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Record Information
StatusDetected and Quantified
Creation Date2006-05-22 15:12:01 UTC
Update Date2019-07-23 05:45:35 UTC
Secondary Accession Numbers
  • HMDB02655
Metabolite Identification
Common NameIsorhamnetin
DescriptionIsorhamnetin is the methylated metabolite of quercetin. Quercetin is an important dietary flavonoid with in vitro antioxidant activity. However, it is found in human plasma as conjugates with glucuronic acid, sulfate or methyl groups, with no significant amounts of free quercetin present. Isorhamnetin prevents endothelial cell injuries from oxidized LDL via inhibition of lectin-like ox-LDL receptor-1 upregulation, interference of ox-LDL-mediated intracellular signaling pathway (p38MAPK activation, NF-kappaB nuclear translocation, eNOS expression) and the antioxidant activity of isorhamnetin. Isorhamnetin prevents endothelial dysfunction, superoxide production, and overexpression of p47phox induced by angiotensin II. Isorhamnetin appears to be a potent drug against esophageal cancer due to its in vitro potential to not only inhibit proliferation but also induce apoptosis of Eca-109 cells. (PMID: 15493462 , 17368593 , 17374653 , 16963021 ).
Quercetin 3'-methyl etherChEBI
Chemical FormulaC16H12O7
Average Molecular Weight316.2623
Monoisotopic Molecular Weight316.058302738
IUPAC Name3,5,7-trihydroxy-2-(4-hydroxy-3-methoxyphenyl)-4H-chromen-4-one
Traditional Nameisorhamnetin
CAS Registry Number480-19-3
InChI Identifier
Chemical Taxonomy
Description belongs to the class of organic compounds known as flavonols. Flavonols are compounds that contain a flavone (2-phenyl-1-benzopyran-4-one) backbone carrying a hydroxyl group at the 3-position.
KingdomOrganic compounds
Super ClassPhenylpropanoids and polyketides
Sub ClassFlavones
Direct ParentFlavonols
Alternative Parents
  • 3p-methoxyflavonoid-skeleton
  • 3-hydroxyflavone
  • 3-hydroxyflavonoid
  • 4'-hydroxyflavonoid
  • 5-hydroxyflavonoid
  • 7-hydroxyflavonoid
  • Hydroxyflavonoid
  • Chromone
  • Benzopyran
  • 1-benzopyran
  • Methoxyphenol
  • Phenoxy compound
  • Anisole
  • Methoxybenzene
  • Phenol ether
  • 1-hydroxy-4-unsubstituted benzenoid
  • 1-hydroxy-2-unsubstituted benzenoid
  • Alkyl aryl ether
  • Pyranone
  • Phenol
  • Benzenoid
  • Monocyclic benzene moiety
  • Pyran
  • Vinylogous acid
  • Heteroaromatic compound
  • Ether
  • Organoheterocyclic compound
  • Oxacycle
  • Polyol
  • Organic oxygen compound
  • Organooxygen compound
  • Organic oxide
  • Hydrocarbon derivative
  • Aromatic heteropolycyclic compound
Molecular FrameworkAromatic heteropolycyclic compounds
External Descriptors

Route of exposure:


Biological location:


Biological role:

Physical Properties
Experimental Properties
Melting Point311 - 314 °CNot Available
Boiling PointNot AvailableNot Available
Water SolubilityNot AvailableNot Available
LogPNot AvailableNot Available
Predicted Properties
Water Solubility0.15 g/LALOGPS
pKa (Strongest Acidic)6.44ChemAxon
pKa (Strongest Basic)-4ChemAxon
Physiological Charge-1ChemAxon
Hydrogen Acceptor Count7ChemAxon
Hydrogen Donor Count4ChemAxon
Polar Surface Area116.45 ŲChemAxon
Rotatable Bond Count2ChemAxon
Refractivity81.34 m³·mol⁻¹ChemAxon
Polarizability30.58 ųChemAxon
Number of Rings3ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleNoChemAxon
MDDR-like RuleNoChemAxon
Spectrum TypeDescriptionSplash KeyView
GC-MSGC-MS Spectrum - EI-B (Non-derivatized)splash10-014i-2219000000-20feeef38553ee7cdd29Spectrum
GC-MSGC-MS Spectrum - EI-B (Non-derivatized)splash10-014i-2219000000-20feeef38553ee7cdd29Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positivesplash10-000i-0591000000-2e1f6e28bf0d47d5e240Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (4 TMS) - 70eV, Positivesplash10-001u-0041090000-7e13d91dc4b2bd93fc17Spectrum
