Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references
Chemical compound
Vitamin A2 is a subcategory of vitamin A.[1]
As with all vitamin A forms, A2 can exist as an aldehyde, Dehydroretinal (3,4-dehydroretinal), an alcohol, 3,4-dehydroretinol (vitamin A2 alcohol) or an acid, 3,4-dehydroretinoic acid (vitamin A2 acid). Many cold-blooded vertebrates use the aldehyde for their visual system to obtain a red-shifted sensitive spectrum.[2]
Human skin naturally contains the alcohol form.[3][4] In humans, CYP27C1 converts ordinary A1 (all-trans retinoids) to A2. The enzyme also converts 11-cis-retinal.[2]
Vitamin A2 was first identified by Richard Alan Morton using newly-developed absorption spectroscopy in 1941.[5]
^Babino D, Golczak M, Kiser PD, Wyss A, Placzewski K, von Lintig J (2016). "The Biochemical Basis of Vitamin A3 Production in Arthropod Vision". ACS Chem Biol. 11 (4): 1049–1057. doi:10.1021/acschembio.5b00967. PMC 4841470. PMID 26811964.
^Törmä H, Vahlquist A (1985). "Biosynthesis of 3-dehydroretinol (vitamin A2) from all-trans-retinol (vitamin A1) in human epidermis". J Invest Dermatol. 85 (6): 498–500. doi:10.1111/1523-1747.ep12277290. PMID 4067325.
^Vahlquist A (1980). "The identification of dehydroretinol (vitamin A2) in human skin". Experientia. 36 (3): 317–318. doi:10.1007/bf01952299. PMID 7371787. S2CID 31357743.
^Goodwin, T W (1977). "R. A. Morton". Nature. 266 (5600): 394. Bibcode:1977Natur.266..394G. doi:10.1038/266394a0. S2CID 31211784.
VitaminA2 is a subcategory of vitamin A. As with all vitamin A forms, A2 can exist as an aldehyde, Dehydroretinal (3,4-dehydroretinal), an alcohol, 3...
4-dehydroretinal) is a derivative metabolite of retinal belonging to the group of vitaminA2 as a retinaldehyde form, besides the endogenously present 3,4-dehydroretinol...
compounds in this group are vitamin D3 (cholecalciferol) and vitamin D2 (ergocalciferol). The major natural source of vitamin D is synthesis of cholecalciferol...
4-didehydroretinal (vitaminA2), (3R)-3-hydroxyretinal, (3S)-3-hydroxyretinal (both vitamin A3), and (4R)-4-hydroxyretinal (vitamin A4). Many fish and...
main function of the CYP27C1 enzyme is conversion of vitamin A1 (all-trans retinol) to vitaminA2 (all-trans 3,4-dehydroretinal). The basic reaction for...
Lynestrenol, a progestogen hormone Retinal, one of the three forms of vitamin A Tigestol Vitamin_A2 This set index page lists chemical structure articles associated...
always grouped together with the inherited versions, a severe nutritional vitamin B12 deficiency can also result in syndrome with identical symptoms and...
to biological molecules. His research group were the first to identify vitaminA2 and related compounds. They were also among the first to characterise...
include bilin and carotenoids such as idoxanthin, crustaxanthin, and vitaminA2 aldehyde (3-dehydroretinal). The bilin and retinal produces the base green...
that some vitamin and mineral content is lost. Soluble calcium and phosphorus decrease by 5%, thiamin and vitamin B12 by 10%, and vitamin C by 20% or...
The vitamin D receptor (VDR also known as the calcitriol receptor) is a member of the nuclear receptor family of transcription factors. Calcitriol (the...
factors, Vitamin K is itself oxidized. Another enzyme, Vitamin K epoxide reductase (VKORC), reduces vitamin K back to its active form. Vitamin K epoxide...
Thromboxane A2 (TXA2) is a type of thromboxane that is produced by activated platelets during hemostasis and has prothrombotic properties: it stimulates...
The retinoids are a class of chemical compounds that are vitamers of vitamin A or are chemically related to it. Retinoids have found use in medicine where...
it contains "inadequate quantities of iron, folate, vitamins C and D, thiamine, niacin, vitamin B6, and pantothenic acid to meet an infant's nutritional...
rich in vitamin A, vitamin C, and vitamin K, with moderate content of dietary minerals (table). Although seeds generally have lower vitamin content,...
calcium, vitamin A and vitamin D than other types of milk. Milk from Guernsey cows is notable for the levels of beta-carotene, Omega-3 fatty acid and A2 β-casein...
proteins: calbindin, calretinin and S100G. They were originally described as vitamin D-dependent calcium-binding proteins in the intestine and kidney of chicks...
circulation, and increases in the activation of vitamin D3 to calcitriol. Calcitriol, the active form of vitamin D3, promotes absorption of calcium from the...
direct agonists or indirect agonists of dopamine receptor D1 or adrenoceptor A2. Relatively high doses of stimulants cause cognitive deficits. Amphetamine –...
benefits of vitamin C are limited to the first 8 to 12 hours after the first tingling is sensed. Thereafter, vitamin C has far less effect. Vitamin C may cure...
(inhibit phospholipase A2 production) Cyclopentenone prostaglandins may play a role in inhibiting inflammation Vitamin D3 and vitamin K2. Synthetic prostaglandins...
CYP2R1 is cytochrome P450 2R1, an enzyme which is the principal vitamin D 25-hydroxylase. In humans it is encoded by the CYP2R1 gene located on chromosome...
particularly warfarin, which inhibit clot formation by interfering with Vitamin K metabolism, may actually promote arterial calcification in the long term...
of lipids known as eicosanoids. The two major thromboxanes are thromboxane A2 and thromboxane B2. The distinguishing feature of thromboxanes is a 6-membered...
scope including esters of cholesterol, phospholipids, and of lipid-soluble vitamins and sphingomyelinases; however, these are usually treated separately from...
shown to inhibit COX-1 around 3-18 times as much as aspirin. Calcitriol (vitamin D) significantly inhibits the expression of the COX-2 gene. Caution should...
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