purified and characterized by various chromatographic and spectroscopic techniques. The antitumor activity of all the synthesized compounds was screened against human liver and breast cancer cells, which showed that phthalimide ester 6a was the best cytotoxic compound against MCF7 cells, while all of the tested compounds showed a non-cytotoxic effect against HepG2 cells. Compounds 5a, 6a, and 7a possess immunosuppressant effect, while compounds 5c, 5d, 6c, 6d, 7c, and 7d showed an immunostimmulatory effect. Meanwhile, estimation of the binding affinity for all the synthesized compounds toward the vascular endothelial growth factor receptor (VEGFR) showed that compounds 5a, 5b, and 7d were the most potent inhibitors.

  1. 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.

  2. 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.

  3. 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.

  4. Synthesis And Characterization Of Ester Trimethylolpropane Based Jatropha Curcas Oil As Biolubricant Base Stocks

    Directory of Open Access Journals (Sweden)

    Noor Hafizah Arbain

    2011-09-01

    Full Text Available Biolubricant production of ester trimethylolpropane (ET was conducted via esterification of fatty acid (FA of Jatropha curcas oil with trimethylolpropane (TMP. The condition for this reaction was as follows: temperature was 150°C, time of reaction was 3 hours, molar ratio of FA: TMP was 4:1, and 2 % w/w catalyst (based on weight of FA. Sulfuric acid was used as the catalyst in this reaction. The composition of ET was determined by gas chromatography (GC-FID. The ester group was confirmed by fourier transform infrared spectroscopy (FTIR and the structure was confirmed by proton and carbon Nuclear Magnetic Resonance (1H-NMR and 13C-NMR spectra. 55% of product was successfully synthesized in this research. The pour point of the product was observed as low as –30°C, flash point was >300 °C and viscosity was 79 cP.

  5. Synthesis, Properties and Applications of Biodegradable Polymers Derived from Diols and Dicarboxylic Acids: From Polyesters to Poly(ester amides

    Directory of Open Access Journals (Sweden)

    Angélica Díaz

    2014-04-01

    Full Text Available Poly(alkylene dicarboxylates 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 amides derived from naturally occurring amino acids offer great possibilities as biodegradable materials for biomedical applications which are also extensively discussed.

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

    Science.gov (United States)

    Silveira-Dorta, Gastón; Álvarez-Méndez, Sergio J; Martín, Víctor S

    2016-01-01

    Summary 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-(dia)stereoselectivity was observed when compared to the previous one-pot method. The (dia)stereoselectivity 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. PMID:27340486

  7. Synthesis and enzymatic hydrolysis of esters, constituting simple models of soft drugs

    OpenAIRE

    Graffner-Nordberg, Malin; Sjödin, K; Tunek, A; Hallberg, A

    1998-01-01

    One way to minimise systemic side effects of drugs is to design molecules, soft drugs, in such a way that they are metabolically inactivated rapidly after having acted on their pharmacological target. Hydrolases (esterases, peptidases, lipases, glycosidases, etc.) are enzymes well suited to use for drug inactivation since they are ubiquitously distributed. Insertion of ester bonds susceptible to enzymatic cleavage may represent one approach to make the action of a drug more restricted to the ...

  8. Synthesis and mesomorphic properties of new Schiff base esters with different alkyl chains

    Institute of Scientific and Technical Information of China (English)

    Sie Tiong Ha; Lay Khoon Ong; Siew Teng Ong; Guan Yeow Yeap; Joanna Pik Wan Wong; Teck Ming Koh; Hong Cheu Lin

    2009-01-01

    A new series of Schiff base esters, 4-(dimethylamino)benzylidene-4'-alkanoyloxyanilines containing even number of carbons at the end group of the molecules (Cn-1H2n-1COO, n =6, 8, 10, 12, 14, 16, 18) were synthesized. The present compounds were monotropic liquid crystals. It was also found that the end groups of the molecules had effect on the mesomorphic properties.

  9. Synthesis and Properties of Lactic Acid-based Cross-linked Poly(ester-amide)

    Institute of Scientific and Technical Information of China (English)

    Yue Ying HE; Cong Ming XIAO

    2006-01-01

    A novel lactic acid-based cross-linked poly(ester-amide) (LCPEA) was synthesized. The gel fraction of the LCPEA could be modulated by the reaction conditions and it affected the mechanical and thermal properties of the LCPEA. The tensile strength, elastic modulus and bend strength of the LCPEA of 65% gel fraction were 4.65, 136.55 and 39.63 MPa, respectively. The thermal decomposition temperature (50 wt%) of the LCPEA was around 410 ℃.

  10. Synthesis of oleic acid based esters as potential basestock for biolubricant production

    OpenAIRE

    Salih, Nadia; Salimon, Jumat; Yousif, Emad

    2011-01-01

    Ester derivatives of 9, 10-dihydroxystearic acid were prepared and characterized. The processes involved were epoxidation of oleic acid, opening of the oxirane ring, and esterification. The structures of the products were confirmed by FTIR, 1H- and 13C-NMR. The low-temperature properties of each product were characterized using the pour point test. Other physical properties, such as flash point and viscosity, were also determined. The results show that desirable low temperature pro...

  11. Synthesis and Application of a New Acrylic Ester Resin for Recycling SIPA from its Water Solution

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A new acrylic ester polymer YWB-7 resin was prepared and characterized. The properties of YWB-7 resin were compared with those of the commercial Amberlite XAD-7, Diaion HP2MG and hypercrosslinked macroporous polymer NDA-150 resins. Both surface area and micropore area of YWB-7 resin were bigger than those of XAD-7 resin and HP2MG resin. The YWB-7 resin was successfully employed to recycle 5-sodiosulfoisophthalic acids (SIPA) from its solutions with and without methanol.

  12. Synthesis and Biological Activity of 3-Methyl-1H-pyrazole-4-carboxylic Ester Derivatives

    Institute of Scientific and Technical Information of China (English)

    ZHAO Wei-Guang; LI Zheng-Ming; YUAN Ping-Wei; WANG Wen-Yan

    2001-01-01

    In search of novel pyrazole derivatives with bioactivity,a se-ries of 3-methyl- 1H-pyrazole-4-caboxylic ester derivatives were synthesized via α-oxoketene dithioacetals as starting ma-terial.The structures of al1 compounds prepared were con-firmed by 1HNMR, IR, MS and elemental analyses.Prelimi-nary bioassays indicated that some compounds showed fungici-dal activity against wheat rust,phoma asparagi and antiviral activity against TMV.

  13. Synthesis and Primary Research on Antitumor Activity of Three New Panaxadiol Fatty Acid Esters

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    For making use of Ginseng resources that exhibit an antitumor activity and for finding new anticancer drugs,three new fatty acid ester compounds: 3β-acetoxy panaxadiol ( Ⅰ ), 3β-palmitic acid aceloxy panaxadiol ( Ⅱ ), and 3β-octadecanoic acid aceloxy panaxadiol( Ⅰ , Ⅱ , and Ⅲ ) were synthesized with panaxadiol, diacetyl oxide, palmityl chloride and stearyl chloride, and their structures were determined via MS, 13C NMR, IR, TLC, and so on. The molar yields of the three compounds are 75.14%, 79. 08%, and 72. 57%, respectively. Meanwhile, the antitumor activity of the three new panaxadiol fatty acid ester derivatives and panaxadiol was compared by using the method of MTT. Tumor cell used was Vero cell line. Positive control was 5-FU, blank was an RPMI1640 culture medium, negative control was an RPMI1640 culture medium and the solvent for drugs to be tested. Compound Ⅰ has the strongest antitumor activity followed by panaxadiol; compounds Ⅱ and Ⅲ have similar and weakest antitumor activities.Furthermore, the antitumor activities of the panaxadiol fatty acid ester derivatives show positive correlation with the concentration of the test group, but show no relationship with the molecular weight of fatty acid. The methods that are used to synthesize the three compounds with high yields and strong antitumor activities are simple and show a great potential for meeting the needs of industrial manufacture of these drugs.

  14. Synthesis and in vitro biological evaluation of dihydroartemisinyl-chalcone esters.

    Science.gov (United States)

    Smit, Frans J; van Biljon, Riëtte A; Birkholtz, Lyn-Marie; N'Da, David D

    2015-01-27

    A series of dihydroartemisinyl-chalcone esters were synthesized through esterification of chalcones with dihydroartemisinin (DHA). The hybrids were screened against chloroquine (CQ) sensitive (3D7) and CQ resistant (W2) strains of intraerythrocytic Plasmodium falciparum parasites, and were all found to be active, with IC50 values ranging between 1.5 and 11 nM against both strains, with SI values over 5800. The esters featuring oxygenated aryl rings (7, 10 and 11), were found to be equipotent to DHA, but were 2-3 times more active than artesunate against the 3D7 and W2 strains of the malaria parasites. They were also screened in vitro against a panel of three cancer cell lines consisting of TK-10, UACC-62 and MCF-7. Compound 7, bearing a furan ring, displayed the most potent overall antitumor activity against all three cancer cell lines. TGA revealed that the targeted hybrids were all thermally more stable than DHA, which may be beneficial to the high temperature storage conditions that prevail in malaria endemic countries. During this study, ester 7 was identified as the best candidate for further investigation as a potential drug in search for new, safe and effective antimalarial drugs.

  15. Synthesis, cytotoxicity and antibacterial activity of new esters of polyether antibiotic - salinomycin.

    Science.gov (United States)

    Antoszczak, Michał; Popiel, Katarzyna; Stefańska, Joanna; Wietrzyk, Joanna; Maj, Ewa; Janczak, Jan; Michalska, Greta; Brzezinski, Bogumil; Huczyński, Adam

    2014-04-09

    A series of 12 novel ester derivatives of naturally occurring polyether antibiotic - salinomycin were synthesized, characterised by spectroscopic method and evaluated for their in vitro antibacterial activity and cytotoxicity. The new esters were demonstrated to form complexes with monovalent and divalent metal cation of 1:1 stoichiometry in contrast to the salinomycin which forms only complexes with monovalent cations. All the obtained compounds show potent antiproliferative activity against human cancer cell lines and a good selectivity index for cancer versus mammalian cells. Additionally, 3 compounds showed higher antiproliferative activity against the drug-resistant cancer cells and lower toxicity towards normal cells than those of unmodified salinomycin and standard anticancer drugs such as cisplatin and doxorubicin. Some of the synthesized compounds showed good inhibitory activity against Staphylococcus strains and clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus epidermidis (MRSE). These studies show that salinomycin esters are interesting scaffolds for the development of novel anticancer and Gram-positive antibacterial agents.

  16. 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.

  17. 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.

  18. Synthesis and Calcium Channel Blocking Activity of 1, 4-Dihydropyridine Derivatives Containing Ester Substitute and Phenyl Carbamoyl Group

    Directory of Open Access Journals (Sweden)

    Bassem Sadek

    2011-01-01

    Full Text Available Problem statement: Several studies on the synthesis of new nifedipine analogs have been carried out, but the literature reveled that no study on the synthesis and calcium channel blocking activity of the substituted ester with an amide (5-phenylcarbamoyl moiety has been reported. Approach: Six new derivatives of m-nifedipine have been successfully synthesized by substituting an ester moiety with an amide (5-phenylcarbamoyl moiety, using a modified Hantzsch reactions and tested for their pharmacological activities. The nifedipine analogs 1-6 were characterized and confirmed using elemental analysis, Infrared spectroscopy (IR, Nuclear Magnetic Resonance (1H NMR and Mass spectroscopy. The purity of the compounds was ascertained by melting point and TLC. The in vitro calcium channel blocking activities were evaluated using the high K+ concentration of Porcine Coronary Artery Smooth Muscles (PCASM assay. Results: The compounds (1-2 failed to exhibit any blocking activity (IC50 = 10−7 to 10−5 M range, while the compounds 3-6 relaxed precontracted porcine coronary artery smooth muscles with pEC50 values ranging between 4.37±0.10 (compound 3 and 6.46±0.07 (compound 5, indicating that compounds 3-6 exhibit comparable potencies in blocking calcium channels to reference drug varapamil (6.97±0.15 and m-nifedipine (6.48±0.05. Conclusion: The results of this study showed that some of the developed new compounds possess maximal calcium channel blocking effects comparable to m-nifedipine. The developed compounds in the present study will predicatively show an increased metabolic stability and consequently longer duration of actions compared to m-nifedipine and could be, therefore, suitable candidates for further optimization to be evaluated as a new class of antihypertensive drugs.

  19. 新型可降解聚硅基酯的合成及性质研究%Synthesis and properties of new degradable poly (silyl ester)s

    Institute of Scientific and Technical Information of China (English)

    岳芸; 刘宗林; 王进喜

    2009-01-01

    主链中含有不稳定的硅酯键的聚硅基酯是一种新型的可降解聚合物.合成并研究了新型聚硅基酯即聚(己二酸四甲基二硅氧烷基硅基酯):首次利用熔融缩聚法使己二酸与1,1,3,3-四甲基二硅氧烷为单体合成了聚硅基酯,并用1H-NMR对该聚合物进行了结构表征,利用差示扫描量热(DSC)、热重分析(TGA)对其热力学性质进行了研究,利用凝胶渗透色谱(GPC)就分子量分布及降解性质进行了研究.%Polymers composed of silyl ester bonds in the main chain were investigated as a new class of degradable polymers. This paper first reported the synthesis and properties of degradable poly (silyl ester) s by 1,1,3,3-tetramethyldi-acetoxydisiloxanes with adipic acid.. The chemical structures of the polymer was confirmed by 1H-NMR. The properties of the poly(silyl ester)s was researched by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA)and gel permeation chromatography(GPC).

  20. [Effect of protein-vitamin deficiency on the enzyme activity of lipolysis and the synthesis of cholesterol esters during hypokinesia].

    Science.gov (United States)

    Koshkenbaev, B Kh; Tazhibaev, Sh S; Maksimenko, V B; Sisemalieva, Zh S

    1985-01-01

    Balanced diet during 60-day hypokinesia leads to inhibition of lipoprotein lypase (LPLA) and liver triglyceride lypase (L-TGLA) activity of the rat blood serum. The level of very low density lipoproteins (VLDLP) grows, and suppression of lecithin-cholesteryl-acyltransferase (LCAT) activity is accompanied by reduction of the share of cholesterol derivatives with polyunsaturated fatty acids. Combined effects of protein-vitamin insufficiency and hypokinesia result in parversion of the lipolysis processes, that manifests in prevalence of L-TGLA over LPLA. The levels of VLDLP increase, and growth of LCAT activity is acompanied by the growth of cholesteryl linoleate share and level. Hypokinesia combined with the studied experimental diets was found to lead to increase of the free fatty acid level and to decrease of the blood serum levels of phospholipids and triglycerides.

  1. 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.

  2. 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

  3. Synthesis and dopamine transporter binding of 2beta-isopropyl ester analogs of cocaine.

    Science.gov (United States)

    El-Moselhy, Tarek F; Avor, Kwasi S; Basmadjian, Garo P

    2002-02-01

    A series of 2beta-isopropyl ester analogs of cocaine (7-11) was synthesised and evaluated in an in vitro dopamine transporter (DAT) binding assays. Ecgonine HCl (5) was obtained from (-)-cocaine (1) by hydrolysis using 1 N HCl. Acid catalysed esterification of 5 using 2-propanol and HCl gas afforded 2beta-isopropyl ecgonine (6). Compounds 7-9 were obtained via esterification of the 3beta-hydroxyl group of 6 using the appropriate acid chloride. Compound 10 was obtained via selective hydrolysis and re-esterification of 7 using 2-propanol and HCl gas. Compound 11 was obtained by reduction of 9 using H(2)/Pd-C. Compounds 7, 10 and 11 showed high binding affinity to the DAT (as indicated from the inhibition of the binding of [(3)H]WIN 35,428 (3)) with IC(50) values (mean +/- S.E.M.) 208.5 +/- 9.5, 47.43 +/- 1.79 and 11.25 +/- 3.37 nM, respectively). Compound 7 is comparatively as active as cocaine, 10 is ca. fivefold more active than cocaine and 11 is ca. 20-fold more active than cocaine and even twice more active than the radioligand 3. Compound 11, like its methyl ester analog (2' aminococaine), exhibited the highest affinity to the DAT. These results, along with previous results, emphasise the importance of a hydrogen-bond donor group at the 2'-position of cocaine and its isopropyl ester analogs to enhance binding affinity to the DAT.

  4. 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.

  5. Synthesis and mesomorphic properties of Schiff base esters possessing terminal chloro substituent

    Institute of Scientific and Technical Information of China (English)

    Sie

    2010-01-01

    A homologous series of Schiff base esters, 4-chlorobenzylidene-4'-n-alkanoyloxyanilines, containing even number of carbons at the end groups of the molecules (Cn-1H2n-1COO-, n = 4,6,8,10,12,14,16) were synthesized. The mesomorphic properties were investigated by differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). It was found that the end groups of the molecules had an effect on the mesomorphic properties. n-Butanoyloxy was found non-mesogenic, whilst n-hexanoyloxy exhibited monotropic smectic phase. The higher members in this homologous series were enantiotropic smectogens.

  6. Synthesis and Biological Activity of Arylspiroborate Salts Derived from Caffeic Acid Phenethyl Ester

    Directory of Open Access Journals (Sweden)

    Martin J. G. Hébert

    2015-01-01

    Full Text Available Two novel boron compounds containing caffeic acid phenethyl ester (CAPE derivatives have been prepared and characterized fully. These new compounds and CAPE have been investigated for potential antioxidant and antimicrobial properties and their ability to inhibit 5-lipoxygenase and whether chelation to boron improves their biological activity. Sodium salt 4 was generally more active than ammonium salt 5 in the biological assays and surpassed the radical scavenging ability of CAPE. Compounds 4 and 5 were more active than CAPE and Zileuton in human polymorphonuclear leukocytes. These results clearly show the effectiveness of the synthesized salts as transporter of CAPE.

  7. SYNTHESIS, CHARACTERIZATION OF CHIRAL POLY(ESTER AMIDE)S DERIVED FROM L-ISOLEUCINE

    Institute of Scientific and Technical Information of China (English)

    Xing-He Fan; Jing-Lun Zhou; Xiao-Fang Chen; Xin-Hua Wan; Qi-Feng Zhou

    2004-01-01

    A series of new optically active aromatic poly(ester amide)s containing a chiral group in the side chain prepared from the p-toluenesulfonic acid salt of o,o'-bis(leucyl)-hexanediol (TS-+LHD+TS-) and p-phthaloyl chloride and styrene-2,5-dicarbonyl chloride styrene have been synthesized by interfacial polymerization. The structure of the monomer is elucidated by FT-IR and elemental analysis. The thermal properties of the polymers were studied by DSC and TGA. The chiroptical properties of the above polymer have also been studied by circular dichroism (CD) spectroscopy. Results indicated that these polymers form helical structures.

  8. Synthesis ,Structure and Biological Activities of Some Novel Anthranilic Acid Esters Containing N-Pyridyl-pyrazole

    Institute of Scientific and Technical Information of China (English)

    DONG,Weili; XU,Junying; XIONG,Lixia; LIU,Xinghai; LI,Zhengming

    2009-01-01

    In search of environmentally benign insecticides with high activity,low toxicity and low residue,a novel series of anthranilic acid esters containing N-pyridylpyrazole were designed and synthesized.All of the compounds were characterized and confirmed by IR,1H NMR,MS and elemental analysis.The single crystal structure of 14d was determined by X-ray diffraction.The bioassay tests showed that the synthesized compounds exhibited good insecti-tidal activities against Mythimna separata Walker and Culex pipiens pallens.

  9. Synthesis of octadecyl esters of histidine-containing tripeptides as potential regulators of plant growth

    Energy Technology Data Exchange (ETDEWEB)

    Ogrel, A.A.; Zvonkova, E.N. [Lomonosov Academy of Fine Chemical Technology, Moscow (Russian Federation); Gafurov, R.G. [Institute of Physiologically Active Substances, Chernogolovka (Russian Federation)

    1995-08-01

    Octadecyl esters of dipeptides and tripeptides of the type Phe-His, Val-His, Phe-Val-His and Val-Phe-His were synthesized using different methods. The minimum energy conformations of these peptides were calculated with computer minimization programs and compared with those of paclobutrazol, a well-known regulator of plant growth. It was demonstrated that the elongation of the peptide chain leads to a higher topochemical correspondence between paclobutrazol and the peptide derivatives than between paclobutrazol and amino acid derivatives. 9 refs., 2 figs., 3 tabs.

  10. 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.

  11. Lipase-catalyzed Synthesis of Caffeic Acid Phenethyl Ester in Ionic Liquids:Effect of Specific Ions and Reaction Parameters

    Institute of Scientific and Technical Information of China (English)

    王俊; 李晶; 张磊霞; 顾双双; 吴福安

    2013-01-01

    Caffeic acid phenethyl ester (CAPE) is a rare, naturally occurring phenolic food additive. This work systematically reported fundamental data on conversion of caffeic acid (CA), yield of CAPE, and reactive selectiv-ity during the lipase-catalyzed esterification process of CA and phenylethanol (PE) in ionic liquids (ILs). Sixteen ILs were selected as the reaction media, and the relative lipase-catalyzed synthesis properties of CAPE were meas-ured in an effort to enhance the yield of CAPE with high selectivity. The results indicated that ILs containing weakly coordinating anions and cations with adequate alkyl chain length improved the synthesis of CAPE. [Emim][Tf2N] was selected as the optimal reaction media. The optimal parameters were as follows by response surface methodology (RSM):reaction temperature, 84.0 °C;mass ratio of Novozym 435 to CA, 14︰1;and molar ratio of PE to CA, 16︰1. The highest reactive selectivity of CAPE catalyzed by Novozym 435 in [Emim][Tf2N] reached 64.55%(CA conversion 98.76%and CAPE yield 63.75%, respectively). Thus, lipase-catalyzed esterifica-tion in ILs is a promising method suitable for CAPE production.

  12. Synthesis of lipophilic tyrosyl esters derivatives and assessment of their antimicrobial and antileishmania activities

    Directory of Open Access Journals (Sweden)

    Aissa Imen

    2012-01-01

    Full Text Available Abstract Background Preparation of tyrosyl lipophilic derivatives was carried out as a response to the food, cosmetic and pharmaceutical industries' increasing demand for new lipophilic antioxidants. Results A large series of tyrosyl esters (TyC2 to TyC18:1 with increasing lipophilicity was synthesized in a good yield using lipase from Candida antarctica (Novozyme 435. Spectroscopic analyses of purified esters showed that the tyrosol was esterified on the primary hydroxyl group. Synthetized compounds were evaluated for either their antimicrobial activity, by both diffusion well and minimal inhibition concentration (MIC methods, or their antileishmanial activity against Leishmania major and Leishmania infantum parasite species. Among all the tested compounds, our results showed that only TyC8, TyC10 and TyC12 exhibited antibacterial and antileishmanial activities. When MIC and IC50 values were plotted against the acyl chain length of each tyrosyl derivative, TyC10 showed a parabolic shape with a minimum value. This nonlinear dependency with the increase of the chain length indicates that biological activities are probably associated to the surfactant effectiveness of lipophilic derivatives. Conclusion These results open up potential applications to use medium tyrosyl derivatives surfactants, antioxidants, antimicrobial and antileishmanial compounds in cosmetic, food and pharmaceutical industries.

  13. SYNTHESIS AND CHARACTERIZATION O F SODIUM METHYL ESTER SULFONATE FOR CHEMICALLY-ENHANCED OIL RECOVERY

    Directory of Open Access Journals (Sweden)

    K. Babu

    2015-09-01

    Full Text Available AbstractAttention has been given to reduce the cost of surfactant by using castor oil as an alternative natural source of feedstock. A new surfactant, sodium methyl ester sulfonate (SMES was synthesised using ricinoleic acid methyl ester, which is obtained from castor oil, for enhanced oil recovery in petroleum industries. The performance of SMES was studied by measuring the surface tension with and without sodium chloride and its thermal stability at reservoir temperature. SMES exhibited good surface activity, reducing the surface tension of surfactant solution up to 38.4 mN/m and 27.6 mN/m without and with NaCl, respectively. During the thermal analysis of SMES, a 31.2% mass loss was observed from 70 ˚C to 500 ˚C. The phase behavior of the cosurfactant/SMES-oil-water system plays a key role in interpreting the performance of enhanced oil recovery by microemulsion techniques. Flooding experiments were performed using a 0.5 pore volume of synthesized SMES solutions at three different concentrations. In each case chase water was used to maintain the pressure gradient. The additional recoveries in surfactant flooding were found to be 24.53%, 26.04% and 27.31% for 0.5, 0.6 and 0.7 mass% of surfactant solutions, respectively.

  14. Synthesis, algal inhibition activities and QSAR studies of novel gramine compounds containing ester functional groups

    Institute of Scientific and Technical Information of China (English)

    LI Xia; YU Liangmin; JIANG Xiaohui; XIA Shuwei; ZHAO Haizhou

    2009-01-01

    2,5,6-Tribromo-l-methylgramine (TBG), isolated from bryozoan Zoobotryon pellucidum was shown to be very efficient in preventing recruitment of larval settlement. In order to improve the compatibility of TBG and its analogues with other ingredients in antifouling paints, structural modification of TBG was focused mainly on halogen substitution and N-substitution. Two halogen-substitute gramines and their derivatives which contain ester functional groups at N-position of gramines were synthesized. Algal inhibition activities of the synthesized compounds against algae Nitzschia closterium were evaluated and the Median Effective Concentration (EC50) range was 1.06-6.74 μg ml-1. Compounds that had a long chain ester group exhibited extremely high antifouling activity. Quantitive Structure Activity Relationship (QSAR) studies with multiple linear regression analysis were applied to find correlation between different calculated molecular descriptors and biological activity of the synthesized compounds. The results show that the toxicity (log (1/EC50)) is correlated well with the partition coefficient log P. Thus, these products have potential function as antifouling agents.

  15. Chiral Borated Esters in Asymmetric Synthesis:1.The First Asymmetric Reaction Catalyzed by Chiral Spiroborated Esters with an O3BN Framework

    Institute of Scientific and Technical Information of China (English)

    LIU, De-Jun(刘德军); SHAN, Zi-Xing(单自兴); QIN, Jin-Gui(秦金贵)

    2004-01-01

    The first asymmetric reaction catalyzed by chiral spiroborated esters with an O3BN framework was reported. In the presence of 0.1 equivalent of (R,S)-1 or (S,S)-1, acetophenone was reduced by 0.6 equivalent of borane in THF at 0-5 ℃ for 2 h to give (R)-1-phenylethanol of up to 76% ee and 73% isolated yield. Influence of reaction conditions on the stereoselectivity of the reduction was investigated and a possible catalytic mechanism of the chiral spiroborated esters toward the reduction was also suggested.

  16. Synthesis, stability studies, anti-inflammatory activity and ulcerogenicity of morpholinoalkyl ester prodrugs of niflumic acid.

    Science.gov (United States)

    Talath, Sirajunisa; Gadad, Andanappa K

    2006-01-01

    In search for potential prodrugs for anti-inflammatory drug candidates in the niflumate series, novel morpholinoalkyl ester prodrugs of niflumic acid (CAS 4394-00-7) 5a-b were prepared by esterification of appropriate morpholinylalkyl alcohols 3a-b with niflumic acid 4 in the presence of dicyclohexyl carbodiimide (DCC) and catalyst dimethylamino pyridine (DMAP) at 0-5 degrees C. The structures were confirmed by elemental and spectral data (UV, IR, 1H-NMR, 13C-NMR, and EI-MS). The ester prodrugs 5a-b showed better solubility than the parent drug niflumic acid 4 in simulated gastric fluid (SGF) and phosphate buffer (pH 7.4). The in vitro hydrolysis studies were conducted at pH 1.3 (SGF), phosphate buffer (pH 7.4) and in human plasma diluted with phosphate buffer (pH 7.4) at 37+/-0.5 degrees C using HPLC with UV detection. The ester prodrugs 5a-b were quantitatively hydrolyzed to the parent drug niflumic acid 4 by enzymatic and/or chemical means. It is observed that an increase in the carbon chain length rendered the prodrugs 5a-b more stable in phosphate buffer (pH 7.4) than in pH 1.3 (SGF), but they were rapidly hydrolyzed in human plasma at 37+/-0.5 degrees C. They exhibited longer hydrolytic half-lives of 16.11-53.30 h in aqueous buffer solutions (pH 1.3 and 7.4) and 1.63-2.73 min in human plasma, respectively. The title compounds were evaluated in vivo for anti-inflammatory activity in carrageenan induced rat paw oedema model in rats at the doses 45, 90, 150 mg/kg b.w. The test compounds exhibited good anti-inflammatory activity (46.6-53.2 % at the dose of 150 mg/kg b. w.) with respect to niflumic acid (78.7 % at the dose of 90 mg/kg b.w.). The compounds were also screened for in vivo ulcerogenicity, it was observed that the prodrug 5b was significantly less irritating to gastric mucosa than compound 5a and the parent drug niflumic acid 4 following single and chronic oral administration in rats.

  17. Introduction of ester and amido functions in tetrairon(III) single-molecule magnets: synthesis and physical characterization.