LC-MS/MSLC-MS/MS Spectrum - DI-ESI-qTof , Positivesplash10-0udi-0394000000-f903b8df9b79e6a94f44Spectrum
LC-MS/MSLC-MS/MS Spectrum - DI-ESI-qTof , Negativesplash10-0udi-0956000000-6286c6784746c9eba0e8Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QTOF , negativesplash10-0gb9-0219000000-c620190cc3878a4242f9Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QTOF , negativesplash10-0zfr-1941000000-10313269e61a0584f37fSpectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QTOF , negativesplash10-0gb9-0109000000-082620470bd7fd8a6897Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QTOF , positivesplash10-0ufr-0491000000-da6ec11ed89cc64a7972Spectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QTOF , positivesplash10-014i-0139000000-141b68c1e564685b35ceSpectrum
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QTOF , positivesplash10-014i-0139000000-8fa57905e16cdfcc4e9eSpectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-014i-0019000000-bb7cbcffdd9f296b6b9bSpectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-014i-0079000000-c73663231834b1b1b79aSpectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-0uds-3790000000-3b8ca78684ffcba51bf1Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-014i-0009000000-57dd2505d869c8f411dcSpectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-014i-0169000000-38b50b4081dff638023bSpectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-0frb-3890000000-3525a3f4676b6a964b71Spectrum
Biological Properties
Cellular Locations
  • Membrane (predicted from logP)
Biospecimen Locations
  • Blood
  • Urine
Tissue Locations
  • Fibroblasts
  • Intestine
  • Liver
  • Neuron
  • Neutrophil
  • Pancreas
  • Platelet
  • Prostate
Normal Concentrations
BloodDetected and Quantified0.0388 +/- 0.0454 uMAdult (>18 years old)BothNormal details
BloodDetected and Quantified0.0399 +/- 0.0450 uMAdult (>18 years old)BothNormal details
BloodDetected and Quantified0.043 (0.040-0.046) uMAdult (>18 years old)Not SpecifiedNormal details
BloodDetected and Quantified0-0.157 uMAdult (>18 years old)BothNormal details
UrineDetected and Quantified0.00432 umol/mmol creatinineAdult (>18 years old)BothNormal details
UrineDetected and Quantified0.0300 +/- 0.0300 umol/mmol creatinineAdult (>18 years old)BothNormal details
UrineDetected and Quantified0.0333 +/- 0.0333 umol/mmol creatinineAdult (>18 years old)BothNormal details
UrineDetected and Quantified0.02 umol/mmol creatinineAdult (>18 years old)Both
UrineDetected and Quantified0.02 umol/mmol creatinineAdult (>18 years old)Both
UrineDetected and Quantified0.0065 +/- 0.0065 umol/mmol creatinineAdult (>18 years old)Both
UrineDetected and Quantified0.019 +/- 0.0065 umol/mmol creatinineAdult (>18 years old)Both
UrineExpected but not Quantified Not AvailableNot AvailableConsuming polyphenols described by Phenol-Explorer entry 318 details
UrineExpected but not Quantified Not AvailableNot AvailableConsuming polyphenols described by Phenol-Explorer entry 318 details
UrineExpected but not Quantified Not AvailableNot AvailableConsuming polyphenols described by Phenol-Explorer entry 318 details
UrineDetected and Quantified0.0347 umol/mmol creatinineAdult (>18 years old)Both
UrineDetected and Quantified0.0546 +/- 0.0420 umol/mmol creatinineAdult (>18 years old)Both
Abnormal Concentrations
Not Available
Associated Disorders and Diseases
Disease ReferencesNone
Associated OMIM IDsNone
DrugBank IDNot Available
Phenol Explorer Compound ID318
FoodDB IDFDB000604
KNApSAcK IDC00004635
Chemspider ID4444973
KEGG Compound IDC10084
BioCyc IDCPD-8004
BiGG IDNot Available
Wikipedia LinkIsorhamnetin
PubChem Compound5281654
PDB IDNot Available
ChEBI ID6052
Food Biomarker OntologyNot Available
VMH IDNot Available
Synthesis ReferenceHeap, Tom; Robinson, Robert. Synthesis of kaempferide and of isorhamnetin. Journal of the Chemical Society (1926), 2336-44.
