Provided in the present invention is a compound having these structure of formula I or a pharmaceutically acceptable salt thereof. Also provided in the present invention is a pharmaceutical composition containing the compound, and a use of the compound for treating cancers.

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The present disclosure provides a semi-synthetic method of dihydroquercetin, belonging to the field of synthesis of organic drugs. The semi-synthetic method includes the following steps: adding quercetin dihydrate to solvent water adjusted to be alkaline with an alkalizing reagent, heating and stirring to dissolve the mixture, and then adding thiourea dioxide under the protection of an inert gas to perform a reduction reaction, to obtain an endpoint reduction reaction solution; diluting the endpoint reduction reaction solution with water and cooling the resultant, and then acidizing, aging, and filtering the resultant to obtain a filtrate and a filter cake; extracting, washing, drying, concentrating, and repeatedly crystallizing the filtrate to obtain dihydroquercetin; and recycling the filter cake after being washed.

The present disclosure provides a semi-synthetic method of dihydroquercetin, belonging to the field of synthesis of organic drugs. The semi-synthetic method includes the following steps: adding quercetin dihydrate to solvent water adjusted to be alkaline with an alkalizing reagent, heating and stirring to dissolve the mixture, and then adding thiourea dioxide under the protection of an inert gas to perform a reduction reaction, to obtain an endpoint reduction reaction solution; diluting the endpoint reduction reaction solution with water and cooling the resultant, and then acidizing, aging, and filtering the resultant to obtain a filtrate and a filter cake; extracting, washing, drying, concentrating, and repeatedly crystallizing the filtrate to obtain dihydroquercetin; and recycling the filter cake after being washed.

The present disclosure provides a preparation method of dihydroquercetin, belonging to the field of synthesis of drugs. The method includes steps of: adjusting reaction solvent water to be alkaline with an alkalizing reagent, to obtain an alkaline aqueous solution; dissolving quercetin dihydrate in the alkaline aqueous solution, and adding a sulfite binary combined reducing agent to carry out reduction reaction, to obtain an endpoint reduction reaction solution; diluting the endpoint reduction reaction solution with water, and then acidizing, aging, and filtering the resultant to obtain a filtrate and a filter cake; subjecting the filtrate to extraction, washing, drying, and vacuum concentration to obtain a concentrated crude product; and repeatedly crystallizing the concentrated crude product to obtain dihydroquercetin. The preparation method of the present disclosure has readily available raw materials, a simple process, and low production costs, and is particularly suitable for industrial production.

The present disclosure provides a preparation method of dihydroquercetin, belonging to the field of synthesis of drugs. The method includes steps of: adjusting reaction solvent water to be alkaline with an alkalizing reagent, to obtain an alkaline aqueous solution; dissolving quercetin dihydrate in the alkaline aqueous solution, and adding a sulfite binary combined reducing agent to carry out reduction reaction, to obtain an endpoint reduction reaction solution; diluting the endpoint reduction reaction solution with water, and then acidizing, aging, and filtering the resultant to obtain a filtrate and a filter cake; subjecting the filtrate to extraction, washing, drying, and vacuum concentration to obtain a concentrated crude product; and repeatedly crystallizing the concentrated crude product to obtain dihydroquercetin. The preparation method of the present disclosure has readily available raw materials, a simple process, and low production costs, and is particularly suitable for industrial production.

This application discloses a method for extracting and separating dihydromyricetin from rattan tea, which belongs to the technical field of natural medicine extraction and separation. The specific steps are as follows: 1) weighing rattan tea leaves, then adding solvent thereto, stirring and refluxing to extract, filtering, keeping on refluxing extraction of residue, and combining extract; 2) adding activated carbon to the extract, performing decolorization, filtering, retaining the filtrate, and then concentrating the filtrate; and 3) crystallizing the concentrated filtrate, filtering, and washing the crystals with cold water and vacuum drying. The invention disclosure has simple process, high yield and stability, and is easy to realize industrialized production.

This application discloses a method for extracting and separating dihydromyricetin from rattan tea, which belongs to the technical field of natural medicine extraction and separation. The specific steps are as follows: 1) weighing rattan tea leaves, then adding solvent thereto, stirring and refluxing to extract, filtering, keeping on refluxing extraction of residue, and combining extract; 2) adding activated carbon to the extract, performing decolorization, filtering, retaining the filtrate, and then concentrating the filtrate; and 3) crystallizing the concentrated filtrate, filtering, and washing the crystals with cold water and vacuum drying. The invention disclosure has simple process, high yield and stability, and is easy to realize industrialized production.

This invention relates to a method for preparing a desired isomer of a substituted 2-trifluoromethyl-2H-chromene-3-carboxylic acid, which is characterized by comprising: (a) contacting the substituted 2-trifluoromethyl-2H-chromene-3-carboxylic acid with a chiral amine to form salts, wherein the chiral amine is selected so that the solubility of the amine salt of the undesired substituted 2-trifluoromethyl-2H-chromene-3-carboxylic acid is greater than the amine salt of the desired substituted 2-trifluoromethyl-2H-chromene-3-carboxylic acid, and (b) irradiating the mixture with an ultraviolet (UV) light, wherein the irradiation increases the amount of the less soluble chiral amine salt of the substituted of the 2-trifluoromethyl-2H-chromene-3-carboxylic acid in the mixture.

The world is plagued with several viruses some of which have prevention and treatment tools available, while every so often a new strain will show up without sensitivity to existing drugs. The present invention provides plant-based flavonoid pharmaceutical compositions for inhibition of kinases, particularly phosphatidylinositol-4-kinases (PI4Kiiiβ), AAK1, BIKE, GAK and other transcription factors required for viral entry, replication and survival, and consequent for prevention and treatment of RNA viruses including but not limited to adenoviruses, alphaviruses, coronaviruses, enteroviruses, flaviviruses, hepatitis, herpes, influenza viruses, measles, picornaviruses, vesicular stomatitis and associated disorders. A method for synthesizing the flavonoids and formulation into therapeutic products are also disclosed.

The present disclosure provides a preparation method of dihydroquercetin, belonging to the field of synthesis of drugs. The method includes steps of: adjusting reaction solvent water to be alkaline with an alkalizing reagent, to obtain an alkaline aqueous solution; dissolving quercetin dihydrate in the alkaline aqueous solution, and adding a sulfite binary combined reducing agent to carry out reduction reaction, to obtain an endpoint reduction reaction solution; diluting the endpoint reduction reaction solution with water, and then acidizing, aging, and filtering the resultant to obtain a filtrate and a filter cake; subjecting the filtrate to extraction, washing, drying, and vacuum concentration to obtain a concentrated crude product; and repeatedly crystallizing the concentrated crude product to obtain dihydroquercetin. The preparation method of the present disclosure has readily available raw materials, a simple process, and low production costs, and is particularly suitable for industrial production.