    Science.gov (United States)

    Rodriguez-Douton, Maria Jesus; Cornia, Andrea; Sessoli, Roberta; Sorace, Lorenzo; Barra, Anne-Laure

    2010-07-07

    Tetrairon(III) complexes with a propeller-like structure derived from [Fe(4)(OMe)(6)(dpm)(6)] (1) (Hdpm = 2,2,6,6-tetramethylheptane-3,5-dione) are providing a growing class of Single Molecule Magnets (SMMs) displaying unprecedented synthetic flexibility and ease of functionalization. Herein we report the synthesis, crystal structures and magnetic properties of two novel tetrairon(III) SMMs, [Fe(4)(esterC5)(2)(dpm)(6)] (2) and [Fe(4)(amideC5)(2)(dpm)(6)].Et(2)O.4MeOH (3.Et(2)O.4MeOH), in which functionalization of the cluster core is achieved using ester and amido linkages, respectively. To this aim, two new tripodal ligands were prepared by acylation of pentaerythritol (2,2-bis(hydroxymethyl)propane-1,3-diol) and TRIS (2-amino-2-(hydroxymethyl)propane-1,3-diol), namely H(3)esterC5 = RC(O)OCH(2)C(CH(2)OH)(3) and H(3)amideC5 = RC(O)NHC(CH(2)OH)(3) with R = n-butyl. The compounds were structurally investigated by single-crystal XRD, which demonstrated coordination of the tripodal ligands to the cluster core. The products display SMM behavior with anisotropy barriers U(eff)/k(B) congruent with 11 K due to a high-spin (S = 5) ground state and an easy axis anisotropy, described by D = -0.421 cm(-1) in 2 and -0.414 cm(-1) in 3.Et(2)O.4MeOH. The departure of U(eff) from the total splitting of the S = 5 ground multiplet, U/k(B) congruent with 15 K, has to be ascribed to the sizeable rhombic anisotropy that characterizes the two compounds (E = 0.021 cm(-1) in 2 and 0.019 cm(-1) in 3.Et(2)O.4MeOH), as confirmed by master matrix calculations of the temperature-dependent relaxation time.

  18. 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

  19. N-( p-Ethynylbenzoyl) derivatives of amino acid and dipeptide methyl esters - Synthesis and structural study

    Science.gov (United States)

    Eißmann, Frank; Weber, Edwin

    2011-11-01

    A series of N-( p-ethynylbenzoyl) derivatives ( 1-4) of the amino acids glycine and L-alanine as well as the dipeptides glycylglycine and L-alanylglycine has been synthesized via a two-step reaction sequence including the reaction of an appropriate N-( p-bromobenzoyl) precursor with trimethylsilylacetylene followed by deprotection of the trimethylsilyl protecting group, respectively. X-ray crystal structures of the amino acid and dipeptide methyl esters 1-4 are reported. The amide and peptide bonds within each molecular structure are planar and adopt the trans-configuration. The packing structures are governed by N sbnd H⋯O interactions leading to the formation of characteristic strand motifs. Further stabilization results from weaker C sbnd H⋯O and C sbnd H⋯π contacts.

  20. SYNTHESIS AND PHOTOCHROMISM OF ACRYLIC ESTER COPOLYMERS BEARING PENDANT VIOLOGEN GROUPS

    Institute of Scientific and Technical Information of China (English)

    SUN Xuehui; YANG Yukun

    1996-01-01

    A series of acrylic ester copolymers with viologen group as pendant were synthesized through the reaction of MMA-EBA (Ethenyl bromoacetate) copolymer with 4-(4'-pyridyl)-N-alkyl (or arylalkyl) pyridiniums. These viologen copolymers can exchange their anion with NH4PF6 in methanol to improve their solubility in organic solvents such as DMF and acetone. Compared with the corresponding low molecular viologens, these viologen copolymers have relatively lower color development rate under UV light and fade faster in air due to less affinity to photo-reductant and deficiency of association between their cation radicals. Their photofatigue resistant ability is also slightly better than that of low molecular viologens.

  1. HEAT-RESISTANT PYRIDINE-BASED POLY(ETHER-ESTER)S: SYNTHESIS,CHARACTERIZATION AND PROPERTIES

    Institute of Scientific and Technical Information of China (English)

    Shahram Mehdipour-Ataei; Ali Mahmoodi

    2013-01-01

    A pyridine-based diacid was synthesized via nucleophilic substitution reaction of 4-hydroxy benzoic acid with 2,6-dichloropyridine in the presence of potassium carbonate.The diacid was characterized using FT-IR and 1H-NMR spectroscopic methods and also with elemental analysis.Polycondensation reaction of the diacid with different diols including 1,4-dihydroxy benzene,1,5-dihydroxy naphthalene,bis-phenol A and bis-phenol-P resulted in preparation of pyridine-based poly(ether-ester)s.The polymers were characterized and their physical and thermal properties including inherent viscosity,molecular weight,solubility,thermal stability,thermal behavior and crystallinity were studied.They revealed high heat-resistance and improved solubility in polar solvents.Structure-property relations for the prepared polyester were also studied.

  2. Green polymer chemistry VIII: synthesis of halo-ester-functionalized poly(ethylene glycol)s via enzymatic catalysis.

    Science.gov (United States)

    Castano, Marcela; Seo, Kwang Su; Kim, Eun Hye; Becker, Matthew L; Puskas, Judit E

    2013-09-01

    Halo-ester-functionalized poly(ethylene glycol)s (PEGs) are successfully prepared by the transesterification of alkyl halo-esters with PEGs using Candida antarctica lipase B (CALB) as a biocatalyst under the solventless conditions. Transesterifications of chlorine, bromine, and iodine esters with tetraethylene glycol monobenzyl ether (BzTEG) are quantitative in less than 2.5 h. The transesterification of halo-esters with PEGs are complete in 4 h. (1) H and (13) C NMR spectroscopy with MALDI-ToF and ESI mass spectrometry confirm the structure and purity of the products. This method provides a convenient and "green" process to effectively produce halo-ester PEGs.

  3. 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.

  4. Silane Reduction of 5-Hydroxy-6-methyl-pyridine-3,4-dicarboxylic Acid Diethyl Ester: Synthesis of Vitamin B6

    Directory of Open Access Journals (Sweden)

    Andrew G. Gum

    2003-12-01

    Full Text Available Alternative methods for the synthesis of pyridoxine have been investigated. The key intermediate, 5-hydroxy-6-methyl-pyridine-3,4-dicarboxylic acid diethyl ester (5, was reduced with either a silane monomer (MeSiH(OEt2 or a polysiloxane (polymethylhydrosiloxane, PMHS to afford crude pyridoxine. An isolation technique utilizing a commercially available resin was devised, affording the desired product, vitamin B6, in an overall yield of 38-54 % and a purity of 76%.

  5. Iodine Catalyzed One-pot Synthesis of 3,4-Dihydroquinazolin-4-ones from Anthranilic Acids, Ortho Esters and Amines under Solvent-free Conditions

    Institute of Scientific and Technical Information of China (English)

    WANG,Hong-She; ZENG,Jun-E

    2008-01-01

    A simple and efficient procedure has been developed for the one-pot synthesis of 3,4-dihydroquinazolin-4-ones from anthranilic acids, ortho esters and amines using a catalytic amount of iodine under solvent-free conditions to afford the corresponding products in excellent yields. The direct use of commercially available catalyst, mild and solvent-free reaction conditions, short reaction time, easy workup and excellent yields are the advantages of the present protocol.

  6. Synthesis and quantitative structure–activity relationship study of substituted imidazophosphor ester based tetrazolo[1,5-b]pyridazines as antinociceptive/anti-inflammatory agents

    Directory of Open Access Journals (Sweden)

    Wafaa M. Abdou

    2013-08-01

    Full Text Available A high-yielding general synthesis of imidazophosphor ester based tetrazolo[1,5-b]pyridazines is described. A conjugated reaction between 3,6-diazidopyridazine and different types of phosphonyl carbanion reagents followed by intramolecular cyclization afforded the target products, by using sodium ethanolate solution as a reaction medium. Among the products, five compounds, at a dose of 50 mg per kilogram body weight, showed a notable antinociceptive and anti-inflammatory activity without toxic side-effects.

  7. Enzymatic synthesis of polyol esters in aqueous-organic two-phase systems.

    NARCIS (Netherlands)

    Janssen, A.E.M.

    1993-01-01

    The last decade increasingly attention is paid to lipases as catalysts for synthesis of components, such as fatty acid-based surfactants, flavors, edible oil equivalents, monomers and polymers, and amides. In this thesis, the lipase-catalyzed esterification of polyols and fatty acids is described. T

  8. Mutation of residues 423 (Met/Ile), 444 (Thr/Met), and 506 (Asn/Ser) confer cholesteryl esterase activity on rat lung carboxylesterase. Ser-506 is required for activation by cAMP-dependent protein kinase.

    Science.gov (United States)

    Wallace, T J; Kodsi, E M; Langston, T B; Gergis, M R; Grogan, W M

    2001-08-31

    Site-directed mutagenesis is used to identify amino acid residues that dictate reported differences in substrate specificity between rat hepatic neutral cytosolic cholesteryl ester hydrolase (hncCEH) and rat lung carboxylesterase (LCE), proteins differing by only 4 residues in their primary sequences. Beginning with LCE, the substitution Met(423) --> Ile(423) alone or in combination with other mutations increased activity with p-nitrophenylcaprylate (PNPC) relative to more hydrophilic p-nitrophenylacetate (PNPA), typical of hncCEH. The substitution Thr(444) --> Met(444) was necessary but not sufficient for expression of cholesteryl esterase activity in COS-7 cells. The substitution Asn(506) --> Ser(506), creating a potential phosphorylation site, uniformly increased activity with both PNPA and PNPC, was necessary but not sufficient for expression of cholesteryl esterase activity and conferred susceptibility to activation by cAMP-dependent protein kinase, a property of hncCEH. The 3 mutations in combination were necessary and sufficient for expression of cholesteryl esterase activity by the mutated LCE. The substitution Gln(186) --> Arg(186) selectively reduced esterase activity with PNPA and PNPC but was not required for cholesteryl esterase activity. Homology modeling from x-ray structures of acetylcholinesterases is used to propose three-dimensional models for hncCEH and LCE that provide insight into the effects of these mutations on substrate specificity.

  9. Catalytic synthesis of butyric esters with TiSiW12O40/TiO2

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The catalytic activities of TiSiW12O40/TiO2 in synthesizing ethyl ester, propyl ester, n-butyl ester, and amyl esterwere reported. It was demonstrated that TiSiW12O40/TiO2is an excellent catalyst. Various factors concemed with esterifica-tion were investigated. The optimum conditions were found: the mole ratio of alcohol to acid is 1.3:1, the mass ratio ofcatalyst to reactants is 1.5%, and the reaction time is 1.0 h. Under the optimum conditions, the yields are 88.0% for ethylester, 94.5% for propyl ester, 98.6% for n-butyl ester, 99.1% for n-amyl ester, and 96.7% for iso-amyl ester, respectively.

  10. Solvent-Free Synthesis of Flavour Esters through Immobilized Lipase Mediated Transesterification

    OpenAIRE

    Vijay Kumar Garlapati; Rintu Banerjee

    2013-01-01

    The synthesis of methyl butyrate and octyl acetate through immobilized Rhizopus oryzae NRRL 3562 lipase mediated transesterification was studied under solvent-free conditions. The effect of different transesterification variables, namely, molarity of alcohol, reaction time, temperature, agitation, addition of water, and enzyme amount on molar conversion (%) was investigated. A maximum molar conversion of 70.42% and 92.35% was obtained in a reaction time of 14 and 12 h with the transesterifica...

  11. Synthesis, antimicrobial and antifungal possessions of tramadol esters: In vitro studies.

    Science.gov (United States)

    Qadir, Muhammad Abdul; Ahmed, Mahmood; Ikram, Rabia

    2015-07-01

    Tramadol esters were prepared by refluxing equimolar concentration of tramadol with leucine and asparagine separately with methanol, sulphuric acid and phthalic anhydride for 10 hours and temperature was maintained at 75°C. After refluxing, the colour of sample solutions were changed from colorless to yellow, blank solution was prepared in the same way as the sample solution except the Tramadol. Both the products and blank were neutralized with sodium carbonate and excess of sodium bicarbonate was precipitated as sodium sulphate, which was washed with acetone. The structures of both the products were confirmed with spectral data (FT-IR, 1HNMR and 13CNMR). Antimicrobial and anti-fungal property of derivative of analgesic tramadol drug was tested with one fungus and three sensitive bacteria belonging to both gram positive and gram-negative types. Esterified product of tramadol with leucine and asparagine showed moderate activity against Escherichia coli and Tricophyton rubrum. Both the products showed marked activity against Staphylococcus aureus and found no activity against Salmonella spp.

  12. Facile one-pot synthesis of functionalized organophosphonate esters via ketone insertion into bulky arylphosphites

    Indian Academy of Sciences (India)

    Ramaswamy Murugavel; Subramaniam Kuppuswamy

    2008-01-01

    The reaction of phosphorus trichloride with 2,6-diisopropyl phenol in the presence of LiCl under reflux conditions for 24 h produces a mixture of (ArO)PCl2 and (ArO)2PCl (Ar = 2,6-Pr2C6H3). The hydrolysis of the aryloxy compounds in acetone/H2O results in the formation of two novel phosphonate ester derivatives [(ArO)P(O)(OH)(CMe2OH)] (1) and [(ArO)2P(O)(CMe2OH)] (2), respectively in a moderate yield. The title compounds have presumably formed via acetone insertion to the P-H bonds of (ArO)P(O)(H)(OH) and (ArO)2P(O)(H), respectively, in the presence of HCl produced during the hydrolysis. Compounds 1 and 2 have been characterized by elemental analysis, and ESI-mass, Infrared and NMR spectroscopic techniques. Further, solid state structures of 1 and 2 have been established by single crystals X-ray diffraction studies.

  13. Synthesis, Crystal Structure and Biological Activities of Naproxen-eugenol Ester Prodrug

    Institute of Scientific and Technical Information of China (English)

    LIANG Di; YANG Xiao-hong; SUN Wei; WANG Wen-na; YANG Jin-zhu; LIU Yin-yan; WANG Guang-shu

    2013-01-01

    The prodrug,naproxen-eugenol ester,was synthesized by acyl chloride method with naproxen and eugenol as the raw materials.The structure was identified by proton nuclear magnetic resonance(1H NMR),mass spectrometry(MS),infrared spectrometry(IR) and X-ray diffraction.The compound was crystallized in the or-thorhombic system,space group P212121 with unit cell dimensions a=0.60563(12) nm,b=1.0234(2) nm,c=3.2654(7) nm,α=90°,β=90°,γ=90°,V=2.0240(7) nm3,Z=4.Calculated density 1.235 Mg/m3; absorption coefficient:0.083 mm-1; F(000)=800; final R1=0.0564.The analgesic activity and anti-inflammatory were similar to those of naproxen,and the results of ulcerogenic activity indicate that the prodrug can significantly decrease the irritation after oral administration.

  14. Synthesis and Evaluation as Prodrugs of Hydrophilic Carbamate Ester Analogues of Resveratrol.

    Science.gov (United States)

    Azzolini, Michele; Mattarei, Andrea; La Spina, Martina; Marotta, Ester; Zoratti, Mario; Paradisi, Cristina; Biasutto, Lucia

    2015-09-08

    Resveratrol (3,5,4'-trihydroxy-trans-stilbene) is an unfulfilled promise for health care: its exploitation is hindered by rapid conjugative metabolism in enterocytes and hepatocytes; low water solubility is a serious practical problem. To advantageously modify the physicochemical properties of the compound we have developed prodrugs in which all or part of the hydroxyl groups are linked via an N-monosubstituted carbamate ester bond to promoieties derived from glycerol or galactose, conferring higher water solubility. Kinetic studies of hydrolysis in aqueous solutions and in blood indicated that regeneration of resveratrol takes place in an appropriate time frame for delivery via oral administration. Despite their hydrophilicity some of the synthesized compounds were absorbed in the gastrointestinal tract of rats. In these cases the species found in blood after administration of a bolus consisted mainly of partially deprotected resveratrol derivatives and of the products of their glucuronidation, thus providing proof-of-principle evidence of behavior as prodrugs. The soluble compounds largely reached the lower intestinal tract. Upon administration of resveratrol, the major species found in this region was dihydroresveratrol, produced by enzymes of the intestinal flora. In experiments with a fully protected (trisubstituted) deoxygalactose containing prodrug, the major species were the prodrug itself and partially deprotected derivatives, along with small amounts of dihydroresveratrol. We conclude that the N-monosubstituted carbamate moiety is suitable for use in prodrugs of polyphenols.

  15. Gene cloning and molecular characterization of the Talaromyces thermophilus lipase catalyzed efficient hydrolysis and synthesis of esters.

    Science.gov (United States)

    Romdhane, Ines Belhaj-Ben; Frikha, Fakher; Maalej-Achouri, Inès; Gargouri, Ali; Belghith, Hafedh

    2012-02-15

    A genomic bank from Talaromyces thermophilus fungus was constructed and screened using a previously isolated fragment lipase gene as probe. From several clones isolated, the nucleotide sequence of the lipase gene (TTL gene) was completed and sequenced. The TTL coding gene consists of an open reading frame (ORF) of 1083bp encoding a protein of 269 Aa with an estimated molecular mass of 30kDa. The TTL belongs to the same gene family as Thermomyces lanuginosus lipase (TLL, Lipolase®), a well known lipase with multiple applications. The promoter sequence of the TTL gene showed the conservation of known consensus sequences PacC, CreA, Hap2-3-4 and the existence of a particular sequence like the binding sites of Oleate Response Element (ORE) and Fatty acids Responsis Element (FARE) which are similar to that already found to be specific of lipolytic genes in Candida and Fusarium, respectively. Northern blot analysis showed that the TTL expression was much higher on wheat bran than on olive oil as sole carbon source. Compared to the Lipolase®, this enzyme was found to be more efficient for the hydrolysis and the synthesis of esters; and its synthetic efficiency even reached 91.6% from Waste Cooking Oil triglycerides.

  16. Enhancement of Lipase-catalyzed Synthesis of Caffeic Acid Phenethyl Ester in Ionic Liquid with DMSO Co-solvent☆

    Institute of Scientific and Technical Information of China (English)

    Shuangshuang Gu; Jun Wang; Xianbin Wei; Hongsheng Cui; Xiangyang Wu; Fuan Wu

    2014-01-01

    Caffeic acid phenethyl ester (CAPE) is a natural and rare ingredient with several biological activities, but its indus-trial production using lipase-catalyzed esterification of caffeic acid (CA) and 2-phenylethanol (PE) in ionic liquids (ILs) is hindered by low substrate concentrations and long reaction time. To set up a high-efficiency bioprocess for production of CAPE, a novel dimethyl sulfoxide (DMSO)–IL co-solvent system was established in this study. The 2%(by volume) DMSO–[Bmim][Tf2N] system was found to be the best medium with higher substrate solu-bility and conversion of CA. Under the optimum conditions, the substrate concentration of CA was raised 8-fold, the reaction time was reduced by half, and the conversion reached 96.23%. The kinetics follows a ping-pong bi-bi mechanism with inhibition by PE, with kinetic parameters as follows:Vmax=0.89 mmol · min−1 · g−1, Km,CA=42.9 mmol · L−1, Km,PE=165.7 mmol · L−1, and Ki,PE=146.2 mmol · L−1. The results suggest that the DMSO co-solvent effect has great potential to enhance the enzymatic synthesis efficiency of CAPE in ILs.

  17. BIODIESEL SYNTHESIS OF COTTON SEEDS OIL (CEIBAPENTANDRA BY CHEMICALLY TRANSESTERIFICATION PROCESS AND ION FRAGMENTATION OF METHYL ESTER

    Directory of Open Access Journals (Sweden)

    Erin Ryantin Gunawan

    2016-08-01

    Full Text Available Fossil fuel is commercial energy sources in many communities where their abundance progressively reduced and the resulting environmental pollution. Biodiesel is one alternative fuel made from vegetable which oils are suitable to replace the function of fossil fuels and environmentally friendly. Synthesis of biodiesel from cotton seeds oil was carried out by chemically ransesterification process. Composition of methyl esters in biodiesel thatwas analyzed by GC-MS are methyl palmitate (16.71%, methyl 8,11-octadecadienoic (46.45 % and methyl linoleate (4.21 %.The highest amount of biodiesel conversion isat ratio of oil and methanol (1:1 with the catalyst 1% (weight of oil. The produced biodiesel was 93.7 %. Chemical properties of the produced biodiesel meets the standard SNI 04-7182-2006 i.e. saponification value of 120.167 mg KOH / g, acid value of 0.28 mg KOH / g and iod value 55.84g iod/100g of sample.

  18. Study on Catalysis Synthesis of Formylacetic Ester%甲酰乙酸乙酯的合成研究

    Institute of Scientific and Technical Information of China (English)

    唐敏

    2012-01-01

    以乙醇钠为催化剂,通过乙酸乙酯与甲酸乙酯反应合成了甲酰乙酸乙酯,研究了催化剂等有关因素对产品收率的影响。实验表明,乙醇钠是合成甲酰乙酸乙酯的良好催化剂,在乙酸乙酯与甲酸乙酯物质的量比为1∶1.4(mol)、催化剂用量为反应物的110%(mol)、反应时间为10h时,收率可达48.5%。%Formylacetic ester was synthesized from ethyl formate and acetic ether using Sodium ethylate as catalyst.The factors influencing the synthesis were discussed and best conditions were found out.The optimum conditions are as follows:the molar ratio of acetic ether to ethyl formate was 1.0∶1.4,the amount of catalyst was 110%(mol) ethyl formate,the reaction time was 10h.The yield is over 48.5%.

  19. The stereodirecting effect of the glycosyl C5-carboxylate ester: stereoselective synthesis of beta-mannuronic acid alginates.

    Science.gov (United States)

    Codée, Jeroen D C; van den Bos, Leendert J; de Jong, Ana-Rae; Dinkelaar, Jasper; Lodder, Gerrit; Overkleeft, Herman S; van der Marel, Gijsbert A

    2009-01-02

    Glycosylations of mannuronate ester donors proceed highly selectively to produce the 1,2-cis-linked products. We here forward a mechanistic rationale for this counterintuitive selectivity, based on the remote stereodirecting effect of the C5-carboxylate ester, which has been demonstrated using pyranosyl uronate ester devoid of ring substituents other than the C5- carboxylate ester. It is postulated that the C5-carboxylate ester prefers to occupy an axial position in the oxacarbenium intermediate, thereby favoring the formation of the (3)H4 half-chair over the (4)H3 conformer. Nucleophilic attack on the (3)H4 half-chair intermediate occurs in a beta-fashion, providing the 1,2-cis-mannuronates with excellent stereoselectivity. The potential of the mannuronate ester donors in the formation of the beta-mannosidic linkage has been capitalized upon in the construction of a mannuronic acid alginate pentamer using a convergent orthogonal glycosylation strategy.

  20. Pancreatic carboxyl ester lipase: a circulating enzyme that modifies normal and oxidized lipoproteins in vitro.

    OpenAIRE

    Shamir, R.; Johnson, W. J.; Morlock-Fitzpatrick, K; R. Zolfaghari; Li, L; mas, e; Lombardo, D; Morel, D W; Fisher, E A

    1996-01-01

    Pancreatic carboxyl ester lipase (CEL) hydrolyzes cholesteryl esters (CE), triglycerides (TG), and lysophospholipids, with CE and TG hydrolysis stimulated by cholate. Originally thought to be confined to the gastrointestinal system, CEL has been reported in the plasma of humans and other mammals, implying its potential in vivo to modify lipids associated with LDL, HDL (CE, TG), and oxidized LDL (lysophosphatidylcholine, lysoPC). We measured the concentration of CEL in human plasma as 1.2+/-0....

  1. Direct Asymmetric Aldol Type Reaction with Ethyl Diazoacetate: Stereoselective Synthesis of α, β-Dihydroxy Esters

    Institute of Scientific and Technical Information of China (English)

    LIAO Ming-Yi; YAO Wen-Gang; FENG Hai-Tao; WANG Jian-Bo

    2003-01-01

    @@ Enantioselective aldol condensation under catalytic condition remains a challenging task in modern organic synthesis, and numerous efforts have been directed to this area. In particular, the direct catalytic asymmetric aldol reaction is very attractive considering the requirement of atom efficiency. This has been studied only recently, and several very practical processes have been developed. We have recently initiated a study on the direct asymmetric aldol type reaction with ethyl diazoacetate as nucleophile. Moderate enantioselectivities (65% ~91% ee ) were achieved in the condensation of aldehydes with ethyl diazoacetate catalyzed by the chiral complex of BINOL derivatives-Zr (OBu- t )4. [1

  2. Synthesis of acylamino acid esters of nucleoside 5'-phosphates and their investigation with PMR and CD spectra.

    Science.gov (United States)

    Azhayev, A V; Popovkina, S V; Tarussova, N B; Kirpichnikov, M P; Florentiev, V L; Krayevsky, A A; Kukhanova, M K; Gottikh, B P

    1977-01-01

    The acylamino acid esters of nucleoside 5'-phosphates are synthesized via condensation of N-(N'-acylaminoacyl) imidazoles with nucleoside 5'-phosphates. The PMR and CD spectra of the esters obtained are studied. The 3'-isomers of the substances under study are observed to have a shift in the conformational N in equilibrium S equilibrium of the carbohydrate moiety in favour of the S-form as compared to the initial nucleosides and their 2'-acyl esters. PMID:909771

  3. Immobilization of lipases in PSS/PEO blends and applications in esters synthesis; Imobilizacao de lipases em blendas de PSS/PEO e aplicacoes na sintese de esteres

    Energy Technology Data Exchange (ETDEWEB)

    Vecchia, Roberto D. [Universidade do Vale do Itajai (UNIVALI), Florianopolis, SC (Brazil). Nucleo de Investigacoes Quimico-Farmaceuticas (NIQFAR)]. E-mail: rdv@ccs.univali.br; Nascimento, Maria G.; Soldi, Valdir [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Quimica]. E-mail: graca@qmc.ufsc.br; vsoldi@qmc.ufsc.br

    2001-07-01

    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)

  4. Synthesis of novel tri- and tetrasubstituted C18 furan fatty esters.

    Science.gov (United States)

    Lie Ken Jie, Marcel S F; Lau, Maureen M L; Lam, Corey N W

    2003-12-01

    A methylene-interrupted C18 keto-acetylenic fatty ester (methyl 12-oxo-9-octadecynoate) was obtained from methyl ricinoleate by bromination-dehydrobromination followed by oxidation. Reaction of methyl 12-oxo-9-octadecynoate with bis(benzonitrile) palladium(II) chloride, allyl bromide, or methyl-allyl bromide furnished methyl 8-[5-hexyl-3-allyl-furan-2-yl]-octanoate (1, 56%) or methyl 8-15-hexyl-3-(2-methyl-allyl)-furan-2-yl]-octanoate (2, 55%). Reaction of methyl 12-oxo-11-chloro- or 11-fluoro-9-octadecynoate (prepared from methyl santalbate--methyl 11-E-9-octadecynoate, found in sandalwood, Santalum album, seed oil) with bis(benzonitrile) palladium(II) chloride gave methyl 8-(4-chloro-5-hexyl-furan-2-yl)-octanoate (3, 59%) or methyl 8-(4-fluoro-5-hexyl-furan-2-yl)-octanoate (4, 50%), respectively. And when methyl 12-oxo-11-chloro- or 11-fluoro-9-octadecynoate was treated with a mixture of bis(benzonitrile) palladium(II) chloride, allyl bromide, or methyl-allyl bromide, the reaction yielded tetrasubstituted C18 furan derivatives, viz., methyl 8-(3-allyl-4-chloro-5-hexyl-furan-2-yl)-octanoate (5, 54%), methyl 8-[4-chloro-5-hexyl-3-(2-methyl-allyl)-furan-2-yl]-octanoate (6, 54%), methyl 8-(3-allyl-4-fluoro-5-hexyl-furan-2-yl)-octanoate (7, 10%), and methyl 8-14-fluoro-5-hexyl-3-(2-methyl-allyl)-furan-2-yl]-octanoate (8, 10%). The presence of a fluorine atom in the furan derivatives 4, 7, and 8 was readily characterized by the appearance of doublets for carbon nuclei, which were coupled to the fluorine atom in the 13C NMR spectra. All furan fatty derivatives from this work were characterized by NMR spectroscopic and mass spectrometric analyses. The yields of compounds 7 and 8 were very low (10%) despite attempts to improve the procedure by increasing the amounts of the reactants and catalyst.

  5. Synthesis and biological evaluation of new creatine fatty esters revealed dodecyl creatine ester as a promising drug candidate for the treatment of the creatine transporter deficiency.

    Science.gov (United States)

    Trotier-Faurion, Alexandra; Dézard, Sophie; Taran, Frédéric; Valayannopoulos, Vassili; de Lonlay, Pascale; Mabondzo, Aloïse

    2013-06-27

    The creatine transporter deficiency is a neurological disease caused by impairment of the creatine transporter SLC6A8, resulting in mental retardation associated with a complete absence of creatine within the brain and cellular energy perturbation of neuronal cells. One of the therapeutic hypotheses was to administer lipophilic creatine derivatives which are (1) thought to have better permeability through the cell membrane and (2) would not rely on the activity of SLC6A8 to penetrate the brain. Here, we synthesized creatine fatty esters through original organic chemistry process. A screening on an in vitro rat primary cell-based blood-brain barrier model and on a rat primary neuronal cells model demonstrated interesting properties of these prodrugs to incorporate into endothelial, astroglial, and neuronal cells according to a structure-activity relationship. Dodecyl creatine ester showed then a 20-fold increase in creatine content in pathological human fibroblasts compared with the endogenous creatine content, stating that it could be a promising drug candidate.

  6. Synthesis and evaluation of odour-active methionyl esters of fatty acids via esterification and transesterification of butter oil.

