10567-18-7Relevant articles and documents
1-[2-Hydroxy-3-octadecan-1'-oate]propyl-2'',2'',5'',5''-tetramethyl Pyrolidine-N-oxyl-3''-carboxylate as a potential spin probe for membrane structure studies
Katoch, Rita,Trivedi, Girish K.,Phadke, Ratna S.
, p. 2753 - 2758 (1999)
The synthesis of a new minimum steric perturbing proxyl nitroxide, which is a derivative of glycerol and contains a stearic acid moiety, has been carried out. Its localization in model membrane L-α-dipalmitoyl phosphatidyl choline (DPPC) was ascertained with the help of ESR, DSC, 1H and 31P NMR techniques. The nitroxide was used for detecting the changes in the phase transition temperature of the model membranes in the presence and absence of drugs. The permeation of the vasodilating drug epinephrine has also been studied using this spin label. The results prove the potential applicability of the new spin probe in the spin labeling of biomembranes. Copyright (C) 1999 Elsevier Science Ltd.
The Synthesis of Some Esters of Glycerol with Special Attention to the Problem of Acyl Migration
Cockman, Samantha J.,Joll, Cynthia A.,Mortimer, Bok-Cheng,Redgrave, Trevor G.,Stick, Robert V.
, p. 2093 - 2097 (1990)
Various triglycerides have been prepared by the acylation of either cis-1,3-O-benzylideneglycerol or 2,3-O-isopropylideneglycerol, followed by removal of the protecting group and acylation of the resultant diol.Alternatively, acylation of dihydroxyacetone, reduction of the intermediate ketone with sodium cyanoborohydride (pH 4) and acylation of the resultant alcohol also provide triglycerides in good yields.In some of these esters of glycerol, 13C n.m.r. spectroscopy (125.7 MHz) was used to monitor potential acyl migration.Finally, 2-halopyridinium salts were investigated as an alternative to the normal dicyclohexylcarbodiimide/dimethylaminopyridine couple for glycerol esterification.
Kinetics and mechanism of lipase catalyzed monoacylglycerols synthesis
Itabaiana Jr.,Goncalves,Cordeiro,Zoumpanioti,Leal,Miranda,De Souza,Xenakis
, p. 34 - 39 (2013)
Monoacylglycerols are increasingly used in several industrial applications as effective and cheap emulsifiers. In the present work monostearin synthesis has been studied, using lipase as a biocatalyst of the esterification reaction of stearic acid with (R,S)-1,2-O-iso-propylidene glycerol (solketal). The lipase from Candida antarctica (CaL B) was immobilized in AOT/isooctane water in oil microemulsions. Optimization of the reaction conditions have shown that the highest production (80% in 30 min) could be achieved at 40 °C, in microemulsions with relatively low water content (wo = 8). Kinetic studies have shown that the esterification reaction of stearic acid with solketal catalyzed by CaL B occurs via the ordered bi-bi mechanism, in which inhibition by the acid was identified. Moreover, at high fixed solketal concentrations a negative cooperativity is pronounced, which means that binding of the alcohol lowers the affinity of the enzyme for binding of the acid. Values of all kinetic parameters have been determined.
Fatty acids residue from palm oil refining process as feedstock for lipase catalyzed monoacylglicerol production under batch and continuous flow conditions
Junior, Ivaldo I.,Flores, Marcela C.,Sutili, Felipe K.,Leite, Selma G.F.,De M. E Miranda, Leandro S.,Leal, Ivana C.R.,De Souza, Rodrigo O.M.A.
, p. 53 - 58 (2012)
Free fatty acids are used in many cases for the production of soaps, candles and assist processing of rubber products, but we believe that new process technology should be developed to produce products with higher added value. Monoacylglycerols (MAGs) are nonionic surfactant, highly hydrophobic and has been used as controlled release systems for drugs. The results presented here for the lipase-catalyzed MAG production show that both batch and continuous flow conditions can lead to the desired product in short reaction time and high yield (70-95%) but the use of packed bed reactors (PBR) shows higher efficiency when compared to batch reactors.
Design and synthesis of fluorescence-labeled closo-dodecaborate lipid: Its liposome formation and in vivo imaging targeting of tumors for boron neutron capture therapy
Nakamura, Hiroyuki,Ueda, Noriko,Ban, Hyun Seung,Ueno, Manabu,Tachikawa, Shoji
, p. 1374 - 1380 (2012)
The fluorescence-labeled closo-dodecaborane lipid (FL-SBL) was synthesized from (S)-(+)-1,2-isopropylideneglycerol as a chiral starting material. FL-SBL was readily accumulated into the PEGylated DSPC liposomes prepared from DSPC, CH, and DSPE-PEG-OMe by the post insertion protocol. The boron concentrations and the fluorescent intensities of the FL-SBL-labeled DSPC liposomes increased with the increase of the additive FL-SBL, and the maximum emission wavelength of the liposomes appeared at 531 nm. A preliminary in vivo imaging study of tumor-bearing mice revealed that the FL-SBL-labeled DSPC liposomes were delivered to the tumor tissue but not distributed to hypoxic regions.
