Taxifolin
- (2R, 3R ) - ( )- taxifolin
- 2,3- dihydroquercetin ( DHQ )
- 3,3 ', 4' ,5,7- pentahydroxyflavanone
- 3,3 ', 4' ,5,7- pentahydroxy -2 ,3- dihydroflavon
- (2R, 3R ) -2 - ( 3,4- dihydroxyphenyl ) -2,3 -dihydro- 3,5,7 - trihydroxy -4H- 1-benzopyran -4-one
Pale yellow, odorless solid
Fixed
238-240 ° C
Poorly in water
- 985 mg · kg -1 ( LD50, mouse, ip)
- 1200 mg · kg -1 ( LD50, rat, ip)
Template: Infobox chemical / molecular formula search available
Taxifolin is an organic compound which chemically to the naturally occurring Flavanonolen counts (see structure, diversity and subgroups of flavonoids). Taxifolin is in a pure state as a white to light yellow powder.
Pharmacology
Antioxidant effects on metabolic functions in humans, such as for many flavonoids proved. Taxifolin has - compared to the 2,3- unsaturated quercetin - only about 50% of its antioxidant effect. The presence of an unsaturated group (such as the enol function ), and thus a possibility of stabilization conditions more unfavorable energetically thus appears to be an essential feature of antioxidant flavonoids. The lack of a double bond at the C-ring might also be the consequence that Taxifolin not mutagenic and no toxic effect in comparison with quercetin.
On the basis of results of an in vitro study on colon cancer cells modulating chemopreventive regulating genes was postulated by taxifolin. It was also demonstrated that, among other things Taxifolin in vitro inhibits ovarian cancer cell growth dose-dependent. A strong correlation exists between the inhibitory effect of Taxifolin derivatives on tissue proliferation in murine cell lines of the skin and in human breast cancer cells.
Epidemiological and in vivo studies suggest a positive effect of flavonoids in various cardiovascular diseases. Traditionally, these effects were attributed only to the antioxidant activity. However, there is in addition to the direct binding of reactive oxygen species, a variety of other effects, which may be responsible in pharmacologically attainable concentrations and for the positive influencing cardiovascular. These include in particular the inhibition of ROS - forming enzymes, inhibition of platelet function, inhibition of leukocyte activation, high blood pressure-lowering and vasodilator properties.
Taxifolin inhibits cellular melanogenesis ebensoso effective as arbutin, one of the most widely used remedies hyperpigmentation in cosmetics. However, Arbutin acts as quercetin extremely mutagenic, carcinogenic and toxic. In animal experiments in mice prevention of the production of inflammatory cytokines and a reduction of skin inflammation was observed after topical treatment with taxifolin.
Taxifolin significantly reduces the production of the blue dye pyocyanin and the enzyme elastase in widespread hospital germ Pseudomonas aeruginosa. The flavonoid thus inhibits the virulence of pathogenic bacteria by engaging in their quorum sensing mechanism. Similarly, the efficacy of conventional antibiotics such as levofloxacin and ceftazidime was improved by taxifolin in vitro.
Taxifolin inhibits the production of lipopolysaccharide -induced prostaglandin E. In addition to other substances Taxifolin from Cercidiphyllum japonicum was isolated and showed - like Minoxidil and procyanidin B-2 - significant, the hair - young -stimulating activity on mouse skin epithelial cells. On the protein and RNA synthesis in liver cells similarly strong effects could be detected as silibinin by taxifolin.
Occurrence and extraction
Certain parts of the trunks of coniferous trees, particularly the larch, have a relatively high proportion of taxifolin ( DHQ ). The phenolic compounds, in relation to herbal metabolic reactions are crucial for the natural durability and resistance of the wood to pests, UV radiation and weathering. In the larch comes here specifically the Taxifolin crucial. The total of the phenolic content materials is 3 to 4 % rare addition. The first step is the extraction of taxifolin, the lower stem ends of the larches, which are obtained as waste products in the production of wood, bark and chaffed. The following laboratory tests provide information on the proportion of chips to DHQ ( dihydroquercetin ). By classical extraction methods Taxifolin is a purity of max. Reached 85 to 88 %. Only the subsequent multi-stage liquid chromatography ( LC), resulting in a degree of purity of almost 100%. This labor-intensive and therefore costly process is necessary in order to effectively remove unwanted impurities such as resins and other substances from the recovered substance.