    Science.gov (United States)

    Li, Cheng; Sun, Jingcan; Fu, Caili; Yu, Bin; Liu, Shao Quan; Li, Tianhu; Huang, Dejian

    2014-02-15

    Methionol-derived fatty acid esters were synthesised by both chemical and lipase catalysed esterification between fatty acids and methionol. Beneficial effects of both methods were compared qualitatively and quantitatively by GC-MS/GC-FID results. And the high acid and heat stability of our designed methionyl esters meet the requirement of the food industry. Most importantly, the sensory test showed that fatty acid carbon-chain length had an important effect on the flavour attributes of methionyl esters. Moreover, through Lipozyme TL IM-mediated transesterification, valuable methionol-derived esters were synthesised from the readily available natural material butter oil as the fatty acid source. The conversion of methionol and yield of each methionyl ester were also elucidated by GC-MS-FID.

  7. Preparation and Characterization of a Novel Benzimidazolium Br(φ)nsted Acid Ionic Liquid and Its Application in the Synthesis of Arylic Esters

    Institute of Scientific and Technical Information of China (English)

    WANG,Yuan-Yuan; LI,Wei; XU,Cheng-Di; DAI,Li-Yi

    2007-01-01

    A novel Brφnsted acid task specific ionic liquid 1-ethylbenzimidazolium tetrafluoroborate ([Hebim]BF4) with functional benzimidazolium cation was synthesized and characterized by 1H NMR, IR, MS spectra and elemental analysis. This novel ionic liquid was successfully used as dual solvent-catalyst for the synthesis of arylic esters.Higher yields were obtained in the presence of [Hebim]BF4 in comparison with other imidazolium ionic liquids because of the good solubility of the aromatic alcohols and aromatic carboxylic acids in [Hebim]BF4. The product could be separated conveniently from the reaction system, and the ionic liquid could be easily reused after removal of water under vacuum. After 10 times reuse, the selectivity of the ester was still 100%.

  8. Solvent-Free Synthesis of Flavour Esters through Immobilized Lipase Mediated Transesterification.

    Science.gov (United States)

    Garlapati, Vijay Kumar; Banerjee, Rintu

    2013-01-01

    The synthesis of methyl butyrate and octyl acetate through immobilized Rhizopus oryzae NRRL 3562 lipase mediated transesterification was studied under solvent-free conditions. The effect of different transesterification variables, namely, molarity of alcohol, reaction time, temperature, agitation, addition of water, and enzyme amount on molar conversion (%) was investigated. A maximum molar conversion of 70.42% and 92.35% was obtained in a reaction time of 14 and 12 h with the transesterification variables of 0.6 M methanol in vinyl butyrate and 2 M octanol in vinyl acetate using 80 U and 60 U immobilized lipase with the agitation speed of 200 rpm and 0.2% water addition at 32°C and 36°C for methyl butyrate and octyl acetate, respectively. The immobilized enzyme has retained good relative activity (more than 95%) up to five and six recycles for methyl butyrate and octyl acetate, respectively. Hence, the present investigation makes a great impingement in natural flavour industry by introducing products synthesized under solvent-free conditions to the flavour market.

  9. Solvent-Free Synthesis of Flavour Esters through Immobilized Lipase Mediated Transesterification

    Directory of Open Access Journals (Sweden)

    Vijay Kumar Garlapati

    2013-01-01

    Full Text Available The synthesis of methyl butyrate and octyl acetate through immobilized Rhizopus oryzae NRRL 3562 lipase mediated transesterification was studied under solvent-free conditions. The effect of different transesterification variables, namely, molarity of alcohol, reaction time, temperature, agitation, addition of water, and enzyme amount on molar conversion (% was investigated. A maximum molar conversion of 70.42% and 92.35% was obtained in a reaction time of 14 and 12 h with the transesterification variables of 0.6 M methanol in vinyl butyrate and 2 M octanol in vinyl acetate using 80 U and 60 U immobilized lipase with the agitation speed of 200 rpm and 0.2% water addition at 32°C and 36°C for methyl butyrate and octyl acetate, respectively. The immobilized enzyme has retained good relative activity (more than 95% up to five and six recycles for methyl butyrate and octyl acetate, respectively. Hence, the present investigation makes a great impingement in natural flavour industry by introducing products synthesized under solvent-free conditions to the flavour market.

  10. Efficient Synthesis of β-Acetamido Ketones and Esters Using Aluminum Chloride as an Inexpensive and Green Catalyst%Efficient Synthesis of β-Acetamido Ketones and Esters Using Aluminum Chloride as an Inexpensive and Green Catalyst

    Institute of Scientific and Technical Information of China (English)

    Mohammad Ali, Zolfigol; Ardeshir, Khazaei; Mohammad, Mokhlesi; Abdolkarim, Zare; Maliheh, Safaiee; Fatemeh, Derakhshan-Panah; Hassan, Keypour; Ahmad, Ali Dehghani-Firouzabadi; Maria, Merajoddin

    2012-01-01

    Aluminum chloride (AlCl3) efficiently catalyzes one-pot multicomponent condensation of enolizable ketones or alkyl acetoacetates with aldehydes, acetonitrile and acetyl chloride to afford β-acetamido ketone or ester derivatives in high to excellent yields and in relatively short reaction times. Moreover, by this synthetic method, some novel β-acetamido ketones and esters (i.e. one complex structure) are prepared.

  11. The impact of cholesteryl ester transfer protein on glucose metabolism in 3T3-L1 adipocytes%胆固醇酯转运蛋白对3T3-L1脂肪细胞糖代谢的影响

    Institute of Scientific and Technical Information of China (English)

    朱晓慧; 常毅娜; 付真真; 郭雯; 高贝贝; 符金香; 陈晓丽; 周红文

    2014-01-01

    3T3-L1 adipocytes stably expressing different levels of human cholesterol ester transfer protein (CETP) were constructed and identified.Glucose uptake and glucose transporter 4 (GLUT4) protein levels of these cells were also measured.Insulin-stimulated 2-deoxyglucose uptake was significantly higher in 3T3-L1 adipocytes which expressed high,medium,and low levels of CETP than that in control ceils,and the elevated levels of glucose uptake were positively related with CETP expression in a dose-dependent manner.After insulin stimulation,there was no difference in GLUT4 protein expression among control cell and those expressing CETP.CETP plays a role in the regulation of glucose metabolism in adipocytes.%建立人胆固醇酯转运蛋白(CETP)不同表达水平的3T3-L1脂肪前体细胞株,并进行鉴定,测定葡萄糖摄取率以及葡萄糖转运体4(GLUT4)蛋白表达水平.与对照组相比,表达CETP的3T3-L1脂肪细胞葡萄糖摄取显著增高,且此作用与CETP表达量呈正相关.胰岛素刺激后,稳定表达CETP的3T3-L1脂肪细胞GLUT4蛋白表达水平与对照组相比无显著差异.推测CETP可能通过调节脂肪细胞内胆固醇含量的变化而促进脂肪细胞的糖代谢.

  12. Synthesis, Resolution, and Enantiomeric Purity Assay of 2-n-Butylbutanedioic Acid 4-t-Butyl Esters

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Racemic 2-n-butylbutanedioic acid 4-t-butyl esters were synthesized from methyl hexanoate and t-butyl α-iodoacetate via alkylation and subsequently selective hydrolyzation. The (R)-and (S)-2-n-butylbutanedioic acid 4-t-butyl esters were obtained by the resolution of the above-mentioned racemic compounds with(S)-( - ) or(R)-( + )-α-methylbenzylamine, respectively. The e.e. values of the two optical active products were determined to be above 99% by HPLC after the formation of two pairs of diastereoisomers with ( R)-( + )-α-methylbenzylamine and (S)-phenylalanine methyl ester.

  13. 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.

  14. Growth and wax ester production of an Acinetobacter baylyi ADP1 mutant deficient in exopolysaccharide capsule synthesis.

    Science.gov (United States)

    Kannisto, Matti; Efimova, Elena; Karp, Matti; Santala, Ville

    2017-01-01

    Acinetobacter baylyi ADP1 naturally produces wax esters that could be used as a raw material in industrial applications. We attempted to improve wax ester yield of A. baylyi ADP1 by removing rmlA, a gene involved in exopolysaccharide production. Growth rate, biomass formation and wax ester yield on 4-hydroxybenzoate were not affected, but the rmlA (-) strain grew slower on acetate, while reaching similar biomass and wax ester yield. The rmlA (-) cells had malformed shape and large size and grew poorly on glucose without expression of the gene for pyruvate kinase (pykF) from Escherichia coli. The pykF-expressing rmlA (-) strain had similar growth rate, lowered biomass formation and improved wax ester production on glucose as compared to the wild-type strain expressing pykF. Cultivation of the pykF-expressing rmlA (-) strain on an elevated glucose concentration in a medium supplemented with amino acids resulted in doubled molar wax ester yield and acetate production.

  15. 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.

  16. 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.

  17. Synthesis of chromatographic standards and establishment of a method for the quantification of the fatty ester composition of biodiesel from babassu oil; Sintese de padroes cromatograficos e estabelecimento de metodo para dosagem da composicao de esteres de acidos graxos presentes no biodiesel a partir do oleo de babacu

    Energy Technology Data Exchange (ETDEWEB)

    Urioste, Daniele; Castro, Matheus B.A.; Biaggio, Francisco C.; Castro, Heizir F. de [Universidade de Sao Paulo (USP), Lorena, SP (Brazil). Escola de Engenharia]. E-mail: heizir@dequi.eel.usp.br

    2008-07-01

    Several alkyl esters were synthesized, purified, characterized by {sup 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{sub 2} to C{sub 4}), using Lipozyme as catalyst. (author)

  18. SYNTHESIS AND CHARACTERIZATION OF THERMOTROPIC COPOLYESTERS AND COPOLY (ESTER-AMIDE)S CONTAINING OXYETHYLENE-ETHER AS THE SPACER

    Institute of Scientific and Technical Information of China (English)

    WANG Shanger; MO Zhishen; ZHANG Hongfang; FENG Zhiliu

    1995-01-01

    Flexible oxyethylene-ether was introduced into the aromatic copolyesters and copoly (ester-amide)s to reduce the melting point of resulting polymers. The melting point was greatly reduced to 200℃ or even lower in some cases, and the molecular weight was satisfactorily high as reflected by inherent viscosity. The polymers exhibited high thermal stability and good mechanical properties as determined by TGA and mechanical tests. The copolyester showed better crystallinity and liquid crystallinity than corresponding copoly(ester-amide)s with similar monomer composition as reflected by POM observation and WAXD study. The melting points for both copolyesters and copoly (ester-amide)s showed great dependence on the pacetoxybenzoic acid (PAB) content in monomer composition and reached the lowest value when PAB was 29 mol%.

  19. 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.

  20. Tandem beta-enamino ester formation and cyclization with o-alkynyl anilines catalyzed by InBr3: efficient synthesis of beta-(N-indolyl)-alpha,beta-unsaturated esters.

    Science.gov (United States)

    Murai, Kenichi; Hayashi, Shoko; Takaichi, Nobuhiro; Kita, Yasuyuki; Fujioka, Hiromichi

    2009-02-06

    A tandem reaction providing beta-(N-indolyl)-alpha,beta-unsaturated esters from beta-keto esters and o-alkynyl anilines was developed. Z-Alkenes were selectively formed due to the stability of the beta-enamino ester as an intermediate of the reaction. This reaction includes the intermolecular beta-enamino ester formation and intramolecular cyclization catalyzed by InBr(3).

  1. Synthesis of p-aminophenyl aryl H-phosphinic acids and esters via cross-coupling reactions: elaboration to phosphinic acid pseudopeptide analogues of pteroyl glutamic acid and related antifolates.

    Science.gov (United States)

    Yang, Yonghong; Coward, James K

    2007-07-20

    The synthesis of suitably protected p-aminophenyl H-phosphinic acids and esters from the corresponding para-substituted aryl halides has been accomplished via the Pd-catalyzed cross-coupling reaction of anilinium hypophosphite, either in the absence or presence of a tetraalkyl orthosilicate, to provide the free H-phosphinic acid or the corresponding ester, respectively. Subsequent conjugate addition of either a PIII species or phosphorus anion, generated in situ from either the free H-phosphinic acid or ester, to a 2-methylene glutaric acid ester provided the aryl phosphinic acid analogue of p-aminobenzoyl glutamic acid. Alkylation of these suitably protected p-aminophenyl phosphinic acid esters with a 6-(bromomethyl)pteridine or the corresponding (bromomethyl)pyridopyrmidine, followed by hydrolytic removal of protecting groups, provided the target aryl phosphinic acid analogues of folic acid and related antifolates. Alternatively, for the synthesis of the folate or 5-deazafolate analogues on a slightly larger scale, reductive amination with either N2-acetyl or N2-pivaloyl-6-formylpterin or the corresponding formylpyridopyrmidine and the same suitably protected p-aminophenyl phosphinic acid esters, followed by removal of protecting groups, is preferred. In the course of this research, it was observed that the nucleophilicity of both the aniline nitrogen and various PIII species derived from p-aminophenyl phosphinic acid derivatives is significantly reduced compared to that of the unsubstituted counterpart.

  2. Ester Formation

    NARCIS (Netherlands)

    Lopez Garzon, C.S.; Straathof, A.J.J.

    2014-01-01

    The present invention is in the field of a process for producing an ester, such as a biobased ester, from an aqueous biomass comprising solution, batch wise or continuously, wherein use of raw material is limited and if possible re-used. The present invention is in the field of green technology.

  3. Transesterification reaction for synthesis of palm-based ethylhexyl ester and formulation as base oil for synthetic drilling fluid.

    Science.gov (United States)

    Abdul Habib, Nor Saiful Hafiz; Yunus, Robiah; Rashid, Umer; Taufiq-Yap, Yun H; Abidin, Zurina Zainal; Syam, Azhari Muhammad; Irawan, Sonny

    2014-01-01

    The use of vegetable oil-based ester as a base fluid in synthetic drilling fluid has become a trend in drilling operations due to its environmental advantages. The transesterification reaction of palm oil methyl ester (POME) with 2-ethylhexanol (2EH) produced 98% of palm oil-based ethylhexyl ester in less than 30 minutes. Since the transesterification reaction of POME with 2EH is a reversible reaction, its kinetics was studied in the presence of excess EH and under vacuum. The POME-to-EH molar ratio and vacuum pressure were held constant at 1:2 and 1.5 mbar respectively and the effects of temperature (70 to 110°C) were investigated. Using excess of EH and continual withdrawal of methanol via vacuum promoted the reaction to complete in less than 10 minutes. The rate constant of the reaction (k) obtained from the kinetics study was in the range of 0.44 to 0.66 s⁻¹ and the activation energy was 15.6 kJ.mol⁻¹. The preliminary investigations on the lubrication properties of drilling mud formulated with palm oil-based 2EH ester indicated that the base oil has a great potential to substitute the synthetic ester-based oil for drilling fluid. Its high kinematic viscosity provides better lubrication to the drilling fluid compared to other ester-based oils. The pour point (-15°C) and flash point (204°C) values are superior for the drilling fluid formulation. The plastic viscosity, HPHT filtrate loss and emulsion stability of the drilling fluid had given acceptable values, while gel strength and yield point could be improved by blending it with proper additives.

  4. 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

    and cholesterol, and the structures analyzed by transmission electron microscopy. 3-O-(Manp(13)Glcp)hederagenin was found to produce numerous ring-like micelles when formulated, while C-28 choline ester derivatives preferred self-assembly and did not interact with the liposomes. When alone and in the presence...... 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...

  5. Lipase-catalyzed Regioselective Synthesis of Vinyl Ester Derivatives of Thiamphenicol: Novel Thiamphenicol Monomers for Preparation of Macromolecular Antibiotic

    Institute of Scientific and Technical Information of China (English)

    Yu Zhen SHI; Zhi Chun CHEN; Na WANG; Qi WU; Xian Fu LIN

    2005-01-01

    Three polymerizable vinyl thiamphenicol esters with different acyl donor carbon chain length (C4, C6, C10) were regioselectivly synthesized by Lipozyme(R) (immobilized from mucor miehei) in acetone at 50 ℃ for 12 h to give 73%, 81%, 63% yield, respectively. The products were valuable monomers for preparation of macromolecular antibiotic.

  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...

  7. Synthesis, characterization and in vitro studies of celecoxib-loaded poly(ortho ester) nanoparticles targeted for intraocular drug delivery.

    Science.gov (United States)

    Palamoor, Mallika; Jablonski, Monica M

    2013-12-01

    The present investigation is aimed at improving the ocular bioavailability of a poorly water soluble drug, celecoxib, to offer new options in the treatment of chronic eye diseases, such as age-related macular degeneration and diabetic retinopathy. To do so, we developed a novel formulation of drug-loaded poly(ortho ester) nanoparticles (NPs). We characterized the NPs in terms of size, morphology, controlled-release, degradation and cytocompatibity. Stable and transparent NP emulsions were prepared following a double emulsion solvent diffusion method employing poloxamer 188 as a stabilizer. Physical properties showed a narrow range size distribution of 151-164nm with spherical morphology, negative zeta potentials and remarkably high celecoxib encapsulation efficiency (98%) and loading (64%) of poly(ortho ester) NPs. Drug release followed a zero-order release by a surface erosion-controlled mechanism without any burst effect. Degradation of poly(ortho ester) NPs was observed by measuring the concentration of initial degradation product such as, lactic acid. MTT studies revealed minimal toxicity of NPs (up to 1mg/ml) toward HEK 293 cells. Poly(ortho ester) NPs were not internalized by either Müller or HEK 293 cells, which is highly desirable for a drug carrier to deliver the drugs for prolonged periods to the back of eye. These features have the potential to decrease the number of intraocular injections required to treat chronic eye diseases.

  8. Synthesis and Characterization of PEG-scutellarin Conjugates, a Potential PEG Ester Prodrug for the Oral Delivery of Scutellarin

    Institute of Scientific and Technical Information of China (English)

    Qing Song ZHOU; Xue Hua JIANG; Jia Rui YU; Ke Jia LI

    2006-01-01

    Highly water soluble esters of scutellarin with variable molecular weight polyethylene glycol (PEG) were prepared via PEGylation. The physicochemical properties and the stabilities under different conditions were investigated. By PEG modification, the greatly increased water solubility and desirable partition coefficient of scutellarin were obtained, and the results showed that these conjugates were potential prodrugs for the oral delivery of scutellarin.

  9. Surface membrane CD4 turnover in phorbol ester stimulated T-lymphocytes. Evidence of degradation and increased synthesis

    DEFF Research Database (Denmark)

    Møller, B K; Andresen, B S; Christensen, E I

    1990-01-01

    Down-regulation of surface membrane CD4 (smCD4) in phorbol ester stimulated T-cells resulted from internalization. Internalization (T1/2 = 15 min at 50 ng PMA/ml) was followed by degradation of CD4-bound antibodies. Degradation in unstimulated T-cells was comparatively insignificant. Release...

  10. 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…

  11. 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.

  12. ACAT1 deficiency increases cholesterol synthesis in mouse peritoneal macrophages.

    Science.gov (United States)

    Dove, Dwayne E; Su, Yan Ru; Swift, Larry L; Linton, MacRae F; Fazio, Sergio

    2006-06-01

    Acyl-coenzyme A:cholesterol acyltransferase (ACAT) esterifies free cholesterol and stores cholesteryl esters in lipid droplets. Macrophage ACAT1 deficiency results in increased atherosclerotic lesion area in hyperlipidemic mice via disrupted cholesterol efflux, increased lipoprotein uptake, accumulation of intracellular vesicles, and accelerated apoptosis. The objective of this study was to determine whether lipid synthesis is affected by ACAT1. The synthesis, esterification, and efflux of new cholesterol were measured in peritoneal macrophages from ACAT1(-/-) mice. Cholesterol synthesis was increased by 134% (p=0.001) in ACAT1(-/-) macrophages compared to wildtype macrophages. Increased synthesis resulted in a proportional increase in the efflux of newly synthesized cholesterol. Although the esterification of new cholesterol was reduced by 93% (pSREBP1a mRNA was increased 6-fold in ACAT1(-/-) macrophages compared to wildtype macrophages, suggesting an up-regulation of cholesterol and fatty acid synthesis in ACAT1(-/-) macrophages. Increased cholesterol synthesis and up-regulation of SREBP in ACAT1(-/-) macrophages suggests that ACAT1 affects the regulation of lipid metabolism in macrophages. This change in cholesterol homeostasis may contribute to the atherogenic potential of ACAT1(-/-) macrophages.

  13. 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....

  14. 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

  15. Scaling-up the synthesis of myristate glucose ester catalyzed by a CALB-displaying Pichia pastoris whole-cell biocatalyst.

    Science.gov (United States)

    Guo, DongHeng; Jin, Zi; Xu, YanShan; Wang, Ping; Lin, Ying; Han, ShuangYan; Zheng, SuiPing

    2015-01-01

    The novel whole-cell biocatalyst Candida antarctica lipase B displaying-Pichia pastoris (Pp-CALB) is characterized by its low preparation cost and could be an alternative to the commercial immobilized Candida antarctica lipase B (CALB). This study addresses the feasibility of using Pp-CALB in large scale glucose fatty acid esters production. 1,2-O-Isopropylidene-α-D-glucofuranose (IpGlc) was used as the acyl acceptor to overcome the low solubility of glucose in an organic solvent and to avoid the addition of toxic co-solvents. IpGlc significantly improved the Pp-CALB catalyzing esterification efficiency when using long chain fatty acids as the acyl donor. Under the preferred operating conditions (50 °C, 40 g/L molecular sieve dosage and 200 rpm mixing intensity), 60.5% of IpGlc converted to 6-O-myristate-1, 2-O-isopropylidene-α-D-glucofuranose (C14-IpGlc) after a 96-h reaction in a 2-L stirred reactor. In a 5-L pilot scale test, Pp-CALB also showed a similar substrate conversion rate of 55.4% and excellent operational stability. After C14-IpGlc was collected, 70% trifluoroacetic acid was adopted to hydrolyze C14-IpGlc to myristate glucose ester (C14-Glc) with a high yield of 95.3%. In conclusion, Pp-CALB is a powerful biocatalyst available for industrial synthesis, and this study describes an applicable and economical process for the large scale production of myristate glucose ester.

  16. 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.)

  17. Synthesis and antimicrobial evaluation of 1,4-disubstituted 1,2,3-triazoles with aromatic ester functionality

    Directory of Open Access Journals (Sweden)

    C.P. Kaushik

    2016-11-01

    Full Text Available A series of 1,4-disubstituted 1,2,3-triazoles having p-substituted aromatic ester functionality were synthesized via Cu(I catalysed click reaction between p-substituted benzoic acid prop-2-ynyl esters and aralkyl azides. The synthesized triazoles were characterized by IR, 1H NMR, 13C NMR and mass spectral techniques. These compounds were evaluated for their antimicrobial activity against Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Mycobacterium tuberculosis, Candida albicans, Aspergillus niger and Aspergillus flavus by two fold serial dilution method. Some of the synthesized 1,4-disubstituted 1,2,3-triazoles possess comparable or even better antibacterial, antitubercular and antifungal activities than reference drugs against tested bacterial, mycobacterial and fungal strains, respectively.

  18. Cinchona Alkaloid Derivative-Catalyzed Enantioselective Synthesis via a Mannich-Type Reaction and Antifungal Activity of β-Amino Esters Bearing Benzoheterocycle Moieties

    Directory of Open Access Journals (Sweden)

    Han Xiao

    2014-04-01

    Full Text Available An efficient synthesis of highly functionalized chiral β-amino ester derivatives containing benzothiophene and benzothiazole moieties is developed by a Mannich-type reaction using a cinchona alkaloid-derived thiourea catalyst. The desired products were obtained in good yields and high enantioselectivities (~86% yield, >99% ee using to the optimized reaction conditions. The synthesized compounds were characterized by 1H-NMR, 13C-NMR, IR, and HREI-MS analyses. The bioassays identified that compound 5dr has excellent antifungal activity, with a 60.53% inhibition rate against F. oxysporum, higher than that of the commercial agricultural fungicide hymexazol, whose inhibition rate was 56.12%.

  19. 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)

  20. Synthesis and characterization of biodegradable polymer: Poly (ethene maleic acid ester-co-D,L-lactide acid)

    Institute of Scientific and Technical Information of China (English)

    Mei Na Huang; Yan Feng Luo; Jia Chen; Yong Gang Li; Chun Hua Fu; Yuan Liang Wang

    2007-01-01

    A novel biodegradable polymer-poly (ethene maleic acid ester-co-D,L-lactide acid) was synthesized by copolymerizing lactide and prepolymer, which was prepared by the condensation of maleic anhydride and glycol, using p-toluene sulphonic acid as a catalyst, attempting to improve the hydrophilicity, increase flexibility and modulate the degradation rate. FTIR, 1H NMR, MALLS and DSC were employed to characterize these polymers.

  1. Chemo-Enzymatic Synthesis of Ester-Linked Docetaxel-Monosaccharide Conjugates as Water-Soluble Prodrugs

    OpenAIRE

    Naoji Kubota; Kei Shimoda

    2011-01-01

    Three new docetaxel prodrugs, i.e., 7-propionyldocetaxel 3''-O-b-D-glycopyranosides, which contain ester-linked monosaccharides, were synthesized by a chemo-enzymatic procedure involving enzymatic transglycosylations with lactase, b-galactosidase, or b-xylosidase. The water-solubility of 7-propionyldocetaxel 3''-O-b-D-glucopyranoside was 52-fold higher than that of docetaxel. 7-Propionyldocetaxel 3''-O-b-D-glucopyranoside and 7-propionyldocetaxel 3''-O-b-D-xylopyranoside were effectively hydr...

  2. SYNTHESIS AND PROPERTIES OF NEW SIDE-CHAIN LIQUID CRYSTALLINE POLYMER WITH LATERALLY ATTACHED MESOGENS BY ESTER GROUP

    Institute of Scientific and Technical Information of China (English)

    Qi-ding Mi; Qi-feng Zhou

    1999-01-01

    New liquid crystalline monomer, 2,5-bis[(4'-methoxyphenoxy)carbonyl]phenyl acrylate was successfully synthesized. Polyacrylate with laterally attached mesogens via ester linkage was also derived.This polymer forms an enantiotropic liquid crystal phase while its monomer exhibits a metastable nematic phase with respect to the crystalline state. However, its liquid crystallinity is very low as compared to that of poly { 2,5-bis[(4'-methoxyphenoxy)carbonyl] -styrene }.

  3. Synthesis and ligand binding studies of 4'-iodobenzoyl esters of tropanes and piperidines at the dopamine transporter.

    Science.gov (United States)

    Singh, S; Basmadjian, G P; Avor, K S; Pouw, B; Seale, T W

    1997-08-01

    Four analogs and two homologs of cocaine, designed as potent cocaine antagonists, were synthesized. The SN2 reaction between ecgonine methyl ester (13) or appropriately substituted piperidinol (19, 21) and appropriately substituted 4-iodobenzoyl chloride gave 4-iodobenzoyl esters of tropanes and piperidines (5-8). 2'-Hydroxycocaine (9) was obtained from 2'-acetoxycocaine (12) by selective transesterification with MeOH saturated with dry HCl gas. 2'-Acetoxycocaine (12) was synthesized from acetylsalicyloyl chloride (23) and ecgonine methyl ester (13). The binding affinities of these compounds were determined at the dopamine transporter for the displacement of [3H]WIN-35428. An iodo group substitution at the 4'-position of cocaine decreased dopamine transporter binding potency, while a hydroxy or acetoxy group at the 2'-position exhibited increased binding potency for the dopamine transporter compared to cocaine (10- and 3.58-fold, respectively). 2'-Hydroxylation also enhanced the bidning potency of 4'-iodococaine (5) by 10-fold. Replacement of the tropane ring with piperidine led to poor binding affinities.

  4. Novel Fluorinated Phosphorus–Sulfur Heteroatom Compounds: Synthesis and Characterization of Ferrocenyl- and Aryl-Phosphonofluorodithioic Salts, Adducts, and Esters

    Directory of Open Access Journals (Sweden)

    Guoxiong Hua

    2015-07-01

    Full Text Available A series of novel ferrocenyl- and aryl-phosphonofluorodithioic salts, adducts, and esters has been prepared. The reaction of 2,4-diferrocenyl-1,3,2,4-diathiadiphosphetane 2,4-disulfide {[FcP(μ-SS]2, FcLR} with dry KF or tetrabutylammonium fluoride (TBAF led to the corresponding potassium and tetrabutylammonium salts of ferrocenyldithiofluorophosphinic acids. Treating potassium ferrocenyldithiofluorophosphinic acid with an equimolar amount of tetraphenylphosphonium chloride readily yielded the corresponding organic adducts, and with mono- and di-halogenated alkanes generated a series of the corresponding esters of ferrocenylphosphonofluoridodithioates. Similarly, using 1,3-epithionaphtho[1,8-cd][1,2,6] oxadiphosphinine 1,3-disulfide or Belleau’s Reagent in place of FcLR resulted in the corresponding novel salts, adducts, and ester derivatives. All new compounds have been characterized by means of multi-NMR (1H, 13C, 31P, 19F spectroscopy and accurate mass measurement in conjunction with single crystal X-ray crystallography of four structures.

