View source for Daidzein

{{Distinguish|Daidzin}}
{{Lead too short|date=April 2013}}
{{Use dmy dates|date=March 2020}}
{{Chembox
| Watchedfields = changed
| verifiedrevid = 443560562
| Reference = <ref>''Merck Index'', 11th Edition, '''2805'''.</ref>
| ImageFile = Daidzein.svg
| ImageSize = 220px
| ImageFile1 = Daidzein-3D-balls.png
| ImageSize1 = 220
| ImageAlt1 = Diazein molecule
| IUPACName = 4′,7-Dihydroxyisoflavone
| SystematicName = 7-Hydroxy-3-(4-hydroxyphenyl)-4''H''-1-benzopyran-4-one
| OtherNames = 7-Hydroxy-3-(4-hydroxyphenyl)chromen-4-one<br />Daidzeol<br />Isoaurostatin
|Section1={{Chembox Identifiers
| IUPHAR_ligand = 2828
| Abbreviations =
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 4445025
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 6287WC5J2L
| InChIKey = ZQSIJRDFPHDXIC-UHFFFAOYAG
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 8145
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C15H10O4/c16-10-3-1-9(2-4-10)13-8-19-14-7-11(17)5-6-12(14)15(13)18/h1-8,16-17H
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = ZQSIJRDFPHDXIC-UHFFFAOYSA-N
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 486-66-8
| EINECS =
| PubChem = 5281708
| SMILES = O=C\1c3c(O/C=C/1c2ccc(O)cc2)cc(O)cc3
| InChI = 1/C15H10O4/c16-10-3-1-9(2-4-10)13-8-19-14-7-11(17)5-6-12(14)15(13)18/h1-8,16-17H
| RTECS =
| MeSHName =
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 28197
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = C10208
}}
|Section2={{Chembox Properties
| Formula = C<sub>15</sub>H<sub>10</sub>O<sub>4</sub>
| MolarMass = 254.23 g/mol
| Appearance = Pale yellow prisms
| Density =
| MeltingPtC = 315 to 323
| MeltingPt_notes = (decomposes)
| BoilingPt =
| BoilingPt_notes =
| Solubility =
| SolubleOther =
| Solvent =
| pKa =
| pKb = }}
|Section7={{Chembox Hazards
| MainHazards =
| NFPA-H =
| NFPA-F =
| NFPA-R =
| NFPA-S =
| FlashPt =
| AutoignitionPt =
| ExploLimits =
| PEL = }}
}}

'''Daidzein (7-hydroxy-3-(4-hydroxyphenyl)-4H-chromen-4-one)''' is a naturally occurring compound found exclusively in soybeans and other [[legumes]], and structurally belongs to a class of compounds known as [[isoflavones]].<ref name="lpi">{{cite web |title=Soy isoflavones |url=https://lpi.oregonstate.edu/mic/dietary-factors/phytochemicals/soy-isoflavones |publisher=Micronutrient Information Center, Linus Pauling Institute, Oregon State University |access-date=11 April 2025 |date=2016}}</ref> Daidzein and other isoflavones are produced in plants through the [[Phenylpropanoids metabolism|phenylpropanoid pathway]] of secondary metabolism and are used as signal carriers, and defense responses to pathogenic attacks.<ref name=Jung>{{Cite journal |last1=Jung W.S. |last2=Yu |first2=O. |last3=Lau, C., S.M. |last4=O'Keefe |first4=D.P. |last5=Odell |first5=J. |last6=Fader |first6=G. |last7=McGonigle |first7=B. |date=2000 |title=Identification and expression of isoflavone synthase, the key enzyme for biosynthesis of isoflavones in legumes |url=https://www.nature.com/articles/nbt0200_208 |journal=Nature Biotechnology |volume=18 |issue=2 |pages=208–212 |doi=10.1038/72671 |pmid=10657130 |s2cid=1717934 |issn=1546-1696|url-access=subscription }}</ref> Upon consumption of isoflavone-rich foods, daidzein has poor [[bioavailability]] and low water [[solubility]].<ref>{{ cite journal
 | last1 = Wang Y.C.
 | last2=Yang M.
 | last3 = Qin J.J.
 | last4 = Wa W.Q.
 | date = 2022
 | title = Interactions between puerarin/daidzein and micellar casein
 | journal = Journal of Food Biochemistry
 | volume = 46
 | issue = 2
 | page = e14048
 | doi = 10.1111/jfbc.14048
 | pmid=34981538
 | s2cid=245670986
 | doi-access = free
 }}</ref>

