Method for extracting alkaloid from macleaya cordata

Abstract

The invention belongs to the technical field of extraction of traditional Chinese medicinal materials, and particularly relates to a method for extracting alkaloid from macleaya cordata, which realizes efficient, safe, environment-friendly, simple and convenient alkaloid extraction by adopting microwave-assisted acid water extraction, has the advantages of remarkable extraction efficiency, energy conservation, environment friendliness, stable structure and the like, and is suitable for industrial production. And a foundation is laid for industrial production of macleaya cordata alkaloid.

Description

Technical Field

[0001] The invention belongs to the technical field of traditional Chinese medicine extraction, and particularly relates to a method for extracting alkaloids from Macleaya cordata. Background Art

[0002] Macleaya cordata alkaloids are compounds extracted from Macleaya cordata (Willd.) R.Br., a plant of the genus Macleaya in the Papaveraceae family, mainly including sanguinarine, chelerythrine, bocconaline, protopine, etc. These alkaloids have a variety of pharmacological activities, such as antibacterial, anti-inflammatory, anti-tumor and antioxidant, etc. Among them, sanguinarine and chelerythrine have attracted widespread attention due to their significant antibacterial and anti-tumor activities.

[0003] At present, the conventional extraction methods of alkaloids in Macleaya cordata mainly include: solvent extraction, ultrasound-assisted extraction, supercritical fluid extraction, and microwave-assisted extraction. The thermal effect of microwaves accelerates the dissolution of alkaloids, but requires a large amount of solvent. The use of organic solvents is unsafe and costly, and brings inconvenience to post-processing.

[0004] The patent with publication number CN109468350A discloses a method for synthesizing sanguinarine and chelerythrine using Macleaya cordata leaf stock solution as a substrate, which specifically includes the following steps: S1, pre-treatment of Macleaya cordata leaf stock solution; S2, construction of yeast engineering bacteria; S3, using the Macleaya cordata leaf stock solution pre-treated in step S1 as a substrate, and feeding the yeast engineering bacteria constructed in step S2 with the precursor; S4, collecting the cultured yeast engineering bacteria, lysing the bacteria, separating and purifying, and obtaining the obtained products. However, this scheme has the problems of high cost, high operation requirements, and unsatisfactory process stability.

[0005] Patent publication number CN101020703A discloses a method for extracting alkaloids from Macleaya cordata by adopting the steps of ethanol step-by-step impregnation, ultrasonic extraction, macroporous resin separation and purification, microwave vacuum drying and other production process refining steps. However, this method requires multi-gradient elution, has low elution efficiency, large solvent consumption and high cost.

[0006] Patent publication number CN115505011A discloses a scheme of pre-treating Macleaya oleifera pod powder with petroleum ether, thereby removing a large amount of fat-soluble impurities, pigments, etc. in the Macleaya oleifera pod powder while fully retaining the active ingredients, and then extracting alkaloids from Macleaya oleifera by ethanol-microwave extraction and macroporous resin adsorption purification. However, this method leads to high subsequent purification costs due to the problem of solvent residue.

[0007] Patent publication number CN102258580A discloses a method for extracting alkaloids from Macleaya cordata by integrating ultrasonic countercurrent continuous extraction, ceramic membrane purification, sodium filter membrane concentration, and intelligent static microwave vacuum drying technology. However, this method is extremely costly and is not conducive to industrial production.

[0008] The patent with publication number CN101849994A discloses the use of acid water percolation, alkali precipitation, and then reflux extraction with low-carbon alcohol, and then acid crystallization and salting after concentrating the extract to obtain a Macleaya cordata alkaloid with a sanguinarine content of not less than 40%; and the patent with publication number CN104739939A discloses the use of acid water reflux extraction, adjusting the pH to neutral, adding ethanol to obtain an extract, and then adjusting the pH and extracting by alkali precipitation to achieve the extraction of the obtained Macleaya cordata total alkaloids. However, both CN101849994A and CN104739939A require the use of a large amount of alcohols, which increases the cost of organic reagents, and these reagents may also interfere with the pharmacological activity of alkaloids. Therefore, it is urgent to find an extraction method that is simple to operate, fast and efficient, and suitable for large-scale extraction of Macleaya cordata alkaloids. Summary of the invention

[0009] Aiming at the deficiencies of the prior art, the invention proposes a method for extracting alkaloids from Macleaya cordata.