  5. Synthesis and high in vitro cytotoxicity of some (S,S-ethylenediamine-N,N’-di-2-propanoate dihydrochloride esters

    Directory of Open Access Journals (Sweden)

    Pantelić Nebojša

    2014-01-01

    Full Text Available Novel (S,S-R2eddip ester, O,O’-diisoamyl-(S,S-ethylenediamine-N,N’-di-2-propanoate dihydrochloride, 1, was synthesized and characterized by IR, 1H and 13C NMR spectroscopy, mass spectroscopy and elemental analysis.In vitro antitumor action of 1, and two more R2eddip esters, O,O’-dialkyl-(S,S-ethylenediamine-N,N’-di-2-propanoate dihydrochlorides, obtained before, (alkyl = n-Bu, n-Pe; 2 and 3, respectively, was determined against cervix adenocarcinoma (HeLa, human melanoma (Fem-x, human chronic myelogenous leukemia (K562 cells, and a non-cancerous cell line human embryonic lung fibroblast (MRC-5, using MTT assay. Esters 1-3 showed higher cytotoxicity and better selectivity in comparison to cisplatin, used as reference compound. The highest activityis expressed by1,with IC50(Fem-xvalue1.51 ± 0.09 µM. [Projekat Ministarstva nauke republike Srbije, br. 172035 i br. 175011

  6. Targeting cholesteryl ester transfer protein for the prevention and management of cardiovascular disease

    NARCIS (Netherlands)

    P.J. Barter; J.J.P. Kastelein

    2006-01-01

    Epidemiologic studies have shown that the concentration of high-density lipoprotein cholesterol (HDL-C) is a strong, independent, inverse predictor of coronary heart disease risk. This identifies HDL-C as a potential therapeutic target. Compared with low-density lipoprotein cholesterol (LDL-C)-lower

  7. 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.

  8. Advance in synthesis of phytosterol esters of unsaturated fatty acids%不饱和脂肪酸植物甾醇酯的合成工艺研究进展

    Institute of Scientific and Technical Information of China (English)

    张品; 邓乾春; 黄庆德; 黄凤洪

    2009-01-01

    详细介绍了不饱和脂肪酸植物甾醇酯的性质、应用、合成方法及国内外研究进展,为开发不饱和脂肪酸植物甾醇酯功能性食品添加剂提供参考.不饱和脂肪酸植物甾醇酯的合成方法有化学法和酶法.随着生物技术与食品科技的发展,不饱和脂肪酸植物甾醇酯的合成工艺将朝着绿色、低能耗、无污染和高安全性方向发展.%The property,application,various synthesis methods of phytosterol esters of unsaturated fatty acid in domestic and overseas were described so as to offer reference for the application of phytosterol esters of unsaturated fatty acids in functional food as food additives.The synthesis method of phytosterol esters of unsaturated fatty acids includes chemical method and enzyme method.With the development of biotechnology,and food science and technology,the synthesis process of phytosterol esters of unsaturated fatty acids will develop in the direction of green,low-energy consumption,non-polluting and high-security.

  9. 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…

  10. Design and synthesis of peptide YY analogues with c-terminal backbone amide-to-ester modifications

    DEFF Research Database (Denmark)

    Albertsen, Louise; Andersen, J.J.; Paulsson, J.F.;

    2013-01-01

    Peptide YY (PYY) is a gut hormone that activates the G protein-coupled neuropeptide Y (NPY) receptors, and because of its appetite reducing actions, it is evaluated as an antiobesity drug candidate. The C-terminal tail of PYY is crucial for activation of the NPY receptors. Here, we describe...... the design and preparation of a series of PYY(3-36) depsipeptide analogues, in which backbone amide-to-ester modifications were systematically introduced in the C-terminal. Functional NPY receptor assays and circular dichroism revealed that the ψ(CONH) bonds at positions 30-31 and 33-34 are particularly...

  11. Synthesis and biological activity of ester derivatives of mycophenolic acid and acridines/acridones as potential immunosuppressive agents.

    Science.gov (United States)

    Cholewinski, Grzegorz; Iwaszkiewicz-Grzes, Dorota; Trzonkowski, Piotr; Dzierzbicka, Krystyna

    2016-12-01

    Improved derivatives of mycophenolic acid (MPA) are necessary to reduce the frequency of adverse effects, this drug exerts in treated patients. In this study, MPA was coupled with N-(ω-hydroxyalkyl)-9-acridone-4-carboxamides or N-(ω-hydroxyalkyl)acridine-4-carboxamides to give respective ester conjugates upon Yamaguchi protocol. This esterification required protection of phenol group in MPA. Designed conjugates revealed higher potency in vitro than parent MPA. Acridine derivatives were more active than acridone analogs and length of the alkyl linker between MPA and heterocyclic units influenced the observed cytotoxicity. Derivatives 2b, 2d, 3a, 3b displayed the most promising immunosuppressive activity.

  12. Enzyme-catalyzed Transesterification of Unusual Substrate: Synthesis of Acyclovir and L-ascorbic Acid (Vitamin C) Vinyl Esters

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The synthesis of acyclovir and L-ascorbic acid with divinyladipate was performed with alkaline protease from Bacillus subtilis and lipase from Lipozyme (immobilized from Mucor miehei) in different anhydrous organic solvents. Two corresponding derivatives were obtained.

  13. Synthesis of Wax Esters by Lipase-catalyzed Esterification with Immobilized Lipase from Candida sp. 99-125

    Institute of Scientific and Technical Information of China (English)

    邓利; 王晓静; 聂开立; 王芳; 刘军峰; 王璞; 谭天伟

    2011-01-01

    Wax esters were synthesized in a solvent free system catalyzed by immobilized lipase from Candida sp. 99-125, with oleic acid and cetyl alcohol. The effects of substrate molar ratio, lipase dosage and water removal were investigated in a 50 ml flask incubated in a thermostatic cultivation cabinet. The optimized conditions were: temperature 40 ℃, shaking at 170 r·min-1, acid/alcohol molar ratio 1:0.9, lipase dosage in 10% (by mass) of oleic acid, and open reaction for water removal. As a result, the conversion rate reached 98% for reaction of 8 h. The volume of reactor was scaled up to 1 L three-neck flask. The optimized parameters were: 200 r·min-1 agitation speed, 2.5% (by mass) lipase dosage, others were the same as the parameters described above. The conversion rate reached 95% for reaction of 24 h. The lipase retained 46% conversion rate after reuse for 6, 7 batches. The products were purified by removing remained cetyl alcohol and fatty acids with ethanol and saturated sodium carbonate so-lution, respectively. The purity of the wax ester, cetyl oleate, was 96%. The physical and chemical properties of cetyl oleate were tested and compared with those of jojoba oil. The results show that the product cetyl oleate has great potential to use as the substitute of natural jojoba oil.

  14. 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.

  15. Ultrasound in fatty acid chemistry: synthesis of a 1-pyrroline fatty acid ester isomer from methyl ricinoleate.

    Science.gov (United States)

    Lie Ken Jie, M S; Syed-Rahmatullah, M S; Lam, C K; Kalluri, P

    1994-12-01

    A novel 1-pyrroline fatty acid ester isomer (viz. 8-5-hexyl-1-pyrrolin-2-yl) octanoate) has been synthesized from methyl ricinoleate by two routes with an overall yield of 42 and 30%, respectively. Most of the reactions are carried out under concomitant ultrasonic irradiation (20 KHz, ca. 53 watts/cm2). Under such a reaction condition, the reaction time is considerably shortened, and product yields are high. Dehydrobromination under concomitant ultrasonic irradiation of methyl 9, 10-dibromo-12-hydroxyoctadecanoate with KOH in EtOH furnishes methyl 12-hydroxy-9-octadecynoate (66%) within 15 min. Hydration of the latter under ultrasound with mercury(II)acetate in aqueous tetrahydrofuran yields exclusively methyl 12-hydroxy-9-oxo-octadecanoate (95%) in 30 min. The hydroxy group in the latter compound is transformed to the azido function via the mesylate, and treatment of the azido-oxo intermediate (methyl 12-azido-9-oxooctadecanoate) with Ph3P under ultrasonic irradiation furnishes the requisite 1-pyrroline fatty acid ester (77%). The same azido-oxo intermediate has also been obtained by the oxidation of methyl 12-azido-9-cis-octadecenoate using benzoquinone and a catalytic amount of Pd(II)chloride in aqueous tetrahydrofuran under concomitant ultrasonic irradiation (90 min) to give the product in 45% yield. The latter reaction does not take place even under prolonged silent stirring of the reaction mixture.

  16. 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.

  17. Highly efficient synthesis of β-amino esters via Mannich-type reaction under solvent-free conditions using ZnCl2 catalyst

    Institute of Scientific and Technical Information of China (English)

    Xue Ming Chen; Xing Shu Li; Albert S.C. Chan

    2009-01-01

    β-Amino esters were synthesized via ZnCl2-catalyzed Mannich-type reaction of imines and malonate esters under solvent-free conditions in 6 min.The β-amino ester was converted into the corresponding aspartic acid derivatives.

  18. Production and Optimization of Oleic Acid Ethyl Ester Synthesis Using Lipase From Rice Bran (Oryza sativa L. and Germinated Jatropha Seeds (Jatropha curcas L. by Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Indro Prastowo

    2015-11-01

    Full Text Available Normal 0 false false false MicrosoftInternetExplorer4 Recently, the fatty acid ethyl ester has been synthesized in place of fatty acid methyl ester since ethanol has been more renewable. In this research, oleic acid ethyl ester (OAEE was synthesized using germinated jatropha seeds (Jatropha curcas.L and rice bran (Oryza sativa as source of lipase. The objective of the research was to optimize the synthesis conditions using Response Surface Methodology. Factors, such as crude enzyme concentration, molar ratio of oleic acid to ethanol, and the reaction time, were evaluated. The results show that lipase from germinated jatropha seeds had the hydrolitic and esterifi cation activity about 6.73 U/g and 298.07 U/g, respectively. Lipase from rice bran had the hydrolitic and esterifi cation activity about 10.57 U/g and 324.03 U/g, respectively. The optimum conditions of esterifi cation reaction using germinated jatropha seed lipase as biocatalyst were crude enzyme concentration of 0.31 g/ml, molar ratio of oleic acid to ethanol of 1 : 1.81, and reaction time of 50.9 min. The optimum conditions of esterifi cation reaction using rice bran lipase were crude enzyme concentration of 0.29 g/ml, molar ratio of oleic acid to ethanol of 1 : 2.05, and reaction time of 58.61 min. The obtained amounts of OAEE were 810.77 μmole and 626.92 μmole for lipases from rice bran and germinated jatropha seed, respectively. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;}

  19. Dehydrogenative Cross-Coupling Reaction between N-Aryl α-Amino Acid Esters and Phenols or Phenol Derivative for Synthesis of α-Aryl α-Amino Acid Esters.

    Science.gov (United States)

    Salman, Muhammad; Zhu, Zhi-Qiang; Huang, Zhi-Zhen

    2016-04-01

    A novel dehydrogenative cross-coupling (DCC) reaction between N-arylglycine esters and phenols or 1,3,5-trimethoxybenzene was developed by copper catalysis using di-tert-butyl peroxide (DTBP) as an oxidant. Under optimized conditions, a range of N-arylglycine esters 1 underwent the DCC reaction smoothly with various phenols 2 or 1,3,5-trimethoxybenzene 4 to give desired α-aryl α -amino acid esters 3 or 5, respectively, with high ortho regioselectivities in a moderate to excellent yield. A possible mechanism involving aromatic electrophilic substitution is proposed.

  20. Synthesis, spectral studies and anti-inflammatory activity of glycolamide esters of niflumic acid as potential prodrugs.

    Science.gov (United States)

    Gadad, Andanappa K; Bhat, Shailija; Tegeli, Varsha S; Redasani, Vivek V

    2002-01-01

    In order to reduce the gastric irritation caused by direct contact mechanism of the carboxylic acid group, a series of glycolamide esters of niflumic acid (CAS 4394-00-7) (1) have been prepared as bio-labile prodrugs by reacting appropriate 2-chloroacetamides with niflumic acid. The required 2-chloroacetamides were obtained by the condensation of chloroacetyl chloride and corresponding amine. Their structures were confirmed by UV, IR and 1H NMR spectra. Selected compounds were evaluated for anti-inflammatory activity in carrageenan induced paw oedema in rats at the doses of 45, 90 and 150 mg/kg b.w. Prodrugs showed comparable anti-inflammatory activity (67.1-79.4%) at 150 mg/kg b.w. with respect to niflumic acid (70.3%) at 45 mg/kg b.w., indicating moderate release of niflumic acid in vivo. The highest activity was observed with diethylamine (4) and pyrrolidine (9) derivatives.

  1. Synthesis and Crystal Structure of 4-(4,6-dimethoxyl -pyrimidin-2-yl)-3-thiourea Carboxylic Acid Methyl Ester

    Institute of Scientific and Technical Information of China (English)

    HUANG Jie; SONG Ji-Rong; REN Ying-Hui; XU Kang-Zhen; MA Hai-Xia

    2006-01-01

    The title compound 4-(4,6-dimethoxylpyrimidin-2-yl)-3-thiourea carboxylic acid methyl ester was synthesized by the reaction of 2-amino-4,6-dimethoxyl pyrimidine, potassium thiocyanate and methyl chloroformate in ethyl acetate. Single crystals suitable for X-ray measurement were obtained by recrystallization with the solvent of dimethyl formamide at the room temperature. The structure was characterized by elemental analysis and IR and determined by X-ray diffraction analysis. Crystallographic data: C9H12N4O4S, Mr = 272.29, monoclinic, space group C2/m with a = 1.6672(3), b = 0.66383(12), c = 1.1617(2) nm, β = 109.275(2)°, V = 1.2136(4) nm3, Dc = 1.490 g/cm3, μ = 0.281 mm-1, F(000) = 568, Z = 4, R1 = 0.0341and wR2 = 0.1042.

  2. Esterification and Chemoselective Synthesis of R-Tetrahydrothiazo-2- thione-4-carboxylic Esters Catalyzed by TiCl4

    Institute of Scientific and Technical Information of China (English)

    SHANG Yan-mei; LI Jing; SONG Zhi-guang; LI Ye-zhi; HUANG Hua-min

    2007-01-01

    A series of esters of R-tetrahydrothiazo-2-thione-4-carboxylic acid[ R-TTCA] was synthesized by direct esterification of R-TTCA with alcohols(CH3OH, C2H5OH, n-C3H7OH, i-C3H7OH, n-C4H9OH, sec-C4H9OH) in the presence of TiCl4 as the catalyst at room temperature without using any other solvent or dehydrant in high yields,91.6%-99.1% for primary alcohols and 55%- 80% for secondary alcohols. The catalyst has a strong chemoselecfive activity for the esterification of primary alcohols with R-TTCA in the presence of secondary alcohols. Owing to high yield, high chemoselectivity, and mild conditions used, this is an efficient method for the esterification of primary alcohols with R-TTCA.

  3. Addition of ester enolates to N-alkyl-2-fluoropyridinium salts: total synthesis of (+/-)-20-deoxycamptothecin and (+)-camptothecin.

    Science.gov (United States)

    Bennasar, M-Lluïsa; Zulaica, Ester; Juan, Cecília; Alonso, Yolanda; Bosch, Joan

    2002-10-18

    Several 4-substituted dihydropyridones or 2-pyridones have been prepared by nucleophilic addition of alpha-(methylsulfanyl)ester enolates to N-alkyl-2-fluoropyridinium salts, followed by acid hydrolysis or oxidation with concomitant hydrolysis, of the intermediate 2-fluoro-1,4-dihydropyridine adducts, respectively. Addition of the enolate derived from isopropyl alpha-(methylsulfanyl)butyrate to N-(quinolylmethyl)-2-fluoropyridinium triflate 21 followed by DDQ treatment gave pyridone 29, from which (+/-)-20-deoxycamptothecin (31), a known precursor of camptothecin, was synthesized by a radical cyclization-desulfurization, with subsequent elaboration of the lactone E ring by chemoselective reduction. A similar sequence starting from the enolate of a chiral 2-hydroxybutyric acid derivative (33) provides access to natural (+)-camptothecin (37).

  4. Cross-linked PEG via degradable phosphate ester bond: synthesis, water-swelling, and application as drug carrier.

    Science.gov (United States)

    Liu, Zhaoxing; Wang, Lei; Bao, Chunyan; Li, Xinxin; Cao, Lei; Dai, Kerong; Zhu, Linyong

    2011-06-13

    A new series of degradable and water-swellable cross-linked PEG phosphoester polymers (CPPs) based on a facile cross-linked reaction between diphosphoesters of polyethylene glycol (P-PEG-P) and diglycidyl ether of polyethylene glycol (E-PEG-E) has been prepared and characterized. The molecular weights and ratios of the prepolymers played an important role for the properties of CPPs polymers, such as mechanical property, swelling, and degradation rates. In the curing process, the glycidyl ether was consumed by both hydroxyl of the phosphoester (P-OH) and hydroxyl generated from the opened glycidyl ethers (C-OH) with the presence of acid, which generated degradable phosphate esters as cross-linked points and ether bonds as the short branches, respectively. Drug entrapment and release test and biological cytotoxicity studies in vitro suggested that the polymers and generated hydrogels have great potential applications in drug delivery system and biological materials.

  5. Chemo-Enzymatic Synthesis of Ester-Linked Docetaxel-Monosaccharide Conjugates as Water-Soluble Prodrugs

    Directory of Open Access Journals (Sweden)

    Naoji Kubota

    2011-08-01

    Full Text Available Three new docetaxel prodrugs, i.e., 7-propionyldocetaxel 3''-O-b-D-glycopyranosides, which contain ester-linked monosaccharides, were synthesized by a chemo-enzymatic procedure involving enzymatic transglycosylations with lactase, b-galactosidase, or b-xylosidase. The water-solubility of 7-propionyldocetaxel 3''-O-b-D-glucopyranoside was 52-fold higher than that of docetaxel. 7-Propionyldocetaxel 3''-O-b-D-glucopyranoside and 7-propionyldocetaxel 3''-O-b-D-xylopyranoside were effectively hydrolyzed by the relevant enzyme(s of human cancer cells to release docetaxel, whereas 7-propionyldocetaxel 3''-O-b-D-galactopyranoside was relatively resistant under similar conditions. 7-Propionyldocetaxel 3''-O-b-D-glucopyranoside and 7-propionyldocetaxel 3''-O-b-D-xylopyranoside showed in vitro cytotoxic activity against human cancer cells, whereas 7-propionyldocetaxel 3''-O-b-D-galactopyranoside exerted low cytotoxicity.

  6. 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.

  7. Synthesis of rod-like bis-ester liquid crystals and their influence on photoelectric properties of liquid crystalline materials

    Institute of Scientific and Technical Information of China (English)

    Min Yan Zheng; Yong Sheng Wei; Zhong Wei An; Shan Wang

    2009-01-01

    Six novel rod-like magnetic liquid crystals have been prepared,in which trans-bicyclobexyl or trans-cyclobexylphenyl and biphenylcarboxylic acid phenyl ester mesogenic cores with n-propyl and n-pentyl substituents were terminated by 4-hydroxylTEMPO (TEMPO = 2,2,6,6-tetramethylpiperidine-l-oxy).Their structures were confirmed by elemental analysis,IR and MS.Determined by SQUID,EPR,DSC and HS-POM (heat stage polarizing optical microscope),the six compounds all have both magnetic and liquid crystalline properties; their temperature ranges of mesophase were from 16.0 to 24.8 ~C,and the magnetic liquid crystal molecules could obviously improve the response sensitivity of liquid crystal materials.

  8. Synthesis, characterization and superoxide dismutase activity of bi-copper(II)-bisacetato-−phthalicacid[bis(benzyloxy)ethyl]ester

    Indian Academy of Sciences (India)

    Babita Sarma; Pradip K Bhattacharyya; Diganta Kumar Das

    2015-03-01

    A new binuclear copper(II) complex, bridged by the ligand phthalicacid[bis(benzyloxy)ethyl]ester, where each copper(II) is coordinated to one carboxylate (from ligand) and one acetate in square planar mode is reported. The ligand synthesized by the reaction of phthalic anhydride and ethylene glycol, has been characterized by FT-IR, 1HNMR and LCMS. The binuclear Copper(II) complex has been characterized by UV/visible spectra, FTIR spectra, EPR spectra, ESI-MS spectra, magnetic moment measurement and thermogravimetric analysis. DFT calculation has shown a Z type structure for the complex. Excellent superoxide dismutase activity with IC50 value 8.6 × 10−6 M for the complex has been observed.

  9. Synthesis and mesomorphism of mixed ether-ester tail triphenylene discotic liquid crystals with long alkyloxy peripheral chains

    Institute of Scientific and Technical Information of China (English)

    Biqin WANG; Caiyan GAO; Keqing ZHAO; Ping HU

    2009-01-01

    Symmetrical and asymmetrical triphenylene discotic liquid crystals with two kinds of different peripheral chains, .sym-TP(OC11H23)3(O2CR)3 and asym-TP(OC11H23)3(O2CR)3, (R = CH2OC2H5,CH2OC3H7, CH2OC4H9, CH2OC5H11, C3H7, C4H9, C5H11, C6H13, C7H15) were synthesized. Their thermotropic liquid crystalline properties were studied by polarizing optical microscopy (POM) and differential scanning calorimetry (DSC). The results showed that the asymmetrical compounds had higher melting and clearing points than that of their corresponding symmetrical compounds. For the same series of compounds, TP(OC11H23)3(O2CR)3, their melting points decrease and clearing points increase gradually with the lengthening of ester chains. Most of the β-oxygen containing esters of triphenylene derivatives, TP (OC11H23)3(O2CR)3, (R = CH2OC2H5, CH2OC3H7, CH2OC4H9, CH2OC5H11), symmetrically or asymmetrically attached on triphenylene cores, have higher melting and clearing points than those of triphenylene derivatives, TPCOC11H23)3(O2CR)3, (R= C4H9, C5HU, C6H13, C7H15), with the same length of peripheral chains. The triphenylene derivatives with longer peripheral chains have shown mesophase at room temperature.

  10. 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

    OpenAIRE

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

    2010-01-01

    Boron oxide adsorbed on alumina (B2O3/Al2O3 ) 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 cat...

  11. A facile synthesis of novel optically active R,R-2-(4-(2-(4-(5-chloro-3-halo-pyridin-2-yloxy)-phenoxy)-propionyloxy)-phenoxy)-propionic acid esters using cyanuric chloride as potential herbicide

    Institute of Scientific and Technical Information of China (English)

    Hassan Tajik; Akbar Dadras; Shokufeh Aghabeygi

    2011-01-01

    A facile method for the synthesis of a new series of R,R-2-(4-(2-(4-(5-chloro-3-halopyridin-2-yloxy)-phenoxy)-propionyloxy)-phenoxy)-propionic acid ester derivatives containing a halo-substituted pyridine carrying two R,R chiral centers from (R)-2-(4-hydroxyphenoxy)propionic acid, halopyridines and alcohols using base/cyanuric chloride/catalyst system is reported. Their herbicidal activities against grass weeds and crops selectivity were evaluated.

  12. Synthesis of the [beta]-D-glucosyl ester of [carbonyl-[sup 13]C]-indole-3-acetic acid

    Energy Technology Data Exchange (ETDEWEB)

    Jakas, A.; Magnus, V. (Rudjer Boskovic Inst., Zagreb (Croatia)); Horvat, S.; Sandberg, G. (Swedish Univ. of Agricultural Sciences, Uppsala (Sweden))

    1993-10-01

    An efficient, operationally simple synthetic approach to 1-O-([carbonyl-[sup 13]C]-indole-3'-ylacetyl)-[beta]-D-glucopyranose is described. The synthesis was carried out by fusing a fully benzylated 1-O-glucosylpseudourea intermediate with [carbonyl-[sup 13]C]-indole-3-acetic acid, followed by hydrogenolytic removal of the protective groups. (Author).

  13. An Enantio‐ and Diastereoselective Chemoenzymatic Synthesis of α‐Fluoro β‐Hydroxy Carboxylic Esters

    OpenAIRE

    Howard, JK; Muller, M; A. Berry; A. Nelson

    2016-01-01

    Abstract The trans‐o‐hydroxybenzylidene pyruvate aldolase‐catalysed reactions between fluoropyruvate and many (hetero)aromatic aldehydes yield aldol adducts without subsequent dehydration. Treatment of the reaction products with hydrogen peroxide yields the corresponding syn‐configured α‐fluoro β‐hydroxy carboxylic acids which have >98 % ee. The overall chemoenzymatic approach, in which fluoropyruvate serves as a fluoroacetate equivalent, may be exploited in the synthesis of polar building bl...

  14. Synthesis, Spectroscopic Properties and Structural Characterization of Tri(o-chlorobenzyl)tin Ester of 4-Pyridinecarboxylic Acid

    Institute of Scientific and Technical Information of China (English)

    尹汉东; 王其宝; 薛绳才

    2005-01-01

    The title complex, tri(o-chlorobenzyl)tin ester of 4-pyridinecarboxylic acid, has been synthesized by the reaction of bis[tri(2-chlorobenzyl)tin] oxide with 4-pyridinyl carboxylic acid and characterized by elemental analysis, IR and 1H NMR, and its crystal structure was determined by X-ray single-crystal diffraction. The crystal belongs to triclinic, space group P21/n with a = 8.821(7), b = 18.888(15), c = 15.333(12) (A), β= 92.390(12)°, Z = 4, V = 2552(3) (A)3, Dc = 1.607 g/cm3, μ = 1.340 mm-1, F(000) = 1232, R = 0.0408 and wR = 0.0962. In the molecular structure of the title complex, the tin atoms are five-coordinated into a trigonal bipyramidal geometry by coordinating to the intermolecular pyridine N atoms of carboxylate groups. The resulting structure is a one-dimensional linear polymer containing Sn-O (2.150(4) (A)) and Sn-N (2.522(4) (A)) bonds.

  15. Electrospun biodegradable calcium containing poly(ester-urethane)urea: synthesis, fabrication, in vitro degradation, and biocompatibility evaluation.

    Science.gov (United States)

    Nair, Priya A; Ramesh, P

    2013-07-01

    In this work an in vitro degradable poly(ester-urethane)urea (PEUU) was synthesized using polycaprolactone diol, hexamethylene diisocyanate, and calcium salt of p-aminobenzoic acid. The synthesized polymer was characterized by (1) H-NMR and FTIR spectroscopy and viscosity studies. Scaffolds having random micro fibrous structures were fabricated from PEUU by electrospinning process. The thermal properties of the scaffold were evaluated by thermogravimetric analysis and dynamic mechanical analysis. The mechanical property evaluation showed that the scaffold possess sufficiently high tensile strength of 16 MPa. The in vitro degradation studies of the electrospun scaffold were carried out in phosphate buffer saline for 6 months. The average mass loss of the scaffold after 6 months of hydrolytic degradation was 25%. FTIR spectroscopy study confirmed the degradation of the PEUU from decrease in intensity of 1400 cm(-1) peak corresponding to ionic carboxylate group. Presence of amine group and calcium ions in the degradation medium further confirmed the degradation of the hard segment in the hydrolytic medium. The mechanical property evaluation of the scaffold indicated a gradual decrease in tensile strength and modulus whereas percentage elongation of the scaffold increases with time of in vitro degradation. The morphological evaluation of the scaffold after degradation by SEM shows evidence of broken fibers and pores in the scaffold. Preliminary in vitro cytotoxicity test demonstrated that both the material and the degradation products were noncytotoxic in nature and the material showed good proliferation to L-929 cells.

  16. Two-step synthesis of fatty acid ethyl ester from soybean oil catalyzed by Yarrowia lipolytica lipase

    Directory of Open Access Journals (Sweden)

    Chen Jinnan

    2011-03-01

    Full Text Available Abstract Background Enzymatic biodiesel production by transesterification in solvent media has been investigated intensively, but glycerol, as a by-product, could block the immobilized enzyme and excess n-hexane, as a solution aid, would reduce the productivity of the enzyme. Esterification, a solvent-free and no-glycerol-release system for biodiesel production, has been developed, and two-step catalysis of soybean oil, hydrolysis followed by esterification, with Yarrowia lipolytica lipase is reported in this paper. Results First, soybean oil was hydrolyzed at 40°C by 100 U of lipase broth per 1 g of oil with approximately 30% to 60% (vol/vol water. The free fatty acid (FFA distilled from this hydrolysis mixture was used for the esterification of FFA to fatty acid ethyl ester by immobilized lipase. A mixture of 2.82 g of FFA and equimolar ethanol (addition in three steps were shaken at 30°C with 18 U of lipase per 1 gram of FFA. The degree of esterification reached 85% after 3 hours. The lipase membranes were taken out, dehydrated and subjected to fresh esterification so that over 82% of esterification was maintained, even though the esterification was repeated every 3 hours for 25 batches. Conclusion The two-step enzymatic process without glycerol released and solvent-free demonstrated higher efficiency and safety than enzymatic transesterification, which seems very promising for lipase-catalyzed, large-scale production of biodiesel, especially from high acid value waste oil.

  17. Synthesis, Crystal Structure and Inhibition of N-2-Thiophenesulfonyl-α-L-phenylalanine Ethyl Ester on K562 Cell Proliferation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The title compound N-2-thiophenesulfonyl-α-L-phenylalanine ethyl ester has been synthesized. Complete assignments were achieved by IR, MS, 1H NMR and single-crystal X-ray diffraction analyses. Using MTT assay, the inhibitory rate of the title compound on K562 cells (chronic myeloid 1eukemic cells) was measured and the result of preliminary bioassay showed that the title compound possesses antiproliferation effects on K562 cells. In order to investigate the relationship between structure and activity of the target compound, we report its crystal structure and biological behavior in the present paper. Crystallographic data: C15H17NO4S2, Mr = 339.42, monoclinic, space group P21, flack = -0.15(12), a = 5.7916(10), b = 11.5078(19), c = 12.924(2) (A), β = 97.781(3)°, Z = 2, V = 853.4(2) (A)3, Dc = 1.321 g/cm3, F(000) = 356, -7≤h≤7, -10≤k≤14, -15≤l≤15, R = 0.0628, wR = 0.1540 and μ(MoKα) = 0.327 mm-1. The molecule comprises a benzene and a thiofuran rings, and the intramolecular N(1)-H(1A)…O(1) makes a five-membered ring of O(1)-C(6)-C(5)-N(1)-H(1A).