Study of the effect of DATEM. 1. Influence of fatty acid chain length on rheology and baking
Koehler, Peter,Grosch, Werner
, p. 1863 - 1869 (1999)
To answer the question of which fatty acid residue is the most effective, diacetyltartaric esters of monoglycerides (DATEMs) with fatty acids of chain lengths 6:0-20:0 were synthesized. The activity of synthesized DATEMs and commercial DATEM products was studied by means of rheological methods and a microscale baking test with 10 g of flour. Variation of the acyl residue from 6:0 to 22:0 showed that stearic acid (18:0) had the best effect on the baking activity of DATEM (loaf volume increased by 62%). DATEMs containing unsaturated fatty acids (18:1, 18:2) or DATEMs produced from diacylglycerols instead of monoacylglycerols showed a slight increase of the loaf volumes. A slight effect of DATEM on the rheology of dough was observed. However, much greater was the effect on the gluten isolated from doughs prepared with DATEM. The resistance of gluten to extension was increased after the addition of increasing amounts of DATEM (0.1-0.5%). Within the series of DATEMs derived from the homologous series of monoacylglycerols the product based on glycerol monostearate (18:0) showed a maximum increase of the gluten resistance.
Synthesis of the fatty esters of solketal and glycerol-formal: Biobased specialty chemicals
Perosa, Alvise,Moraschini, Andrea,Selva, Maurizio,Noè, Marco
, (2016)
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.
Lp-PLA2 inhibitory activities of fatty acid glycerols isolated from Saururus chinensis roots
Woo, Song Lee,Mi, Jeong Kim,Beck, Young-Il,Park, Yong-Dae,Jeong, Tae-Sook
, p. 3573 - 3575 (2005)
(R)-Glycerol-monolinoleate 4 and (R)-glycerol-monostearate 5 were isolated from the ethyl acetate extracts of Saururus chinensis roots and (R)- or (S)-fatty acid glycerols 4 and 5 were synthesized for confirming their structures and evaluating their inhibitory activities against Lp-PLA 2. The (R)-4 and (S)-4 exhibited Lp-PLA2 inhibitory activities with IC50 values of 45.0 and 52.0 μM, respectively.
Optically active monoacylglycerols: Synthesis and assessment of purity
Chen, Chao-Yuan,Han, Wei-Bo,Chen, Hui-Jun,Wu, Yikang,Gao, Po
, p. 4311 - 4318 (2013)
Despite their simple structures, synthesis of 1(or 3)-acyl-sn-glycerols remains a challenge that cannot be ignored because of facile acyl migrations, which not only complicate the synthesis but also make direct GC or HPLC analysis unfeasible. Assessment of the optical purity of monoacylglycerols has, to date, relied almost exclusively on specific rotation data, which are small in value and thus insensitive to impurities. Now, a simple means to "magnify" the small specific rotations has been found, along with practical methods for the measurement of both 1,2-and 1,3-acyl migrations, which offer a convenient and straightforward alternative to Mori's NMR analysis of Mosher esters. With the aid of these methods, a range of conditions for deacetonide removal were examined en route to the synthesis of two natural monoacylglycerols. Refined hydrolysis conditions, along with useful knowledge about the solubility and reactivity of substrates with an ultra long alkyl chain are also presented. Copyright
Microemulsion-based organogels as an efficient support for lipase-catalyzed reactions under continuous-flow conditions
Itabaiana, Ivaldo,Gonalves, Karen M.,Zoumpanioti, Maria,Leal, Ivana C. R.,Miranda, Leandro S. M. E,Xenakis, Aristotelis,De Souza, Rodrigo O. M. A.
, p. 1372 - 1376 (2014)
In this work, microemulsion-based organogels (MBGs) containing lipase are reported as an efficient catalytic system for monoacylglyceride (MAG) synthesis. More specifically, Candida antarctica lipase B (CaLB) was immobilized on an MBG matrix (MBGCaLB) formed with (hydroxypropyl)methyl cellulose as a gelling agent, and this catalyst revealed high conversion yields (expressed in grams of ester per hour per gram of enzyme) under both batch and continuous-flow conditions. Under flow conditions, 1:1 stearic acid/solketal (100 mM in n-heptane) could be converted to protected MAG (>99%) in a residence time of 11 min at 45 °C. A recycle study showed that the MBGCaLB system can be recycled 15 times without activity loss, a number 2 times higher than under batch conditions catalyzed by immobilized lipase, in agreement with green chemistry protocols.