[0010] This is achieved specifically through the following technical solutions:

[0011] The object of the present invention is to provide: a method for extracting alkaloids from Macleaya cordata, comprising the following steps:

[0012] (1) Pretreatment: Take the leaves or fruits of Bohollandia schreberi and dry them in the sun, crush them and dry them to obtain Bohollandia schreberi powder;

[0013] (2) Mixing: The Macleaya cordata powder and the acid aqueous solution are uniformly mixed in a mass volume ratio of 1:10 to 1:50 to obtain a mixture;

[0014] (3) Microwave extraction: The mixture is placed in a microwave environment, subjected to microwave heating extraction, and then naturally cooled to room temperature, and then filtered under reduced pressure to obtain an acid water extract;

[0015] (4) Alkali precipitation: adding sodium hydroxide or ammonia water to the acid water extract to adjust the pH value to 9-11, allowing to stand and filtering to obtain a filter cake, and vacuum drying the filter cake to obtain the total alkaloids of Macleaya cordata;

[0016] (5) Content detection:

[0017] 5.1 Preparation of test solution

[0018] Take the filter cake and wash it with acid solution for 2-3 times. Transfer the filtrate to a volumetric flask and dissolve it to obtain the solution to be tested.

[0019] 5.2 UV spectrophotometry

[0020] 5.2.1 Standard curve drawing

[0021] Accurately weigh an appropriate amount of sanguinarine reference substance, dissolve it in methanol-water containing hydrochloric acid, transfer it to a volumetric flask, make it up to volume and shake it well to make a standard stock solution; then accurately transfer the standard stock solution to make a series of standard measurement solutions with a concentration gradient, measure the absorbance at the maximum absorption wavelength of 275nm after scanning the solvent as a reference spectrum, draw an absorbance-concentration curve, and the regression equation is y=0.10175x+0.00015 (r=0.999995);

[0022] 5.2.2 Sample determination

[0023] Accurately pipette the test solution into a volumetric flask and add acid aqueous solution to make up the volume. Measure the absorbance at 275nm with the acid aqueous solution as a reference, and repeat 3 times. The extraction rate of Macleaya cordata alkaloids is calculated as follows:

[0024]

[0025] Where: 1 is the extraction rate (%); c is the concentration of Macleaya cordata alkaloids in the extract (μg / mL); V is the final volume of the extract (mL); N is the dilution multiple; m is the mass of Macleaya cordata powder (g);

[0026] 5.3 High performance liquid chromatography

[0027] 5.3.1 Chromatographic conditions

[0028] Acetonitrile (A)-0.1% phosphoric acid (B) was used as the mobile phase, the flow rate was 0.8 mL / min, the chromatographic column was used, and the gradient elution was as follows: 0-14 min, 25% A; 14-27 min, 25-60% A; 27-29 min, 60-25% A; 29-35 min, 25% A; the detection wavelength was 275 nm; the injection volume was 10 μL; the column temperature was 30° C.;

[0029] 5.3.2 Standard curve drawing

[0030] Accurately weigh appropriate amounts of ortho-opine, allocryptine, sanguinarine, and chelerythrine reference substances, dissolve them in methanol-water containing 0.1 mol / L hydrochloric acid, transfer to a volumetric flask, dilute to volume and shake well to prepare mixed reference substance stock solutions with concentrations of 246, 236, 160, and 170 μg / mL; accurately transfer 0.50, 1.00, 2.00, 3.00, 4.00, and 5.00 mL of the diluted solution to a 10 mL volumetric flask, filter through a microporous filter membrane, perform liquid phase analysis according to chromatographic conditions, and draw a peak area-concentration curve; the four components show a good linear relationship as follows:

[0031] Original opium: Linear regression equation y = 8.85541x + 7.37381e -1 , R = 0.99999;

[0032] Allocryptine: y = 7.4978x + 6.09104e -1 , R = 0.99999;

[0033] Sanguinarine: y = 43.63126x + 3.51276, R = 0.99999;

[0034] Chelerythrine: y = 53.91609x + 5.50234, R = 0.99999;

[0035] 5.3.3 Sample determination

[0036] The test solution was filtered through a microporous membrane and the concentrations of the above four alkaloids were determined according to chromatographic conditions. The extraction rate of Macleaya cordata alkaloids was calculated according to the following formula:

[0037]

[0038] Where: 2 is the extraction rate (%); c is the concentration of the four alkaloids in the extract (μg / mL); V is the final volume of the extract (mL); m is the mass of Macleaya cordata powder (g).