  18. 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.

  19. Synthesis of High Performance Cyclic Olefin Polymers (COPs with Ester Group via Ring-Opening Metathesis Polymerization

    Directory of Open Access Journals (Sweden)

    Jing Cui

    2015-08-01

    Full Text Available Novel ester group functionalized cyclic olefin polymers (COPs with high glass transition temperature, high transparency, good mechanical performance and excellent film forming ability have been achieved in this work via efficient ring-opening metathesis copolymerization of exo-1,4,4a,9,9a,10-hexahydro-9,10(1′,2′-benzeno-l,4-methanoanthracene (HBM and comonomers (5-norbornene-2-yl methylacetate (NMA, 5-norbornene-2-yl methyl 2-ethylhexanoate (NME or 5-norbornene-2-yl methyldodecanoate (NMD utilizing the Grubbs first generation catalyst, Ru(CHPh(Cl2(PCy32 (Cy = cyclohexyl, G1, followed by hydrogenation of double bonds in the main chain. The fully hydrogenated copolymers were characterized by nuclear magnetic resonance, FT-IR spectroscopy analysis, gel permeation chromatography, and thermo gravimetric analysis. Differential scanning calorimetry curves showed that the glass transition temperatures (Tg linearly decreased with the increasing of comonomers content, which was easily controlled by changing feed ratios of HBM and comonomers. Static water contact angles tests indicate that hydrophilicity of copolymers can also be modulated by changing the comonomers incorporation. Additionally, the mechanical performances of copolymers were also investigated.

  20. Synthesis and Evaluation of Molecularly Imprinted Polymer for the Determination of the Phthalate Esters in the Bottled Beverages by HPLC

    Directory of Open Access Journals (Sweden)

    Ya-Feng Jin

    2013-01-01

    Full Text Available A molecularly imprinted polymer (MIP was prepared in acetonitrile by bulk polymerization, using di-n-octylphthalate (DOP as a template molecular, α-methacrylic acid (MAA as a functional monomer, and ethylene dimethacrylate (EDMA as a crosslinker. Characterization and evaluation of the prepared MIP were carried out by scanning electron microscope (SEM, infrared absorption spectroscopy (IR, and the Scatchard analysis, respectively. Through the optimization of washing solvent, eluting solvent amount, flow rate of loading solution, and loading sample volume, an analysis method was established for DOP related compounds with high selectivity and sensitivity by using the selective molecularly imprinted solid-phase extraction (MI-SPE technique. Moreover, under the optimal conditions, the extraction effects were comparatively investigated by using MIP cartridge, NIP cartridge, and the commercial PLS cartridge used especially for phthalic acid esters (PAEs, respectively. The results showed that the recoveries of spiked PAEs are in the range of 90.4%–97.8% with the relative standard deviation (RSD of 1.6%–3.8% on the resulted MIP cartridge, whilst lower recoveries were obtained ranging from 80.2% to 88.9% with an RSD of 1.4%–5.2% on the commercial PLS cartridge.

  1. 2-吲哚乙酸乙酯的合成%Synthesis of 2-indoleacetic Acid Ethyl Ester

    Institute of Scientific and Technical Information of China (English)

    陈芬; 覃宇

    2015-01-01

    丙二酸二乙酯在醇溶液中,与氢氧化钾皂化得到丙二酸单乙酯钾盐,然后在N, N'-羰基二咪唑(CDI)作用下,与2-硝基苯乙酸进行亲核加成得到4-(2-硝基苯基)-乙酰乙酸乙酯,再经三氯化钛的催化还原环化制得医药中间体2-吲哚乙酸乙酯,收率达72.2%。%2- indole acetic acid ethyl ester, the important drug intermediate, was synthesized from diethyl malonate by saponification reaction with potassium hydroxide in the presence of alcohol solution to give ethyl malonate potassium salt and nucleophilic addition with 2-nitrophenyl acetic acid to give 4-(2-nitrophenyl)-ethylacetoacetate using N,N'-carbonyldiimidazole(CDI), and then reduct cyclization reaction upon the catalysis of titanium trichloride with an overall yield of about 72.2%.

  2. 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.

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

    Science.gov (United States)

    Raghavendra, Tripti; Panchal, Nilam; Divecha, Jyoti; Shah, Amita; Madamwar, Datta

    2014-01-01

    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-(ethylhexyl)sulfosuccinate (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. PMID:25093166

  4. L-天门冬氨酸-β-苄酯的制备研究%Synthesis and characterization of L-aspartic acid-β-benzyl ester

    Institute of Scientific and Technical Information of China (English)

    王昌济; 王永秋

    2013-01-01

    L-aspartic acid and benzyl alcohol as raw materials, studied on the synthesis of L-aspartic acid-/3-benzyl ester. The results showed that the best experimental conditions was; the concentrated sulfuric acid as catalyst,n (L-aspartic acid) : n (benzyl alcohol) = 1 : 10,100℃ reflux reaction 3 h,placed at room temperature 24 h, in this condition, the yield was about 60% .%以L-天门冬氨酸和苯甲醇为原料,对L-天门冬氨酸-β-苄酯的合成进行了研究.结果表明,较佳实验条件是:以浓硫酸为催化剂,n(L-天门冬氨酸)∶n(苯甲醇)=1∶10,100℃回流反应3h,室温放置24h,在该条件下,产率约60%.

  5. 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.

  6. Real-Time monitoring of intracellular wax ester metabolism

    Directory of Open Access Journals (Sweden)

    Karp Matti

    2011-09-01

    Full Text Available Abstract Background Wax esters are industrially relevant molecules exploited in several applications of oleochemistry and food industry. At the moment, the production processes mostly rely on chemical synthesis from rather expensive starting materials, and therefore solutions are sought from biotechnology. Bacterial wax esters are attractive alternatives, and especially the wax ester metabolism of Acinetobacter sp. has been extensively studied. However, the lack of suitable tools for rapid and simple monitoring of wax ester metabolism in vivo has partly restricted the screening and analyses of potential hosts and optimal conditions. Results Based on sensitive and specific detection of intracellular long-chain aldehydes, specific intermediates of wax ester synthesis, bacterial luciferase (LuxAB was exploited in studying the wax ester metabolism in Acinetobacter baylyi ADP1. Luminescence was detected in the cultivation of the strain producing wax esters, and the changes in signal levels could be linked to corresponding cell growth and wax ester synthesis phases. Conclusions The monitoring system showed correlation between wax ester synthesis pattern and luminescent signal. The system shows potential for real-time screening purposes and studies on bacterial wax esters, revealing new aspects to dynamics and role of wax ester metabolism in bacteria.

  7. Stereoselective synthesis of 2α-Chloropicropodophyllotoxins and insecticidal activity of their esters against oriental armyworm, Mythimna separata walker.

    Science.gov (United States)

    Fan, Lingling; Guo, Yong; Zhi, Xiaoyan; Yu, Xiang; Xu, Hui

    2014-04-30

    As part of ongoing efforts to discover new natural-product-based insecticidal agents, in the present study, an efficient method for the stereoselective α-chlorination at the C-2 position of 2'(2',6')-(di)halogenopodophyllotoxin derivatives was first developed. Subsequently, a series of novel esters of 2α-chloro-2'(2',6')-(di)halogenopicropodophyllotoxin with modified C, D, and E rings of podophyllotoxin were smoothly obtained. Finally, all of the title compounds were tested against the pre-third-instar larvae of oriental armyworm (Mythimna separata Walker) at 1 mg/mL. It was found that besides their 2'-halogen-substituted E ring, the stereoselective α-chlorination at the C-2 position of 2'(2',6')-(di)halogenopodophyllotoxins was also related to the chlorination reagents. Especially 2α-chloro-4α-(benzoyl)oxy-2'-chloropicropodophyllotoxin (6e) and 2α-chloro-4α-(2-chlorophenylacyl)oxy-2'-bromopicropodophyllotoxin (8f) showed the most potent insecticidal activities, with final mortality rates of >60%. For 4α-(alkylacyl)oxy derivatives of 2α-chloro-2'(2',6')-(di)halogenopicropodophyllotoxin, the effect of the length of their side chain at the C-4 position of podophyllotoxin skeleton on the insecticidal activity was not very obvious. For 4α-(arylacyl)oxy derivatives of 2α-chloro-2'-chloro/bromopicropodophyllotoxin, an electronic effect of the substituents on their phenyl ring at the C-4 position of podophyllotoxin skeleton on the insecticidal activity was observed.

  8. 微波协同树脂催化合成酯类化合物的研究进展%Research advance in microwave assisted synthesis of esters catalysized by resin

    Institute of Scientific and Technical Information of China (English)

    李忠军; 黎彧; 黄利; 方楚生; 周丽琴; 彭志; 赖志彬

    2011-01-01

    Esters are important fine chemicals which are widely used in perfume, antiseptic, antioxidant, plastic and medicine, etc. The microwave assisted synthesis of esters catalysized by resin have the advantages such as less time, efficiency, low energy consumption and safety compared with the traditional process. This article reviewed the research progress of microwave assisted synthesis of esters catalysized by resin and its future development.%酯类是重要的精细化学品,广泛用于香料、防腐剂、抗氧剂、塑料及药物等方面.传统方法合成酯类具有反应时间长、产率低、污染大及后处理困难等缺点,微波协同树脂催化合成酯类具有反应快、高效、能耗低及安全等优点.该文综述了微波协同树脂催化合成酯类的研究进展,并展望该方法在酯类合成中的发展前景.

  9. Improvement of synthesis of vegetable oil methyl ester%植物油甲酯的合成工艺改进

    Institute of Scientific and Technical Information of China (English)

    周丽平; 洪永德; 徐维锋; 吴文忠

    2014-01-01

    The synthesis process of vegetable oil methyl ester was improved so as to increase the conver-sion rate and yield of vegetable oil methyl ester. The synergistic effect of shearer introduced to the trans-esterification was investigated, and the shortest reaction time was determined. The feasibility of sulfuric acid-catalyzed esterification of fatty acid saponifiable matter to improve the separation efficiency and yield was also researched. The results showed that the transesterification efficiency of the improved process increased greatly. The contents of monoglycerides, diglycerides and triglycerides were less than 0. 5%, 1% and undetectable respectively only in 5 min with laboratory device, and the conversion rate reached 99. 1%. The fatty acid saponifiable matter, the by-product in the reaction was neutralized by sulfuric acid and then esterified with methanol, the shortest reaction time was 1 h, and the acid value of the product was below 0. 8 mgKOH/g. Since emulsification effect caused by the fatty acid saponifiable matter was eliminated, the quick separation of oil and water was realized, and all the by-products trans-formed to fatty acid methyl ester, so the yield of the product reached 99. 5%. All the raw materials were industrial grade with low cost and wide selection of raw oils.%为了提高植物油甲酯的转化率和收率,对植物油甲酯的合成工艺进行了改进。考察了酯交换反应中引入剪切机的增效作用,确定了最短反应时间;并考察了硫酸催化副产物脂肪酸皂化物酯化来提高分离效率和收率的可行性。结果表明:经过改进的工艺,酯交换反应效率得到了大幅提高,实验室装置下只需5 min就可以达到单甘酯含量小于0.5%,二甘酯含量小于1%,三甘酯含量未检出的水平,甲酯转化率达到99.1%;反应生成的副产物脂肪酸皂化物被硫酸中和后与甲醇发生酯化反应,最短反应时间为1 h,产品酸值(KOH)小于0.8 mg/g;由于消除

  10. Synthesis of Palm Acide Polyol Esters Catalyzed by Acidic Ionic Liquid%酸性离子液体催化合成棕榈油酸多元醇酯

    Institute of Scientific and Technical Information of China (English)

    牛玉莲; 邢宝妹; 陆杨; 李在均; 刘俊康; 黄路

    2011-01-01

    laboratory, their conversions were 94.6% , 94.5% , 97.0% , 98.5% and 99.2%, respectively. After the completion of reaction, the triethylammonium sulfate precipitates and separates from the system with decreasing the temperature. The ionic liquid obtained can be used to subsequent new synthesis of palm acide polyol ester. The physicochemical properties of fivepalm acide polyol esters were investigated, the results exhibited these are of excellent fluid and low temperature characteristics, their viscosity index and pour point were in the range of 184 ~ 388 and - 23 ~- 40 ℃ respectively, the data confirm palm acide polyol ester can be used as base oil of biodegradable lubricant.

  11. 麦芽糊精硬脂酸酯的酶法合成及其乳化性的研究%Lipase-Catalyzed Synthesis and Emulsification of Dextrin Ester

    Institute of Scientific and Technical Information of China (English)

    孙平; 杨惠娟; 王雅琦; 刘可志; 徐雅雯

    2013-01-01

    研究了麦芽糊精硬脂酸酯的酶法合成工艺及其性能,对该工艺的影响因素进行单因素及正交试验.所确定的较佳工艺条件为:硬脂酸与糊精质量比为4∶1,酶添加量为7g/L,反应温度65℃,反应时间60 h,并研究了其结构与乳化性能.结果表明:乳液的乳化性随糖酯的质量分数增加而增加.在相同质量分数下,麦芽糊精硬脂酸酯乳化性最好,高于麦芽糖脂肪酸酯以及淀粉脂肪酸酯.%In this paper,the process of enzymatic catalysis for the synthesis of dextrin ester was investigated. The single factor and the orthogonal experiments for the affecting factors of this technology were carried out. Under the optimum conditions of 7 g/L lipase from Novozym 435, and acid/dextrin molar ratio of 4:1 at 65 t for 60 h,the optimum process was achieved. The results showed that:the emulsification increased with the concentration of dextrin esters. At the same concentration, the emulsification of the dextrin ester is higher than that of maltose ester and starch ester.

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

    Science.gov (United States)

    Dohme-Meier, F; Bee, G

    2012-01-01

    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 implies that

  13. One-Pot Synthesis of Pyrrolo[1,2-a]indoles by Chiral N-Triflyl Phosphoramide Catalyzed Friedel-Crafts Alkylation of 4,7-Dihydroindole with ②, y-Unsaturated a-Keto Esters

    Institute of Scientific and Technical Information of China (English)

    曾蜜; 张玮; 游书力

    2012-01-01

    Chiral N-triflyl phosphoramide was found an efficient catalyst for the enantioselective Friedel-Crafts alkylation reaction of 4,7-dihydroindole with β, γ-unsaturated a-keto esters. In the presence of 5 tool% of the optimized catalyst, various pyrrolo[1,2-a]indoles were obtained in excellent enantioselectivity, moderate yields and up to 3 : 1 di- astereoselectivity based on the one-pot synthesis including the Friedel-Crafts alkylation reaction and the subsequent p-benzoquinone oxidation.

  14. 酯类与酮类烟用香料的化学合成与加香应用研究进展%Research Progress on Chemical Synthesis and Application of Esters and Ketones Tobacco Spices

    Institute of Scientific and Technical Information of China (English)

    娄本; 刘善宇

    2012-01-01

    低焦油卷烟的发展要求得到足够的香味补偿.化学合成香料因价格低廉、易于得到而受到重视.对酯类和酮类烟用香料的化学合成与加香应用进行了综述.%Development of low-tar cigarette requires for adequate smell as compensation. Chemical synthetic spices have received much attention because of their low price and easy to get. The chemical synthesis and application of the esters and ketones spices were reviewed.

  15. The effect of the sterol oxygen function on the interaction with phospholipids

    NARCIS (Netherlands)

    Demel, R.A.; Lala, A.K.; Kumari, S.N.; Deenen, L.L.M. van

    1984-01-01

    The effect of cholesteryl ethers (namely cholesteryl methyl ether, cholesteryl ethyl ether, cholesteryl n-propyl ether, cholesteryl isopropyl ether, cholesteryl butyl ether, cholesteryl methoxymethyl ether, cholesteryl (2′-hydroxy)-3-ethyl ether) and cholesteryl ester (namely cholesteryl acetate) is

  16. Synthesis and Crystal Structure of a Sodium Monosulfuron-ester (N-[2'-(4-Methyl)pyrimidinyl]-2-carbomethoxy Benzyl Sulfonylurea Sodium)

    Institute of Scientific and Technical Information of China (English)

    KOU Jun-Jie; LI Zheng-Ming; SONG Hai-Bin

    2006-01-01

    Monosulfuron-ester is a novel sulfonylurea herbicide with ultra-low dosage. Herein sodium monosulfuron-ester was synthesized and its crystal structure was determined by X-ray diffraction method. The title compound belongs to monoclinic, space group P21/c with a = 9.335(5), b = 20.632(12), c = 13.853(8) (A), β = 107.193(9)°, Mr = 487.46, Z = 4, Dc = 1.270 g/cm3, μ = 0.293 mm-1, F(000) = 1015, R = 0.0859 and wR = 0.2633. In the title compound, Na coordinates with N(1), O(1) and O(3) from one monosulfuron-ester molecule, N(4A) and O(5A) from the other monosulfuron-ester molecule and one oxygen atom from DMSO to give six coordination bonds.

  17. CHEMOTHERAPEUTIC POLYMERS ⅩⅩⅢ SYNTHESIS AND ANTITUMOR ACTIVITY OF POLYPHOSPHATES CONTAINING BOTH NUCLEIC ACID BASE AND PHOSPHONOACETIC ACID ETHYL ESTER

    Institute of Scientific and Technical Information of China (English)

    ZHUO Renxi; LIU Zhenghua; LI Li

    1989-01-01

    Eight new polyphosphates containing both nucleic acid base and phosphonoacetic acid ethyl ester were synthesized by the polycondensation of P, P- dichloride of phosphonoacetic acid ethyl ester with 1, 3-dihydroxyalkyl - 5 - fluorouracil, 1,3 - dihydroxyalkyl - uracil and 1, 3 - dihydroxyalkylthymine. These polyphosphates were tested against Ehrlich Ascites Carcinoma in mice. Polymer Ⅱa and Ⅱc exhibited excellent antitumor activity. Ⅱc also showed lower toxicity.

  18. Hybrid scorpionate/cyclopentadienyl magnesium and zinc complexes: synthesis, coordination chemistry, and ring-opening polymerization studies on cyclic esters.

    Science.gov (United States)

    Garcés, Andrés; Sánchez-Barba, Luis F; Alonso-Moreno, Carlos; Fajardo, Mariano; Fernández-Baeza, Juan; Otero, Antonio; Lara-Sánchez, Agustín; López-Solera, Isabel; Rodríguez, Ana María

    2010-03-15

    The reaction of the hybrid scorpionate/cyclopentadienyl lithium salt [Li(bpzcp)(THF)] [bpzcp = 2,2-bis(3,5-dimethylpyrazol-1-yl)-1,1-diphenylethylcyclopentadienyl] with 1 equiv of RMgCl proceeds cleanly to give very high yields of the corresponding monoalkyl kappa(2)-NN-eta(5)-C(5)H(4) magnesium complexes [Mg(R)(kappa(2)-eta(5)-bpzcp)] (R = Me 1, Et 2, (n)Bu 3, (t)Bu 4, CH(2)SiMe(3) 5, CH(2)Ph 6). Hydrolysis of the hybrid lithium salt [Li(bpzcp)(THF)] with NH(4)Cl/H(2)O in ether cleanly affords the two previously described regioisomers: (bpzcpH) 1-[2,2-bis(3,5-dimethylpyrazol-1-yl)-1,1-diphenylethyl]-1,3-cyclopentadiene (a) and 2-[2,2-bis(3,5-dimethylpyrazol-1-yl)-1,1-diphenylethyl]-1,3-cyclopentadiene (b). Subsequent reaction of the bpzcpH hybrid ligand with ZnR(2) quantitatively yields the monoalkyl kappa(2)-NN-eta(1)(pi)-C(5)H(4) zinc complexes [Zn(R){kappa(2)-eta(1)(pi)-bpzcp}] (R = Me 7, Et 8, (t)Bu 9, CH(2)SiMe(3) 10). Additionally, magnesium alkyls 1, 2, 4, and 5 can act as excellent cyclopentadienyl and alkyl transfers to the zinc metal center and yield zinc alkyls 7-10 in good yields. The single-crystal X-ray structures of the derivatives 4, 5, 7, and 10 confirm a 4-coordinative structure with the metal center in a distorted tetrahedral geometry. Interestingly, whereas alkyl magnesium derivatives 4 and 5 present a eta(5) coordination mode for the cyclopentadienyl fragment, zinc derivatives 7 and 10 feature a peripheral eta(1)(pi) arrangement in the solid state. Furthermore, the reaction of the hybrid lithium salt [Li(bpzcp)(THF)] with 1 equiv of ZnCl(2) in tetrahydrofuran (THF) affords very high yields of the chloride complex [ZnCl{kappa(2)-eta(1)(pi)-bpzcp}] (11). Compound 11 was used as a convenient starting material for the synthesis of the aromatic amide zinc compound [Zn(NH-4-MeC(6)H(4)){kappa(2)-eta(1)(pi)-bpzcp}] (12), by reaction with the corresponding aromatic primary amide lithium salt. Alternatively, aliphatic amide and alkoxide derivatives were

  19. Synthesis and Structure Characterization of Rosin Starch Ester%松香酸淀粉酯的合成与结构表征

    Institute of Scientific and Technical Information of China (English)

    唐世华; 李景权; 覃浩鹏; 杨酉宝; 林宇

    2011-01-01

    In the presence of DMF/LiCl solvent, rosin starch ester with the degree of substitution ( Ds) of 0. 125 2 was synthesized by O-acylation of starch with rosin acid chloride. The target product was analyzed and characterized by means of FT-IR, solid state 13C NMR, XRD and SEM. The reaction conditions were studied with single factor experiments and response surface methodology. A reaction model and the optimum conditions were obained. The optimum synthesis conditions were as follows; reaction time 6.5 h, reaction temperature 95 T , pyridine amount 3. 5 mL, activation time of starch 52. 5 min, DMF 29 mL and molar ratio 1: 1 ( rosin acid chloride/the hydroxyl group per D-glucose unil). Under optimal conditions, the yield of RSE and Ds were 65.89% and 0.1252, respectively. Furthermore, its solubility and diaphaneity were determined. The results showed that compared with the unmodified starch, the crystal liru'ty and diaphaneity of the target product decreased, and its hydrophobicity increased.%以二甲基酰胺( DMF)/LiCl为溶剂,由淀粉与松香酰氯通过O-酰化反应合成了取代度(Ds)为0.1252的松香酸淀粉酯(RSE).利用FT-IR、固体13C NMR、XRD和SEM对目标产物进行了分析和表征,测试了目标产物的溶解性能和透明度.基于单因素试验数据,利用响应面软件优化,建立了教学模型,得出最佳合成条件为:反应时间6.5h,温度95℃,吡啶3.5 mL,活化时间52.5 min,DMF用量29 mL,松香酰氯与葡萄糖单元中羟基物质的量之比1∶1.此条件下得到的RSE产率为65.89%,取代度为0.125 2.结果表明,淀粉经松香酯化改性后,结晶度降低;透明度由原淀粉的99.66%降低为91.67%,疏水性增强.

  20. Synthesis and pharmacological evaluation of some dual-acting amino-alcohol ester derivatives of flurbiprofen and 2-[1,1'-biphenyl-4-yl]acetic acid: a potential approach to reduce local gastrointestinal toxicity.

    Science.gov (United States)

    Halen, Parmeshwari Kuldeep Kumar; Chagti, Kewal Krishna; Giridhar, Rajani; Yadav, Mange Ram

    2006-11-01

    The search for safer non-steroidal anti-inflammatory drugs (NSAIDs) continues with the failure of anticipated 'ideal' anti-inflammatory agents, the coxibs, on long-term usage. Increased gastric motility and acidity due to the free carboxy group are involved in the etiology of gastric toxicity, common to conventional NSAIDs. Keeping this fact in mind, it was planned to modify some of the conventional NSAIDs to amino-alcohol ester derivatives, which satisfied the structural requirements for these compounds to possess anticholinergic activity in the intact form. Besides blocking the acidic carboxylic group, incorporation of anticholinergic acivity in these molecules was expected to reduce the gastric toxicity by decreasing gastric acid secretion and motility. Synthesis and pharmacological evaluation of six different N,N-disubstituted amino-ethyl ester derivatives, structurally resembling the amino-alcohol ester class of anticholinergic agents, each for [1,1'-biphenyl]-4-acetic acid (3) and flurbiprofen (10), have been reported as potential substitutes for these NSAIDs, with improved therapeutic profile. All the ester derivatives were found to have sufficient chemical stability in buffers (pH 2.0 and 7.4), ensuring them to be absorbed as intact moieties from the gastrointestinal tract. A significant reduction in ulcerogenic potency in comparison to the parent drugs with a slightly higher anti-inflammatory potency suggests that the majority of these candidates have an improved therapeutic profile over their parent drugs. Hence, a promising novel approach, different from the conventional prodrug concept, has been successfully worked out to overcome the local gastric toxicity, yielding therapeutically better compounds for long-term oral anti-inflammatory therapy.

  1. 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

  2. Evidence of a drug-drug interaction linked to inhibition of ester hydrolysis by orlistat.

    Science.gov (United States)

    Bentley, Darren; Young, Anne-Marie; Rowell, Lucy; Gross, Günter; Tardio, Joseph; Carlile, David

    2012-10-01

    : Orlistat, a lipase inhibitor taken with meals at doses of 60 mg (available over-the-counter) or 120 mg (prescription only) for treatment of obesity, is known to impair the absorption of fat-soluble molecules. Dalcetrapib, a modulator of cholesteryl ester transfer protein activity, is a lipophilic thioester prodrug. Lipase-induced and pancreatin-induced hydrolysis of dalcetrapib in biorelevant media in vitro was very efficiently inhibited by orlistat. Thus, the potential for orlistat to affect the bioavailability of concomitantly administered dalcetrapib was studied in an open-label 2-cohort study in 24 healthy volunteers as follows: single 600-mg doses of dalcetrapib were administered with increasing doses of orlistat (cohort A: 10, 40, 120 mg; cohort B: 20, 60, 120 mg). Exposure to the active form of dalcetrapib was more than 50% lower when taken with orlistat 60 mg or 120 mg than when taken alone. Similar trends were observed with lower orlistat doses (20 mg and 40 mg). Concomitant administration of orlistat also reduced the pharmacodynamic effects of dalcetrapib treatment on cholesteryl ester transfer protein activity. The interaction exceeds that predicted on the basis of dalcetrapib lipophilicity. These findings demonstrate the potential for large interactions between orlistat and esters that undergo de-esterification in the gastrointestinal tract, independent of lipophilicity.

  3. L-苯丙氨酸苄酯盐酸盐的合成新工艺研究%Research on a New Techonology of Synthesis of L-Phenylalanine Benzyl Ester Hydrochloride

    Institute of Scientific and Technical Information of China (English)

    王玉琴

    2015-01-01

    The paper proposes a new technology line to synthesize L-Phenylalanine benzyl ester hydrochloride. L-Phenyl?alanine benzyl ester hydrochloride is synthesized from L-phenylalalanine via tert-butoxycarbonylation of amino with di-tert-butyl dicarbonate,condensation with benzyl chloride,and deprotection with hydrochloride solution in ethyl acetate. Through the experiments,the effects of such technology conditions as reaction temperatures,ingredients ratios,acid-binding agents and solvents on the synthesis are explored. The experimental results show that under the optimized techonological conditions , the overall yield of target product is 90.8%,and thus a new option is provided for the synthesis of L-Phenylalanine Benzyl Ester Hydrochloride.%提出了L-苯丙氨酸苄酯盐酸盐合成的新工艺路线,以L-苯丙氨酸为起始原料,先用二碳酸二叔丁酯保护氨基,再与氯化苄缩合得到N-叔丁氧羰基-L-苯丙氨酸苄酯,最后用氯化氢脱保护,得到L-苯丙氨酸苄酯盐酸盐.通过实验探索了反应温度、原料配比、缚酸剂以及溶剂种类等工艺条件对合成的影响.实验结果表明,在优化的工艺条件下,合成总收率为90.8%,为L-苯丙氨酸苄酯盐酸盐的合成提供了新选择.

  4. 合成光学活性菊酸酯的方法%Novel Synthesis of Optically Active Chrysanthemic Acid Ester

    Institute of Scientific and Technical Information of China (English)

    李争宁; 陈惠麟

    2000-01-01

    L-Menthanol ester of chiral chrysanthemic acid was obtained via stereoselective esterification of the racemic acid, and the result was analyzed by MOPAC. Promoted by the above phenomenon, we obtained L-menthol ester of chiral chrysanthemic acid via the isomerization of L-menthol ester of racemic chrysanthemic acid.%L-孟醇与过量外消旋菊酰氯反应表现出非对映异构体选择性,得到了光学活性菊酸的L-孟醇酯.由外消旋菊酸的L-孟醇酯经异构化反应也得到了光学活性菊酸的L-孟醇酯.

  5. Rare linking hydrogels based on acrylic acid and carbohydrate esters

    Directory of Open Access Journals (Sweden)

    U. Akhmedov

    2012-09-01

    Full Text Available The process of copolymerization of acrylic acid and esters poliallil sucrose; pentaerythritol and sorbitol, some of its laws are identified. The kinetic regularities of copolymerization and the optimum conditions of synthesis was established.

