:Natsudaidain

{{chembox

| Verifiedfields = changed

| Watchedfields = changed

| verifiedrevid = 423308339

| Name = Natsudaidain

| ImageFile = Natsudaidain.svg

| ImageSize = 250px

| ImageName = Natsudaidain structure

| IUPACName = 3-Hydroxy-3′,4′,5,6,7,8-hexamethoxyflavone

| SystematicName = 2-(3,4-Dimethoxyphenyl)-3-hydroxy-5,6,7,8-tetramethoxy-4H-1-benzopyran-4-one

| OtherNames=

|Section1={{Chembox Identifiers

| CASNo_Ref = {{cascite|correct|??}}

| CASNo = 35154-55-3

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = 28441ILD21

| PubChem = 3084605

| SMILES = COC1=C(C=C(C=C1)C2=C(C(=O)C3=C(O2)C(=C(C(=C3OC)OC)OC)OC)O)OC

| ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}}

| ChemSpiderID = 2341642

| InChI = 1/C21H22O9/c1-24-11-8-7-10(9-12(11)25-2)16-15(23)14(22)13-17(26-3)19(27-4)21(29-6)20(28-5)18(13)30-16/h7-9,23H,1-6H3

| InChIKey = CCJBNIRSVUKABH-UHFFFAOYAO

| StdInChI_Ref = {{stdinchicite|changed|chemspider}}

| StdInChI = 1S/C21H22O9/c1-24-11-8-7-10(9-12(11)25-2)16-15(23)14(22)13-17(26-3)19(27-4)21(29-6)20(28-5)18(13)30-16/h7-9,23H,1-6H3

| StdInChIKey_Ref = {{stdinchicite|changed|chemspider}}

| StdInChIKey = CCJBNIRSVUKABH-UHFFFAOYSA-N

}}

|Section2={{Chembox Properties

| Formula = C₂₁H₂₂O₉

| MolarMass = 418.39 g/mol

| Density =

| MeltingPt =

| BoilingPt =

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Natsudaidain is an O-methylated flavonol, a type of chemical compound. It can be isolated from Citrus plants{{Cite journal

| last1 = Matsui | first1 = T.

| last2 = Ito | first2 = C.

| last3 = Itoigawa | first3 = M.

| last4 = Okada | first4 = T.

| last5 = Furukawa | first5 = H.

| title = Effect of natsudaidain isolated from Citrus plants on TNF-α and cyclooxygenase-2 expression in RBL-2H3 cells

| doi = 10.1211/jpp/61.01.0015

| journal = Journal of Pharmacy and Pharmacology

| volume = 61

| issue = 1

| pages = 109–114

| year = 2009

| pmid = 19126304

| pmc =

}} (Rutaceae). The name of the molecule comes from Citrus natsudaidai (Natsumikan, lit. "summer tangerine"), a fruit of Japan developed in 1740 with a particularly tart/sour taste.