Material Safety Data Sheet (MSDS)Download (PDF)
General References
  1. Sheu JR, Hsiao G, Chou PH, Shen MY, Chou DS: Mechanisms involved in the antiplatelet activity of rutin, a glycoside of the flavonol quercetin, in human platelets. J Agric Food Chem. 2004 Jul 14;52(14):4414-8. [PubMed:15237945 ]
  2. Chanoine JP, Braverman LE: The role of transthyretin in the transport of thyroid hormone to cerebrospinal fluid and brain. Acta Med Austriaca. 1992;19 Suppl 1:25-8. [PubMed:1519447 ]
  3. Ritter J, Kahl R, Hildebrandt AG: Effect of the antioxidant (+)-cyanidanol-3 on H2O2 formation and lipid peroxidation in liver microsomes. Res Commun Chem Pathol Pharmacol. 1985 Jan;47(1):48-58. [PubMed:3983470 ]
  4. Kandaswami C, Lee LT, Lee PP, Hwang JJ, Ke FC, Huang YT, Lee MT: The antitumor activities of flavonoids. In Vivo. 2005 Sep-Oct;19(5):895-909. [PubMed:16097445 ]
  5. Lee HJ, Noh YH, Lee DY, Kim YS, Kim KY, Chung YH, Lee WB, Kim SS: Baicalein attenuates 6-hydroxydopamine-induced neurotoxicity in SH-SY5Y cells. Eur J Cell Biol. 2005 Nov;84(11):897-905. [PubMed:16323286 ]
  6. Chen CY, Milbury PE, Lapsley K, Blumberg JB: Flavonoids from almond skins are bioavailable and act synergistically with vitamins C and E to enhance hamster and human LDL resistance to oxidation. J Nutr. 2005 Jun;135(6):1366-73. [PubMed:15930439 ]
  7. Lindahl M, Tagesson C: Flavonoids as phospholipase A2 inhibitors: importance of their structure for selective inhibition of group II phospholipase A2. Inflammation. 1997 Jun;21(3):347-56. [PubMed:9246576 ]
  8. Wenisch C, Biffignandi PM: Effect of bioflavonoids (trihydroxyethylrutin and disodium flavodate) in vitro on neutrophil reactive oxygen production and phagocytic ability assessed by flow cytometry. Curr Med Res Opin. 2001;17(2):123-7. [PubMed:11759181 ]
  9. Hubbard GP, Wolffram S, Lovegrove JA, Gibbins JM: Ingestion of quercetin inhibits platelet aggregation and essential components of the collagen-stimulated platelet activation pathway in humans. J Thromb Haemost. 2004 Dec;2(12):2138-45. [PubMed:15613018 ]
  10. Shoab SS, Porter JB, Scurr JH, Coleridge-Smith PD: Effect of oral micronized purified flavonoid fraction treatment on leukocyte adhesion molecule expression in patients with chronic venous disease: a pilot study. J Vasc Surg. 2000 Mar;31(3):456-61. [PubMed:10709057 ]
  11. Lu J, Feng X, Sun Q, Lu H, Manabe M, Sugahara K, Ma D, Sagara Y, Kodama H: Effect of six flavonoid compounds from Ixeris sonchifolia on stimulus-induced superoxide generation and tyrosyl phosphorylation in human neutrophils. Clin Chim Acta. 2002 Feb;316(1-2):95-9. [PubMed:11750278 ]
  12. Spencer JP, Schroeter H, Crossthwaithe AJ, Kuhnle G, Williams RJ, Rice-Evans C: Contrasting influences of glucuronidation and O-methylation of epicatechin on hydrogen peroxide-induced cell death in neurons and fibroblasts. Free Radic Biol Med. 2001 Nov 1;31(9):1139-46. [PubMed:11677047 ]
  13. Miniscalco A, Lundahl J, Regardh CG, Edgar B, Eriksson UG: Inhibition of dihydropyridine metabolism in rat and human liver microsomes by flavonoids found in grapefruit juice. J Pharmacol Exp Ther. 1992 Jun;261(3):1195-9. [PubMed:1602384 ]
  14. Engler MB, Engler MM, Chen CY, Malloy MJ, Browne A, Chiu EY, Kwak HK, Milbury P, Paul SM, Blumberg J, Mietus-Snyder ML: Flavonoid-rich dark chocolate improves endothelial function and increases plasma epicatechin concentrations in healthy adults. J Am Coll Nutr. 2004 Jun;23(3):197-204. [PubMed:15190043 ]