  6. Synthesis and characterization of 5-(4-hydroxy-3-methoxy-phenyl-3,7-dimethyl-5H-thiazolo[3,2-a]pyrimidine-2,6-dicarboxylic acid 2-ethyl ester 6-methyl ester and its 6-ethyl ester 5-naphthalene derivative

    Directory of Open Access Journals (Sweden)

    H. Nagarajaiah

    2015-11-01

    Full Text Available The compounds 5-(4-hydroxy-3-methoxy-phenyl-3,7-dimethyl-5H-thiazolo[3,2-a]pyrimidine-2,6-dicarboxylic acid 2-ethyl ester 6-methyl ester (2a and 3,7-dimethyl-5-naphthalen-1-yl-5H-thiazolo[3,2-a]pyrimidine-2,6-dicarboxylic acid diethyl ester (2b were synthesized by the base catalyzed cyclocondensation of 3,4-dihydropyrimidine-2-thione with ethylacetoacetate. IR, 1H NMR, 13C NMR spectra and elemental analysis were used to characterize these compounds. The structures were determined by single crystal X-ray diffraction. The crystal structure is stabilized by intermolecular O–H…N, C–H…O, C–H…π and π…π weak interactions.

  7. Ester Prodrugs of Ketoprofen: Synthesis, In Vitro Stability, In Vivo Biological Evaluation and In Silico Comparative Docking Studies Against COX-1 and COX-2.

    Science.gov (United States)

    Ahmed, Musa; Azam, Faizul; Gbaj, Abdul; Zetrini, Abdulmottaleb E; Abodlal, Amna Salem; Rghigh, Abir; Elmahdi, Eman; Hamza, Amel; Salama, Mabruk; Bensaber, Salah M

    2016-01-01

    Prompted by the ineptness of the currently used non-steroidal antiinflammatory drugs (NSAIDs) to control gastric mucosal and renal adverse reactions, several ester prodrugs of ketoprofen were synthesized and characterized by IR, 1H NMR and mass spectral data. Physicochemical properties such as aqueous solubility, octanol-water partition coefficient log P, chemical stability and enzymatic hydrolysis of the synthesized molecules have been studied to assess their potential as prodrugs. The obtained results confirmed that all ester prodrugs are chemically stable, possess increased lipophilicity compared to their parent compounds and converted to the active drugs in vivo. All of the tested ester prodrugs exhibited marked anti-inflammatory activity ranging from 91.8% to 113.3% in comparison with the parent drug, ketoprofen. A mutual prodrug obtained from two antiinflammatory molecules, ketoprofen and salicylic acid has been noted to potentiate the activity making it most active molecule of the series. The ulcerogenic index of the ester prodrugs was significantly lower than the parent drug, ketoprofen. Comparative docking studies against X-ray crystal structures of COX-1 and COX-2 further provided understanding of their interaction with the cyclooxygenases that will facilitate design of better inhibitors (or prodrugs) with sufficient specificity for COX-2 against COX-1. The study offers an innovative strategy for finding a molecule with safer therapeutic profile for longterm treatment of inflammatory diseases.

  8. Synthesis, morphology and properties of segmented poly(ether ester amide)s comprising uniform glycine or β-alanine extended bisoxalamide hard segments

    NARCIS (Netherlands)

    Sijbrandi, N.J.; Kimenai, A.J.; Mes, E.P.C.; Broos, R.; Bar, G.; Rosenthal, M.; Odarchenko, Y.; Ivanov, D.A.; Feijen, J.; Dijkstra, P.J.

    2012-01-01

    Segmented poly(ether ester amide)s comprising glycine or β-alanine extended bisoxalamide hard segments are highly phase separated thermoplastic elastomers with a broad temperature independent rubber plateau. These materials with molecular weights, Mn, exceeding 30 × 103 g mol−1 are conveniently prep

  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. Synthesis and Characterization of Dehydroabietic Acid-alcohol Spice Esters%去氢枞酸醇类香料酯的合成与表征

    Institute of Scientific and Technical Information of China (English)

    覃珊; 段文贵; 赖刚; 吴光燧; 马长花

    2013-01-01

    以去氢枞酸为原料,经去氢枞酸酰氯与醇类香料的O-酰化反应,合成得到去氢枞酸肉桂酯、去氢枞酸葑醇酯、去氢枞酸龙脑酯和去氢枞酸薄荷酯等4种去氢枞酸醇类香料酯,其中去氢枞酸肉桂酯和去氢枞酸葑醇酯为新化合物.目标产物的适宜合成条件为:反应时间10 h,反应温度95~100℃,反应物n(醇)∶n(酰氯)=1.2∶1.采用IR、UV、NMR和MS等方法对目标产物进行了结构表征.%Four types of dehydroabietic acid-alcohol spice esters, i. e. dehydroabietic acid-cinamic alcohol ester, dehydroabietic acid-fenchol ester, dehydroabietic acid-bomeol ester and dehydroabietic acid-menthol ester, were synthesized by O-acylation reaction of dehydroabietyl acyl chloride and alcohol spices using dehydroabietic acid as starting material. Suitable synthetic conditions of the target products were found to be as follows: reaction time 10 h, reaction temperature 95-100℃, molar ratio of react-ants 1.2:1 (alcohol: chloride). The target products were characterized by means of IR, UV, NMR, and MS.

  11. γ-Hydroxy-α,β-acetylenic esters:asymmetric syntheses and applications

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    γ-Hydroxy-α,β-acetylenic esters are versatile synthetic precursors to many organic compounds.This paper reviews the synthesis of chiral γ-hydroxy-α,β-acetylenic esters by asymmetric reduction of γ-oxo-α,β-acetylenic esters,enantioselective addition to aldehydes in the presence of chiral catalysts,and diastereoselective addition to chiral aldehydes.The preparation of racemic γ-hydroxy-α,β-acetylenic esters is also included.Examples are provided for the application of γ-hydroxy-α,β-acetylenic esters in organic synthesis.

  12. 离子液体催化合成柠檬酸植物甾烷醇酯的研究%Synthesis of citrate phytosterol esters in the presence of ionic liquid

    Institute of Scientific and Technical Information of China (English)

    李静静; 何文森; 潘晓霞; 王梅桂; 贾承胜; 张晓鸣; 冯骉

    2013-01-01

    The synthesis of citrate phytosterol esters in the presence of various ionic liquids was studied. The highest yield ( >91%) of citrate phytosterol esters was obtained under the optimal conditions; [pmim] [HSO4] dosage 7% (based on the phytostanol mass) ,molar ratio of citric acid to phytostanol 3:1 .phytostanol concentration 0. 15 mmol/mL,toluene as water - entrainer,reaction temperature 110℃, reaction time 5 h. [ pmim] [ HSO4 ] had highly catalytic activity after six operation runs. The product was confirmed to be citrate phytosterol esters by mass spectroscopy.%研究了离子液体在柠檬酸植物甾烷醇酯合成中的应用.通过植物甾烷醇酯化率的对比,确定最佳反应条件为:离子液体[pmim][HSO4]用量为植物甾烷醇质量的7%,酸醇摩尔比3:1,植物甾烷醇的浓度0.15 mmol/mL,带水剂为甲苯,反应温度110℃,反应时间5h.在最佳条件下,经3次平行实验测得平均酯化率大于91%.离子液体[pmim][HSO4]在循环使用6次后仍有较高的催化活性.由质谱分析可知,合成的产物为柠檬酸植物甾烷醇酯.

  13. 多酯基取代的叶绿素类二氢卟吩衍生物的合成%Synthesis of Multi-ester Substitutied Chlorin Derivatives Related to Chlorophyll-a

    Institute of Scientific and Technical Information of China (English)

    殷军港; 王振; 杨泽; 刘超; 赵丽丽; 王进军

    2012-01-01

    From methyl pheophorbide-a which was used as a starting material, purpurin-7 trimethyl ester and chlorin-p6 trimethyl ester were synthesized by hydrogation-opening ring, allomerization and rearrangement reaction. The synthesis of ten unreported chlorin derivatives related to chlorophyll-a was accomplished by electrophilic adduction, electrophilic substitution, 1,3-dipolar cycloadduction and oxidation-rearrangement reaction to chemical modifications for C(3)-vinyl group, 20-meso-position, methyl group at 12-position and ester moieties at terminal positions. The structures of all new chlorins were characterized by UV, IR, 'H NMR spectra and elemental analysis.%以脱镁叶绿酸-a甲酯为起始原料,通过碱性条件下的水解开环、空气氧化和重排反应,分别合成了红紫素-7三甲酯和二氢卟吩-P6三甲酯.然后对其C(3)-乙烯基、20-meso-位、12-位甲基以及尾端酯基进行化学修饰,通过亲电加成、亲电取代、1,3-偶极环加成和氧化重排等反应,完成10种具未见报道的的叶绿素类二氢卟吩衍生物,其化学结构均经UV,IR,1H NMR光谱及元素分析予以表征.

  14. Wax esters of different compositions produced via engineering of leaf chloroplast metabolism in Nicotiana benthamiana.

    Science.gov (United States)

    Aslan, Selcuk; Sun, Chuanxin; Leonova, Svetlana; Dutta, Paresh; Dörmann, Peter; Domergue, Frédéric; Stymne, Sten; Hofvander, Per

    2014-09-01

    In a future bio-based economy, renewable sources for lipid compounds at attractive cost are needed for applications where today petrochemical derivatives are dominating. Wax esters and fatty alcohols provide diverse industrial uses, such as in lubricant and surfactant production. In this study, chloroplast metabolism was engineered to divert intermediates from de novo fatty acid biosynthesis to wax ester synthesis. To accomplish this, chloroplast targeted fatty acyl reductases (FAR) and wax ester synthases (WS) were transiently expressed in Nicotiana benthamiana leaves. Wax esters of different qualities and quantities were produced providing insights to the properties and interaction of the individual enzymes used. In particular, a phytyl ester synthase was found to be a premium candidate for medium chain wax ester synthesis. Catalytic activities of FAR and WS were also expressed as a fusion protein and determined functionally equivalent to the expression of individual enzymes for wax ester synthesis in chloroplasts.

  15. 逆相转移催化合成葵花籽油蔗糖酯%Synthesis of sunflower oil sucrose ester catalyzed by inverse phase - transfer catalyst

    Institute of Scientific and Technical Information of China (English)

    樊国栋; 康丽; 林振宇

    2012-01-01

    Using water solvent method, sunflower oil sucrose ester was synthesized by inverse phase -transfer catalyst DMAP with sucrose and fatty acid methyl ester prepared by ester - exchange method in the presence of basic catalyst from sunflower oil and methanol. The effects of molar ratio of fatty acids methyl ester to sucrose, catalyst dosage, reaction temperature and reaction time were studied. The results showed that the optimal conditions were as follows; molar ratio of fatty acids methyl ester to sucrose 2.5:1, catalyst dosage 4% , reaction temperature 85 °C and reaction time 7 h. Under the optimal conditions, the conversion rate of sunflower oil fatty acid methyl ester could reach 65. 32%. The final product had good surface activity, the critical micelle concentration(CMC) was 6. 5 g/L, surface tension was 27.41 mN/ m, emulsifying power was 79s, water count was 7. 2 mL, HLB was 10. 1 and iodine value was 126. 9 gI/ 100 g.%先由食用葵花籽油和甲醇在碱性催化剂条件下酯交换反应制得脂肪酸甲酯,然后脂肪酸甲酯与蔗糖通过水溶剂法,以逆相转移催化剂DMAP催化制备蔗糖脂肪酸酯.通过对酯糖摩尔比、催化剂用量、反应温度、反应时间进行考察,确定最佳合成条件为:酯糖摩尔比2.5∶1,催化剂用量4%,反应温度 85℃,反应时间7h.在最佳合成条件下,葵花籽油脂肪酸甲酯的转化率高达65.32%,所得产品具有良好的表面活性,其临界胶束质量浓度(CMC)为6.5 g/L,表面张力为27.41 mN/m,乳化力为79 s,浊点指数为7.2 mL,HLB值为10.1,碘值(Ⅰ)为126.9 g/100 g.

  16. Calculation of the T-X phase diagrams for binary mixtures of cholestanyl myristate-cholesteryl myristate and cholestanyl myristate-cholesteryl oleate.

    Science.gov (United States)

    Yurtseven, Hamit; Sen, Sema

    2009-04-01

    T-X phase diagrams of binary mixtures of cholestanyl myristate (CnM)-cholesteryl myristate (CrM) and cholestanyl myristate (CnM)-cholesteryl oleate (CO) are calculated using the mean field theory. We expand the free energies for the phases of cholesteric, smectic, and solid solutions in terms of the order parameters for these binary mixtures (X is the concentration of CrM for CnM-CrM and the concentration of CnM for CnM-CO). From this expansion, we obtain the phase line equations for the transitions among the isotropic liquid, cholesteric, smectic, and solid solutions for both binary mixtures. Taking into account the temperature and concentration dependences of the coefficients in the free energy expansion, we fit our phase line equations to the experimentally measured T-X phase diagrams for these two binary mixtures. Our calculated phase lines coincide with the measured T-X phase diagrams, and the critical behavior of the thermodynamic quantities, including the order parameter, the specific heat, and the susceptibility, can be predicted from the mean field expansions.

  17. Synthesis and properties of a modified cyanate esters prepolymer%一种改性氰酸酯预聚体的合成和性能研究

    Institute of Scientific and Technical Information of China (English)

    魏运召; 张恩天; 陈维君; 崔宝军; 李刚; 宋军军

    2011-01-01

    The prepolymerization of polysulfone resins (PSF) and bisphenol A type cyanatc esters resin (DCE) was conducted at a certain condition. The obtained prepolymer resin and its cured product were analyzed and characterized by FT-IR, DSC and SEM. The results showed that the modified cyanate esters prepolymer had excellent mechanical properties and good dirlrctrical properties.%将聚砜树脂(PSF)和双酚A型氰酸酯树脂(BCE)在一定条件下进行预聚反应,通过红外光谱(FT-IR)、差热扫描(DSC)、扫描电镜(SEM)对所得到的预聚体树脂及其固化后产物进行分析和表征.结果表明改性后的氰酸酯预聚体具有优异的力学性能和良好的介电性能.

  18. Synthesis, Molecular Docking and Antimicrobial Activity of 2-(3, 4-dihydro-3-oxo-2H-benzo [b] [1, 4] thiazin-2-yl acetic acid Esters

    Directory of Open Access Journals (Sweden)

    A. P. Rajput

    2016-05-01

    Full Text Available Esters of 2-(3, 4-dihydro-3-oxo-2H-benzo[b] [1, 4] thiazin-2-yl acetic acid are synthesized and evaluated for their antimicrobial activity in vivo. All compounds are characterized by spectroscopic techniques such as FTIR, H1 NMR, C13 NMR and Mass. Molecular docking of these compounds is carried out in silico. The Molecular docking study provides detailed information about the nature and reactivity of the compounds. This helps to judge the biological activity of compounds using computer softwares. Molecular docking of these compounds is done with alpha amylase enzyme responsible for microbial attack. The result shows that all these esters are excellent inhibitors of alpha amylase.

  19. 有机相固定化酶催化合成维生素A酯%Synthesis of Vitamin A Esters by Immobilized Candida sp. Lipase in Organic Media

    Institute of Scientific and Technical Information of China (English)

    尹春华; 刘涛; 谭天伟

    2006-01-01

    Vitamin A ester was synthesized in organic solvents with immobilized lipase from Candida sp. The types of lipases, influences of solvent, the molar ratio of substrates, the reaction temperature and the water activity in the reaction were studied in detail in order to obtain the optimum conditions for Vitamin A palmitate synthesis. In a system of hexane,100mg immobilized Candida sp. lipase was used in the presence of 1.2mmol vitamin A acetate and 3.6mmol palmitic acid. The yield of vitamin A palmitate reached 81% in 12h at 25℃. The immobilized Candida sp. lipase was prepared by adsorbing Candida sp. fermentation broth on pretreated textile and could be reused for at least six batches.

  20. Short-chain flavor ester synthesis in organic media by an E. coli whole-cell biocatalyst expressing a newly characterized heterologous lipase.

    Science.gov (United States)

    Brault, Guillaume; Shareck, François; Hurtubise, Yves; Lépine, François; Doucet, Nicolas

    2014-01-01

    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.

  1. Comparison of estimation capabilities of response surface methodology (RSM with artificial neural network (ANN in lipase-catalyzed synthesis of palm-based wax ester

    Directory of Open Access Journals (Sweden)

    Salleh Abu

    2007-08-01

    Full Text Available Abstract Background Wax esters are important ingredients in cosmetics, pharmaceuticals, lubricants and other chemical industries due to their excellent wetting property. Since the naturally occurring wax esters are expensive and scarce, these esters can be produced by enzymatic alcoholysis of vegetable oils. In an enzymatic reaction, study on modeling and optimization of the reaction system to increase the efficiency of the process is very important. The classical method of optimization involves varying one parameter at a time that ignores the combined interactions between physicochemical parameters. RSM is one of the most popular techniques used for optimization of chemical and biochemical processes and ANNs are powerful and flexible tools that are well suited to modeling biochemical processes. Results The coefficient of determination (R2 and absolute average deviation (AAD values between the actual and estimated responses were determined as 1 and 0.002844 for ANN training set, 0.994122 and 1.289405 for ANN test set, and 0.999619 and 0.0256 for RSM training set respectively. The predicted optimum condition was: reaction time 7.38 h, temperature 53.9°C, amount of enzyme 0.149 g, and substrate molar ratio 1:3.41. The actual experimental percentage yield was 84.6% at optimum condition, which compared well to the maximum predicted value by ANN (83.9% and RSM (85.4%. The order of effective parameters on wax ester percentage yield were; respectively, time with 33.69%, temperature with 30.68%, amount of enzyme with 18.78% and substrate molar ratio with 16.85%, whereas R2 and AAD were determined as 0.99998696 and 1.377 for ANN, and 0.99991515 and 3.131 for RSM respectively. Conclusion Though both models provided good quality predictions in this study, yet the ANN showed a clear superiority over RSM for both data fitting and estimation capabilities.

  2. 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.

  3. Studies on synthesis of coconut oil monoethanolamide propoxy esters%椰子油单乙醇酰胺丙氧基醚的合成研究

    Institute of Scientific and Technical Information of China (English)

    赵强; 刘传玉

    2012-01-01

    The coconut oil monoethanolamide propoxy esters was prepared from coconut oil monoethanolamide and epoxypropane by polymerization method.The reaction conditions of coconut oil monoethanolamide propoxy esters were investigated. The optimum reaction conditions are obtained as follows: The amount of KOH catlyst is 0.5% to total reactant(mol), The molar ratio of coconut oil monoethanolamide and epoxypropane is 1:2, reaction temperature was 145℃ and reaction time was 3 hours,The conversion rate of epoxypropane was 99.9%. The coconut oil monoethanolamide propoxy esters have lower viscosity Higher water-soluble and similar foam stability compared to the coconut oil monoethanolamide propoxy esters by test.%以椰子油单乙醇酰胺、环氧丙烷为原料,进行开环聚合反应合成椰子油单乙醇酰胺丙氧基醚,考察了椰子油单乙醇酰胺丙氧基醚合成的条件,实验表明,在催化剂氢氧化钾用量为反应物总物质的量的0.5%,反应物椰子油单乙醇酰胺与环氧丙烷物质的量比为1∶2,反应温度145℃,反应时间3h的条件下,环氧丙烷的转化率可达99.9%.经测试,椰子油单乙醇酰胺丙氧基醚与椰子油单乙醇酰胺的稳泡性能相近,具有黏度低,水溶性好的特点.

  4. A Convenient Hydrogenation Method for the Synthesis of Metallo-mesoporphyrin IX Dimethyl Esters via Self-catalyzed CoCI2-NaBH4 Reagent System

    Institute of Scientific and Technical Information of China (English)

    徐士超; 胡炳成; 胡田菁; 王欢; 黄修有; 娄兴焜; 刘祖亮

    2012-01-01

    A convenient protocol has been developed for the hydrogenation of metallo-protoporphyrin IX dimethyl esters (MPPDMEs) to their mesoporphyrin analogues using CoC12-NaBH4 reagent system. Metallo-porphyrin complexes were found to perform as self-catalysts in this procedure. This method provides several advantages such as safe and simple procedure, short reaction time, high yields and low cost.

  5. β-氨基酸乙酯盐酸盐的合成与表征%Synthesis and Characterization of β-Amino Acid Ethyl Ester Hydrochlorides

    Institute of Scientific and Technical Information of China (English)

    韩秋敏; 李登超

    2011-01-01

    β-Phenylalanine ethyl ester hydrochloride,2-F-β-phenylalanine ethyl ester hydrochloride and 3-F-β-phenylalanine ethyl ester hydrochloride were synthesized by reacting amino acids with ethanol in the presence of thionyl chloride,respectively.The structures of these compounds were characterized by melting point,1H-NMR,13C-NMR and mass spectrometry.This synthetic method was simple,with mild reaction conditions and the yields above 85%.%以三种β-苯丙氨酸、二氯亚砜、乙醇为原料分别合成了β-苯丙氨酸乙酯盐酸盐、2F-β-苯丙氨酸乙酯盐酸盐和3F-β-苯丙氨酸乙酯盐酸盐三种稳定的β-氨基酸乙酯盐酸盐,并通过熔点、核磁和质谱对化合物的结构进行了表征。该合成方法操作简单、反应条件温和,收率均在85%以上。

  6. Synthesis of sn-2 docosahexaenoyl monoacylglycerol by mild enzymatic transesterification of docosahexaenoic acid ethyl ester and glycerol in a solvent-free system

    Directory of Open Access Journals (Sweden)

    Sonia Moreno-Perez

    2016-12-01

    Full Text Available The enzymatic transesterification of docosahexaenoic acid (DHA ethyl ester with glycerol was performed with several lipases in a solvent-free system and it involves the initial formation of sn-2 docosahexaenyl monoacylglyceride. This DHA derivative is highly relevant for improving the bioavailability of DHA and it has received increasing interest in the field of nutrition. Three commercial lipases, from Rhizomucor miehei (RML, Alcaligenes sp (QL, and Candida antarctica-fraction B (CALB were tested. In certain cases (CALB, using an excess of DHA ethyl ester and high temperatures the transesterification reaction continues to the formation of triacylglycerides, but in other cases, sn-2 monoacylglyceride (2-MG is the unique synthetic product even in the presence of high concentrations of DHA ethyl ester. At low temperatures (e.g. 37°C, RML derivatives synthesize only 2-MG in 15 min. These very mild conditions are very interesting for the thermal oxidative stability of the omega-3 fatty acid and for the thermal stability of the biocatalyst. Using Normal Phase HPLC-ELSD and accurate markers, the formation of the 2-MG was confirmed.

  7. Amphiphilic block copolymers bearing six-membered ortho ester ring in side chains as potential drug carriers: synthesis, characterization, and in vivo toxicity evaluation.

    Science.gov (United States)

    Luo, Shi; Tao, Yangyang; Tang, Rupei; Wang, Rui; Ji, Weihang; Wang, Chun; Zhao, Youliang

    2014-07-01

    A new type of amphiphilic block copolymers, poly(ethylene glycol)-block-poly(2-methyl-acrylicacid 2-methoxy-5-methyl-[1,3]dioxin-5-ylmethyl ester) (PEG-b-PMME), bearing acid-labile six-membered ortho ester rings in side chains was synthesized by reversible addition-fragmentation chain-transfer polymerization, and the influence of chain length of the hydrophobic PMME block on micelle properties was investigated. The PEG-b-PMME micelles were stable in aqueous buffer at physiological pH with a low critical micelle concentration. Nile Red as a model drug was encapsulated into the micelles to explore the release profiles. The Nile Red-loaded polymeric micelles showed rapid release of Nile Red in weakly acidic environments (pH 5) but slow release under physiological condition (pH 7.4), due to different hydrolysis rate of ortho ester side chains of PEG-b-PMME. The Paclitaxel (PTX)-loaded micelles retained potency in killing lung cancer cells (A549), compared with the free PTX. No obvious toxicity was found in vitro and in vivo after intraperitoneal injection of the micelles, which confirms that the PEG-b-PMME micelles with unique acid-labile characteristic have great potential as nano-scaled carriers for drug delivery.

  8. VC复合脂肪酸酯的合成及抗氧化性能%SYNTHESIS AND ANTIOXIDANT EFFECTS OF ASCORBYL COMPOSITE ALIPHATIC ESTER

    Institute of Scientific and Technical Information of China (English)

    冯光炷; 谢文磊

    2001-01-01

    猪油与甲醇进行酯交换制备复合脂肪酸甲酯,得率97.2%.再以浓硫酸为溶剂和催化剂,VC和复合脂肪酸甲酯进行酯交换合成VC复合脂肪酸酯.考察了反应时间、反应物配比及浓硫酸用量对酯交换反应的影响,结果表明,最适宜的反应条件为:n(VC)∶n(复合脂肪酸酯)为1∶1.2,反应时间为26h,n(浓H2SO4)∶n(VC+复合脂肪酸酯)为1∶0.15,反应温度为25℃,产率达76%.产品的抗氧化性能测试表明VC复合脂肪酸酯是一种优良的无毒抗氧化剂.%Ascorbyl composite aliphatic ester was synyhesized by transesterificantion of L-ascorbic acid with methyl composite aliphatic ester which is synthesized from lard and methyl alcohol using concentrated sulfuric acid as sol ve nt and catalyst. The yield was up to 76%. The effects of reaction temperature, r atio of reactant, amount of concentrated sulfuric acid on transesterification ha ve been investigated. The optimum synthetic conditions are that the ratio of Vc to composite aliphatic ester is 1∶1.2,reaction time is 26 h, the ratio of conce ntrated H2SO4 to composite aliphatic ester is 1∶0.15,reaction temperatur e is 25 ℃ .The test of antioxidant shows that Ascorbyl composite aliphatic ester is a good oxidant without poison.

  9. Synthesis Technology of Octenyl Succinic Acid Cross - Link Starch Esters%辛烯基琥珀酸交联淀粉酯合成工艺研究

    Institute of Scientific and Technical Information of China (English)

    石海信; 谢新玲; 张友全; 童张法

    2009-01-01

    以木薯淀粉为原料,用环氧氯丙烷作交联剂,辛烯基琥珀酸酐作酯化剂,采用湿法工艺合成辛烯基琥珀酸交联淀粉酯.探讨了淀粉乳浓度、反应温度、反应时间、pH和沉降积对辛烯基琥珀酸交联淀粉酯取代度的影响,确定制备辛烯基琥珀酸交联淀粉酯的最佳工艺参数为:淀粉乳浓度35%,酯化pH 8.0,酯化温度35℃,酯化时间3 h.交联淀粉的沉降积对酯化取代度影响较小,在生产中可根据最终产品的用途选用合适沉降积的交联淀粉进行酯化复合变性.复合变性淀粉符合食品行业标准,可以在食品工业中应用.扫描电镜对其结构进行观察显示淀粉中受侵蚀颗粒增多,颗粒表面的小凹痕数量增加.%Octenyl succinic acid cross - link starch esters were prepared by wet process with cassava starch as raw material, epichlorohydrin as cross - link agent and octenyl succinic anhydride as esterifying agent. The effects of starch slurry concentration, reaction temperature, reaction time, pH and sediment volume on the substitution degree of octenyl succinic acid cross - link starch esters were studied. Results; The optimal conditions for preparing octenyl succinic acid cross -link starch esters are starch slurry concentration 35% , esterification pH 8.0, esterification temperature 35 ℃ and esterification time 3 h. The sediment volume of cross - link starch has little effect on the substitution degree. Thus, a proper sediment volume can be determined according to the usage of final octenyl succinic acid cross - link starch esters. The produced octenyl succinic acid cross - link starch esters are identified safe to be used in food industry. The result of scanning electron microscope observation shows that the number of dents and splits in the granule surface of the prepared starch increases.

  10. Online LC-GC analysis of free sterols/stanols and intact steryl/stanyl esters in cereals.

    Science.gov (United States)

    Esche, Rebecca; Scholz, Birgit; Engel, Karl-Heinz

    2013-11-20

    The suitability of online liquid chromatography-gas chromatography for the analysis of free sterols/stanols, steryl/stanyl fatty acid esters, and trans-steryl/stanyl ferulic acid esters in cereals is demonstrated. The silylated lipid extracts were fractionated via liquid chromatography on a normal phase, and the fractions containing the sterol classes were transferred online to the gas chromatograph for the analysis of their individual compositions. The study provides for the first time data on free sterols/stanols and intact steryl/stanyl esters in sweet corn, popcorn, and proso millet. Sweet corn revealed the highest contents of free sterols/stanols and steryl/stanyl fatty acid esters, and popcorn, in turn, the highest amounts of trans-steryl/stanyl ferulic acid esters. The distribution patterns of the proso millet samples revealed pronounced differences from those of sweet corn and popcorn as they particularly exhibited high proportions of free cholesterol and cholesteryl fatty acid esters. Furthermore, no trans-steryl/stanyl ferulic acid esters could be detected.

