阅读说明：本技术 一种通过化学转化法间接测定中药材或中成药中藁本内酯含量的方法 (Method for indirectly measuring content of ligustilide in traditional Chinese medicinal material or Chinese medicinal material by chemical conversion method ) 是由 柳军玺 伍鹏程 于 2020-07-09 设计创作，主要内容包括：本发明公开了一种通过化学转化法间接测定中药材或中成药中藁本内酯准确含量的方法,是通过对中药材或中成药粉末中的藁本内酯进行提取和/或转化,使中药材或中成药中化学结构不稳定的藁本内酯转化为结构稳定的环丙藁本,再通过HPLC外标法直接测定环丙藁本的含量,然后通过等摩尔量间接计算得到中药材或中成药中藁本内酯的含量。本发明方法用于定量检测药物中藁本内酯的含量,其结果可靠,准确度高,方法稳定性、重现性良好,通过该方法的应用达到有效控制药物质量的直接目标。(The invention discloses a method for indirectly measuring the accurate content of ligustilide in a traditional Chinese medicinal material or a Chinese patent medicine by a chemical conversion method, which comprises the steps of extracting and/or converting the ligustilide in the traditional Chinese medicinal material or Chinese patent medicine powder to convert the ligustilide with unstable chemical structure in the traditional Chinese medicinal material or Chinese patent medicine into the ligustilide with stable structure, directly measuring the content of the ligustilide with stable structure by an HPLC (high performance liquid chromatography) external standard method, and indirectly calculating by equimolar amount to obtain the content of the ligustilide in the traditional Chinese medicinal material or Chinese patent medicine. The method is used for quantitatively detecting the content of the ligustilide in the medicine, has reliable result, high accuracy and good stability and reproducibility, and achieves the direct aim of effectively controlling the quality of the medicine by the application of the method.)

1. A method for indirectly measuring the content of ligustilide in Chinese medicinal materials or Chinese patent medicines by chemical conversion method comprises extracting and/or converting ligustilide in Chinese medicinal materials or Chinese patent medicines powder to convert the unstable ligustilide in the Chinese medicinal materials or Chinese patent medicines into stable ligustilide cycloproplea, directly measuring the content of ligustilide cyclopropanolate by HPLC external standard method, and indirectly calculating by equimolar amount to obtain the content of ligustilide in the Chinese medicinal materials or Chinese patent medicines.

2. The method for indirectly measuring the content of ligustilide in the traditional Chinese medicine or the Chinese traditional medicine by the chemical conversion method as claimed in claim 1, which is characterized in that: firstly, organic solvent and cyclopropylamine are adopted to extract and/or react ligustilide in the traditional Chinese medicine or the Chinese patent medicine synchronously, so that the degradation of the ligustilide in the extraction and reaction processes is prevented, the fixation of the ligustilide is accelerated by ultrasonic-assisted treatment, and the dissolution of the fixed ligustilide in plant cells is promoted; and finally, after the reaction system is fully eluted, transferred, diluted and quantified by using a solvent, the content of the ligustilide in the medicine is indirectly obtained by calculating the equimolar amount.

3. The method for indirectly measuring the content of ligustilide in the traditional Chinese medicine or the Chinese traditional medicine by the chemical conversion method as claimed in claim 2, which is characterized in that: the specific process comprises the following steps:

(1) preparation of a test solution: pulverizing the Chinese medicinal materials and sieving with a No. four pharmacopoeia sieve; adding the traditional Chinese medicine powder and cyclopropylamine into an organic solvent, and performing electromagnetic stirring extraction/reaction in a water bath at 0-60 ℃ for 5-20 min; carrying out ultrasonic extraction for 2-10 min, then continuing electromagnetic stirring extraction/reaction in a water bath at 0-60 ℃ for 30-90 min, carrying out suction filtration on the reactant, eluting the reactant with an organic solvent for three times, and combining the elution solutions; diluting until the concentration of the Cyclopropylate ligusticum is 80-400 mug/mL, and taking the diluted solution as a test solution; adding the medicinal material powder into an organic solvent according to the ratio of 0.05 g/mL-0.5 g/mL; the mass-volume ratio of the traditional Chinese medicine powder to the cyclopropylamine is 0.1 g/mL-0.77 g/mL;

(2) determining the content of rhizoma ligustici wallichii in the test solution by an HPLC external standard method: chromatographic conditions for measuring the content of the ligusticum ciprofloxacin by an HPLC external standard method are as follows: the mobile phase consists of methanol and water, the volume ratio of the methanol to the water is 35:65, the sample amount is as follows: 20 μ L, flow rate: 1 mL/min; measuring wavelength: 200-400 nm;

(3) the content of ligustilide in the medicine is indirectly obtained by calculating the equimolar amount.

4. The method for indirectly measuring the content of ligustilide in the traditional Chinese medicine or the Chinese traditional medicine by the chemical conversion method as claimed in claim 1, which is characterized in that: firstly, completely extracting ligustilide in the medicine powder by adopting an organic solvent, then adding cyclopropylamine into the ligustilide extract to carry out ligustilide chemical conversion reaction, diluting a conversion reaction system after the reaction is finished, quantifying, and directly measuring the content of the ligustilide by an HPLC external standard method; the content of ligustilide in the medicine is indirectly calculated by an equimolar amount and/or correction coefficient method.

