Method for preparing quercetin by using troxerutin waste liquid powder

Abstract

The present application relates to the technical field of preparation of quercetin, and discloses a method for preparing quercetin by using troxerutin waste liquid powder, which comprises the following steps: step S1, dissolving the troxerutin waste liquid powder in a protonic acid or a Lewis acid, heating and refluxing until the reaction is complete; and step S2, reducing to normal temperature, filtering, washing the filter cake with deionized water until neutral, and drying to obtain quercetin. In the technical solution, the acid is used as a catalyst, the sugar molecules are hydrolyzed while the hydroxyethyl groups are removed, all the rutin substitutes in the waste liquid powder are converted into quercetin, the hydrolysis of two molecules of sugar on the rutin molecules and the removal of the hydroxyethyl groups are completed at the same time in one step, the process time is effectively shortened, the production cost is reduced, and good economic benefits are achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of quercetin preparation, in particular, to a method for preparing quercetin by using troxerutin waste liquid powder. BACKGROUND

[0002] Troxe rutin is also known as hydroxyethyl rutin, 3', 4', 7-tris [O- (2-hydroxyethyl) ] rutin, etc. It can coagulate platelets and prevent the formation of cerebral thrombosis. It can also resist vascular damage caused by 5-hydroxytryptamine and bradykinin, increase capillary resistance, and reduce capillary permeability. It can prevent edema caused by increased vascular permeability and has a significant protective effect on acute ischemic brain injury. Troxerutin is suitable for hemiplegia, aphasia caused by cerebral thrombosis and cerebral embolism, premyocardial infarction syndrome, arteriosclerosis, etc.

[0003] Troxerutin is generally prepared by reacting rutin with ethylene oxide. The flavonoid nucleus of rutin has four phenolic hydroxyl groups, and their activities are not much different. Therefore, it is difficult to accurately control the reaction to occur at the 3', 4', and 7' positions to obtain compound III (troxerutin). The reaction products coexist, and after the separation of troxerutin (compound III), the mother liquor contains one-substituted, two-substituted, and four-substituted products and part of troxerutin. After the solvent is recovered, this part of by-products has not been well treated, and eventually becomes waste, which increases the environmental protection pressure and raises the production cost of troxerutin.

[0004] In the public reports, there are few reports on the recycling of troxerutin waste liquid powder. Patent CN107501366 reports that the troxerutin waste liquid powder is separated and recovered by silica gel column chromatography. The hydroxyethyl one-substituted, two-substituted, three-substituted, and four-substituted products of rutin are not recycled, resulting in waste of resources.

[0005] Patent CN202010301247.2 reports that two sugar molecules on the hydroxyethyl substituent of rutin are hydrolyzed by glycoside hydrolase, and then dehydroxyethyl with pyridine hydrochloride to convert into quercetin for recycling. Although this method recycles the hydroxyethyl one-substituted, two-substituted, three-substituted, and four-substituted products of rutin, it needs two steps to complete, and a large amount of wastewater is generated during the treatment of the intermediate product, resulting in loss of product and reduction of product yield. The catalyst used in the second step has reproductive toxicity and may cause infertility, which is not friendly to operators. In addition, this method also has the disadvantages of high reaction temperature and long reaction time. SUMMARY

[0006] In order to solve the defects of the prior art, the application discloses a method for preparing quercetin from troxerutin waste liquid powder, which converts all rutin substitutes in the waste liquid powder into quercetin, hydrolyzes two molecules of sugar on the rutin molecule and removes hydroxyethyl in one step, effectively shortens the process time, reduces the production cost, and has good economic benefits.

[0007] The application discloses a method for preparing quercetin from troxerutin waste liquid powder, which comprises the following steps:

[0008] In step S1, the troxerutin waste liquid powder is dissolved in a protonic acid or a Lewis acid, and heated to reflux until the reaction is complete.

[0009] In step S2, the temperature is lowered to room temperature, and the filter cake is washed to neutral with deionized water, and then dried to obtain quercetin.

[0010] Further, in step S1, the protonic acid is one of HBr, HCl and H2SO4.

[0011] Further, in step S1, the Lewis acid is one of AlCl3 and BBr3.

[0012] Further, the reaction temperature of step S1 is the reflux temperature, and the reaction time is 8-15h.

[0013] Further, the drying temperature in step S2 is 50-100 DEG C.

[0014] Further, the drying temperature in step S2 is 70 DEG C.

[0015] The working principle and beneficial effects of the application are as follows:

[0016] The technical solution selects an acid as a catalyst, which can hydrolyze sugar molecules while removing hydroxyethyl groups, converts all rutin substitutes in the waste liquid powder into quercetin, hydrolyzes two molecules of sugar on the rutin molecule and removes hydroxyethyl groups in one step, effectively shortens the process time, reduces the production cost, and has good economic benefits. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a synthetic route map of patent No. CN202010301247.2;

[0018] Figure 2 is a synthetic route map of the application.