[0039] The drying temperature is 55-65°C, preferably 60°C.

[0040] The acid aqueous solution is composed of inorganic acid, methanol and water; the content of inorganic acid in the acid aqueous solution is 0.05-0.3 mol / L, and the volume concentration of methanol is 50-70%.

[0041] The inorganic acid is any one or more of hydrochloric acid, sulfuric acid and nitric acid.

[0042] The microwave heating conditions are as follows: microwave power is 100-700W, heating temperature is 50-80°C, and time is 2-12min.

[0043] The vacuum drying temperature is 50-60°C.

[0044] The standing time is 6-12h.

[0045] Beneficial effects:

[0046] The present invention realizes efficient, safe, environmentally friendly and simple alkaloid extraction by using microwave-assisted acid-water extraction. The specific technical principles and effects are as follows:

[0047] 1. Improve the extraction rate.

[0048] Microwave selective heating: Microwaves interact with polar molecules inside the substance (such as acid water and Macleaya cordata alkaloids) to achieve simultaneous heating inside and outside. This uniform and rapid thermal effect can effectively promote the dissolution of alkaloids and significantly improve the extraction efficiency.

[0049] Acid water and alkaloids form salts: The hydrogen ions in the acid-water solution combine with the Macleaya alkaloids to form salts, which further accelerates the dissolution process of intracellular substances.

[0050] The combined use of the two can significantly improve the extraction rate of alkaloids in Macleaya cordata leaves and fruits, significantly reduce the extraction temperature of Macleaya cordata alkaloids, shorten the extraction time, and increase the extraction yield, and has no effect on the structure and physicochemical properties of Macleaya cordata alkaloid extracts.

[0051] 2. Shorten extraction time and reduce energy consumption

[0052] Since microwave heating has the characteristics of efficient energy utilization and rapid and efficient heating, it can reach the required extraction temperature in a short time, significantly shorten the extraction time, reduce energy consumption, and thus save production costs.

[0053] 3. Retain active ingredients and maintain stable structure

[0054] Microwave heating is selective and can act preferentially on polar molecules, without significantly affecting the structure and physicochemical properties of Macleaya cordata alkaloids, which is beneficial to improving the accuracy of the detection method.

[0055] 4.Precise quality control

[0056] The present invention combines two content detection methods, UC and HPLC, to detect the contents of total alkaloids, protopine, allocryptine, sanguinarine and chelerythrine, so as to evaluate the product quality more objectively and scientifically, reduce the content detection error and improve the accuracy of the result through scientific solvent and detection condition screening.

[0057] In summary, the present invention has the advantages of significant extraction efficiency, energy saving and environmental protection, stable structure, etc., and lays a foundation for the industrial production of Macleaya cordata alkaloids. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 :The effect of hydrochloric acid concentration on the extraction rate of Macleaya cordata alkaloids;

[0059] Figure 2 :Effect of methanol concentration on the extraction rate of Macleaya cordata alkaloids;

[0060] Figure 3 :The effect of extraction temperature on the extraction rate of Macleaya cordata alkaloids;

[0061] Figure 4:The effect of extraction time on the extraction rate of Macleaya cordata alkaloids;

[0062] Figure 5 : Effect of solid-liquid ratio on the extraction rate of alkaloids from Macleaya cordata. DETAILED DESCRIPTION

[0063] The specific embodiments of the present invention are further described in detail below, but the present invention is not limited to these embodiments, and any improvement or substitution based on the basic spirit of the present embodiment still falls within the scope of protection required by the claims of the present invention.