==Natural occurrence==
Daidzein and other isoflavone compounds, such as [[genistein]], are present in a number of [[plant]]s and [[herb]]s like kwao krua (''[[Pueraria mirifica]]'') and [[kudzu]]. It can also be found in ''[[Maackia amurensis]]'' cell cultures.<ref>{{Cite journal |last1=Fedoreyev |first1=S.A. |last2=Pokushalova |first2=T.V. |last3=Veselova |first3=M.V. |last4=Glebko |first4=L.I. |last5=Kulesh |first5=N.I. |last6=Muzarok |first6=T.I. |last7=Seletskaya |first7=L.D. |last8=Bulgakov |first8=V.P. |last9=Zhuravlev |first9=Y.N. |date=2000 |title=Isoflavonoid production by callus cultures of Maackia amurensis |url=https://www.sciencedirect.com/science/article/pii/S0367326X00001295 |journal=Fitoterapia |volume=71 |issue=4 |pages=365–372 |doi=10.1016/S0367-326X(00)00129-5|pmid=10925005 |url-access=subscription }}</ref> Daidzein can be found in food such as mature [[soybean]]s and soy products like soy protein concentrate, [[tofu]] and [[textured vegetable protein]].<ref name=lpi/> 

Total isoflavones in soybeans are—in general—37 percent daidzein, 57 percent genistein and 6 percent [[glycitein]], according to [[United States Department of Agriculture|USDA]] data.<ref>{{ cite web | title = Isoflavones contents of food | url = http://www.isoflavones.info/isoflavones-content.php | publisher = Top Cultures | access-date = 2012-05-15 }}</ref> Soy germ contains 41.7 percent daidzein.<ref>{{cite journal | last = Zhang | first = Y. |author2=Wang, G. J. |author3=Song, T. T. |author4=Murphy, P. A. |author5=Hendrich, S. | title = Urinary disposition of the soybean isoflavones daidzein, genistein and glycitein differs among humans with moderate fecal isoflavone degradation activity | journal = The Journal of Nutrition | year = 1999 | volume = 129 | issue = 5 | pages = 957–962 | pmid = 10222386 | doi = 10.1093/jn/129.5.957 | doi-access = free }}</ref>

== Biosynthesis ==

===History===
The [[isoflavonoid]] pathway has long been studied because of its prevalence in a wide variety of plant species, including as pigmentation in many flowers, as well as serving as signals in plants and microbes. The isoflavone synthase (IFS) enzyme was suggested to be a P-450 oxygenase family, and this was confirmed by Shinichi Ayabe's laboratory in 1999. IFS exists in two isoforms that can use both [[liquiritigenin]] and [[naringenin]] to give daidzein and [[genistein]] respectively.<ref name =Winkel>{{ cite journal
 | last = Winkel-Shirley
 | first = B.
 | date = 2001
 | title = Flavonoid Biosynthesis. A Colorful Model for Genetics, Biochemistry, Cell Biology, and Biotechnology
 | journal = Plant Physiology
 | volume = 126
 | issue = 2
 | pages = 485–493
 | doi = 10.1104/pp.126.2.485
 | pmid = 11402179
 | pmc = 1540115
 | doi-access = free
 }}</ref>

===Pathway===
Daidzein is an isoflavonoid derived from the [[shikimate pathway]] that forms an oxygen containing heterocycle through a cytochrome P-450-dependent enzyme that is [[Nicotinamide adenine dinucleotide phosphate|NADPH]] dependent.<ref name=lpi/>

The biosynthesis of daidzein begins with L-phenylalanine and undergoes a general phenylpropanoid pathway where the shikimate derived aromatic ring is shifted to the adjacent carbon of the heterocycle.<ref name=Dewick>{{Cite book |last=Dewick |first=P.M. |title=Medicinal Natural Products: A Biosynthetic Approach |publisher=Wiley |year=2009 |isbn=978-0-470-74168-9 |edition=3rd |pages=137–175 |type=E-book |oclc=259265604}}</ref> The process begins with phenylalanine ligase (PAL) cleaving the amino group from L-Phe forming the unsaturated carboxylic acid, [[cinnamic acid]]. Cinnamic acid is then hydroxylated by membrane protein cinnamate-4-hydroxylase (C4H) to form [[p-coumaric acid]]. P-coumaric acid then acts as the starter unit which gets loaded with [[coenzyme A]] by 4-coumaroyl:CoA-ligase (4CL). The starter unit (A) then undergoes three iterations of [[malonyl-CoA]] resulting in (B), which enzymes [[chalcone synthase]] (CHS) and chalcone reductase (CHR) modify to obtain trihydroxychalcone. CHR is NADPH dependent. [[Chalcone isomerase]] (CHI) then isomerizes trihydroxychalcone to [[liquiritigenin]], the precursor to daidzein.<ref name =Winkel />

