A simple synthesis of phosphonate - containing lipids. Introduction of the phosphonic acid moiety into hydrolytically-labile compounds

Synthesis and antineoplastic properties of an ether glycerophosphonocholine, and analog of ET-18-OCH3-GPC

A glycerophosphonocholine analog of the ether-linked lipid, rac-1-O-octadecyl-2-O-methyl-glycero-3-phosphocholine (ET-18-OCH3-GPC), was synthesized in which the head group is nonhydrolyzable by phospholipase C. The phosphonate analog used in this study is rac-3-octadecyloxy-2-methoxy-propyl-phosphonocholine, C18H37OCH2CH(OCH3)CH2P(O)(O)OCH2CH2N+(CH3)3. The activity of the synthetic phosphonate was tested in the human leukemic cell line, HL-60, and the human undifferentiated cervical carcinoma, C-41. The glycerophosphonocholine inhibited [3H]thymidine uptake by HL-60 cells with an EC50 value of 5-7 microM. The glycerophosphate ET-18-OCH3-GPC had an EC50 value of approximately 2 microM against HL-60 cells. The EC50 values estimated from cell viability experiments were similar to that for [3H]thymidine uptake. The EC50 value for C-41 cells was about 10-15 microM. The data demonstrate that the glycerophosphonocholine is a promising anti-cancer drug for the treatment of both leukemia and solid tumors. Furthermore, the data demonstrate that phospholipase C-catalyzed hydrolysis of ET-18-OCH3-GPC does not play an important role in the cytotoxic action of the ether-linked glycerolipids.

Synthesis of phosphonate and ether analogs of rac-phosphatidyl-L-serine

The chemical synthesis of four phosphonate-containing phosphatidylserine analogs namely, L-serine (+/-)-[2,3-bis(hexadecyloxy) and 2,3-bis(Palmitoyloxy)-propyl] phosphonates, and L-serine (+/-)-[3,4-bis(hexadecyloxy and 3,4-bis(palmitoyloxy)-butyL]phosphonates is descirbed. (+/-)-2,3-Bis(hexadecyloxy) and 2,3-bis(palmitoyloxy)-prophylphosphonic acids and (+/-)-3,4-bis(hexadecyloxy)butylphosponic acid were prepared by reaction of tris(trimethylsily) phosphite on the corresponding haloalkane. Condensation of the above phosphonic acids or (+/-)-3,4-bis(palmitoyloxy)butylphosphonic acid with N-carboxy-L-serine dibenzyl ester in the presence of trichloroacetonitrile or triisopropylbenzenesulfonyl chloride yielded the protected serine intermediates, which on hydrogenolysis gave the desired L-serine analogs. By a similar route, 1,2-dihexadecyl-rac-glycero-3-phosphoric acid was converted to 1,2-dihexadecyl-rac-glycerophospho-L-serine (L-serine (+/-)-2,3-bis(hexadecyloxy)propyl hydrogen phosphate(ester).

Isosteres of natural phosphates. 5. The preparation of phosphotidycholine, phosphotidylethanolamine and phosphotidylglycerol

Isosteric phosphonate analogues of phosphatidylcholine, phosphatidylethanolamine and phosphatidylglycerol have been prepared in which the normal oxygen atom of the phosphate ester linkage in the glycerol backbone of the molecule has been replaced by a methylene group. These have been prepared by the coupling of the previously reported phosphotidic acid (isosteric analogue of phosphatidic acid) with the appropriate protected hydroxyl compound mediated by trichloroacetonitrile. In all cases, racemic materials have been isolated: for the analogue of phosphatidylglycerol, a mixture of two enantiomeric pairs is isolated.

Isosteres of natural phosphates. 4. The synthesis of phosphonic acid analogues of phosphatidic acid and acyldihydroxy acetone phosphate

The chemical synthesis of 3,4-diacyloxybutyl-1-phosphonic acids having palmitoyl and oleoyl groups is described. These were prepared by reaction of the appropriate 3,4-diacyloxybutyl-1-bromide with tris(trimethylsilyl) phosphite followed by mild hydrolysis of the trimethyl-silyl groups from the phosphonic acid. Also reported is the preparation of 4-palmitoyl-3-oxobutyl-1-phosphonic acid by the acylation of 4-hydroxy-3-oxobutyl-1-phosphonic acid. This latter compound is an isosteric analogue of acyldihydroxyacetone phosphate.

Synthesis of DL-2,3-diacyloxypropylphosphonyl-cholines from DL-2,3-diacyloxyiodopropanes

The chemical synthesis of racemic diacyloxypropylphosphonylcholines having octanoyl, myristoyl, oleoyl and stearoyl groups is described. The route involved reaction of dioactanoyloxy-dimyristoyloxy-dioleoyloxy-, and distearoyloxpropyliodide with tris (trimethylsilyl) phosphite to yield the corresponding bis (trimethylsilyl) phosphonate. Removal of the trimethylsilyl groups by neutral aqueous hydrolysis gave the free diacylpropylphosphonic acids, which, when treated with choline toluenesulfonate, yielded the desired dioctanoyloxy-, dimyristoyloxy-, dioleoyloxy-, and distearoyloxypropylphosphonylcholines. The paper also describes the synthesis of 2-octadecyleicosylphosphorylcholine.