Myricetin

Myricetin is a kind of flavonols compounds, which extracted from the bark of myricaceae plant. Waxberry is one of the subtropical fruit trees native to China, and The growth history of wild has been over 7000 years, and artificial cultivation has more than 2000 years. There are very rich resources of the bark of myricaceae in Eastern China, hunan, guangdong, guangxi, guizhou and other regions, but the trimmed discarded arbutus tree branches can be as a large number of plant sources for a long time. But due to reasons such as extraction process, the current study of arbutus pigment mainly comes from the vine tea, source of strawberry tree is very little. And cany tea mainly comes from dihydrogen arbutus pigment and limited resources, and has the limitation to the long-term development and utilization on myricetin.
Red bayberry bark is used as antibacterial and anti-inflammatory drugs, and arbutus pigment and arbutus glucosidethe are contained in the red bayberry bark. At home and abroad in recent years, studies have shown that myricetin has a variety of activities. Antagonism of platelet activating factor(PAF), fall blood sugar function, antioxidation, protect liver function, the solution of light alcohol poisoning, the active ingredient myricetin in red bayberry bark and leaves has the proven pharmacological effects, also has anti-inflammatory, antitumor, resistance mutation, prevention of dental caries, oxidation resistance, elimination of free radicals and other pharmacological activities.

The molecular structural formula of myricetin
The above information is collected by Chemicalbook of XiaoNan.

Myricetin is a kind of flavonoids which extracted from the fruits of arbutus, has scavenging free radicals, antioxidation, antitumor, reduces nerve toxicity, affects lymphocyte activation and proliferation, platelet activating factor, reduces blood sugar, removes alcohol, prevention of alcoholic liver, fatty liver, liver cell deterioration, reduces the incidence of liver cancer, protects liver to protect liver, anti-inflammatory and other functions.
The main functions of myricetin:
1) The role of the antioxidant: myricetin is a kind of very strong antioxidant, and oxidative stress plays a key role in various neurological diseases including ischemia and old age dementia. Myricetin is reducing generation and toxicity of beta amylaseby by conformational change effect. Statistics can be used to progress in the senile dementia.
2)The effect of anti-tumor: Myricetin is a kind of effective carcinogenic chemical control agent.
3) Reduce the nerve toxicity: Myricetin can inhibit to protect neurons induced by glutamate neurotoxicity through different way, thus effectively prevent nerve damage.
4) The influence on lymphocyte activation and proliferation: Myricetin can inhibit activation index expression of CD69 of early T cell, and can suppress lymphocyte proliferation response.
5) The antagonism of platelet activating factor (PAF): The concentration dependence of myricetin outside to inhibit PAF induced WRP gathered and the release of 52HT. At the same time it can obviously inhibit PAF caused by increase of platelet Ca2+. So myricetin has antithrombotic, against myocardial ischemia, improving microcirculation, etc various cardiovascular pharmacological effects.
6) Fall the blood sugar function: myricetin has evident fall on blood sugar function.
7)The function of protect liver:The dihydrogen arbutus pigment can obviously inhibit activities of the serum alanine aminotransferase (ALT) and radix asparagi ammonia enzyme aminotransferase (AST) and reduce serum total bilirubin, having obvious the action of fall enzymes back yellow.

Yellow needle crystal (ethanol), melting point is 357 ℃, the maximum absorption wavelength (ethanol) : 375, 255 nm; Soluble in ethanol, methanol, acetone, soluble in hot water, insoluble in chloroform, acetic acid.

Chen Wenmei and Zang Baoxia wash platelet (WRP) by measuring the rabbit, suggesting that myricetin can significantly inhibit PAF caused by increased platelet Ca2+, and inhibit specificity combination PAF with rabbit platelet receptor. It shows myricetin can inhibit the effects of the PAF, as a new PAF receptor antagonist. So myricetin has antithrombotic, against myocardial ischemia and improve microcirculation and other various cardiovascular pharmacological effects, is expected to be developed for promoting blood circulation to remove blood stasis drugs.

Foreign researcher Yoshikawa M on the study of the resistance drug mechanism of diabetes found that myricetin play a role of hyperglycemia. Studies use models about diabetes caused by alloxan model, the high sugar lever mice model caused by epinephrine and glucose, as well as the normal mice. After oral dosing, determination kinds of the model about mice blood sugar levels. Conclusion has the function of hypoglycemic effect in Alloxan diabetic mice and hyperglycemia mice induced by Adrenalin. The treatment effect is good, but had no hypoglycemic effect on the normal mice.Myricetin has good fall blood sugar effect for a variety of animal models, and it is expected to develop fall blood sugar medicine.
Mice caused by different factors such as diabetes, as well as the normal small rat poison, the determination of kinds of the model mice’s blood sugar levels. Result has the function of hypoglycemic effect in Alloxan diabetic mice and hyperglycemia mice induced by Adrenalin, but had no hypoglycemic effect on the normal mice. In addition, they found in further study, myricetin has good fall blood sugar for a variety of animal models, and it is expected to develop fall blood sugar medicine or as diabetes patients using food additives.

Studies using Rancimat method determine its antioxidant properties. The results show that the grease is excellent antioxidant, obviously stronger than the synthetic antioxidant BHT (3, 5-tertiary butyl-4-methyl benzene) can be used as natural antioxidant used in grease on higher food preservation. Other studies have suggested myricetin is a kind of very strong antioxidant, oxidative stress plays a key role in various neurological diseases including ischemia and old age dementia.

