Search results
Results from the WOW.Com Content Network
Ether phospholipids: phospholipids are known to have ether-linked "tails" instead of the usual ester linkage. [1] Ether on sn-1, ester on sn-2: "ether lipids" in the context of bacteria and eukaryotes refer to this class of lipids. Compared to the usual 1,2-diacyl-sn-glycerol (DAG), the sn-1 linkage is replaced with an ester bond. [1] [2] [3]
[4] [5] The amide group is called a peptide bond when it is part of the main chain of a protein, and an isopeptide bond when it occurs in a side chain, as in asparagine and glutamine. It can be viewed as a derivative of a carboxylic acid ( R−C(=O)−OH ) with the hydroxyl group ( −OH ) replaced by an amine group ( −NR′R″ ); or ...
In sphingomyelin and glycolipids, the amino group of sphingosine is linked to FAs by an amide bond. In sphingomyelin the primary hydroxyl group of sphingosine is esterified to phosphoryl choline. Space-filling models of (a) sphingomyelin and (b) cholesterol. In glycolipids, the sugar component is attached to this group.
The long-chain bases, sometimes simply known as sphingoid bases, are the first non-transient products of de novo sphingolipid synthesis in both yeast and mammals. These compounds, specifically known as phytosphingosine and dihydrosphingosine (also known as sphinganine, [4] although this term is less common), are mainly C 18 compounds, with somewhat lower levels of C 20 bases. [5]
Structurally, amino esters consist of three molecular components: a lipophilic part (ester); an intermediate aliphatic chain; a hydrophilic part (amine); The chemical linkage between the lipophilic part and the intermediate chain can be of the amide-type or the ester-type, and is the general basis for the current classification of local anesthetics.
Therapeutic agents can be linked to dextran via an ester bond which can be hydrolyzed slowly by esterases to produce sustained, stable drug release. Drug-dextran complexes can also be formed by chemical linkage through an amide bond, which is hydrolyzed by amidase. Prodrugs coupled by amide bonds provide much slower drug release than by ester ...
Phosphatidylserine (PS) is the major acidic phospholipid class that accounts for 13–15% of the phospholipids in the human cerebral cortex. [7] In the plasma membrane, PS is localized exclusively in the cytoplasmic leaflet where it forms part of protein docking sites necessary for the activation of several key signaling pathways.
Acid–base-catalysed hydrolyses are very common; one example is the hydrolysis of amides or esters. Their hydrolysis occurs when the nucleophile (a nucleus-seeking agent, e.g., water or hydroxyl ion) attacks the carbon of the carbonyl group of the ester or amide. In an aqueous base, hydroxyl ions are better nucleophiles than polar molecules ...