[0064] Example 1

[0065] A method for extracting alkaloids from Macleaya cordata, comprising the following steps:

[0066] (1) Pretreatment:

[0067] Take 100 g of Macleania scoparia leaves, dry them naturally in the sun for 5 days, crush them and dry them at 60°C to obtain Macleania scoparia powder;

[0068] (2) Mixing:

[0069] Mix 0.50 g of Macleaya cordata powder and 10 mL of a 50% methanol-water solution containing 0.1 mol / L hydrochloric acid to obtain a mixture;

[0070] (3) Microwave extraction:

[0071] The mixture was placed in a microwave environment with a microwave heating power of 400 W, a heating temperature of 70° C., and a treatment time of 4 minutes. After naturally cooling to room temperature, the mixture was filtered under reduced pressure to obtain an acid water extract.

[0072] (4) Alkali precipitation:

[0073] Adding ammonia water to the acid water extract, adjusting the pH value to 10, standing for 8 hours, filtering to obtain a filter cake, and then vacuum drying the filter cake at a temperature of 50° C. for 6 hours to obtain the total alkaloids of Macleaya cordata;

[0074] (5) Content detection:

[0075] 5.1 Preparation of test solution

[0076] Take the filter cake and wash it with acid solution for 2-3 times. Transfer the filtrate to a volumetric flask and dissolve it to obtain the solution to be tested.

[0077] 5.2 UV spectrophotometry

[0078] 5.2.1 Standard curve drawing

[0079] Accurately weigh an appropriate amount of sanguinarine reference substance, add methanol-water (50:50) containing 0.1 mol / L hydrochloric acid to dissolve, transfer to a 50 mL volumetric flask, dilute and shake well to prepare a 400 μg / mL standard stock solution; then accurately transfer 2.50 mL of the standard stock solution to a 25 mL volumetric flask, and then accurately transfer 0.50, 1.00, 2.00, 3.00, 4.00, and 5.00 mL of the diluted solution to a 25 mL volumetric flask to prepare a series of standard measurement solutions with a concentration gradient, use methanol-water (50:50) containing 0.1 mol / L hydrochloric acid as a reference spectrum scan, and measure the absorbance at the maximum absorption wavelength of 275 nm, draw an absorbance-concentration curve, and the regression equation is y=0.10175x+0.00015 (r=0.999995);

[0080] 5.2.2 Sample determination

[0081] Accurately pipette 0.50 mL of the test solution into a 25 mL volumetric flask and add acid aqueous solution to make up the volume. Measure the absorbance at 275 nm using the acid aqueous solution as a reference, and repeat 3 times. The extraction rate of Macleaya cordata alkaloids is calculated as follows:

[0082]

[0083] Where: 1 is the extraction rate (%); c is the concentration of Macleaya cordata alkaloids in the extract (μg / mL); V is the final volume of the extract (mL); N is the dilution multiple; m is the mass of Macleaya cordata powder (g);

[0084] 5.3 High performance liquid chromatography

[0085] 5.3.1 Chromatographic conditions

[0086] Acetonitrile (A)-0.1% phosphoric acid (B) was used as the mobile phase, the flow rate was 0.8 mL / min, the chromatographic column was used, and the gradient elution was as follows: 0-14 min, 25% A; 14-27 min, 25-60% A; 27-29 min, 60-25% A; 29-35 min, 25% A; the detection wavelength was 275 nm; the injection volume was 10 μL; the column temperature was 30° C.;

[0087] 5.3.2 Standard curve drawing

[0088] Accurately weigh appropriate amounts of ortho-opine, allocryptine, sanguinarine, and chelerythrine reference substances, dissolve them in methanol-water (50:50) containing 0.1 mol / L hydrochloric acid, transfer to a 50 mL volumetric flask, dilute to volume and shake well to prepare mixed reference substance stock solutions with concentrations of 246, 236, 160, and 170 μg / mL; accurately transfer 0.50, 1.00, 2.00, 3.00, 4.00, and 5.00 mL of the diluted solution to a 10 mL volumetric flask, filter through a 0.45 μm microporous filter membrane, perform liquid phase analysis according to chromatographic conditions, and draw a peak area-concentration curve; the four components show a good linear relationship as follows:

[0089] Original opium: Linear regression equation y = 8.85541x + 7.37381e -1 , R = 0.99999;

[0090] Allocryptine: y = 7.4978x + 6.09104e -1 , R = 0.99999;

[0091] Sanguinarine: y = 43.63126x + 3.51276, R = 0.99999;

[0092] Chelerythrine: y = 53.91609x + 5.50234, R = 0.99999;