Myricetin has a protection of liver, reduction enzyme and retreat yellow, strengthen the nonspecific immune function in mice and immunocompromised mice humoral immune function, thus protect liver function.
Zheng-xian zhong, etc can take carbon tetrachloride, D2 galactosamine and isothiocyanate naphthalene ester to acute liver injury in mice model, observe myricetin to play a role of protection for liver damage, And watch the immune enhancement effect on myricetin. Results confirmed that myricetin can significantly reduce carbon tetrachloride, D2 galactosamine and isothiocyanate naphthalene ester to acute liver injury in mice model, which toxins content in serum, reducing the degeneration and necrosis of liver tissue, and enhance mononuclear macrophage phagocytosis and hemolysin content. It Illustrates the myricetin has protection of liver, reduction enzyme and retreat yellow, strengthens the nonspecific immune function in mice and immunocompromised mice humoral immune function, thus protecting liver function, provide reference for the clinical application of myricetin.

Zhejiang folk has a useful experiences bubble wine tradition, waxberry wine imported liquor taste, and not easy to intoxicate. Hase-K people in experiments in alcohol agents found myricetin has removed the effects of alcohol poisoning. Later found in the study of the mechanism, the principle of myricetin can reduce alcohol poisoning, mainly protecting the liver, reduce hexanol of liver damage.

The FDA in USA has myricetin widely used in medicine, food, health care products and cosmetics. Foreign health products in American, health care medicine FYI has myricetin as additives which are treatment for the prevention of arthritis and various kinds of inflammation, especially for pregnancy and lactation is more suitable for women and babies. Myricetin with high purity has been widely used in food, medicine and cosmetic fields. As the further study for myricetin of the pharmacological effects, the demand of market of myricetin will increase sharply, The research and development prospect of myricetin are broad.
Myricetin is specialty resources in China. In view of the regional differences, the international on the research of myricetin is just started. In China now only the research of guangxi rattan tea containing myricetin study more, but zhejiang as big provinces is origin of myricetin. The research about the active ingredient for special local economic crops is one of the few. For myricetin, the research is relatively backward. In Ningbo, related companies have begun to development and application of myricetin in preliminary, striving for its industrialization. Liquid could be used in food additives, such as coarse extraction, separation and purifying of crude extract of active ingredients and pharmacological activity research, etc., and further accelerate the speed of traditional Chinese medicine (TCM) modernization in China.

Myricetin[529-44-2] is a flavonoid compound found in many fruits and vegetables, including red wine, that acts as a powerful antioxidant. Myricetin inhibits TBARS formation with an IC₅₀ value of 6.34 and at 20 μM, blocks oxLDL uptake by U937-derived macrophages, reducing CD36 expression. Myricetin demonstrates potent chemopreventative potential by binding JAK1/STAT3 to inhibit the neoplastic transformation of murine JB6 P+ cells and inhibiting MEK1 kinase activity.

The substance is a brown-yellow to brown-green crystalline powder. It can dissolve in methanol, ethanol, acetone, and ethyl acetate, and has a low solubility in water. It is not soluble in chloroform and petroleum ether. This compound is derived from the fruit of Myrica rubra (Lour.) Sieb. et Zucc. and belongs to the Populus family.

Myricetin is used as an antioxidant. It is a cell-permeable flavonoid used in inflammatory, diabetes, and cancer studies. It is effective in protecting neurons against oxidative stresses. Further, it inhibits yeast alfa-glucosidase,1 glyoxalase I in vitro and bovine milk xanthine oxidase.

ChEBI: Myricetin is a hexahydroxyflavone that is flavone substituted by hydroxy groups at positions 3, 3', 4', 5, 5' and 7. It has been isolated from the leaves of Myrica rubra and other plants. It has a role as a cyclooxygenase 1 inhibitor, an antineoplastic agent, an antioxidant, a plant metabolite, a food component, a hypoglycemic agent and a geroprotector. It is a hexahydroxyflavone and a 7-hydroxyflavonol. It is a conjugate acid of a myricetin(1-).

Myricetin is a novel flavanoid compound useful as chemotherapeutic, chemopreventive, and antiangiogenic agent. It also acts as an antioxidant, anti-inflammatory, and anti-cancer agent, and can inhibit the activity of reverse transcriptase.

Myricetin exerts anti-oxidant effects, and anti-inflammatory effects by regulating multiple signal pathways. It also displays anti-diabetic and hepatoprotective effects. Myricetin strongly inhibits yeast α-glucosidase, glyoxalase I in vitro, and bovine milk xanthine oxidase. It also promotes complex formation between DNA and both topoisomerase I and II, an effect that may have implications in cancer chemotherapy. Myricetin also has various nutraceuticals values and therapeutic effects.

Myricetin (Cannabiscetin, 3,3',4',5,5',7-hexahydroxyflavone) [529-44-2] M 318.2, m > 3 0 0o, 357o(dec) (polyphenolic pKEst~8-11). Recrystallise myricetin from aqueous EtOH (m 357o dec, as monohydrate) or Me2CO (m 350o dec, with one mol of Me2CO) as yellow crystals. It is almost insoluble in CHCl3 and AcOH. The hexaacetate has m 213o. [Hergert J Org Chem 21 534 1956, Spada & Cameroni Gazzetta 86 965, 975 1956, Kalff & Robinson J Chem Soc 127 181 1925, Beilstein 18/5 V 670.]