- Taxifolin preparation method
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The invention relates to a method for synthesizing a raw material medicine, in particular to a taxifolin preparation method, aiming to solve the technical problems that waste of plant resources and solvents is great during separation and purification of taxifolin from plants, complete synthesis methods of the taxifolin have long synthetic routes, many complicated raw ingredients are involved, theoverall yield is low and the methods are not suitable for industrial production in the prior art. The taxifolin preparation method has the advantages that dihydromyricetin is selected as a starting material, a crude taxifolin product is obtained by hydrolysis and catalysis closed-loop two-step reactions, and a qualified refined taxifolin product is obtained through purification and refining; the raw material is easy to obtain, the operation is simple, the cost is low, environment friendliness and small pollution are realized, and the taxifolin preparation method is suitable for industrial production.
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Paragraph 0036-0038; 0046-0048; 0056-0058; 0065; 0066-0068
(2019/03/08)
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- Preparation method of kaempferol
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The invention relates to a synthesis method of a bulk drug, in particular to a preparation method of kaempferol. The preparation method of the kaempferol is provided in order to solve the technical problems that in the prior art, when purified kaempferol is separated from plants, waste of plant resources and solvents is large, and a total-synthesis method of the kaempferol is long in synthesis route, many in step, low in yield, and difficult to meet the requirements of industrial production are difficult to meet. According to the preparation method, dihydromyricetin is selected as a starting raw material, a kaempferol crude product is obtained through three step reactions of hydrolysis, catalytic closed-loop and oxidation, and the kaempferol crude product is purified and refined to obtainkaempferol refined product with the qualified quality. According to the preparation method of the kaempferol, raw materials are easy to obtain, operation is easy, the cost is low, and the preparationmethod is suitable for industrial production.
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Paragraph 0034-0036; 0044-0046; 0054-0056; 0063-0066
(2019/03/08)
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- Isotopic labelling of quercetin 3-glucoside
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The potentially important dietary antioxidant, quercetin 3-O-β-d-glucoside, has been 13C-labelled at C-2 of the flavonoid unit by synthesis in 15% yield over five steps from [13C]carbon dioxide. The route is appropriate for radiochemical synthesis. Formation of the protected 3-glucosylated flavonol appears to result from [1,7]-sigmatropic rearrangement with migration of a benzyl group followed by cyclisation. A free 5-OH results even when a phosphazene superbase is used.
- Caldwell, Stuart T.,Petersson, Hanna M.,Farrugia, Louis J.,Mullen, William,Crozier, Alan,Hartley, Richard C.
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p. 7257 - 7265
(2007/10/03)
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