:Dehydroretinal

{{chembox

| ImageFile = Dehydroretinal.svg

| ImageSize = 220

| ImageAlt = Skeletal formula of dehydroretinal

| ImageFile1 = Dehydroretinal 3D ball.png

| ImageSize1 = 240

| ImageAlt1 = Ball-and-stick model of the dehydroretinal molecule

| IUPACName = 3,4-Didehydroretinal

| SystematicName = (2E,4E,6E,8E)-3,7-Dimethyl-9-(2,6,6-trimethylcyclohexa-1,3-dien-1-yl)nona-2,4,6,8-tetraenal

| OtherNames = 3,4-Dehydroretinal; 3,4-Didehydroretinaldehyde

|Section1={{Chembox Identifiers

| ChemSpiderID = 4444397

| InChI = 1/C20H26O/c1-16(8-6-9-17(2)13-15-21)11-12-19-18(3)10-7-14-20(19,4)5/h6-13,15H,14H2,1-5H3/b9-6+,12-11+,16-8+,17-13+

| InChIKey = QHNVWXUULMZJKD-OVSJKPMPBA

| StdInChI=1S/C20H26O/c1-16(8-6-9-17(2)13-15-21)11-12-19-18(3)10-7-14-20(19,4)5/h6-13,15H,14H2,1-5H3/b9-6+,12-11+,16-8+,17-13+

| StdInChIKey = QHNVWXUULMZJKD-OVSJKPMPSA-N

| CASNo=472-87-7

| PubChem=5280866

| KEGG = C05918

| 3DMet = B00875

| ChEBI = 28537

| EC_number = 207-457-7

| UNII = HV8T003XO1

| SMILES = O=C\C=C(\C=C\C=C(\C=C\C1=C(\C=C/CC1(C)C)C)C)C

| MeSHName=Dehydroretinal

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|Section2={{Chembox Properties

| C=20 | H=26 | O=1

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|Section3={{Chembox Hazards

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Dehydroretinal (3,4-dehydroretinal) is a derivative metabolite of retinal{{Citation| editor1-first = Michael J. | editor1-last = Gibney| editor2-first = Barrie M.| editor2-last = Margetts| editor3-first = John M.| editor3-last = Kearney| editor4-first = Lenore| editor4-last = Arab| display-editors = 3| title = Public Health Nutrition| publisher = John Wiley & Sons|page = 210 |year = 2012|isbn = 978-1118574225 |url = https://books.google.com/books?id=WtRFYyts5IwC&pg=PA210}} belonging to the group of vitamin A₂ as a retinaldehyde form, besides the endogenously present 3,4-dehydroretinol and 3,4-dehydroretinoic acid.{{cite journal |vauthors=Törmä H, Vahlquist A |title=Biosynthesis of 3-dehydroretinol (vitamin A2) from all-trans-retinol (vitamin A1) in human epidermis |journal= J. Invest. Dermatol. |volume= 85 |issue= 6 |pages=498–500 |year= 1985| pmid= 4067325 |doi=10.1111/1523-1747.ep12277290|doi-access= free }}{{cite journal |vauthors=Vahlquist A |title=The identification of dehydroretinol (vitamin A2) in human skin |journal= Experientia |volume= 36 |issue= 3 |pages=317–318 |year= 1980 |pmid=7371787 |doi=10.1007/bf01952299|s2cid=31357743 }}

The livers of some freshwater fishes and some fish found in India contain a higher ratio of dehydroretinal to retinal than do other species.{{cite journal |vauthors=MortonRA, Stubbs AL |title= Ling cod and other fish liver oils rich in vitamin A2 |journal= Biochem J |volume= 40 |issue= 5–6 |pages=lix |year=1946| pmid= 20277273}}{{Citation| author = Food and Agriculture Organization of the United Nations| title = Requirements of Vitamin A, Thiamine, Riboflavin & Niacin: Report of a Joint Fao-Who Expert Group| publisher = United Nations|page = 26| year = 1967|isbn = 9251004536|url = https://books.google.com/books?id=mXHCL4M0FNMC&pg=PA26}}