- Diplasmenylcholine-folate liposomes: An efficient vehicle for intracellular drug delivery
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Most pharmaceutical and gene therapy applications of targeted liposomes presently suffer from inefficient contents delivery to the cytoplasm of target cells. We report a plasma-stable liposome, composed of synthetic, naturally occurring diplasmenylcholine (1,2-di-O-(Z-1′-hexadecenyl)-sn-glycero-3-phosphocholine; DPPlsC), that rapidly and efficiently releases its contents at endosomal pHs. Acid-catalyzed hydrolysis of these liposomes produces glycerophosphocholine and fatty aldehydes, leading to greatly enhanced liposome permeability (t50% release ? 1-4 h between pH 4.5-5.5) when > 20% of the vinyl ether lipid has been hydrolyzed. Plasma stability of nonhydrolyzed 9:1 DPPlsC/dihydrocholesterol liposomes exceeds 48 h at 37°C, pH 7.4 in 50% serum; pure DPPlsC liposomes remain stable in 10% serum under the same conditions. Fluorescence assays of KB cells treated with 99.5:0.5 DPPlsC/DSPE-PEG3350-folate liposomes containing encapsulated propidium iodide (PI) indicate that 83% of the PI escapes the endosomal compartment within 8 h to produce intensely stained nucleii. The IC50 value of 1-β-arabinofuranosylcytosine (Ara-C) encapsulated in DPPlsC/DSPE-PEG3350-folate liposomes is 0.49 μM in KB cell cultures, a approx. 6000-fold enhancement in cytotoxicity compared with free drug (2.8 mM). Empty DPPlsC/DSPE-PEG3350-folate liposomes had no effect on DNA synthesis, indicating that DPPlsC and its degradation products are benign to cell function at these lipid concentrations. Our results suggest that concurrent application of selective targeting and membrane translocation mechanisms in drug carriers can significantly increase their efficacy. Most pharmaceutical and gene therapy applications of targeted liposomes presently suffer from inefficient contents delivery to the cytoplasm of target cells. We report a plasma-stable liposome, composed of synthetic, naturally occurring diplasmenylcholine (1,2-di-O-(Z-1'-hexadecenyl)-sn- glycero-3-phosphocholine; DPPIsC), that rapidly and efficiently releases its contents at endosomal pHs. Acid-catalyzed hydrolysis of these liposomes produces glycerophosphocholine and fatty aldehydes, leading to greatly enhanced liposome permeability (t(50% release) ? 1-4 h between pH 4.5-5.5) when >20% of the vinyl ether lipid has been hydrolyzed. Plasma stability of nonhydrolyzed 9:1 DPPlsC/dihydrocholesterol liposomes exceeds 48 h at 37°C, pH 7.4 in 50% serum; pure DPPlsC liposomes remain stable in 10% serum under the same conditions. Fluorescence assays of KB cells treated with 99.5:0.5 DPPlsC/DSPE-PEG3350-folate liposomes containing encapsulated propidium iodide (PI) indicate that 83% of the PI escapes the endosomal compartment within 8 h to produce intensely stained nucleii. The IC50 value of 1-β- arabinofuranosylcytosine (Ara-C) encapsulated in DPPlsC/DSPE-PEG3350-folate liposomes is 0.49 μM in KB cell cultures, a ~6000-fold enhancement in cytotoxicity compared with free drug (2.8 mM). Empty DPPlsC/DSPE-PEG3350- folate liposomes had no effect on DNA synthesis, indicating that DPPlsC and its degradation products are benign to cell function at these lipid concentrations. Our results suggest that concurrent application of selective targeting and membrane translocation mechanisms in drug carriers can significantly increase their efficacy.
- Rui, Yuanjin,Wang, Susan,Low, Philip S.,Thompson, David H.
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- Glycerin phosphatidyl choline preparation method
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The invention discloses a preparation method of glycerinum phosphatidylcholine. The preparation method comprises the following steps: (1) mixing a compound shown in formula (I) and anhydrous sodium carbonate to obtain a mixture M1; (2) placing the mixture M1 and (R)-(-)-3-chlorine-1,2-propanediol in anhydrous ethanol, and carrying out the refluxing to obtain a mixture M2; (3) filtering the mixture M2, carrying out the membrane separation, removing sodium chloride in the mixture M2, and obtaining filter liquid M3; (4) adding zinc chloride into the filter liquid M3, and dissolving the zinc chloride by adding water to obtain a mixture M4; (5) enabling the mixture M4 to flow by ion exchange resin, filtering the mixture M4, obtaining the filter liquid, and preparing the glycerinum phosphatidylcholine; (see the specifications), wherein R is Ca or Mg. By adopting the method, the glycerinum phosphatidylcholine is simple to prepare, and the yield is high, so that an effect of simple preparation method, high synthesis rate and low production cost can be realized.
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Paragraph 0030; 0063; 0064; 0065; 0066
(2018/04/20)
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- Fluorogenic probes to monitor cytosolic phospholipase A2 activity
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Arachidonic acid derivatives equipped with either one or two fluorescent groups attached to the tip of the alkyl chains were synthesized and shown to function as inhibitor and substrate probes of cPLA2. The inhibitor probe was demonstrated to p
- Ng, Cheng Yang,Kwok, Timothy Xiong Wei,Tan, Francis Chee Kuan,Low, Chian-Ming,Lam, Yulin
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supporting information
p. 1813 - 1816
(2017/02/10)
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- A L-α-Ganong choline phosphate preparation method
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The invention discloses a preparation method of L-alpha-choline glycerophosphate. According to the method, (2S)-3-halogenated-1,2-propylene oxide and phosphoryl choline salt are used as the raw materials, and are subjected to esterification and hydrolysis reaction in a solvent to obtain the L-alpha-choline glycerophosphate crude product, and the crude product is subjected to silica gelcolumn chromatography and purification through ion exchange resin to obtain the L-alpha-choline glycerophosphate pure product. Compared with the prior art, the preparation method disclosed by the invention has the advantages that the operation is simpler; the adopted chiral material (2S)-3-halogenated-1,2-propylene oxide is cheap and easy to obtain; the prepared crude product is subjected to silica gelcolumn chromatography and purification through ion exchange resin to obtain the L-alpha-choline glycerophosphate product with higher quality, and the L-alpha-choline glycerophosphate content is more than 99%; the technical process is more suitable for large scale production.
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Paragraph 0051-0053
(2017/03/18)
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- SYNTHESIS OF PHOSPHORIC ESTERS
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The present invention relates to a process for the preparation of phosphoric esters, and to selected compounds.
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Page/Page column 5
(2012/09/05)
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- A PROCESS FOR PREPARATION OF L-ALPHA-GLYCEROPHOSPHORYL CHOLINE
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The present invention relates to a process for preparing L-α- glycerophosphorylcholine by reacting phosphocholine chloride to R-(+)-glycidol. The present invention can prepare a compound of formula 1 in short reaction step and high yield.
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Page/Page column 10-11
(2008/06/13)
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