[0093] 5.3.3 Sample determination

[0094] The test solution was filtered through a 0.45 μm microporous membrane and the concentrations of the above four alkaloids were determined according to chromatographic conditions. The extraction rate of Macleaya cordata alkaloids was calculated according to the following formula:

[0095]

[0096] Where: 2 is the extraction rate (%); c is the concentration of the four alkaloids in the extract (μg / mL); V is the final volume of the extract (mL); m is the mass of Macleaya powder (g);

[0097] The total alkaloids of Macleaya cordata are a mixture of sanguinarine, chelerythrine, Macleaya cordata and orthoopine.

[0098] Experimental example: Single factor experiment

[0099] 1.1 Hydrochloric acid concentration

[0100] On the basis of Example 1, the difference from Example 1 is that 6 portions of 0.50g of Macleaya cordata fruit powder were accurately weighed and placed in a 100mL two-necked round-bottom flask, and 10mL of aqueous hydrochloric acid solutions of different concentrations (0, 0.05, 0.10, 0.15, 0.20, 0.25mol / L) were added respectively, and the other steps, conditions, and proportions were the same as in Example 1 to investigate the changes in the extraction rate of Macleaya cordata alkaloids.

[0101] 1.2 Methanol concentration

[0102] On the basis of Example 1, the difference from Example 1 is that 6 portions of 0.50g of Macleaya cordata fruit powder were accurately weighed and placed in a 100mL two-necked round-bottom flask, and 10mL of 50% methanol aqueous solution containing 0.10mol / L hydrochloric acid was added respectively. The other steps, conditions, and proportions were the same as in Example 1, and the changes in the extraction rate of Macleaya cordata alkaloids were investigated.

[0103] 1.3 Extraction temperature

[0104] On the basis of Example 1, the difference from Example 1 is that: 5 portions of 0.50g of Macleaya cordata fruit powder were accurately weighed and placed in a 100mL two-necked round-bottom flask, 10mL of a 50% methanol aqueous solution containing 0.10mol / L hydrochloric acid was added respectively, and heated in a microwave reactor at different temperatures (30, 40, 50, 60, 70°C), and the other steps, conditions, and proportions were the same as in Example 1 to investigate the change in the extraction rate of Macleaya cordata alkaloids.

[0105] 1.4 Extraction time

[0106] On the basis of Example 1, the difference from Example 1 is that 6 portions of 0.50g of Macleaya cordata fruit powder were accurately weighed and placed in a 100mL two-necked round-bottom flask, 10mL of 50% methanol aqueous solution containing 0.10mol / L hydrochloric acid were added respectively, and heated in a microwave reactor for 2, 4, 6, 8, and 10min respectively. The other steps, conditions, and proportions were the same as in Example 1 to investigate the changes in the extraction rate of Macleaya cordata alkaloids.

[0107] 1.5 Material-liquid ratio

[0108] On the basis of Example 1, the difference from Example 1 is that: 4 portions of 0.50g of Macleaya cordata fruit powder were accurately weighed and placed in a 100mL two-necked round-bottom flask, and 50% methanol aqueous solution containing 0.10mol / L hydrochloric acid at different material-liquid ratios (10, 20, 30, 40mL / g) were added respectively. The other steps, conditions, and proportions were the same as in Example 1 to investigate the changes in the extraction rate of Macleaya cordata alkaloids.

[0109] 2. Data Statistics and Analysis

[0110] The experimental data were analyzed and processed using Excel 2019. All experiments were repeated 3 times, and the results were expressed as average values.

[0111] 3. Results and Analysis

[0112] 3.1 Effect of hydrochloric acid concentration on the extraction rate of Macleaya cordata alkaloids (such as Figure 1 )

[0113] Figure 1 The differences in the extraction rate of Macleaya cordata alkaloids determined by two different detection methods (UV and HPLC) at different hydrochloric acid concentrations were compared. Figure 1 It can be seen that with the increase of hydrochloric acid concentration, the alkaloid extraction rate of both detection methods increased. When the hydrochloric acid concentration was low (0.00-0.05mol / L), the extraction rate of the HPLC method was higher than that of the UV method. When the hydrochloric acid concentration was high (0.05-0.25mol / L), the extraction rates of the two methods tended to be consistent and eventually decreased slightly. The results show that the HPLC method performs better at low hydrochloric acid concentrations.

