- Chain Order in Lipid Bilayers: FTIR and Solid State NMR Studies on Bilayer Membranes from 1,2-Dimyristoyl-sn-glycero-3-phosphoglucose
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Multilamellar dispersions from a new synthetic phospholipid, 1,2-dimyristoyl-sn-glycero-3-phosphoglucose (DMPGE), bearing a glucose ring in the polar headgroup, are studied by means of FTIR, 2H, and 31P NMR spectroscopy. The investigations are focused on the evaluation of the molecular ordering of the lipid molecules as a function of temperature and cholesterol content. Information about the conformational order of the acyl chains is obtained from variable temperature FTIR investigations. Analysis of the CH2 stretching and wagging modes of nondeuterated compounds provides the relative changes in conformational order in the vicinity of the main transition and integral values of distinct gauche conformers over the whole acyl chains, respectively. Likewise, CD2 rocking bands are used to derive the amount of gauche conformers at a specific chain segment in samples containing selectively deuterated acyl chains. The present work represents the first report where the orientational order parameter simultaneously is obtained via two independent procedures. The first method is based on the combination of the CD2 rocking band data with those from complementary 2H NMR studies. The second procedure refers to a line shape analysis of variable temperature 31P NMR spectra. A comparison of the available data for the present lipids with those from related systems, such as 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), reveals a minor influence of the glucose headgroup on the (overall) orientational order while some effect is registered for the conformational order of the lipid molecules. In summary, the present work demonstrates the future potential of such combined FTIR and solid-state NMR studies in order to get detailed information of the lipid ordering in phospholipid bilayers. As shown here, such techniques are of general help in order to separate orientational and segmental (conformational) order in disordered alkyl chains, as there is no restriction to lipid systems as examined in the present work.
- Wolfangel, Peter,Müller, Klaus
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- Facile and useful synthesis of enantiomeric phosphatidylcholines
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The synthesis of optically active phosphatidylcholines (D- and L-4) containing two of the same fatty acid moieties in a molecule is described. Optically pure D-enantiomers (D-4) were obtained from 2,3-di-O-acyl-sn- glycerol (D-1) in high yield by phosphorylation with phosphorus oxychloride and subsequent treatment with choline tosylate (11a). L-Enantiomers (L-4) were also prepared in a similar manner from 1,2-di-O-acyl-sn-glycerol (L-1). The whole procedure is easy and useful for the synthesis of enantiomeric phosphatidylcholines.
- Ishihara, Masami,Sano, Atsunori
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- Method for preparing difatty acyl phosphatidylcholine by solid-phase reaction
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The invention relates to a method for preparing difatty acyl phosphatidylcholine by a solid-phase reaction. Glycerol phosphatidylcholine is subjected to wet-process loading by using a high-activity solid adsorbent, and then a condensation reaction is carried out on the glycerol phosphatidylcholine with fatty acid to obtain the difatty acyl phosphatidylcholine. The method comprises the following steps: dissolving glyceryl phosphatidylcholine in an organic solvent, adding a high-activity solid adsorbent, carrying out adsorbing dispersion while stirring, removing the organic solvent by vacuum evaporation, and carrying out vacuum drying on the obtained solid-phase loaded mixed material; dissolving fatty acid in an organic solvent, adding a condensation coupling agent, carrying out heating reflux to prepare active ester of fatty acid, adding the solid-phase loaded glyceryl phosphatidylcholine, and continuing reflux to prepare a difatty acyl phosphatidylcholine crude product; and carrying out filtering to recover the high-activity solid adsorbent, desolventizing mother liquor, pulping a crude product by using an organic solvent, and carrying out recrystallizing to obtain the high-puritydifatty acyl phosphatidylcholine. According to the method, the reaction yield reaches 65% or above, the product purity reaches 99% or above, the process is simple, the production period is short, andindustrial production is easy to achieve.
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Paragraph 0023; 0024
(2019/12/25)
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- Process for the production of phospholipids
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A new enzymatic process for preparing 1,2-diacylated phospholipids using an enzyme preparation possessing phospholipase activity towards acylation at the sn-1 and sn-2 sites in a microaqueous reaction system. More particularly, the 1,2-diacyl-phospholipids produced according to the esterification/transesterification process are obtainable in high yield and purity and carry identical desired carboxylic acid, preferably fatty acid, acyl groups at the sn-1 and sn-2 positions. The process involves esterification/transesterification (acylation) of a glycerophospholipid, preferably glycerophosphoryl choline (GPC) with a desired carboxylic acid, preferably fatty acid, or their derivatives in the presence of the above mentioned appropriate enzyme preparation. The process of the invention further relates to a process for the production of 1-acyl-2-lyso-glycerophospholipid, preferably 2-lyso-PC by reacting glycerophospholipid, preferably glycerophosphoryl choline (GPC) with a desired carboxylic acid, preferably fatty acid, or their derivatives in the presence of a sn-1 specific phospholipase (PLA1 or PLA1,2) and a solvent, in a microaqueous medium.
