Improved synthesis of choline phospholipids

Abstract

Choline phospholipids (diether and dialkyl analogs of phosphatidyl choline, cholesteryl phosphocholine) were prepared, in yields of 72–83%, by condensation of the diglyceride analogs (or cholesterol) with phosphorusoxychloride and choline toluene‐sulfonate.

Effect of cholesterol on calcium-induced aggregation of liposomes and calcium diphosphatidate membrane traversal

“…Among the phospholipids, phosphatidic acid is known to be a calciumspecific ionophore (Serhan et al, 1981(Serhan et al, , 1982Chauhan & Brockerhoff, 1984). In the diether analogue of phosphatidic acid, however, the ability to transport calcium through a bilayer is diminished by more than 90% (Chauhan & Brockerhoff, 1984).…”

“…In the diether analogue of phosphatidic acid, however, the ability to transport calcium through a bilayer is diminished by more than 90% (Chauhan & Brockerhoff, 1984). Kinetic data showed that two phosphatidic acid molecules bind one Ca2+ (Chauhan & Brockerhoff, 1984;Reusch, 1985). A molecular model shows that in this cisCa(PA), complex both Ca2+ and the two phosphatidate head groups are dehydrated with calcium captive in a cage formed by the phosphate and carbonyl oxygens of the two lipid molecules.…”

“…Calcium ion and its interaction with acidic phospholipids (phosphatidate, phosphatidylserine, or phosphatidylglycerol) have been implicated in a critical regulatory role in these membrane fusion phenomena (Poste & Allison, 1973;Douglas, 1975;Papahadjopoulos et al, 1979;Duzgunes et al, 1980). The fusion of unilamellar liposomes among themselves Bentz et al, 1983a,b) or to planar bilayers (Duzgunes & Ohki, 1981;Cohen et al, 1982) involves an aggregation step followed by the fusion event. Although aggregation and fusion can be considered as independent phenomena, aggregation is a necessary prerequisite for membrane fusion, and it is achieved, in all likelihood, by the formation of "trans-" (Le., intervesicle) Ca(PL)21 bridges followed by dehydration of the membrane-water-membrane interfacial system (Papahadjopoulos et al, 1978;Portis et al, 1979).…”

Analysis of the facilitatory effect of the ACTH-(4–9) analog ORG 2766 on active social contact in rats

“…Pyridine (1 ml, 12.5 mmol) and choline toluenesulfonate (1.9 g, 6.9 mmol) were added and stirring was continued for 16 h [17]. After addition of 1 ml each of pyridine and water and stirring for 2 h the reaction was worked up by addition of 50 ml water and 100 ml methanol.…”

Antileishmanial Chemotherapy: A Literature Review

“…[105][106][107][108][109][110][111] Na década de 1980, Hansen e colaboradores obtiveram a miltefosina através da síntese original, descrita por Hirt e Berchtold, 112 com apenas duas etapas reacionais. Este método consiste na reação entre o diclorofosfato de 2-bromoetil (37) e o hexadecanol (38), seguida da troca do halogênio pelo grupo trimetilamina (Esquema 8).…”