PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “ESTERIFICATION”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,099 records · Page 61Linked to original sources
PubMed1976

Carbodiimide-intermediated esterification of the inorganic phosphates and the effect of tertiary amine base.

Detailed analysis of appropriate 31P nuclear-magnetic-resonance spectra shows that under the usual laboratory conditions, carbodiimide-induced condensation of orthophosphoric acid in a number of solvents leads to condensation only slightly beyond the metaphosphate composition in the presence of strong tertiary amines; whereas in the absence of amine, the condensation proceeds into the ultraphosphate region about halfway between the metaphosphate and phosphoric anhydride compositions. With amine, the principal product consists of the cyclic trimetaphosphate anion, with one of the nonbridging oxygen atoms substituted by the urea resulting from hydration of the carboiimide, i.e., (O2-) P-O-P(O2-) -O-P(O) [N[CH(CH3)2] see article [C(O)NHCH(CH3)2]] for the condensation with diisopropylcarbodiimide. Without amine, the major product is the 1,5-mu-oxotetrametaphosphate anion see article. The well-known carbodiimide-mediated phosphorylation of alcohols with orthophosphoric acid is shown to be directly attributable to the high reactivity of the phosphate branch groups of the carbodiimide-generated ultraphosphates.

Amines↗
PubMed1996

Plasma cholesteryl ester transfer protein concentration, high-density lipoprotein cholesterol esterification and transfer rates to lighter density lipoproteins in the fasting state and after a test meal are similar in Type II diabetics and normal controls.

Rates of ester formation from [3H]cholesterol and of [3H]cholesteryl ester transfer from the HDL-containing plasma fraction to lipoproteins of lighter densities (apo B-containing LP) and plasma cholesteryl ester transfer protein concentration (CETP) were measured in normotriglyceridemic Type II diabetics (n = 11) and normal controls (n = 10) both in the fasting state and 4 h after a standard milk-shake test meal (50g of fat/m of body surface). The percent of [3H]cholesteryl ester synthesis was measured in a plasma [3H]cholesterol-HDL containing preparation incubated for 30 min and the [3H]cholesteryl ester transfer was measured upon precipitation of apo B-containing lipoproteins with dextran sulphate/MgCl2 following a 2 h period of plasma incubation with [3H]cholesteryl ester-HDL. The test meal significantly increased the plasma triglyceride concentration and to a similar extent in diabetics and in normal controls. Both a HDL-[3H]cholesteryl ester synthesis and transfer rates were equally stimulated in diabetics and in controls. When data were expressed by the concentration of plasma triglycerides, cholesteryl ester formation and transfer rates were similar in the alimentary and fasting periods, and when expressed per apo B concentration, cholesteryl ester transfer rates rose during the alimentary period in both diabetics and controls indicating that there was a net gain of cholesteryl ester per apo B lipoprotein. Plasma CETP mass, and neutral lipid transfer activity were similar in diabetics and normal controls demonstrating that the reverse transport of cholesterol through the apo B lipoprotein pathway is not altered in normotriglyceridemic Type II diabetics.

Apolipoproteins B↗
PubMed1982

Cholesterol transport between cells and body fluids. Role of plasma lipoproteins and the plasma cholesterol esterification system.

The manner in which cells retain their sterol content is reviewed. Although most of what is known at the molecular level has been defived from studies in continuous cell culture, the findings appear to be broadly applicable to conditions in vivo. The main impetus to this research has come from the potential direct relevance of cell sterol balance to lipid disorders.

Animals↗
PubMed1997

Octanoate metabolism in primary culture of chicken hepatocytes: evidence for high-capacity octanoate esterification.

[14C]Octanoate metabolism was measured in chicken primary hepatocytes, as a function of time in culture. [14C]Octanoate was essentially converted to oxidative products (CO2 and ketone bodies) in freshly isolated cells while [14C]palmitate was exclusively esterified in triacylglycerols (TG). In contrast, in cultured cells, [14C] octanoate was exclusively recovered in TG as radiolabeled octanoate (33%), but also as newly synthetised fatty acids mainly palmitate (37%), stearate (18%), oleate (4.4%), decanoate (2.4%), and myristate (2.2%). Therefore, it may be suggested that the enhanced lipogenic conditions induced by culture enhance octanoate flux toward TG synthesis in this model. It is further suggested that chicken hepatocytes in primary culture could be a useful model to study regulatory mechanisms of several lipogenic enzymes.

Animals↗