We show the thoretical and actual variability in the amount of surface-active lecithin precipitated in the acetone-precipitation step of determining lecithin/sphingomyelin (L/S) ratios in the clinical laboratory. Lecithins precipitated may range from 60 to 90% of the total surface-active lecithins present. The range is sufficient to account for the occasional "immature" L/S ratios (less than 2/...

Considerable interest has developed recently in naturally occurring phosphatides containing ether groups. Two classes of ether-containing phosphatides can be envisaged, i.e. monoether, monoester phosphatides, and diether phosphatides. To date, t,he only monoether, monoester phosphatides known to occur naturally are analogues of phosphatidylethanolamine (1-4) and phosphatidylcholine (5, 6). A ch...

Lecithins are widely used in the food industry as additives. In this regard, requirements for lecithins quality quite high, and development of rapid determination methods their indicators, including acid value, is an urgent task. The article presents research peculiarities vegetable chemical composition a method determining value using pulsed nuclear magnetic relaxation (NMR) method. It was fou...

Despite its importance in cholesterol gallstone formation, crystallization of cholesterol from bile is poorly understood, especially with respect to the influences of other biliary lipids. We reported recently (Konikoff et al. J. Clin. Invest. 1992. 90: 1155-1160) that cholesterol can crystallize from model and native biles as filamentous crystals covered by a surface layer of lecithin molecule...

Two soft biocompatible cationic surfactants from the amino acid arginine, 1,2-dilauroyl-3-acetylarginyl-rac-glycerol (1212RAc) and 1,2-dimirystoyl-3-acetylarginyl-rac-glycerol (1414RAc), were prepared. Their physicochemical properties show that they can be classified as multifunctional surfactants with self-aggregation behaviour comparable to that of short-chain lecithins. The two surfactants c...