  15. Brusselmans K, Vrolix R, Verhoeven G, Swinnen JV: Induction of cancer cell apoptosis by flavonoids is associated with their ability to inhibit fatty acid synthase activity. J Biol Chem. 2005 Feb 18;280(7):5636-45. Epub 2004 Nov 8. [PubMed:15533929 ]
  16. Chen G, Lu H, Wang C, Yamashita K, Manabe M, Meng Z, Xu S, Kodama H: Effect of five flavonoid compounds isolated from leaves of Diospyros kaki on stimulus-induced superoxide generation and tyrosyl phosphorylation of proteins in human neutrophils. Clin Chim Acta. 2002 Dec;326(1-2):169-75. [PubMed:12417109 ]
  17. Young JM, Shand BI, McGregor PM, Scott RS, Frampton CM: Comparative effects of enzogenol and vitamin C supplementation versus vitamin C alone on endothelial function and biochemical markers of oxidative stress and inflammation in chronic smokers. Free Radic Res. 2006 Jan;40(1):85-94. [PubMed:16298763 ]
  18. Meng Z, Zhou Y, Lu J, Sugahara K, Xu S, Kodama H: Effect of five flavonoid compounds isolated from Quercus dentata Thunb on superoxide generation in human neutrophils and phosphorylation of neutrophil proteins. Clin Chim Acta. 2001 Apr;306(1-2):97-102. [PubMed:11282099 ]
  19. Ito H, Gonthier MP, Manach C, Morand C, Mennen L, Remesy C, Scalbert A: Polyphenol levels in human urine after intake of six different polyphenol-rich beverages. Br J Nutr. 2005 Oct;94(4):500-9. [PubMed:16197573 ]
  20. Lin N, Sato T, Takayama Y, Mimaki Y, Sashida Y, Yano M, Ito A: Novel anti-inflammatory actions of nobiletin, a citrus polymethoxy flavonoid, on human synovial fibroblasts and mouse macrophages. Biochem Pharmacol. 2003 Jun 15;65(12):2065-71. [PubMed:12787887 ]
  21. Janisch KM, Williamson G, Needs P, Plumb GW: Properties of quercetin conjugates: modulation of LDL oxidation and binding to human serum albumin. Free Radic Res. 2004 Aug;38(8):877-84. [PubMed:15493462 ]
  22. Ma G, Yang C, Qu Y, Wei H, Zhang T, Zhang N: The flavonoid component isorhamnetin in vitro inhibits proliferation and induces apoptosis in Eca-109 cells. Chem Biol Interact. 2007 Apr 25;167(2):153-60. Epub 2007 Feb 20. [PubMed:17368593 ]
  23. Sanchez M, Lodi F, Vera R, Villar IC, Cogolludo A, Jimenez R, Moreno L, Romero M, Tamargo J, Perez-Vizcaino F, Duarte J: Quercetin and isorhamnetin prevent endothelial dysfunction, superoxide production, and overexpression of p47phox induced by angiotensin II in rat aorta. J Nutr. 2007 Apr;137(4):910-5. [PubMed:17374653 ]
  24. Bao M, Lou Y: Isorhamnetin prevent endothelial cell injuries from oxidized LDL via activation of p38MAPK. Eur J Pharmacol. 2006 Oct 10;547(1-3):22-30. Epub 2006 Jul 22. [PubMed:16963021 ]


General function:
Involved in transferase activity, transferring hexosyl groups
Specific function:
UDPGT is of major importance in the conjugation and subsequent elimination of potentially toxic xenobiotics and endogenous compounds. This isoform glucuronidates bilirubin IX-alpha to form both the IX-alpha-C8 and IX-alpha-C12 monoconjugates and diconjugate. Is also able to catalyze the glucuronidation of 17beta-estradiol, 17alpha-ethinylestradiol, 1-hydroxypyrene, 4-methylumbelliferone, 1-naphthol, paranitrophenol, scopoletin, and umbelliferone.
Gene Name:
Uniprot ID:
Molecular weight:
Isorhamnetin → 6-{[3,7-dihydroxy-2-(4-hydroxy-3-methoxyphenyl)-4-oxo-4H-chromen-5-yl]oxy}-3,4,5-trihydroxyoxane-2-carboxylic aciddetails
Isorhamnetin → 6-{[5,7-dihydroxy-2-(4-hydroxy-3-methoxyphenyl)-4-oxo-4H-chromen-3-yl]oxy}-3,4,5-trihydroxyoxane-2-carboxylic aciddetails
Isorhamnetin → 3,4,5-trihydroxy-6-[2-methoxy-4-(3,5,7-trihydroxy-4-oxo-4H-chromen-2-yl)phenoxy]oxane-2-carboxylic aciddetails