Subject(s)
Diacylglycerol Cholinephosphotransferase/metabolism , Diglycerides/metabolism , Glycerides/metabolism , Lung/enzymology , Phosphotransferases/metabolism , Animals , Chemical Phenomena , Chemistry , Cytidine Diphosphate Choline/metabolism , Egg Yolk , Fatty Acids/analysis , Fatty Acids, Unsaturated/analysis , Female , Lipids/biosynthesis , Liver , Microsomes/enzymology , Phosphatidylcholines , Phospholipases/metabolism , Rats , Structure-Activity RelationshipABSTRACT
Enantiomeric diacylglycerols were emulsified, mole for mole, with lyso(1-acyl) lecithin and were hydrolyzed with lipoprotein lipase in NH4Cl-beef serum albumin buffer at pH 8.6 after a brief incubation with delipidated rat serum. The enzyme was prepared from lyophilized and dialyzed bovine skim milk in a 4 percent solution. The course of hydrolysis for each set of enantiomers was determined by gas-liquid chromatography of the masses of the diacylglycerols remaining or monoacylglycerols released in the medium between 0 and 15 min. The majority of sets of sn-1,2- and 2,3-diacylglycerols, including an isotope-labeled true enantiomeric set which was assessed by mass spectrometry, demonstrated preference by the enzyme for lipolysis at position 1 but with less specificity than previously was shown in sn-triacylglycerol hydrolysis. The results preclude the possibility that the predominance of sn-2,3-diacylglycerol intermediates during triacylglycerol hydrolysis is due solely to a preferential breakdown of the 1,2-isomers and reinforce the conclusion that lipoprotein lipase is specific for position 1.
Subject(s)
Diglycerides/metabolism , Glycerides/metabolism , Lipoprotein Lipase/metabolism , Animals , Cattle , Chromatography, Gas , Hydrolysis , Lysophosphatidylcholines , Mass Spectrometry , Milk/enzymology , Rats , Stereoisomerism , Structure-Activity RelationshipSubject(s)
Lipase/metabolism , Lipoprotein Lipase/metabolism , Pancreas/enzymology , Triglycerides , Animals , Bile Acids and Salts , Carbon Radioisotopes , Cattle , Chromatography, Gas , Chromatography, Thin Layer , Egg Yolk , Enzyme Activation , Female , Glycocholic Acid , Kinetics , Linoleic Acids , Lysophosphatidylcholines , Milk/enzymology , Oleic Acids , Palmitic Acids , Phosphatidylcholines , Structure-Activity RelationshipABSTRACT
A procudure for the synthesis of stereochemically puresn-glycerol-cyclic-phosphodiesters has been developed. The process involves the following sequence of reactions: benzyl-sn-glycerolâbenzyl-sn-glycerol-cyclic(phenyl)-phosphodiesterâsn-glycerol-cyclic-phosphodiester. The following isomers have been synthesized:sn-glycerol-2,3-1,2-, 1,3-cyclic-phosphodiesters and the racemic mixturer. The 2,3- and 1,2-cyclic-phosphodiesters of glycerol are optically active antipodes. They are five-membered ring asymmetrical compounds, with specific rotations of -1.6°±0.1° and +1.6°±0.1°, respectively. These two enantiomers and their racemate are thick liquids and are unstable; therefore they were converted into Ba(glycerol-cyclic-phosphodiester)2 salts, which can be better stored. The six-membered ringsn-glycerol-1,3-cyclic-phosphodiester is a crystalline, stable compound. The physical and chemical properties of these cyclic-phosphodiesters of glycerol are described and their chemical analyses are reported.
Subject(s)
Acyltransferases/metabolism , Glycerides/metabolism , Microsomes/metabolism , Triglycerides/biosynthesis , Acylation , Acyltransferases/antagonists & inhibitors , Animals , Carbon Isotopes , Chromatography, Thin Layer , Fatty Acids/metabolism , Fluorides/pharmacology , In Vitro Techniques , Intestinal Mucosa/metabolism , Intestines/cytology , Intestines/enzymology , Male , Microsomes/enzymology , Microsomes, Liver/enzymology , Microsomes, Liver/metabolism , Rats , Stereoisomerism , TritiumABSTRACT
Procedures have been developed for the synthesis of both enantiomeric forms of mixed fatty acid, saturated and polyunsaturated 1,2-diacyl-sn-glycerols and 2,3-diacyl-sn-glycerols from D-mannitol as starting material. The following diacyl-sn-glycerols have been synthesized: 1-Stearoyl-2-linoleoyl-sn-glycerol, 1-stearoyl-2-linolenoyl-sn-glycerol, 2-linoleoyl-3-stearoyl-sn-glycerol and 2-linolenoyl-3-oleoyl-sn-glycerol. Their specific rotations, refractive indices, densities, solubilities, carbon and hydrogen analysis and iodine values have been reported.
