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A convenient selective synthesis of 2′,3′-di-O-acetyl-nucleotide-5′-phosphates, 2′,3′-di-O-acetyl-nucleotide-5′-triphosphates and 2′,3′,5′-tri-O-acetyl-nucleosides in water has been developed. Furthermore, a long-chain selective glycerol-3-phosphocholine diacylation is elucidated. These reactions are environmentally benign, rapid, high yielding, and the products are readily purified. Importantly, this reaction may indicate a prebiotically plausible reaction pathway for the selective acylation of key metabolites to facilitate their incorporation into protometabolism. more...

Moving the phosphatidylcholine group from the 3-to the 2-position in monolayers of distearoyl -sn- glycero -3- phosphocholine at the oil/water interface expands the surface pressure-area isotherm and markedly increases the surface pressure at which phase separation occurs with only a slight change in the monolayer surface density at the onset of the transition. This is interpreted in terms of a change in an ordering parameter in the solid-condensed state. more...

Earlier studies from our laboratory have shown that PAF and LTB4 biosynthesis are inhibited in rat PMN depleted of its 20∶3 (JBC. '86,261, 7592). To test whether these cells contain sufficient 1-O-alkyl-2-acyl-GPC to support PAF synthesis, phosphotidyl choline was isolated from these 20∶4-depleted cells, fractionated into different subclasses and their fatty acid composition determined. These results were compared with those obtained with control PMN. Both control and 20∶4-depleted PMN contained significantly large amounts of alkylacyl-GPC and diacyl-GPC. Small amounts (4%) of alkenylacyl-GPC were also present. The amount of 20∶3 in 20∶4-depleted cells was more or less equal to the amount of 20∶4 in control cells. About 62% of PC-bond 20∶4 in control PMN and about 56% of PC-bound 20∶3 in the 20∶4-depleted PMN was found associated with the alkylacyl species. These results show that both control and 20∶4 depleted PMN have ample precursor substrates to support PAF biosynthesis and these substrates are enriched with 20∶4 in control cells and with 20∶3 in 20∶4-depleted cells. These findings are consistant with the existance of a highly specific phospholipase A2 capable of distinguising 20∶4 from 20∶3 containing phospholipids. more...