A radical mechanism has been proposed in order to obtain daidzein from liquiritigenin, where an iron-containing enzyme, as well as NADPH and oxygen cofactors are used by a 2-hydroxyisoflavone synthase to oxidize liquiritigenin to a radical intermediate (C). A 1,2 aryl migration follows to form (D), which is subsequently oxidized to (E). Lastly, dehydration of the hydroxy group on C2 occurs through a [[2-hydroxyisoflavanone dehydratase]] (specifically ''[[GmHID1]]'') to give daidzein.<ref name=Dewick /><ref name=Jung />

[[File:Daidzein v2.gif|thumb|Proposed daidzein biosynthesis]]

==Research==
There is preliminary evidence that consuming soy foods rich in daidzein and isoflavones may improve [[Cardiovascular physiology|cardiovascular function]] in [[Menopause|postmenopausal]] women<ref name=lpi/> and lower the risk of [[breast cancer]] in premenopausal and postmenopausal women.<ref name="boutas">{{cite journal |vauthors=Boutas I, Kontogeorgi A, Dimitrakakis C, Kalantaridou SN |title=Soy Isoflavones and Breast Cancer Risk: A Meta-analysis |journal=In Vivo |volume=36 |issue=2 |pages=556–562 |date=2022 |pmid=35241506 |pmc=8931889 |doi=10.21873/invivo.12737}}</ref>

==Pathogen interactions==
Because daidzein is a defensive factor, ''[[Pseudomonas syringae]]'' produces the [[HopZ1b]] effector which degrades a ''GmHID1'' product.<ref name="Bauters-et-al-2021">{{cite journal | last1=Bauters | first1= L. | last2= Stojilković | first2 = B. | last3 =Gheysen | first3 = G. | title=Pathogens pulling the strings: Effectors manipulating salicylic acid and phenylpropanoid biosynthesis in plants | journal=[[Molecular Plant Pathology]] | publisher=[[British Society for Plant Pathology]] ([[Wiley-Blackwell|Wiley]]) | date=2021 | volume= 22 | issue= 11 | pmid=34414650 | doi=10.1111/mpp.13123 |pmc=8518561 | pages=1436–1448| doi-access=free }}</ref>

==Derivatives==
* [[Glyceollin]], a type of [[phytoalexin]]<ref name="Bauters-et-al-2021" />

===Glycosides===
* [[Daidzin]] is the 7-O-[[glucoside]] of daidzein.
* [[Puerarin]] is the 8-C-glucoside of daidzein.

==Plants containing daidzein==
* ''Maackia amurensis''
* [[Pueraria montana var. lobata|''Pueraria montana'' var. ''lobata'']]''{{ space | thin }}<ref name= Chen >{{ cite journal | author = Chen G.  | author2 = Zhang J.X. | author3 = Ye J.N. | year = 2001 | title = Determination of Puerarin, Daidzein and Rutin in ''Pueraria lobata'' (Willd.) Ohwi by Capillary Electrophoresis with Electrochemical Detection | journal = [[Journal of Chromatography A]] | volume = 923 | issue = 1–2 | pages = 255–262 | doi = 10.1016/S0021-9673(01)00996-7 | pmid = 11510548 }}</ref>''<ref name="eisp">{{ cite journal | author = Xu H.N. | author2 = He C.H. | date = 2007 | title = Extraction of Isoflavones from Stem of ''Pueraria lobata'' (Willd.) Ohwi Using n-Butanol / Water Two-Phase Solvent System and Separation of Daidzein | journal = Separation and Purification Technology | volume = 56 | issue = 1 | pages = 255–262 | doi = 10.1016/j.seppur.2007.01.027 }}</ref>
* ''[[Pueraria thomsonii]]''{{ space | thin }}<ref name="sdpd">{{cite journal |author=Zhou H.Y. |author2=Wang J.H. |author3=Yan F.Y. |date=2007 |title=[Separation and Determination of Puerarin, Daidzin and Daidzein in Stems and Leaves of ''Pueraria thomsonii'' by RP-HPLC] |journal=Zhongguo Zhong Yao Za Zhi |language=zh |volume=32 |issue=10 |pages=937–939 |pmid=17655152}}</ref>

==References==
{{Reflist}}

{{Isoflavones}}
{{Phytoestrogens}}
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[[Category:3α-Hydroxysteroid dehydrogenase inhibitors]]
[[Category:Isoflavones]]
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