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| Names | |
|---|---|
| IUPAC name 4′,7-Dihydroxyisoflavone | |
| Systematic IUPAC name 7-Hydroxy-3-(4-hydroxyphenyl)-4H-1-benzopyran-4-one | |
| Other names 7-Hydroxy-3-(4-hydroxyphenyl)chromen-4-one Daidzeol Isoaurostatin | |
| Identifiers | |
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3D model (JSmol) | |
| ChEBI | |
| ChEMBL | |
| ChemSpider |
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| ECHA InfoCard | 100.006.942 |
| KEGG |
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| UNII | |
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| Properties | |
| C15H10O4 | |
| Molar mass | 254.23 g/mol |
| Appearance | Pale yellow prisms |
| Melting point | 315 to 323 °C (599 to 613 °F; 588 to 596 K) (decomposes) |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Daidzein (7-hydroxy-3-(4-hydroxyphenyl)-4H-chromen-4-one) is a naturally occurring compound found exclusively in soybeans and otherlegumes and structurally belongs to a class of compounds known asisoflavones. Daidzein and other isoflavones are produced in plants through thephenylpropanoid pathway of secondary metabolism and are used as signal carriers, and defense responses to pathogenic attacks.[2] In humans, recent research has shown the viability of using daidzein in medicine formenopausal relief,osteoporosis,blood cholesterol, and lowering the risk of some hormone-relatedcancers, andheart disease. Despite the known health benefits, the use of both puerarin and daidzein is limited by their poorbioavailability and low watersolubility.[3]
Daidzein and other isoflavone compounds, such asgenistein, are present in a number ofplants andherbs like kwao krua (Pueraria mirifica) andkudzu. It can also be found inMaackia amurensis cell cultures.[4] Daidzein can be found in food such assoybeans and soy products liketofu andtextured vegetable protein. Soy isoflavones are a group of compounds found in and isolated from the soybean. Of note, total isoflavones in soybeans are—in general—37 percent daidzein, 57 percent genistein and 6 percentglycitein, according toUSDA data.[5] Soy germ contains 41.7 percent daidzein.[6]
Theisoflavonoid 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 bothliquiritigenin andnaringenin to give daidzein andgenistein respectively.[7]
Daidzein is an isoflavonoid derived from theshikimate pathway that forms an oxygen containing heterocycle through a cytochrome P-450-dependent enzyme that isNADPH dependent.
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.[8] 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 formp-coumaric acid. P-coumaric acid then acts as the starter unit which gets loaded withcoenzyme A by 4-coumaroyl:CoA-ligase (4CL). The starter unit (A) then undergoes three iterations ofmalonyl-CoA resulting in (B), which enzymeschalcone synthase (CHS) and chalcone reductase (CHR) modify to obtain trihydroxychalcone. CHR is NADPH dependent.Chalcone isomerase (CHI) then isomerizes trihydroxychalcone toliquiritigenin, the precursor to daidzein.[7]
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 a2-hydroxyisoflavanone dehydratase (specificallyGmHID1) to give daidzein.[8][2]
Daidzein has been found to act as anagonist of theGPER (GPR30).[9]
Because daidzein is a defensive factor,Pseudomonas syringae produces theHopZ1b effector which degrades aGmHID1 product.[10]
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