Myricetin
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Names | |
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IUPAC name
3,3′,4′,5,5′,7-Hexahydroxyflavone
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Systematic IUPAC name
3,5,7-Trihydroxy-2-(3,4,5-trihydroxyphenyl)-4H-1-benzopyran-4-one | |
Other names
Cannabiscetin
Myricetol Myricitin | |
Identifiers | |
3D model (
JSmol ) |
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ChEBI | |
ChEMBL | |
ChemSpider | |
DrugBank | |
ECHA InfoCard
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100.007.695 |
EC Number |
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KEGG | |
PubChem CID
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UNII | |
CompTox Dashboard (EPA)
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Properties | |
C15H10O8 | |
Molar mass | 318.237 g·mol−1 |
Density | 1.912 g/mL |
Hazards | |
GHS labelling: | |
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Warning | |
H315, H319, H335 | |
P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P403+P233, P405, P501 | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Myricetin is a member of the flavonoid class of polyphenolic compounds, with antioxidant properties.[1] Common dietary sources[2] include vegetables (including tomatoes), fruits (including oranges), nuts, berries, tea,[3] and red wine.[4]
Myricetin is structurally similar to
Myricetin is produced from the parent compound taxifolin through the (+)-dihydromyricetin intermediate and can be further processed to form laricitrin and then syringetin, both members of the flavonol class of flavonoids.[6] Dihydromyricetin is frequently sold as a supplement and has controversial function as a partial GABAA receptor potentiator and treatment in Alcohol Use Disorder (AUD). Myricetin can alternatively be produced directly from kaempferol, which is another flavonol.[6]
Sources
Foods | Myricetin
(mg/100g) |
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carob fiber | 48[7] |
fennel leaves, raw | 20[7] |
parsley, fresh | 15[7] |
goji berry, dried | 11[7] |
bog blueberry, frozen | 7[7] |
carob flour | 7[7] |
cranberry | 7[7] |
dock, raw | 6[7] |
European black currant, raw | 6[7] |
crowberry | 5[7] |
rabbit-eye blueberry, raw | 5[7] |
sweet potato leaves, raw | 4[7] |
Oxidative Properties
Antioxidant
Gradual but steady accretion of such damage can lead to the development of many diseases and conditions including thrombosis, diabetes, persistent inflammation, cancer, and atherosclerosis. Flavonoids including myricetin are able to scavenge for ROS and can
Myricetin also enhances the effects of other antioxidants. Myricetin can induce the enzyme glutathione S-transferase (GST). GST has been suggested to protect cells against oxidative stress by protecting cells against free-radicals. In vitro studies have shown that myricetin significantly increased GST activity.[3]
Pro-oxidant
Multiple studies have demonstrated that myricetin also has the potential to act as a pro-oxidant due to its tendency to undergo autoxidation depending upon its environment [citation needed]. It has been seen that when in the presence of cyanide, autoxidation is favored, resulting in superoxide, a byproduct characteristic of causing cellular damage [citation needed]. However, sodium azide, superoxide dismutase, and catalase have been seen to inhibit the autoxidation of myricetin.[1]
Myricetin may also act as a pro-oxidant in its ability to increase the production of
Myricetin's pro-oxidative capabilities can also be seen in its ability to act as an inhibitory agent against
Potential health effects
![]() | This section needs more primary sources. (May 2018) | ![]() |
Anticarcinogen
Myricetin is also effective in protecting cells from
Myricetin also has been shown to inhibit the act of genetic mutation as exhibited by the Ames test. This test showed that myricetin was more effective in preventing mutagenesis initiated by certain carcinogenic polycyclic aromatic hydrocarbons (benzo(a)pyrene, dibenzo(a,h)pyrene, and dibenzo(a,i)pyrene) as compared to others in which it was less effective in preventing against mutagenesis (benzo(a)pyrene 4, 5-oxide and the bay-region diol-epoxides of benzo(a)anthracene, chrysene, and benzo(c)phenathrene).[1] This data shows that myricetin is not unilaterally able to reduce the carcinogenic activity of all polycyclic aromatic hydrocarbons or even the more specific subclass of benzo(a)pyrenes. Myricetin’s exact biochemical activity is still not fully understood. Clearly there is a multifaceted, complex system involved in the anticarcinogenic activity displayed by myricetin that does not apply equally to all carcinogens of the same subfamily.