  11. Synthesis,antibacterial and antioxidant activity of caffeic acid vitamin C ester%咖啡酸维生素C酯的合成、抑菌活性和抗氧化性研究

    Institute of Scientific and Technical Information of China (English)

    刘菊香; 范广璞; 刘长春

    2012-01-01

    A facile one-pot method for synthesis of caffeic acid vitamin C ester via Knoevenagel condensation and esterification from 3,4-dihydroxybenzaldehyde,malonate and vitamin C were studied.Antibacterial and antioxidant activity of caffeic acid vitamin C ester were determined.In the presence of SO2-4/ZrO2 catalyst,caffeic acid was synthesized by Knoevenagel condensation of 3,4-dihydroxybenzaldehyde with malonate,then esterified with vitamin C to give caffeic acid vitamin C ester in 85.1% yield.The structure of target compound was confirmed by1H NMR and IR spectrum.The antibacterial tests indicated that caffeic acid vitamin C ester exhibited good inhibition activity on Staphylococcus aureus,Escherichia coli,Bacillus subtilis,Saccharomyces cerevisiae,Penicillium chrysogenum,Aspergillus flavus and Aspergillus niger.And the inhibition activity of caffeic acid vitamin C ester on bacteria and yeast were much higher than those on mould.The antioxidant tests indicated that caffeic acid vitamin C ester could efficiently scavenge DPPH free radical and hydroxyl free radical,which was significantly higher than that of vitamin C.%研究了以3,4-二羟基苯甲醛、丙二酸和维生素C为原料,经过Knoevenagel缩合和直接酯化一锅法合成咖啡酸维生素C酯的方法,并考察了咖啡酸维生素C酯的抑菌活性和抗氧化性。在催化剂SO42-/ZrO2的作用下,3,4-二羟基苯甲醛与丙二酸首先发生Knoevenagel缩合生成咖啡酸,产物不需要分离,加入维生素C继续进行酯化反应,以85.1%的产率得到了咖啡酸维生素C酯,产物结构用1HNMR和IR进行确证。抑菌活性实验表明,咖啡酸维生素C酯对金黄色葡萄球菌、大肠杆菌、枯草杆菌、酿酒酵母、青霉、黄曲霉和黑曲霉均有较强的抑制作用,对细菌和酵母的抑制作用高于霉菌。抗氧化性实验表明,咖啡酸维生素C酯可以有效清除DPPH自由基和羟基自由基,清除效果明显好于维生素C。

  12. 植物甾醇烟酸酯的合成及HPLC法的测定%Synthesis of bionic ester of phytosterol and analysis of it by HPLC

    Institute of Scientific and Technical Information of China (English)

    施光宗; 洪挺; 陆豫

    2011-01-01

    The overall yield of the two-step synthesising bionic ester of phytosterol was 87. 4% and the production was validated by liquid chromatograph/mass spectrometer (HPLC/MS). Homemadebionic ester of stigmasterol for the standard substance, The HPLC methods for bionic ester of phytosterol was established ,Chromatographic condition: reversed-phase column(150 mm×4. 6 mm)filled with 5 μm Eclipse XDB C18 Column as the solid phase, mobile phase was CH3OH, flow-rate was 1. 2 mL/min, detection wavelength was 210 nm,column temperature was 35℃. The experimental results showed that the method was simple,sensitive and accurate .%采用两步法合成植物甾醇烟酸酯,产物总收率为87.4%.通过液质联用仪对产物进行验证.豆甾醇烟酸酯为标准物,应用高效液相色谱法对产物中植物甾醇烟酸酯的含量进行了分析测定.以Eclipse XDB-C18柱(4.6mm×150 mm,5μm)为分析柱,甲醇为流动相,流速是1.2 mL/min,紫外210 nm检测,柱温35℃.实验结果表明,该方法快速、简便、分离度好.

  13. 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

    Energy Technology Data Exchange (ETDEWEB)

    Bell, F.P.

    1983-06-01

    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.

  14. Synthesis, Relaxivity and MRI Enhancement of Linear Oligo-Gd(m) Complexes with Poly (DTPA-ester) Ligands Derived from Amino Acids

    Institute of Scientific and Technical Information of China (English)

    YU,Kai-Chao (俞开潮); WANG,Xin-Bing(王新兵); YE,Chao-Hui(叶朝辉); LI,Li-Yun(李丽云); LIU,Mai-Li(刘买利); ZHUO,Ren-Xi(卓仁禧)

    2001-01-01

    Six linear oligo-DrPA-ester Gd(Ⅲ) conplexes being used for potential MRI contrast agents were synthesized from amino acids and characterized. Their longitudinal relaxation rates were measured. One of them, the pheny derivative, with high rciaxivity, was chosen for the acute toxicity and T1weighted imaging test. The results indicated that there was no obvious toxicity for fhis new oligomeric Gd(Ⅲ) complex, and it exhibits the highly enhanced MRI signal intensity and the increasing signal duration in the liver tissue conpared to Gd-DTPA.

  15. Cu(II), Ni(II), and Zn(II) Complexes of Salan-Type Ligand Containing Ester Groups: Synthesis, Characterization, Electrochemical Properties, and In Vitro Biological Activities

    OpenAIRE

    Jeslin Kanaga Inba, P.; B. Annaraj; Thalamuthu, S.; Neelakantan, M.A.

    2013-01-01

    A salen ligand on reduction and N-alkylation affords a novel [N2O2] chelating ligand containing ester groups [L = diethyl-2,2′-(propane-1,3-diylbis((2-hydroxy-3-methoxy benzyl)azanediyl))diacetate]. The purity of the ligand was confirmed by NMR and HPLC chromatograms. Its Cu(II), Ni(II), and Zn(II) complexes were synthesized and characterized by a combination of elemental analysis, IR, NMR, UV-Vis, and mass spectral data, and thermogravimetric analysis (TG/DTA). The magnetic moments, UV-Vis, ...

  16. 新型聚原酸酯共聚物的合成及性能研究%Synthesis and Characterization of Poly(ortho ester)

    Institute of Scientific and Technical Information of China (English)

    陶扬洋; 巩凯; 王睿; 唐汝培

    2013-01-01

    以二聚甘油为原料,经过酯交换及氨基脱保护反应合成了一种两端含氨基的环状原酸酯新单体.该单体与辛二酸/十二烷二酸活性酯缩聚得到两种新的疏水性聚原酸酯共聚物POEAd-1和POEAd-2,其数均分子量分别由凝胶渗透色谱(GPC)测得为1.24×104及1.81×104,分散度(PDI)分别为1.59及1.93.热失重分析法证实POEAd-1和POEAd-2具有较高的热稳定性能,其起始降解温度分别可达198.5℃及202.5℃.溶血试验和MTT细胞毒性试验表明,POEAd-1和POEAd-2均具有良好生物相容性,作为一种潜在的生物医用材料,在药物缓控释领域将具有广阔的应用前景.%A new diamine monomercontaining a built-in,stabilized ortho ester group was synthesized by diglycerol with two steps of transesterification.Two new highly hydrophobic copolymer poly(ortho ester amide) (POEAd-1 and POEAd-2) were obtained by polycondensation ofthe monomer with suberic acid bis(N-hydroxysuccinimide ester)and dodecanedioic acid bis(N-hydroxysuccinimide ester).The number average molecular weight of POEAd-1 and POEAd-2were determined by gel permeation chromatography (GPC),and calculated to be 1.24 × 104 and 1.81× 104 with polydispersity index(PDI) of 1.59 and 1.93,respectively.Thermal stabilityof POEAd-1 and POEAd-2 via thermogravimetric analysis (TGA) were investigated),the temperature of the onset 5% weight loss is up to 198.5℃ and 202.5℃,respectively.Hemolysis test and MTT cytotoxicity test indicate that POEAd-1 and POEAd-2 has good biocompatibility as a potential biomedical materials,can bewidely used in the field of controlled drug deliever.

  17. Synthesis of Novel Amphiphilic Poly (ester-amine) Dendrimers and Their Recognition of Hg2+ at the Air/Water Interface

    Institute of Scientific and Technical Information of China (English)

    申亮; 李富友; 沙耀武; 潘峥峥; 洪啸吟; 黄春辉

    2003-01-01

    Two novel amphiphilic poly(ester-amine)dendrimers were synthesized and characterized by 1H NMR,13C NMR and IR spectra.Their properties of Langmuir film were investigated at the air/water interface.The relationship between the surface pressure and area isotherms of the dendrimers was found to be dependent on the nature of subphases,Interaction between HgCl2 and the dendrimers was observed,indicating that the amphiphilic dendrimers could act as a sensor for Hg2+.

  18. 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

    OpenAIRE

    2016-01-01

    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 caffeoylq...

  19. 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

    Directory of Open Access Journals (Sweden)

    Ling-Na Wang

    2016-06-01

    Full Text Available 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.

  20. Synthesis and Application of Borate Ester Coupling Agent%硼酸酯偶联剂的合成与应用研究

    Institute of Scientific and Technical Information of China (English)

    郑俊良

    2014-01-01

    Using boric acid, isopropanol and octadecanol as main raw materials, strong acid ion exchange resin DNW-1 as catalyst, the borate ester coupling agent was prepared in N2 atmosphere condition. The influence of water carrying agent and mole ratio of raw materials on esterification rate was studied, and the borate ester coupling agent was characterized by IR and1H NMR. The results show that the best reaction conditions of the esterification reaction are as follows: the best water carrying agent is the mixture of benzol and toluene,n(boric acid):n(octadecanol):n(isopropanol)= 0.9: 2.0: 1.2; under above conditions, the esterification rate can reach to 94.57%.And the borate ester coupling agent prepared was used in the composite of brucite/HDPE. The result shows that the tensile strength of modified brucite/HDPE is better than the unmodified brucite/HDPE; when dosage of the borate ester coupling agent is 50%, the tensile strength of modified brucite/HDPE can increase by about 3.1%, and the value of LOI is 24.5.%以硼酸、异丙醇和十八醇为主要原料,催化剂是采用DNW-1强酸性离子交换树脂,在氮气保护下合成了硼酸酯偶联剂。考察了带水剂及物料摩尔比对酯化率的影响,并用红外光谱和1H NMR对硼酸酯进行了表征。研究发现:在n(硼酸)∶n(十八醇)∶n(异丙醇)=0.9∶2.0∶1.2的条件下,并采用苯和甲苯混合带水剂时,酯化率可达到94.57%。利用所合成的硼酸酯偶联剂应用于水镁石/HDPE 复合体系中,结果表明:改性水镁石/HDPE体系的拉伸强度高于未改性水镁石/HDPE体系的拉伸强度。添加量为50%时,改性水镁石的拉伸性能比未改性前提高了3.1%,LOI值为24.5。

  1. Synthesis and characterization of curdlan piperinic ester%凝胶多糖胡椒酸酯的合成及表征

    Institute of Scientific and Technical Information of China (English)

    韩景芬; 兰景波; 孟和; 娜日苏; 昭日格图; 博日吉汗格日勒图

    2013-01-01

    Curdlan piperinic ester was synthesized from piper-idine and water soluble curdlan in the present of N, N-carbon-yldiimidazole as catalyst. This novel conjugate was characterized by FT-IR,1HNMR and 13CNMR.%以胡椒碱和凝胶多糖为原料,在羰基二咪唑的作用下合成了凝胶多糖胡椒酸酯,并用FT-IR、1HNMR和13CNMR进行了结构表征.

  2. Microwave-assisted synthesis of novel 5-trichloromethyl-4,5-dihydro-1H-1-pyrazole methyl esters under solvent free conditions

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Marcos A.P.; Beck, Paulo; Machado, Pablo; Brondani, Sergio; Moura, Sidnei; Zanatta, Nilo; Bonacorso, Helio G.; Flores, Alex F.C. [Universidade Federal de Santa Maria, RS (Brazil). Dept. de Quimica. Nicleo de Quimica de Heterociclos (NUQUIMHE)]. E-mail: mmartins@base.ufsm.br

    2006-03-15

    Twelve novel 5-trichloromethyl-4,5-dihydro-1H-1-pyrazole ethyl esters have been synthesized in good yields (70-98%) by using environmentally benign microwave induced techniques. The compounds were synthesized from the cyclocondensation of 1,1,1-trichloro-4-alkoxy-3-alken-2-ones [CCl3{sub C}(O)C(R{sup 2})=C(R{sup 1} )OR, where R, R{sup 2} = H, alkyl; R{sup 1} = H, alkyl and aryl] with hydrazine methyl carboxylate. The advantages obtained by the using of microwave irradiation under solvent-free conditions, rather than a conventional method, were demonstrated. (author)

  3. siRNA delivery into tumor cells by lipid-based nanoparticles composed of hydroxyethylated cholesteryl triamine.

    Science.gov (United States)

    Hattori, Yoshiyuki; Nakamura, Tsukasa; Ohno, Hiroaki; Fujii, Nobutaka; Maitani, Yoshie

    2013-02-25

    Previously, we reported that cationic nanoparticles (NP) composed of cholesteryl diamine (OH-Chol, (3S)-N-(2-(2-hydroxyethylamino)ethyl)cholesteryl-3-carboxamide) and Tween 80 could deliver plasmid DNA (pDNA) and small interfering RNA (siRNA) with high transfection efficiency into various tumor cells. In this study, to facilitate the endosomal escape of siRNA transfected by lipid-based nanoparticles, we synthesized new cationic cholesteryl triamine (OH-N-Chol, (3S)-N-(2-(2-(2-hydroxyethylamino)ethylamino)ethyl)cholesteryl-3-carboxamide) with an ethylenimine extension and prepared cationic nanoparticles (NP-N) composed of cholesteryl triamine and Tween 80. Although NP-N/siRNA complex (NP-N nanoplex) after mixing NP-N with siRNA was >350 nm in size, the vortex-mixing during the nanoplex formation decreased it to about 200 nm, which was an injectable size. NP-N nanoplex was mainly internalized by macropinocytosis-mediated endocytosis, as was NP nanoplex, and showed higher gene knockdown efficiency than NP nanoplex in human cervical carcinoma SiHa cells. From these results, cationic nanoparticles composed of OH-N-Chol and Tween 80 may have potential as a gene vector for siRNA transfection to tumor cells.

  4. Lipid synthesis and secretion in HepG2 cells is not affected by ACTH

    Directory of Open Access Journals (Sweden)

    Nilsson-Ehle Peter

    2010-05-01

    Full Text Available Abstract Apolipoprotein B (apoB containing lipoproteins, i.e. VLDL, LDL and Lp(a, are consequently lowered by ACTH treatment in humans. This is also seen as reduced plasma apoB by 20-30% and total cholesterol by 30-40%, mostly accounted for by a decrease in LDL-cholesterol. Studies in hepatic cell line (HepG2 cells showed that apoB mRNA expression is reduced in response to ACTH incubation and is followed by a reduced apoB secretion, which may hypothesize that ACTH lowering apoB containing lipoproteins in humans may be mediated by the inhibition of hepatic apoB synthesis. This was recently confirmed in vivo in a human postprandial study, where ACTH reduced transient apoB48 elevation from the small intestine, however, the exogenic lipid turnover seemed unimpaired. In the present study we investigated if lipid synthesis and/or secretion in HepG2 cells were also affected by pharmacological levels of ACTH to accompany the reduced apoB output. HepG2 cells were incubated with radiolabelled precursors ([14C]acetate and [3H]glycerol either before or during ACTH stimuli. Cellular and secreted lipids were extracted with chloroform:methanol and separated by the thin layer chromatography (TLC, and [14C]labelled cholesterol and cholesteryl ester and [3H]labelled triglycerides and phospholipids were quantitated by the liquid scintillation counting. It demonstrated that ACTH administration did not result in any significant change in neither synthesis nor secretion of the studied lipids, this regardless of presence or absence of oleic acid, which is known to stabilize apoB and enhance apoB production. The present study suggests that ACTH lowers plasma lipids in humans mainly mediated by the inhibition of apoB synthesis and did not via the reduced lipid synthesis.

  5. 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.

  6. Synthesis and biological evaluation of esters of 16-formyl-17-methoxy-dehydroepiandrosterone derivatives as inhibitors of 5α-reductase type 2.

    Science.gov (United States)

    Sánchez-Márquez, Araceli; Arellano, Yazmín; Bratoeff, Eugene; Heuze, Yvonne; Córdova, Karen; Nieves, Gladys; Soriano, Juan; Cabeza, Marisa

    2016-12-01

    In this study, we investigated the in vitro effect of 16-formyl-17-methoxy dehydroepiandrosterone derivatives on the activity of 5α-reductase type 2 (5α-R2) obtained from human prostate. The activity of different concentrations of these derivatives was determined for the conversion of labelled testosterone to dihydrotestosterone. The results indicated that an aliphatic ester moiety at the C-3 position of these derivatives increases their in vitro potency as inhibitors of 5α-R2 activity compared to finasteride®, which is considered to be a potent inhibitor of 5α-R2. In this case, the augmentation of the lipophilicity of these dehydroepiandrosterone derivatives increased their potency as inhibitors of 5α-R2. However, the presence of cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl or cycloheptyl rings as the cycloaliphatic ester moiety at C-3 of the formyl methoxy dehydroepiandrosterone scaffold did not inhibit the activity of this enzyme. This may be due to the presence of steric factors between the enzyme and the spatial structure of these derivatives.

  7. Synthesis of comb type and semi-interpenetrating networks of acryloyl-L-proline methyl ester and poly (acrylic acid) for Cu (II) immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Giovanni [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, A. Postal 70-543, 04510 Mexico, D.F. (Mexico); Burillo, Guillermina, E-mail: burillo@nucleares.unam.m [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, A. Postal 70-543, 04510 Mexico, D.F. (Mexico)

    2010-08-15

    Graft copolymer hydrogels and semi-interpenetrating networks (s-IPN) of acryloyl-L-proline methyl ester (A-ProOMe) and poly (acrylic acid) (PAAc) were synthesized in methanol solutions, by ionizing radiation (gamma rays from a Co{sup 60} source at room temperature). These systems are thermo and pH-sensitive and the pH sensitivity increases from acidic to basic solutions. The Lower Critical Solution Temperature (LCST), due to presence of poly (acryloyl-L-proline methyl ester) (PA-ProOMe) has been found between 18 and 20 deg. C and an unexpected Upper Critical Solution Temperature (UCST) due to poly acrylic acid (PAAc) has been found between 21 and 22 deg. C. Preliminary studies on the immobilization of Cu{sup 2+} for both hydrogels were done at several pH values at room temperature. Other techniques employed to characterize the comb type hydrogels and sIPN included scanning electronic microscopy (SEM) and infrared (FTIR-ATR).

  8. Low cost hydrogen/novel membrane technology for hydrogen separation from synthesis gas, Phase 1. [Poly(etherimide) and poly(ether-ester-amide) membranes

    Energy Technology Data Exchange (ETDEWEB)

    1986-01-01

    During the last quarter several high performance membranes for the separation of hydrogen from nitrogen, carbon monoxide, hydrogen sulfide and carbon dioxide. The heat-resistant resin poly(etherimide) has been selected as the polymer with the most outstanding properties for the separation of hydrogen from nitrogen and carbon monoxide. Flat sheet and hollow fiber poly(etherimide) membranes have been prepared and evaluated with pure gases and gas mixtures at elevated pressures and temperatures. Multilayer composite poly(ether-ester-amide) membranes were also developed. These membranes are useful for the separation of carbon dioxide and hydrogen sulfide hydrogen. They have very high selectivities and extremely high normalized carbon dioxide and hydrogen sulfide fluxes. Separation of carbon dioxide/hydrogen streams is a key problem in hydrogen production from coal. The development of the two membranes now gives us two approaches to separate these gas streams, depending on the stream's composition. If the stream contains small quantities of hydrogen, the hydrogen- permeable poly(etherimide) membrane would be used to produce a hydrogen-enriched permeate. If the stream contains small quantities of carbon dioxide or hydrogen sulfide, the poly(ether-ester-amide) membrane would be used to produce a carbon dioxide/hydrogen sulfide-free, hydrogen-enriched residue stream. 6 fig., 4 tabs.

  9. Rhodotorula glutinis Phenylalanine/Tyrosine Ammonia Lyase Enzyme Catalyzed Synthesis of the Methyl Ester of para-Hydroxycinnamic Acid and its Potential Antibacterial Activity.

    Science.gov (United States)

    MacDonald, Marybeth C; Arivalagan, Pugazhendhi; Barre, Douglas E; MacInnis, Judith A; D'Cunha, Godwin B

    2016-01-01

    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.

  10. 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

  11. 催化合成脂肪族二元酸烷氧基酯的反应动力学研究%Kinetics for catalytic synthesis of aliphatic dicarboxylic acid alkoxy ethyl ester

    Institute of Scientific and Technical Information of China (English)

    陈慕华; 方亮; 刘准; 曹惠庆; 朱新宝

    2012-01-01

    Aliphatic dicarboxylic acid alkoxy ethyl ester is synthesized from aliphatic dicarboxylic acid and ethyle glycol monobutyl ether by using sulfuric acid as catalyst. Apparent rate constants for those acid-catalyzed homogeneous esterification reactions are obtained, and apparent kinetics models are established. The results show that the synthesis of aliphatic dicarboxylic acid alkoxy ethyl ester under the temperature from 453. 15 to 473. 15 K is the third order irreversible reaction. According to the kinetic data of those experiments using different aliphatic dicarboxylic acid (C5-C8), activation energy values (Ea) are all in the range from 220 to 250 kj/mol.%脂肪族二元酸烷氧基酯是一类性能优良的耐寒性增塑剂产品.以二元羧酸及乙二醇丁醚为原料,在硫酸催化下合成烷氧基酯,测定了表观速率常数,并建立了反应体系的酯化反应动力学模型.实验结果表明,在453.15~473.15 K,合成脂肪族二元酸烷氧基酯的宏观动力学符合三级不可逆反应特征,以C5至C8的二元羧酸为原料的酯化过程其反应表观活化能在220~250 kJ/mol内.

  12. Optimization of lipase-catalyzed synthesis of fatty acid ethyl ester from corn oil%脂肪酶催化玉米油合成脂肪酸乙酯工艺研究

    Institute of Scientific and Technical Information of China (English)

    康建波; 胡士恒; 王亚男; 周亚军

    2012-01-01

    为研制食药两用的功能性原料亚油酸乙酯,以玉米油和乙醇为原料,经固定化脂肪酶催化合成脂肪酸乙酯.通过单因素试验和响应面分析法(RSM)研究醇油摩尔比、脂肪酶用量、反应温度、反应时间对玉米油脂肪酸乙酯合成的影响.研究结果表明,玉米油脂肪酸乙酯合成的最佳工艺条件为醇油摩尔比为4∶1,脂肪酶质量分数为30.82%,反应温度为50.39℃,反应时间为24.15 h,在此工艺条件下脂肪酸乙酯转化率为90.20%.%In order to develop the functional raw material linoleic acid ethylester which can be used as both food and medicine, the fatty acid ethyl esters are synthesized by immobilized lipase-catalyzed reaction with corn oil and alcohol as raw material in this study. Based on the single factor experiments and response surface methodology ( RSM ) , the influences of molar ratio ethanol and corn oil, the amount of enzyme, the reaction temperature and reaction time on the synthesis of fatty acid ethyl ester from corn oil are investigated. The obtained optimal parameters are shown as follows -A-1 molar ratio of ethanol to oil,30 % of amount of enzyme,50. 39℃ of reaction temperature and 24 hours of reaction time. The rate of conversion of corn oil can reach 90. 20% .

  13. Lewis酸性离子液体催化合成丁二酸二异丙酯%Synthesis of succinic acid diisopropyl ester catalyzed by Lewis acid ionic liquids

    Institute of Scientific and Technical Information of China (English)

    赵地顺; 葛京京; 翟建华; 张娟; 刘猛帅; 李俊盼

    2014-01-01

    采用两步法制备了9种不同的Lewis酸性离子液体,采用1H NMR、FT-IR对离子液体的结构进行了表征,并系统地考察了其对丁二酸和异丙醇酯化反应的催化性能。结果表明,离子液体随着卤化物用量增加表现出更强的酸性。其中[Bmim]Br-Fe2Cl6催化合成丁二酸二异丙酯效果良好,催化剂用量为丁二酸质量的10.0%,反应温度100℃,反应时间4 h,酸醇摩尔比为1:5,丁二酸二异丙酯收率为88.9%,酯化率达92.7%。离子液体重复使用6次后,产品收率下降1.7%。%Nine kinds of different Lewis acid ionic liquids were synthesized by two-step process and their structures were characterized with 1H NMR and FT-IR. Lewis acid ionic liquids prepared were used to catalyze the esterification reaction of succinic acid and isopropyl alcohol. With the increase of dosage of halide, the ionic liquids showed stronger acidity. [Bmim]Br-Fe2Cl6 had the best catalytic performance, and optimal conditions for the synthesis of succinic acid diisopropyl ester were obtained as follows, amount of catalyst 10.0%(g/g)of succinic acid, reaction temperature 100℃ and reaction time 4 h, succinic acid and isopropyl alcohol ratio 1:5. Under the optimal conditions, the yield of succinic acid diisopropyl ester was up to 88.9%, esterification rate was 92.7%.The catalyst was recycled 6 times, and the yield of succinic acid diisopropyl ester only decreased by 1.7%.

  14. 氨基磺酸催化合成脂肪酸丁酯的研究%Synthesis of fatty acid butyl ester catalyzed by amino sulfonic acid

    Institute of Scientific and Technical Information of China (English)

    程正载; 龚凯; 张卫星; 高松; 雷锐; 颜晓潮; 从野

    2014-01-01

    The fatty acid butyl ester was respectively synthesized by the esterification of oleic acid with bu-tanol and the transesterification of rapeseed oil with butanol catalyzed by amino sulfonic acid. The fatty acid butyl ester product was analyzed by GC and its structure was characterized by FT-IR. The effects of molar ratio of butanol to oil ( oleic acid or rapeseed oil) , catalyst dosage, reaction temperature and reac-tion time on the conversion rates of oleic acid and rapeseed oil were investigated. The results showed that the optimal esterification conditions were obtained as follows: molar ratio of butanol to oleic acid 3∶1 , catalyst dosage 0. 8% (based on the mass of oleic acid), reaction temperature 110℃and reaction time 1. 5 h. Under these conditions, the conversion rate of oleic acid and the yield of fatty acid butyl ester reached 88. 6% and 83. 5%, respectively. The optimal transesterification conditions were obtained as follows:molar ratio of butanol to rapeseed oil 10∶1, catalyst dosage 1. 0% (based on the mass of rapeseed oil), reaction temperature 115℃ and reaction time 2. 0 h. Under the optimal conditions, the conversion rate of rapeseed oil and the yield of fatty acid butyl ester achieved 85. 6% and 80. 1%, respectively.%以氨基磺酸为催化剂,油酸及菜籽油与正丁醇分别进行酯化反应与酯交换反应制备脂肪酸丁酯。并利用气相色谱及红外光谱对产物进行分析及结构表征。考察了醇(正丁醇)油(油酸及菜籽油)摩尔比、催化剂用量、反应温度和反应时间对油酸及菜籽油转化率的影响。结果表明,油酸酯化反应的最佳工艺条件为:醇油摩尔比3∶1,催化剂用量为油酸质量的0.8%,反应温度110℃,反应时间1.5 h,此时油酸转化率达到88.6%,产品收率为83.5%;菜籽油酯交换反应的最佳工艺条件为:醇油摩尔比10∶1,催化剂用量为菜籽油质量的1.0%,反应温度115℃,反应时间2.0 h,

  15. Synthesis of Monomer Hydrogenated Rosin-Acrylic Glycerin Ester%氢化松香-丙烯酸丙三醇酯单体的合成

    Institute of Scientific and Technical Information of China (English)

    李浩; 王春平; 李鹏飞; 雷福厚; 段文贵

    2011-01-01

    Hydrogenated rosin-acrylic glycerin ester is synthesized from hydrogenated rosin modified by thionyl chloride obtained by reaction of hydrogenated rosin and thionyl chloride, glycerin and acryloyl chloride.Hydrogenated rosin acyl chloride is characterized by FTIR spectrum. Hydrogenated rosin glycerin ester obtained by reaction of hydrogenated rosin acyl chloride and glycerin is characterized by FTIR spectrum and determination of acid value, and its optimal synthetic reaction conditions are obtained as follows: molar ratio of hydrogenated rosinacyl chloride to glycerin is 1: 2. 5, pyridine as solvent, reaction time is 3 h, reaction temperature is ll0℃. The acid value of hydrogenated rosin glycerin ester is 21 mg·g-1 under above conditions. The structure of hydrogenated rosin-acrylic glycerin ester is confirmed by FTIR and UV-Vis. The monomer can polymerize in the presence of initiator. For the prepared polymer, its degree of cross linking is 75.1%, its solubility in aviation kerosene, carbinol, methylbenzene or cyclohexane is very small, and its softening point is 235℃.%以氢化松香、二氯亚砜、丙三醇、丙烯酰氯为主要原料,合成了可以均聚的氢化松香-丙烯酸丙三醇酯单体.氢化松香先与二氯亚砜反应制得氢化松香酰氯,通过FTIR对反应过程进行跟踪监测;氢化松香酰氯再与丙三醇经酯化反应合成氢化松香丙三醇酯,优化的反应条件为:吡啶作溶剂、n(氢化松香酰氯):n(丙三醇)=1:2.5、反应温度110℃、反应时间3 h,制得的氢化松香丙三醇酯酸值为21 mg·g-1;最后,氢化松香丙三醇酯与丙烯酰氯经酯化反应制得了氢化松香-丙烯酸丙三醇酯单体,通过FTIR和UV-Vis对其结构进行了表征.单体可以发生均聚反应,生成的颗粒状聚合物交联度为75.1%,在航空煤油、甲醇、甲苯、环己烷中的溶解度均很小,软化点为235℃.

  16. Synthesis of some ester derivatives of 4'-demethoxyepipodophyllotoxin/2'-chloro-4'-demethoxyepipodophyllotoxin as insecticidal agents against oriental armyworm, Mythimna separata Walker.