[0114] 3.2 Effect of methanol concentration on the extraction rate of Macleaya cordata alkaloids (e.g. Figure 2 )

[0115] Figure 2 The differences in the extraction rates of Macleaya cordata alkaloids determined by two different detection methods (UV and HPLC) at different methanol concentrations were compared. Figure 2 It can be seen that with the increase of methanol concentration, the alkaloid extraction rate of both detection methods increased. When the methanol concentration is low (10%-30%), the extraction rate of the HPLC method is higher than that of the UV method. When the methanol concentration is high (40%-70%), the extraction rates of the two methods gradually approach and eventually become consistent. The results show that the HPLC method performs better at low methanol concentrations. As the methanol concentration increases, the difference in the extraction rates of the two methods decreases and eventually becomes consistent.

[0116] 3.3 Effect of extraction temperature on the extraction rate of Macleaya cordata alkaloids (e.g. Figure 3 )

[0117] Figure 3 The differences in the extraction rate of Macleaya cordata alkaloids determined by two different detection methods (UV and HPLC) at different extraction temperatures were compared. Figure 3 It can be seen that with the increase of extraction temperature, the alkaloid extraction rate of both detection methods increased. When the extraction temperature was low (30℃-50℃), the extraction rate of HPLC method was higher than that of UV method. When the extraction temperature was high (50℃-70℃), the extraction rates of the two methods gradually approached and eventually became consistent. The results show that the HPLC method performs better at low extraction temperatures.

[0118] 3.4 Effect of extraction time on the extraction rate of Macleaya cordata alkaloids (e.g. Figure 4 )

[0119] Figure 4 The differences in the extraction rate of Macleaya cordata alkaloids determined by two different detection methods (UV and HPLC) at different extraction times were compared. Figure 4 It can be seen that the alkaloid yield increases first and then decreases with time. When the extraction time is 8 minutes, the alkaloid extraction rate reaches the maximum value. It may be that the longer the microwave time, the greater the damage to the cells. At the same time, the solution temperature continues to rise, which is conducive to the dissolution of alkaloids. At 8 minutes, the alkaloid diffusion has reached equilibrium. Continuing to extend the time makes the alkaloid substances irradiated under microwaves for too long, resulting in the destruction of some alkaloid substances. Therefore, the optimal extraction time is determined to be 8 minutes.

[0120] 3.5 Effect of solid-liquid ratio on the extraction rate of Macleaya cordata alkaloids (e.g. Figure 5 )

[0121] Figure 5 The differences in the extraction rate of Macleaya cordata alkaloids determined by two different detection methods (UV and HPLC) at different solid-liquid ratios (g / mL) were compared. Figure 5 It can be seen that with the increase of the solid-liquid ratio, the alkaloid extraction rate of the two detection methods increased. When the solid-liquid ratio was low (10g / mL), the extraction rate of the HPLC method was higher than that of the UV method. With the increase of the solid-liquid ratio, the difference in the extraction rate of the two methods gradually narrowed. When the solid-liquid ratio was 40g / mL, the extraction rates of the two methods tended to be consistent. The results show that the HPLC method performs better at a low solid-liquid ratio (10g / mL).