Mutagen
It has also been shown that myricetin can itself act as an agent of mutagenicity. Myricetin can produce
Interactions with DNA
Myricetin can act as a pro-oxidant compound when it interacts with DNA. Studies involving in vitro models have shown that myricetin causes the degradation of DNA. Additionally, myricetin, in the presence of Fe3+ and Cu2+, intensified this DNA degradation. The antioxidants catalase, superoxide dismutase, mannitol, and sodium azide in combination with Cu2+ increased the DNA degradation activity of myricetin. Myricetin was shown to create reactive oxygen species that caused the DNA damage.[1]
It has been demonstrated that myricetin, depending on its concentration, displays different oxidizing effects on DNA. Polyphenols like myricetin are able to reduce (donate electrons to) Fe3+. Thus, this reaction yields a less oxidized (more reduced) form of the iron cation: Fe2+ and a less reduced (more oxidized) form of myricetin.
Myricetin also impacts the biochemical efficacy and binding ability of large intracellular biomolecules. Myricetin has been shown to inhibit viral
Antiviral
Myricetin has been seen to demonstrate antiviral activity against a number of viruses including
Antithrombotic
Antidiabetic
Several in vitro and animal studies have indicated the antidiabetic capabilities of myricetin; however, the evidence in clinical trials is less convincing. The flavonoid has been demonstrated to have a hypoglycemic effect by increasing the ability of adipocytes, as well as cells of the soleus muscle and liver of rats, to uptake glucose.
Although myricetin has not been concluded to have more than a neutral effect on humans, it has been used as a form of traditional medicine for diabetes in Northern Brazil and is hypothesized by the Finnish Mobile Clinic Health Examination Survey to potentially be correlated to the lower risk of Type 2 diabetes in individuals whose diets included higher than average amounts of myricetin. However, since studies in the United States, such as the Women's Health Study, do not confirm these results, there is doubt of whether or not the difference is risk can actually be accredited to myricetin and is not the result of the inability to fully control other variables such as racial background or inconsistencies in diet between participants.[10]
There is also evidence indicating that other characteristics of myricetin, such as its effect against
Antiatherosclerotic
Antioxidants, including flavonoids such as myricetin, are often touted to reduce the risk of atherosclerosis, the hardening of arteries associated with high cholesterol. However, in vivo studies are lacking and in vitro studies are contradictory and do not support this claim. This claim is based on myricetin's proposed ability to increase LDL uptake by macrophages, which in theory would protect against atherosclerosis. This theoretical action of myricetin is not supported by experimental data.[11] It is also proposed that myricetin may have the ability as a potent flavonoid antioxidant to prevent LDL oxidation, thus slowing the body's local inflammatory response and delaying the appearance of the first fatty streak and onset of atherosclerosis.[12]
Although mechanisms relating to myricetin specifically have not been proven, a diet that is rich in fruits and vegetables, and therefore rich in antioxidants, correlates with a decreased risk of cardiovascular disease, including atherosclerosis.[13][14]
Neuroprotectant
It has also been shown that myricetin is effective in protecting neurons against oxidative stressors. Researchers have shown that
Anti-inflammatory
Myricetin, along with other lipoxygenase- and cyclooxygenase-blocker flavonoids are seen to have significant anti-inflammatory characteristics, demonstrated by their ability to reduce
Anti-platelet aggregation activity
Exposure to myricetin caused inhibition of rabbit
Immunomodulatory activities
Myricetin's preclinical
References
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- ^ PMID 24084717.
- ^ a b c d e f g h i j k l "USDA Database for the Flavonoid Content of Selected Foods, Release 3" (PDF). U.S. Department of Agriculture. 2011.
- PMID 16323269.
- PMID 24205990.
- ^ .
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