    Science.gov (United States)

    Huang, Jiulin; Xu, Ming; Li, Shaochen; He, Jiani; Xu, Hui

    2017-02-01

    Podophyllotoxin is a naturally occurring non-alkaloid toxin isolated from the roots and rhizomes of Podophyllum peltatum and P. hexandrum. In continuation of our program aimed at the discovery and development of natural product-based insecticides, two series of ester derivatives of 4'-demethoxyepipodophyllotoxin/2'-chloro-4'-demethoxyepipodophyllotoxin were prepared. The structures of the target compounds were well characterized by 1H NMR, IR, optical rotation and mp. The precise three-dimensional structural information of 8j was further determined by single-crystal X-ray diffraction. Their insecticidal activity was tested against Mythimna separata Walker. These compounds showed delayed insecticidal activity. Among all derivatives, some compounds showed more potent insecticidal activity than toosendanin against M. separata; especially compounds 8k and 9k exhibited the most potent activity with the final mortality rates of 71.4%. Their structure-activity relationships were discussed.

  17. Synthesis of novel 5-alkyl/aryl/heteroaryl substituted diethyl 3,4-dihydro-2H-pyrrole-4,4-dicarboxylates by aziridine ring expansion of 2-[(aziridin-1-yl-1-alkyl/aryl/heteroaryl-methylene]malonic acid diethyl esters

    Directory of Open Access Journals (Sweden)

    U. K. Syam Kumar

    2011-06-01

    Full Text Available A novel synthetic methodology has been developed for the synthesis of diethyl 5-alkyl/aryl/heteroaryl substituted 3,4-dihydro-2H-pyrrole-4,4-dicarboxylates (also called 2-substituted pyrroline-4,5-dihydro-3,3-dicarboxylic acid diethyl esters by iodide ion induced ring expansion of 2-[(aziridin-1-yl-1-alkyl/aryl/heteroaryl-methylene]malonic acid diethyl esters in very good to excellent yields under mild reaction conditions. The electronic and steric impact of the substituents on the kinetics of ring expansion of N-vinyl aziridines to pyrrolines has been studied. Various diversely substituted novel pyrroline derivatives have been synthesized by this methodology and the products can be used as key intermediates in the synthesis of substituted pyrrolines, pyrroles and pyrrolidines.

  18. 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

  19. Catalytic Asymmetric Synthesis of Phosphine Boronates

    NARCIS (Netherlands)

    Hornillos, Valentin; Vila, Carlos; Otten, Edwin; Feringa, Ben L.

    2015-01-01

    The first catalytic enantioselective synthesis of ambiphilic phosphine boronate esters is presented. The asymmetric boration of ,-unsaturated phosphine oxides catalyzed by a copper bisphosphine complex affords optically active organoboronate esters that bear a vicinal phosphine oxide group in good y

  20. Estudo da influência do solvente, carboidrato e ácido graxo na síntese enzimática de ésteres de açúcares Study of the influence of solvent, carbohydrate and fatty acid in the enzymatic synthesis of sugar esters by lipases

    OpenAIRE

    2005-01-01

    The aim of this work was to gain knowledge of enzymatic processes for the synthesis fatty acid esters of sugar, with the objective to develop an enzymatic process for the preparation of non-toxic biodegradable surface-active agents derived entirely from renewable resources. A wide range of data were collected for reaction conditions involving different sugars (glucose, fructose and sucrose), fatty acids (oleic, palmitic, lauric), solvents (hexane, heptane and t-butanol) and different sources ...

  1. 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).

  2. Interactions of egg yolk phosphatidylcholine with cholesteryl polyethoxy neoglycolipids containing N-acetyl- D-glucosamine

    Science.gov (United States)

    Kemoun, Rachida; Gelhausen, Micaèle; Besson, Françoise; Lafont, Dominique; Buchet, René; Boullanger, Paul; Roux, Bernard

    1999-03-01

    Series of neoglycolipids containing cholesteryl and N-acetyl- D-glucosaminyl groups were synthesized with various ethoxy linkers. Their self aggregations and intermolecular interactions, without and with egg yolk phosphatidylcholine (EYPC), were characterized in dry and hydrated states, by using infrared spectroscopy. The neoglycolipids in the dry state formed intermolecular hydrogen bonds between the CO and N-H or O-H groups of N-acetyl- D-glucosamine (GlcNAc). In the presence of EYPC, these intermolecular interactions were broken and new hydrogen bonds, involving the phosphate group of EYPC and N-H or O-H groups of GlcNAc of neoglycolipid, were formed. The presence of water molecules altered these intermolecular hydrogen bonds. The CO groups of EYPC were not affected by the presence of neoglycolipids, either in hydrated or in dry states, indicating that the GlcNAc polar groups interacted mostly with EYPC phosphate residues. The phase transition-temperature of mixtures of EYPC containing either cholesterol or neoglycolipid were similar, indicating that the cholesteryl group of the neoglycolipid interacted in the same manner as cholesterol with hydrocarbon chains of EYPC. Some structural models of molecular interactions of neoglycolipids were discussed in relation with the molecular recognition of wheat germ agglutinin.

  3. Gas chromatographic separation of fatty acid esters of cholesterol and phytosterols on an ionic liquid capillary column.

    Science.gov (United States)

    Hammann, Simon; Vetter, Walter

    2015-12-15

    Steryl esters are high molecular weight compounds (600-700g/mol) regularly present as a minor lipid class in animal and plant lipids. Different sterol backbones (e.g., cholesterol, β-sitosterol and brassicasterol) which can be esterified with various fatty acids can result in highly complex steryl ester patterns in food samples. The gas chromatographic (GC) analysis of intact steryl esters is challenging, since high elution temperatures are required for their elution. On nonpolar GC phases, steryl esters with fatty acids with differing degree of unsaturation (e.g., oleate and linoleate) cannot be separated and there are only few polar columns available with sufficient temperature stability. In this study, we used gas chromatography with mass spectrometry (GC/MS) and analyzed intact steryl esters on a commercial room temperature ionic liquid (RTIL) column which was shortened to a length of 12m. The column separated the steryl esters both by total carbon number and by degree of unsaturation of the fatty acid. For instance, cholesteryl esters with stearic acid (18:0), oleic acid (18:1n-9), linoleic acid (18:2n-6) and α-linolenic acid (18:3n-3) could be resolved (R≥1.3) from each other. By analysis of synthesized standard substances, the elution orders for different steryl backbones and different fatty acids on a given sterol backbone could be determined. Analysis of spreads and plant oils allowed to determine retention times for 37 steryl esters, although a few co-elutions were observed. The ionic liquid column proved to be well-suited for the analysis of intact steryl esters.

  4. Synthesis and Molecular Structure of Acetic Acid-3,5-diacetoxy-2-acetoxymethyl-6-(4-quinoxalin-2-yl-phenoxy)-tetrahydro-pyran-4-yl-ester

    Institute of Scientific and Technical Information of China (English)

    WEI Hui-Qin; ZENG Run-Sheng; WU Gui-Ping; WANG Bao-An; ZOU Jian-Ping

    2006-01-01

    The title compound, acetic acid-3,5-diacetoxy-2-acetoxymethyl-6-(4-quinoxalin-2-yl-phenoxy)-tetrahydro-pyran-4-yl-ester 8 (C28H28N2O10, Mr = 552.54), has been synthesized and its crystal structure was determined by X-ray diffraction analysis. It crystallizes in monoclinic,space group P21, a = 10.060(8), b = 5.648(4), c=24.11(2)(A), β=91.078(10)O, Z = 2, V =1369.9(19)(A)3, Dc = 1.339 g/cm3,μ(MoKα) = 1.03 cm-1, F(000) = 580.00, T=193.1 K,θmax =25.03, (△/σ)max = 0.0000, Flack = -0.0(24), the final R = 0.0680 and wR= 0.140 (w =1/[0.0016Fo2+ 1.0000σ(Fo2)]/(4Fo2)) for 3126 observed reflections (I>2σ(I)). The pyranoid ring adopts chair conformation in the sugar moiety, and all of the acetyl groups are in the e bond of the pyranoid ring, so the sugar moiety is very stable.

  5. Catalytic Synthesis of Ethyl Ester of Acetyl Ferulic Acid with DCC/DMAP%DCC/DMAP 催化制备乙酰阿魏酸乙酯

    Institute of Scientific and Technical Information of China (English)

    石翛然

    2014-01-01

    Intermediate 3-( 4-acetoxy-3-methoxyphenyl ) acrylic acid was synthesized by 4-hydroxy-3-methoxybenzaldehyde, with dicyclohexyl carbodiimide ( DCC) and 4-dime-thylamino pyridine ( DMAP) as catalyst. Ethyl ester of acetyl ferulic acid was synthesized by esterification reaction.Target product was characterized by IR, elemental analysis and MS.The experimental results showed at room temperature, the amount of catalyst accounts for 3%of the acetyl ferulic acid, and reaction 4 h was the best condition.%以4-羟基-3-甲氧基苯甲醛为起始原料,合成了中间产物乙酰阿魏酸,再以N,N-二环己基碳二亚胺( DCC)和4-二甲胺基吡啶( DMAP)为催化剂,通过酯化反应制备了乙酰阿魏酸乙酯,各步产物通过红外光谱、质谱和元素分析对其结构进行表征确认。实验结果表明:在室温下,催化剂用量为乙酰阿魏酸用量的3%,反应时间为4 h的条件下,产率达到75%,为最优条件。

  6. Near-field infrared imaging of molecular changes in cholesteryl oleate by free electron laser infrared ablation

    Science.gov (United States)

    Masaki, Tatsuhiro; Goto, Kazuya; Inouye, Yasushi; Kawata, Satoshi

    2004-01-01

    We have applied infrared near-field scanning optical microscopy (IR-NSOM) to enable evaluation of detailed molecular changes in cholesteryl oleate, a primary cause of arteriosclerosis. In our IR-NSOM, a wide wavelength range of 2.9-6.7 μm is achieved by use of an optical parametric amplifier and an apertured cantilever. IR irradiation from a free-electron laser (FEL) tuned to a 5.75 μm wavelength induced molecular structural changes and caused cholesteryl oleate to decompose to cholesterol and fatty acids in the FEL irradiated areas. The IR-NSOM images at two different wavelengths, 5.75 and 5.3 μm, with a 2 μm apertured cantilever probe successfully identified areas of molecular change in cholesteryl oleate beyond the diffraction limit of IR microspectroscopy. In-depth molecular structure changes were also evaluated by the IR-NSOM and we demonstrated that the FEL irradiation induced subsurface molecular structure changes throughout cholesteryl oleate in the irradiated areas.

  7. 3,3-二甲基-4-戊烯酸甲酯合成方法的改进及表征%Improved Synthesis of 3,3-Dimethyl-4-pentenoic Acid Methyl Ester

    Institute of Scientific and Technical Information of China (English)

    廖艳芳; 余慧群; 莫友彬; 周海; 彭初和

    2012-01-01

    采用相模法以原乙酸三甲酯与3-甲基-2-丁烯醇为原料,经过重排反应和酯交换反应,合成了除虫菊酯类杀虫剂的重要中间体3,3-二甲基-4-戊烯酸甲酯.改进相模的工艺更适应工业生产,收率达到85.6%,产品纯度达到99.2%.%3,3 -Dimethyl -4 -pentenoic acid methyl ester is an important intermediate for the synthesis of pyrethroids pesticides. It can be prepared using 3-methyl-2-buten-l-ol and trimethyl orthoacetate as the starting materials, through Claisen rearrangement and transesterification reaction ( Sagami method). This method was improved for industrial production and the product was obtained in 85.5% yield with purity of 99.2%.

  8. 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.

  9. 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.

  10. Synthesis and Properties Research of Copolyether Esters as Defoamers%聚醚酯类消泡剂的制备及性能研究

    Institute of Scientific and Technical Information of China (English)

    胡廷; 王超明; 陆原; 郭海军

    2013-01-01

    No.1 and No.2 polyether with molecular mass of 1500 and 3000,chain arrangement PO-EO and PO-EO-PO,were synthesized with KOH as catalyst,fatty alcohol,ethylene oxide(EO) and propylene oxide(pO) as raw materials.Then,12 kinds of polyether esters defoaming agent were prepared with lauric acid or stearic acid as esterification agent,p-toluene sulfonic acid as catalyst.The effect of reaction time,the molar ratio of polyether and esterification agent and catalyst dosage on the esterification rate of defoaming agent was investigated.The optimum reaction condition was obtained as follows:140-160℃ reaction temperature,1.2∶1 polyether and esterification agent molar ratio,7 h esterification time.The defoaming agent was used to handle the manifold sample of Liida 5-2 comprehensive wellhead in Bohai Sea.Experiment results showed that the defoaming rate of polyether ester defoaming agent was 87.8% with p-toluene sulfonic acid and No.2 polyether as raw materials,which was superior to that of general organic silicon defoaming agent (66.7%) and slightly weaker than that of fluorine alkyl silicone defoamer (91.1%).The application development prospect was good.%以脂肪醇、环氧乙烷(EO)、环氧丙烷(PO)为原料,KOH为催化剂,合成相对分子质量1500、3000,链段排列方式为PO-EO和PO-EO-PO的聚醚,分别记为1号和2号;再以月桂酸或硬脂酸为酯化剂,对甲苯磺酸作催化剂,对聚醚进行酯化,得到12种聚醚酯类消泡剂.考察了反应时间、聚醚与酯化剂摩尔比和催化剂加量对消泡剂酯化率的影响.最佳合成条件为反应温度140~160℃,聚醚、酯化剂摩尔比1.2∶1,酯化时间7h.用所得消泡剂处理渤海旅大5-2井口综合管汇油样,结果表明,以硬脂酸、自制2号聚醚为原料得到的聚醚酯类消泡剂具有最佳的消泡性能,消泡率为87.8%,优于一般有机硅类消泡剂(66.7%),稍弱于氟烃基硅油消泡剂(91.1%),应用开发前景良好.

  11. Synthesis and Antibacterial Activities of Carboxylic Myrtanyl Esters%羧酸桃金娘烷醇酯的合成及抑菌活性研究

    Institute of Scientific and Technical Information of China (English)

    廖圣良; 商士斌; 司红燕; 沈明贵; 饶小平; 宋湛谦

    2015-01-01

    Myrtanol was prepared via hydroboration-oxidation reaction from β-pinene, then eight novel carboxylic myrtanyl esters (myrtanyl acetate (4a), myrtanyl propionate (4b), myrtanyl butyrate (4c), myrtanyl valerate (4d), myrtanyl cyclohexanecarboxylate(4e),myrtanyl benzoate(4f),myrtanyl p-methylbenzoate(4g) and myrtanyl p-methoxybenzoate(4h) were obtained through the reaction of myrtanol and carboxylic acids using N, N′-dicyclohexylcarbodiimide/dimethylaminopyridine ( DCC/DMAP) as catalyst. Structure characterizations were achieved by FT-IR,1 H NMR and ESI-MS. Antibacterial activity assays were carried out by agar dilution method. The results showed that compounds 4b,4c,4f,4g and 4h exhibited inhibitory activities (MIC was 256 mg/L) against the Gram positive bacterial Staphylococcus aureus,and compounds 4a,4b,4c and 4e exhibited inhibitory activities ( MICs were ranged from 128 to 256 mg/L) against the Gram negative bacterial Escherichia coli. more importantly. Compound 4a showed comparable activity ( MIC was 128 mg/L) to that of bromogeramine against E. coli. Comparing with the starting compound β-pinene and the intermediate myrtanol, this series of esters showed better antibacterial activities.%以β-蒎烯为原料,经硼氢化氧化反应合成了桃金娘烷醇,桃金娘烷醇与羧酸在N,N′-二环己基碳酰亚胺/4-二甲氨基吡啶( DCC/DMAP)的催化作用下反应,生成了8个羧酸桃金娘烷醇酯新化合物:乙酸桃金娘烷醇酯(4a)、丙酸桃金娘烷醇酯(4b)、正丁酸桃金娘烷醇酯(4c)、正戊酸桃金娘烷醇酯(4d)、环己烷羧酸桃金娘烷醇酯(4e)、苯甲酸桃金娘烷醇酯(4f)、对甲苯甲酸桃金娘烷醇酯(4g)、对甲氧基苯甲酸桃金娘烷醇酯(4h). 借助FT-IR、1 H NMR和ESI-MS对产物进行了结构表征,通过琼脂稀释法对所合成的化合物进行了抑菌活性测试. 结果表明,在该系列羧酸桃金娘烷醇酯中,化合物4b、4c、4f、4g和4h对革兰氏阳

  12. Cooperative Reinforcement of Ionic Liquid and Reactive Solvent on Enzymatic Synthesis of Caffeic Acid Phenethyl Ester as an In Vitro Inhibitor of Plant Pathogenic Bacteria

    Directory of Open Access Journals (Sweden)

    Yan Xu

    2017-01-01

    Full Text Available It is widely believed that lipases in ionic liquids (ILs possess higher enzyme activity, stability and selectivity; however, reaction equilibrium is always limited by product inhibition, and the product is difficult to separate from non-volatile ILs using distillation. To solve this problem, using trialkylphosphine oxide (TOPO as a complexing agent, a novel biphase of reactive solvent and IL was firstly reported for caffeic acid phenethyl ester (CAPE production from methyl caffeate (MC and 2-phenylethanol (PE catalyzed by lipase via transesterification. The effects of the reaction parameters and their action mechanism were investigated, and the inhibition of CAPE against bacterial wilt pathogen Ralstonia solanacearum was firstly measured. The MC conversion of 98.83% ± 0.76% and CAPE yield of 96.29% ± 0.07% were obtained by response surface methodology in the 25 g/L TOPO-cyclohexane/[Bmim][Tf2N] (1:1, v/v; the complex stoichiometry calculation and FTIR spectrum confirmed that the reversible hydrogen-bond complexation between TOPO and caffeates significantly enhances the cooperative effect of two phases on the lipase-catalyzed reaction. The temperature was reduced by 14 °C; the MC concentration increased by 3.33-fold; the ratio of catalyst to donor decreased by 4.5-fold; and Km decreased 1.08-fold. The EC50 of CAPE against R. solanacearum was 0.17–0.75 mg/mL, suggesting that CAPE is a potential in vitro inhibitor of plant pathogenic bacteria.

  13. Synthesis, structural characterization, and some properties of 2-acylmethyl-6-ester group-difunctionalized pyridine-containing iron complexes related to the active site of [Fe]-hydrogenase.

    Science.gov (United States)

    Song, Li-Cheng; Hu, Fu-Qiang; Wang, Miao-Miao; Xie, Zhao-Jun; Xu, Kai-Kai; Song, Hai-Bin

    2014-06-07

    As biomimetic models for [Fe]-hydrogenase, the 2-acylmethyl-6-ester group-difunctionalized pyridine-containing iron(II) complexes 1-4 have been successfully prepared via the following three separate steps. In the first step, the acylation or esterification of difunctionalized pyridine 2-(p-MeC6H4SO3CH2)-6-HOCH2C5H3N with acetyl chloride or benzoic acid gives the corresponding pyridine derivatives 2-(p-MeC6H4SO3CH2)-6-RCO2CH2C5H3N (A, R = Me; B, R = Ph). The second step involves reaction of A or B with Na2Fe(CO)4 followed by treatment of the intermediate Fe(0) complexes [Na(2-CH2-6-RCO2CH2C5H3N)Fe(CO)4] (M1, R = Me; M2, R = Ph) with iodine to afford 2-acylmethyl-6-acetoxymethyl or 6-benzoyloxymethyl-difunctionalized pyridine-containing Fe(II) iodide complexes [2-C(O)CH2-6-RCO2CH2C5H3N]Fe(CO)2I (1, R = Me; 3, R = Ph). Finally, when 1 or 3 is treated with sodium 2-mercaptopyridinate, the corresponding difunctionalized pyridine-containing Fe(ii) mercaptopyridinate complexes [2-C(O)CH2-6-RCO2C5H3N]Fe(CO)2(2-SC5H4N) (2, R = Me; 4, R = Ph) are produced. While the structures of model complexes 1-4 are confirmed by X-ray crystallography, the electrochemical properties of 2 and 4 are compared with those of the two previously reported models. In addition, complexes 2 and 4 have been found to be catalysts for H2 production in the presence of TFA under CV conditions.

  14. Synthesis of unsymmetrical substituted 1,4-dihydropyridines through thermal and microwave assisted [4+2] cycloadditions of 1-azadienes and allenic esters.

    Science.gov (United States)

    Singh, Lakhwinder; Ishar, M P Singh; Elango, Munusamy; Subramanian, Venkatesan; Gupta, Vivek; Kanwal, Priyanka

    2008-03-21

    Thermal and microwave assisted [4+2] cycloadditions of 1,4-diaryl-1-aza-1,3-butadienes with allenic esters lead to cycloadducts, which after a 1,3-H shift afford variedly substituted unsymmetrical 2-alkyl-1,4-diaryl-3-ethoxycarbonyl-1,4-dihydropyridines in high yields. Reactions carried out under microwave irradiation are cleaner and give higher yields with much shortened reaction times. Density functional theory (DFT) at the B3LYP/6-31G* level has been used to calculate geometric features of the reactants, barrier for s-trans to s-cis and reverse isomerization of azadienes (5a-d, 10a-e), dihedral angles between N(1), C(2), C(3), and C(4) atoms of azadienes along with various indices such as chemical hardness (eta), chemical potential (micro), global electrophilicity (omega), and the difference in global electrophilicity (Deltaomega) between the reacting pairs and Fukui functions (f (+) and f(-)). The results revealed that s-trans is the predominant conformation of azadienes at ambient temperature and the barrier for conversion of the s-trans rotamer of 1-azadienes to s-cis may be the major factor influencing the chemoselectivity, i.e., [4+2] verses [2+2] cycloaddition. The regiochemistry of the observed cycloadditions is collated with the obtained local electrophilicity indices (Fukui functions). Transition states for the formation of both [4+2] and [2+2] cycloadducts as located at the PM3 level indicate that the transition state for the formation of [4+2] cycloadducts has lower energy, again supporting the earlier conclusion that preferred formation of [4+2] cycloaaducts at higher temperature may be a consequence of barrier for s-trans to s-cis transformation of 1-azadienes.

  15. Activation of p38 and JNK MAPK pathways abrogates requirement for new protein synthesis for phorbol ester mediated induction of select MMP and TIMP genes.

    Science.gov (United States)

    Sampieri, Clara L; Nuttall, Robert K; Young, David A; Goldspink, Deborah; Clark, Ian M; Edwards, Dylan R

    2008-03-01

    The human matrix metalloproteinase (MMP) gene family includes 24 genes whose regulated expression, together with that of four tissue inhibitors of metalloproteinases (TIMPs), is essential in tissue remodelling and cell signalling. Quantitative real-time-PCR (qPCR) analysis was used to evaluate the shared and unique patterns of control of these two gene families in human MRC-5 and WI-38 fibroblasts in response to the protein kinase C (PKC) activator phorbol-12-myristate-13-acetate (PMA). The requirement for ongoing translation was analysed using three protein synthesis inhibitors, anisomycin, cycloheximide and emetine. PMA induced MMP1, 3, 8, 9, 10, 12, 13, 14 and TIMP1 and TIMP3 RNAs after 4-8 h, and induction of all except MMP9 and TIMP3 was blocked by all protein synthesis inhibitors. However, even though all inhibitors effectively blocked translation, PMA-induction of MMP9 and TIMP3 was blocked by emetine but was insensitive to cycloheximide and anisomycin. Anisomycin alone induced MMP9 and TIMP3, along with MMP25 and MMP19. The extracellular signal-regulated kinases (ERKs)-1/2 were strongly activated by PMA, while anisomycin activated the c-Jun N-terminal kinase (JNK) and p38 pathways, and cycloheximide activated p38, but emetine had no effect on the stress-activated mitogen-activated protein kinase (MAPK) pathways. The involvement of the p38 and JNK pathways in the selective effects of anisomycin and cycloheximide on MMP/TIMP expression was supported by use of pharmacological inhibitors. These data confirm that most inducible MMPs and TIMP1 behave as "late" activated, protein synthesis-dependent genes in fibroblasts. However, the requirement of protein synthesis for PMA-induction of MMPs and TIMPs is not universal, since it is abrogated for MMP9 and TIMP3 by stimulation of the stress-activated MAPK pathways. The definition of clusters of co-regulated genes among the two gene families will aid in bioinformatic dissection of control mechanisms.

  16. 酶催化合成维生素C脂肪酸酯的反应条件优化%Optimization of the enzymatic synthesis of L-ascorbyl fatty acid esters

    Institute of Scientific and Technical Information of China (English)

    宋秋红; 王熙; 田平芳

    2009-01-01

    以维生素C(Vc)和若干种脂肪酸为底物,采用自制假丝酵母Candida sp. 99-125固定化脂肪酶,催化合成维生素C脂肪酸酯.结果表明,在该酯化反应中,油酸为最佳脂肪酸底物,丙酮为最佳反应介质.同时研究了各反应因素对Vc转化率的影响,优化后的反应条件为:当Vc浓度为0.06mol/L时,温度40*#℃,固定化酶量1.5*#g,油酸与Vc物质的量比为5∶1,反应时间48*#h,分子筛添加量0.5*#g,底物Vc分4次流加,Vc转化率可达91%,批次实验表明该固定化酶在重复使用10次后仍具较高活力.%The enzymatic synthesis of L-ascorbyl fatty acid esters (AFAE) has been studied using a self-made immobilized lipase generated by Candida sp. 99 - 125 as the biocatalyst. Oleic acid was found to be the best source of a fatty acid acyl group in the synthesis of AFAEs. Through screening of different reaction media, ace-tone was found to be the most suitable solvent for the esterification. The effects of various other factors on the synthesis of AFAEs were also investigated. Under the following optimized reaction conditions: initial ascorbic acid (vitamin C) concentration (Vc) of 0.06mol/L at 40℃, 1.5g of immobilized enzyme, substrate molar ratio of 5:1, reaction time of 48 h, content of molecular sieve of 0.5 g and four times fed-batch addition of the sub-strate, an esterification ratio of 91 % was obtained. Furthermore, repeated batch reactions revealed the durabili-ty of the immobilized lipase, which retained high activity after sequential reaction for 10 rounds.

  17. Hydroboration-oxidation: A chemoselective route to cellulose ω-hydroxyalkanoate esters.

    Science.gov (United States)

    Meng, Xiangtao; York, Emily A; Liu, Shu; Edgar, Kevin J

    2015-11-20

    We describe the first synthesis of hydroxy-functionalized polysaccharide esters via chemoselective olefin hydroboration-oxidation in the presence of ester groups. Cellulose esters with terminally olefinic side chains were first synthesized by esterification of commercially available cellulose esters (e.g., cellulose acetate) with undec-10-enoyl chloride or pent-4-enoyl chloride. Subsequent two-step, one-pot hydroboration-oxidation reactions of the cellulose esters were performed, using 9-borabicyclo[3.3.1]nonane as hydroboration agent, followed by oxidizing the intermediate borane to a hydroxyl group using mildly alkaline H2O2. Sodium acetate was used as a weak base to catalyze the oxidation, thereby minimizing undesired ester hydrolysis. Characterization methods including FTIR, (1)H, and (13)C NMR proved the selectivity of the hydroboration-oxidation pathway, providing a family of novel cellulose ω-hydroxyalkanoyl esters that were previously difficult to access.

  18. Cholesteryl oligoethyleneglycol glycosides: fluidizing effect of their embedment into phospholipid bilayers.

    Science.gov (United States)

    Bardonnet, Pierre-Louis; Faivre, Vincent; Pirot, Fabrice; Boullanger, Paul; Falson, Françoise

    2005-04-22

    Glycosides of cholesteryl oligoethyleneglycols have been synthesized and embedded in liposome bilayers. Several methods as steady-state fluorescence polarization, differential scanning calorimetry, zeta potential, and agglutination have been used to describe the physicochemical outcome of the incorporation of these synthetic glycolipids within phospholipid layers. From calorimetry and fluorescence experiments, it is apparent that the glycolipids decrease the transition temperature of the bilayers in a more important extent than cholesterol. Furthermore, the thickness of the aqueous layer fixed around the liposome is independent of the presence of glycolipids, suggesting that their hydrophilic parts (tetraethyleneglycol spacer and sugar moiety) are not completely extended towards the aqueous phase. Nevertheless, an important and specific interaction has been observed between such glycosylated liposomes and vegetal lectins.

  19. 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.

  20. Sulfuric Acid ([3-(3-Silicapropyl)sulfanyl]propyl)ester as a Recyclable Catalyst for the Synthesis of 4,4'-(Arylmethylene)bis(1H-pyrazol-5-ols)%Sulfuric Acid ([3-(3-Silicapropyl)sulfanyl]propyl)ester as a Recyclable Catalyst for the Synthesis of4,4'-(Arylmethylene)bis(1H-pyrazol-5-ols)

    Institute of Scientific and Technical Information of China (English)

    Shekoofeh TAYEBI; Mojtaba BAGHERNEJAD; Dariush SABERI; Khodabakhsh NI KNAM

    2011-01-01

    Sulfuric acid ([3-(3-silicapropyl)sulfanyl]propyl)ester is employed as a recyclable catalyst for the condensation reaction between aromatic aldehydes and 3-methyl-l-phenyl-5-pyrazolone.This condensation reaction was performed in ethanol under refluxing conditions giving 4,4-alkylmethylene-bis(3-methyl-5-pyrazolones) in 74-90% yields.The heterogeneous catalyst was recycled and used in eleven runs for the reaction between benzaldehyde and 3-methyl-l-phenyl-5-pyrazolone without losing catalytic activity.