Immunochemical studies of phospholipids. II. Syntheses of cardiolipin and its analogues

Synthesis of 1,3- and 1,2-Diphosphatidylglycerol

A novel phosphonium salt methodology was utilized for the first time to synthesize 1,3-, and 1,2-diphosphatidylglycerol. Optically active 1,2-di-O-acyl-sn-glyceryl phosphate was coupled with unprotected glycerol in the presence of pyridiniumbromide perbromide and triethylamine to yield, after final removal of phosphate protecting group, the title compounds. The 1,2-diphosphatidylglycerol (1,2-isomer of cardiolipin) may be a member of a new class of phospholipids for industrial applications similar to other phosphocholines.

An efficient and novel method for the synthesis of cardiolipin and its analogs

A novel synthetic method has been developed for cardiolipin and its analog via a chlorophosphoramidite coupling reaction followed by oxidation. The reagent, N,N-diisopropylmethylphosphoramidic chloride, couples effectively with 1,2-O-dimyristoyl-sn-glycerol in the presence of an amidite activator to form a phosphoamidite intermediate, which then reacts with 2-O-benzylglycerol in the presence of a basic catalyst followed by in situ oxidation to give the corresponding protected cardiolipin. Deprotection of the protecting groups provides tetramyristoyl cardiolipin in good overall yield of 60%. The synthetic method is applicable to large-scale synthesis of cardiolipin and various analogs with or without unsaturation for liposomal drug delivery.

A short, concise route to diphosphatidylglycerol (Cardiolipin) and its variants

A new approach is described for the synthesis of the cardiolipin family of phospholipids that uses phosphonium salt methodology. The method involves the reaction of 2-O-protected glycerol with a trialkyl phosphite derived from 1,2-diacylsn-glycerol in the presence of pyridinium bromide perbromide and triethylamine to afford the phosphoric triesters. The synthesis involves three steps and allows the preparation of a wide range of cardiolipins with different substitution patterns and chain lengths, including unsaturated derivatives. The use of inexpensive protecting groups and the ease of purification facilitate this synthetic route and allow its scale-up in a higher overall yield (72%) than the literature methods.

Synthesis of glycerophospholipids

Recent advances in the synthesis of phosphatidic acids, phosphatidylethanolamines and phosphatidylcholines are described. Methods for the synthesis of some alkylacyl and alk-1-enylacyl analogues of the common diacylglycerophospholipids are also discussed. In addition, synthetic routes are described, that lead to unusual phospholipids such as compounds containing the polar group at position 2 of the glycerol moiety, glycerophospholipids containing alkanolamines of different chain lengths, and glycolphospholipids. All of the common glycerophospholipids can be prepared without the use of protecting groups. Major advances in phospholipid synthesis involve the application of novel phosphorylating agents and the use of cyclic intermediates. Although phosphatidylserines and phosphatidylthreonines as well as phosphatidylglycerols and cardiolipins can be prepared by chemical synthesis, further systematic studies are required to work out procedures that lead to these compounds in high yields.