Claims

1. A method for extracting alkaloids from Macleaya cordata, characterized in that: The steps include: (1) Pretreatment: Take the leaves or fruits of Bohollandia schreberi and dry them in the sun, crush them and dry them to obtain Bohollandia schreberi powder; (2) Mixing: Mix the maclea vine powder and the acid aqueous solution in a mass volume ratio of 1:10 to 1:50 to obtain a mixture; (3) Microwave extraction: The mixture is placed in a microwave environment, subjected to microwave heating extraction, and then naturally cooled to room temperature, and then filtered under reduced pressure to obtain an acid water extract; (4) Alkali precipitation: adding sodium hydroxide or ammonia water to the acid water extract to adjust the pH value to 9-11, allowing to stand and filtering to obtain a filter cake, and vacuum drying the filter cake to obtain the total alkaloids of Macleaya cordata; (5) Content detection: 5.1 Preparation of test solution Take the filter cake and wash it with acid solution for 2-3 times. Transfer the filtrate to a volumetric flask and dissolve it to obtain the solution to be tested. 5.2 UV spectrophotometry 5.2.1 Standard curve drawing Accurately weigh an appropriate amount of sanguinarine reference substance, dissolve it in methanol-water containing hydrochloric acid, transfer it to a volumetric flask, make it up to volume and shake it well to make a standard stock solution; then accurately transfer the standard stock solution to make a series of standard measurement solutions with a concentration gradient, measure the absorbance at the maximum absorption wavelength of 275nm after scanning the solvent as a reference spectrum, draw an absorbance-concentration curve, and the regression equation is y=0.10175x+0.00015 (r=0.999995); 5.2.2 Sample determination Accurately pipette the test solution into a volumetric flask and add acid aqueous solution to make up the volume. Measure the absorbance at 275nm with the acid aqueous solution as a reference, and repeat 3 times. The extraction rate of Macleaya cordata alkaloids is calculated as follows: Wherein: ω1 is the extraction rate (%); c is the concentration of Macleaya cordata alkaloids in the extract (μg / mL); V is the final volume of the extract (mL); N is the dilution multiple; m is the mass of Macleaya cordata powder (g); 5.3 High performance liquid chromatography 5.3.1 Chromatographic conditions Acetonitrile (A)-0.1% phosphoric acid (B) was used as the mobile phase, the flow rate was 0.8 mL / min, the chromatographic column was used, and the gradient elution was as follows: 0-14 min, 25% A; 14-27 min, 25-60% A; 27-29 min, 60-25% A; 29-35 min, 25% A; the detection wavelength was 275 nm; the injection volume was 10 μL; the column temperature was 30° C.; 5.3.2 Standard curve drawing Accurately weigh appropriate amounts of ortho-opine, allocryptine, sanguinarine, and chelerythrine reference substances, dissolve them in methanol-water containing 0.1 mol / L hydrochloric acid, transfer to a volumetric flask, dilute to volume and shake well to prepare mixed reference substance stock solutions with concentrations of 246, 236, 160, and 170 μg / mL; accurately transfer 0.50, 1.00, 2.00, 3.00, 4.00, and 5.00 mL of the diluted solution to a 10 mL volumetric flask, filter through a microporous filter membrane, perform liquid phase analysis according to chromatographic conditions, and draw a peak area-concentration curve; the four components show a good linear relationship as follows: Original opium: Linear regression equation y = 8.85541x + 7.37381e -1 , R = 0.99999; Allocryptine: y = 7.4978x + 6.09104e -1 , R = 0.99999; Sanguinarine: y = 43.63126x + 3.51276, R = 0.99999; Chelerythrine: y = 53.91609x + 5.50234, R = 0.99999; 5.3.3 Sample determination The test solution was filtered through a microporous membrane and the concentrations of the above four alkaloids were determined according to chromatographic conditions. The extraction rate of Macleaya cordata alkaloids was calculated according to the following formula: Wherein: ω2 is the extraction rate (%); c is the concentration of the four alkaloids in the extract (μg / mL); V is the final volume of the extract (mL); m is the mass of Macleaya powder (g).

2. The method for extracting alkaloids from Macleaya cordata as claimed in claim 1, characterized in that: The drying temperature is 55-65°C.

3. A method for extracting alkaloids from Macleaya cordata as claimed in claim 1 or 2, characterized in that: The drying temperature is 60°C.

4. The method for extracting alkaloids from Macleaya cordata as claimed in claim 1, characterized in that: The acid aqueous solution is composed of inorganic acid, methanol and water; the content of inorganic acid in the acid aqueous solution is 0.05-0.3 mol / L, and the volume concentration of methanol is 50-70%.

5. The method for extracting alkaloids from Macleaya cordata as claimed in claim 1, characterized in that: The inorganic acid is any one or more of hydrochloric acid, sulfuric acid and nitric acid.

6. The method for extracting alkaloids from Macleaya cordata as claimed in claim 1, characterized in that: The microwave heating conditions are as follows: microwave power is 100-700W, heating temperature is 50-80°C, and time is 2-12min.

7. The method for extracting alkaloids from Macleaya cordata as claimed in claim 1, characterized in that: The standing time is 6-12h.

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