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Page/Page column 17
(2008/06/13)
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- Allylamine-containing liposomes
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The invention concerns liposomal preparations comprising as the active agent a compound of formula I in free base form or in acid addition salt form. It also concerns a method of preparation of such liposomal preparations by encapsulating a compound of formula I with an appropriate liposome forming material, a corresponding pharmaceutical compositions, and methods of treatment of systemic, topical and pulmonal fungal infections.
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- FTIR studies of phospholipid membranes containing monoacetylenic acyl chains
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The conformational behaviour of phosphatidylcholine and phosphatidyl acid membranes derived from octadec-14-ynoic and octadec-9-ynoic acid is studied by FTIR spectroscopy comprising both the liquid crystalline and gel phases. In the vicinity of the transition from the gel to the liquid crystalline phase the conformational changes of the acyl chains are followed by the analysis of the CH2 stretching bands and CH2 wagging band progressions. In the liquid crystalline phase a quantitative determination of the amounts of gauche-trans-gauche, double gauche, and end gauche conformers is achieved by the analysis of the CH2 wagging band region. In this connection, several model compounds (hex-2-yne, and hex-3-yne, oct-4-yne) have been examined to assist the assignment of a special vibration band at 1328 cm-1 due to the CH2-C≡C unit. The results for the phospholipids studied here clearly demonstrate that the conformational properties critically depend on their actual lipid structure, sample composition and sample temperature. The derived data are discussed in conjunction with earlier investigations of more conventional lipid systems - mainly containing saturated acyl chains - to evaluate the specific influence of the incorporation of the C-C triple bond into the fatty acid chains.
- Wolfangel, Peter,Lehnert, Rene,Meyer, Hartmut H.,Mueller, Klaus
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p. 4833 - 4841
(2007/10/03)
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- Polymer-supported bases. XII. Regioselective synthesis of lysophospholipids using polymer-supported bicyclic amidines or guanidines
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1-Acylphosphatidylcholines were prepared in good yields by the regioselective monoacylation of L-α-glycerophosphorylcholine with acylimidazoles in the presence of polymer-supported bicyclic amidine of guanidine.
- Tamura,Fukuda,Tomoi,Tokuyama
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p. 2907 - 2914
(2007/10/02)
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- Process of producing phosphatidylcholine derivatives
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A process of producing phosphatidylcholine derivatives by the reaction of glycerophosphatidylcholine with at least one fatty acid anhydride in the presence of a pyridine catalyst is described. The reaction is carried out in a melt of the glycerophosphatidylcholine, the at least one fatty acid anhydride and the catalyst.
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- Total synthesis of perdeuterated phospholipids
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A general method for the total synthesis of various perdeuterated phospholipids (DMPA, DMPG, DMPE, DMPC) is described.Starting from simple and easily obtainable deuterated precursors, perdeuterated phosphatidic acid (DMPA-d59) was synthesized.DMPA-d59 was coupled to various perdeuterated alcohols in the presence of alkylsulfonyl chlorides as condensing agents.The preparation of the perdeuterated alcohols is also presented.The major advantage of this method lies in the independent synthesis of DMPA and the alcohol moieties, allowing the transformation to the desired phospholipid class in the final reaction step.The reaction scheme presented here can also be used for the synthesis of selectively deuterated phospholipids.Keywords - perdeuterated phospholipids / phosphatidic acid-d59 / phosphatidylglycerol-d64 / phosphatidylcholine-d72 / phopshatidylethanolamine-d63 / total synthesis
- Bersch, B.,Starck, J. P.,Milon, A.,Nakatani, Y.,Ourisson, G.
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p. 575 - 583
(2007/10/02)
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- Syntheses of Phospholipids via Oxazaphospholanes
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A method for the synthesis of the head group of phospholipids is described.It is formed by ring opening of oxazaphospholanes, either by mild tetrazole mediated hydrolysis of λ3-oxazaphospholanes or by methylating ring cleavage of λ5-
- Stumpf, Renate,Lemmen, Peter
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p. 1729 - 1731
(2007/10/02)
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- Composition and method for treatment of disseminated fungal infections in mammals
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A method is disclosed for treatment of disseminated fungal infection in a mammal comprising the administration of a fungicidally effective amount of Amphotericin B encapsulated in a substantially sterol-free liposome to the infected mammal. Also provided is an agent for treatment of disseminated fungal infection in a mammal comprising Amphotericin B encapsulated in a liposome which consists essentially of lipids other than sterols.
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- Acoustic shock wave targeting of drug delivery in patients
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Acoustic shock waves generated outside a patient's body are focused upon selected target zones within a patient's body to cause release of biologically active substances from liposomes administered to the patient. The procedures may serve to increase cell uptake of drugs and reduce systemic toxicity.
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- Viral liposome particle
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The outer membrane of influenza virus is attached to a liposome by two different techniques. In addition, one of the techniques allows the entrapment of intact virus, usually one virus per liposome. The techniques can be performed with either influenza virus A or B.
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