[0019] In the figure, I, II, III and IV respectively refer to hydroxyethyl one-substituted, two-substituted, three-substituted and four-substituted products of rutin. DETAILED DESCRIPTION

[0020] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0021] The present invention discloses a method for preparing quercetin by utilizing troxerutin waste liquid powder, comprising the following steps:

[0022] Step S1, dissolving the troxerutin waste liquid powder in protonic acid or Lewis acid, and heating under reflux until the reaction is complete;

[0023] Step S2, cooling to room temperature, filtering, washing the filter cake with deionized water until neutral, and drying to obtain quercetin.

[0024] In a preferred embodiment, in step S1, the protonic acid is one of HBr, HCl, and H2SO4. When the protonic acid is selected, water is selected as the reaction solvent.

[0025] In a preferred embodiment, in step S1, the Lewis acid is one of AlCl3 and BBr3. When the above-mentioned protonic acid is selected, an anhydrous solvent such as dichloromethane is selected as the reaction reagent. In step S2, after cooling to room temperature, a 5% aqueous NaOH solution is added, stirred thoroughly, and then separated. The aqueous solution is adjusted to pH = 3 with concentrated hydrochloric acid and then filtered.

[0026] In a preferred embodiment, to further improve the preparation quality, the reaction temperature in step S1 is reflux temperature, and the reaction time is 8-15 hours. The drying temperature in step S2 is 50-100°C, preferably 70°C.

[0027] Example 1:

[0028] Weigh 100g of troxerutin waste liquid powder and add it to a 1000ml three-necked flask equipped with a stirrer and a condenser, then add 500ml of 40% HBr aqueous solution, stir and heat to reflux, and sample HPLC detection every hour after reflux for 5 hours. The reaction is complete in 11 hours.

[0029] The mixture was stirred and cooled to room temperature, filtered, and the filter cake was washed with 40 ml of deionized water to obtain 70.86 g of yellow-green aqueous filter cake, which was dried at 70° C. for 8 hours to obtain 54.38 g of dry quercetin.

[0030] Example 2:

[0031] Weigh 100g of troxerutin waste liquid powder, add it to a 1000ml three-necked flask equipped with a stirrer and a condenser, then add 300ml of dichloromethane solution, stir to dissolve, then cool to -10°C in an ice bath, add dropwise soluble BBr3 dichloromethane solution (215g dissolved in 200ml of dichloromethane), slowly heat to reflux, sample every hour after reflux for 5 hours and detect by HPLC, and the reaction is complete in 8 hours.

[0032] The mixture was cooled to room temperature, 200 ml of 5% NaOH aqueous solution was added, the mixture was stirred thoroughly and then separated, the aqueous solution was adjusted to pH 3 with concentrated hydrochloric acid, filtered, the filter cake was washed with 40 ml of deionized water, and the filter cake was dried at 70°C for 8 hours to obtain 47.62 g of dry quercetin.

[0033] Example 3

[0034] Weigh 100g of troxerutin waste liquid powder and add it to a 1000ml three-necked flask equipped with a stirring tube and a condenser, then add 500ml of 36% HCl aqueous solution, stir and heat to reflux, and sample HPLC detection every hour after reflux for 5 hours. The reaction is complete in 15 hours.

[0035] The mixture was stirred and cooled to room temperature, filtered, and the filter cake was washed with 40 ml of deionized water. The filter cake was dried at 70° C. for 8 hours to obtain 49.37 g of dry quercetin.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described in the present invention. Therefore, although this specification has described the present invention in detail with reference to the above embodiments, it should be understood by those skilled in the art that the present invention can still be modified or replaced by equivalents. All technical solutions and improvements that do not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A method for preparing quercetin using troxerutin waste liquid powder, characterized in that: The following steps are involved: Step S1, dissolving the troxerutin waste liquid powder in protonic acid or Lewis acid, and heating under reflux until the reaction is complete; Step S2, cooling to room temperature, filtering, washing the filter cake with deionized water until neutral, and drying to obtain quercetin.

2. A method for preparing quercetin using troxerutin waste liquid powder according to claim 1, characterized in that: In step S1, the protonic acid is one of HBr, HCl, and H2SO4.

3. A method for preparing quercetin by utilizing troxerutin waste liquid powder according to claim 1, characterized in that: In step S1, the Lewis acid is one of AlCl3 and BBr3.

4. A method for preparing quercetin using troxerutin waste liquid powder according to any one of claims 2 or 3, characterized in that: The reaction temperature of step S1 is reflux temperature, and the reaction time is 8-15 hours.

5. A method for preparing quercetin by utilizing troxerutin waste liquid powder according to claim 1, characterized in that: The drying temperature in step S2 is 50-100°C.

6. A method for preparing quercetin using troxerutin waste liquid powder according to claim 5, characterized in that: The drying temperature in step S2 is 70°C.

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