2929-07-9Relevant academic research and scientific papers
Sterol-modified phospholipids: Cholesterol and phospholipid chimeras with improved biomembrane properties
Huang, Zhaohua,Szoka Jr., Francis C.
experimental part, p. 15702 - 15712 (2009/03/12)
We synthesized a family of sterol-modified glycerophospholipids (SML) in which the sn-1 or sn-2 position is covalently attached to cholesterol and the alternative position contains an aliphatic chain. The SML were used to explore how anchoring cholesterol to a phospholipid affects cholesterol behavior in a bilayer. Notably, cholesterol in the SML retains the membrane condensing properties of free cholesterol regardless of the chemistry or position of its attachment to the glycerol moiety of the phospholipid. SMLs by themselves formed liposomes upon hydration and in mixtures between an SML and diacylglycerophospholipids (C14 to C18 chain length) the thermotropic phase transition is eliminated at the SML equivalent of about 30 mol % free cholesterol. Osmotic-induced contents leakage from SML (C14-C18) liposomes depends upon the linkage and position of cholesterol but in general is similar to that observed in 3/2 diacylphosphatidylcholine/cholesterol (mole ratio) liposomes. SML liposomes are exceptionally resistant to contents release in the presence of serum at 37°C. This is probably due to the fact that SML exchange between bilayers is more than 100 fold less than the exchange rate of free cholesterol in the same conditions. Importantly, SML liposomes containing doxorubicin are as effective in treating the murine C26 colon carcinoma as Doxil, a commercial liposome doxorubicin formulation. SMLs stabilize bilayers but do not exchange and hence provide a new tool for biophysical studies on membranes. They may improve liposomal drug delivery in organs predisposed to the extraction of free cholesterol from bilayers, such as the skin, lung, or blood.
Acid-triggered transformation of diortho ester phosphocholine liposome
Huang, Zhaohua,Guo, Xin,Li, Weijun,MacKay, J. Andrew,Szoka Jr., Francis C.
, p. 60 - 61 (2007/10/03)
The use of pH-sensitive liposomes for acid-triggered site-specific drug delivery is one of the more promising approaches to improve the therapeutic index of drugs. Here, we report the synthesis, assembly, and hydrolysis of the first ortho ester phosphocho
Homologues and isomers of noladin ether, a putative novel endocannabinoid: Interaction with rat cannabinoid CB1 receptors
Appendino, Giovanni,Ligresti, Alessia,Minassi, Alberto,Daddario, Nives,Bisogno, Tiziana,Di Marzo, Vincenzo
, p. 43 - 46 (2007/10/03)
Two regioisomers and 13 analogues of the putative endocannabinoid noladin ether (2-arachidonyl glyceryl ether, 2-AGE, 1) were synthesized and tested for their interaction with CB1 receptors in rat brain membranes. The results showed that a C-20 tetra-unsaturated moiety is necessary for high affinity, and that a series of alkyl glyceryl ethers of potential occurrence in brain tissues have less affinity than 2-AGE for CB1 receptors.
Synthesis and biological activities of 2- arachidonoylglycerol, an endogenous cannabinoid receptor ligand, and its metabolically stable ether-linked analogues
Suhara, Yoshitomo,Takayama, Hiroaki,Nakane, Shinji,Miyashita, Tomoyuki,Waku, Keizo,Sugiura, Takayuki
, p. 903 - 907 (2007/10/03)
We synthesized 2-arachidonoylglycerol (1), an endogenous cannabinoid receptor ligand, and its metabolically stable ether- linked analogues. Compound 1 was synthesized from 1,3- benzylideneglycerol (6) and arachidonic acid in the presence of N,N'-dicyclohexylcarbodiimide and 4-dimethylaminopyridine followed by treatment with boric acid and trimethyl borate. An ether-linked analogue of 2-arachidonoylglycerol (2) was synthesized from 6 and 5,8,11,14-eicosatetraenyl iodide (9). The ether-linked analogues of 2-palmitoylglycerol (4) and 2- oleoyglycerol (5) were synthesized from 6 and hexadecyl iodide (12) and 9-octadecenyl iodide (14), respectively. We confirmed that 1 stimulates NG108-15 cells to induce rapid transient elevation of the intracellular free Ca2+ concentrations through a CB1 receptor-dependent mechanism. Noticeably, 2 exhibited appreciable agonistic activity, although its activity was significantly lower than that of 1. Compound 2 would be a useful tool in exploring the physiological significance of 1, because this compound is resistant to hydrolyzing enzymes in contrast to 1. On the other hand, the ether-linked analogues of either 4 or 5 failed to act as a CB1 receptor agonist. Compounds 4 and 5 would also be valuable as control molecules in experiments where 2 is employed.
The Synthesis of Some Ethers and Mixed Ether Esters of Glycerol
Joll, Cynthia A.,Mortimer, Bok-Cheng,Redgrave, Trevor G.,Stick, Robert V.
, p. 1445 - 1448 (2007/10/02)
The syntheses of various monoethers of glycerol, the derived diesters and two triethers are reported.As well, one of the chiral ether diesters of glycerol has been prepared in both optically active forms.
Process for the production of glyceryl ethers
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, (2008/06/13)
The specification describes a process for the production of a 4-alkoxymethyl-1,3-dioxolan in good yield, in high purity and in a simple manner by reacting an alkyl glycidyl ether with a carbonyl compound in the presence of an acid catalyst. The 4-alkoxymethyl-1,3-dioxolan is useful as an intermediate for the production of an α-monoalkyl glyceryl ether by hydrolysis.
