Ad
related to: retinyl palmitate precautions guidelines pdf file converter free download
Search results
Results from the WOW.Com Content Network
Retinyl palmitate, or vitamin A palmitate, is the ester of retinol and palmitic acid, with formula C 36 H 60 O 2. It is the most abundant form of vitamin A storage in animals. [2] An alternate spelling, retinol palmitate, which violates the -yl organic chemical naming convention for esters, is also frequently seen. [citation needed]
In enzymology, a retinyl-palmitate esterase (EC 3.1.1.21) is an enzyme that catalyzes the chemical reaction. retinyl palmitate + H 2 O ⇌ {\displaystyle \rightleftharpoons } retinol + palmitate Thus, the two substrates of this enzyme are retinyl palmitate and H 2 O , whereas its two products are retinol and palmitate .
The enzyme 11-cis-retinyl-palmitate hydrolase (EC 3.1.1.63) catalyzes the reaction 11-cis-retinyl palmitate + H 2 O 11-cis-retinol + palmitate. This enzyme belongs to the family of hydrolases, specifically those acting on carboxylic ester bonds. The systematic name is 11-cis-retinyl-palmitate acylhydrolase.
The major source of retinoids in human diet are plant pigments such as carotenes and retinyl esters derived from animal sources. [15] Retinyl esters are transported through the chylomicron pathway to the liver or fat tissue while retinol or carotenes are transported from the enterocytes to the liver and are processed into retinyl esters by LRAT ...
Vitamin A occurs as two principal forms in foods: A) retinoids, found in animal-sourced foods, either as retinol or bound to a fatty acid to become a retinyl ester, and B) the carotenoids α-carotene (alpha-carotene), β-carotene, γ-carotene (gamma-carotene), and the xanthophyll beta-cryptoxanthin (all of which contain β-ionone rings) that ...
Elevated amounts of retinyl ester (i.e., >10% of total circulating vitamin A) in the fasting state have been used as markers for chronic hypervitaminosis A in humans and monkeys. [21] This increased retinyl ester may be due to decreased hepatic uptake of vitamin A and the leaking of esters into the bloodstream from saturated hepatic stellate cells.
an all-trans-retinyl ester + H 2 O = 11-cis-retinol + a fatty acid. This enzyme belongs to the family of hydrolases, specifically those acting on carboxylic ester bonds. The systematic name is all-trans-retinyl ester acylhydrolase, 11-cis retinol-forming. This enzyme participates in retinol metabolism.
Retinoic acid (simplified nomenclature for all-trans-retinoic acid) is a metabolite of vitamin A 1 (all-trans-retinol) that is required for embryonic development, male fertility, regulation of bone growth and immune function. [2]
Ad
related to: retinyl palmitate precautions guidelines pdf file converter free download