5. The method for indirectly measuring the content of ligustilide in the traditional Chinese medicine or the Chinese traditional medicine by the chemical conversion method as claimed in claim 4, wherein the method comprises the following steps: the specific process comprises the following steps:

(1) preparation of a test solution: pulverizing Chinese medicinal materials or Chinese traditional medicines, sieving with a No. four pharmacopoeia sieve, adding the medicinal powder into organic solvent, and ultrasonic extracting to obtain ligustilide extract; adding cyclopropylamine into ligustilide extract, and stirring at room temperature to completely convert ligustilide; the reaction solution is directly used as a test solution; adding the medicinal powder into an organic solvent according to the proportion of 0.012-0.02 g/mL; the volume of the ligustilide extracting solution for chemical conversion is 0.5 mL, and the addition amount of the cyclopropylamine is 0.1 mL-0.5 mL; the ultrasonic extraction power is 100W-500W and 50 Hz, the ultrasonic temperature is 10 ℃ to 55 ℃, the extraction time is 15-60 min, the reaction temperature is 0 ℃ to 40 ℃, and the reaction time is 0.5-2 h;

(2) determining the content of rhizoma ligustici wallichii in the test solution by an HPLC external standard method: chromatographic conditions for measuring the content of the ligusticum ciprofloxacin by an HPLC external standard method are as follows: the mobile phase consists of methanol and water, the volume ratio of the methanol to the water is 35:65, the sample amount is as follows: 20 mu L of the solution; flow rate: 1 mL/min; measuring wavelength: 200-400 nm;

(3) the content of ligustilide in the medicine is indirectly obtained through calculation by an equimolar amount and/or correction coefficient method, and the range of the correction factor is 1.017-1.065.

6. The method for indirectly measuring the content of ligustilide in the traditional Chinese medicine or the Chinese traditional medicine by the chemical conversion method as claimed in claim 1, which is characterized in that: the Chinese medicinal materials include radix Angelicae sinensis, rhizoma Ligustici Chuanxiong, and rhizoma Ligustici.

7. The method for indirectly measuring the content of ligustilide in the traditional Chinese medicine or the Chinese traditional medicine by the chemical conversion method as claimed in claim 1, which is characterized in that: the Chinese medicinal materials include radix Angelicae sinensis pill, radix Angelicae sinensis bellyache pill, concentrated radix Angelicae sinensis pill, rhizoma Ligustici Chuanxiong pill, SHUNAOXING dripping pill, SUXIAOJIUXIN pill, and GUANXINNING.

8. The method for indirectly measuring the content of ligustilide in the traditional Chinese medicine or the Chinese traditional medicine by the chemical conversion method as claimed in claim 1, which is characterized in that: the organic solvent is one or more of methanol, ethanol, acetonitrile, petroleum ether, diethyl ether, acetone, ethyl acetate, etc.

Technical Field

The invention relates to a method for measuring the content of ligustilide in a traditional Chinese medicinal material or a Chinese traditional medicine, in particular to a method for indirectly calculating the accurate content of ligustilide in the medicinal material or the medicine by measuring the content of the ligustilide in the medicine through chemical conversion, belonging to the field of medicine analysis.

Background

In the Umbelliferae plants, the plants of the Angelica and the Ligusticum contain phthalide compounds, such as medicinal plants of Angelica sinensis, Ligusticum chuanxiong and the like, which are main components of plant volatile oil, mostly have strong aromatic odor and abundant content in the plants. The compounds have more structural types, are generally chemically unstable, and are easily oxidized or degraded by light, heat, enzyme and the like in the environment independently. However, the compounds generally have good pharmacological activities, such as remarkable pharmacological activities of resisting oxidation, resisting platelet aggregation, promoting microcirculation, relieving pain and diminishing inflammation, protecting central nerves, resisting tumors and the like.

Ligustilide (ligustilide) is the main pharmacologically active component in the volatile oil of traditional Chinese medicine of Umbelliferae plants such as radix Angelicae sinensis, rhizoma Ligustici Chuanxiong, etc., and its content is up to about 1-2%. Has obvious pharmacological activity of heart and cerebral vessels. The study results of pharmacological activities of ligustilide by scholars at home and abroad have been and are being carried out, and relevant pharmacological activities such as cerebral neuroprotection, microcirculation improvement, blood vessel relaxation, vascular smooth muscle cell proliferation inhibition, depression resistance, alzheimer resistance, pain alleviation, inflammation diminishing and the like are published, while the study results of pharmacological activities of ligustilide by researchers have been largely reviewed (a. Douglas Kinghorn, Heinz fat, Simon Gibbons, and Jun' ichi kobayashied, Progress of Organic Natural Products, 2017, P127, Springer International publication, laeville, royal, xiahong hong, ligustilide pharmacological and pharmacokinetic studies Progress, chinese journal, 3337 (22): 3350).

The traditional Chinese medicine has complex components and various functions and indications, and the traditional Chinese medicine quality marker can be used for accurately controlling the quality of medicinal materials. Ligustilide is used as the main component of the volatile oil of angelica and ligusticum wallichii, plays a key and main role in improving important pharmacological activity such as hemorheology and the like, and is generally used as a pharmacodynamic marker of the angelica and the ligusticum wallichii. However, the quantitative control index of the angelica and the ligusticum wallichii in the 'Chinese pharmacopoeia' 2015 edition is ferulic acid, which has poor specificity and cannot fully reflect the quality attribute of the medicinal materials and the main efficacy of the medicinal materials in promoting blood circulation and removing blood stasis (Yan Menlin, Dingguo Yu, Conglong Fei, Lier Wen, Dairy, Jiang, Yu, Zhang Fen, Bai Gao, Liu Chang Xiao, near infrared rapid evaluation of the vasodilation efficacy of the angelica based on quality markers, Chinese herbal medicine 2020, 50(19): 4538-4546.).

Ligustilide has a highly unsaturated conjugated system with 3 olefinic bonds and 1 carbonyl double bond, but does not form a stable conjugated system of aromatic rings, has more reaction sites, stronger reaction activity and lower relative free energy, so that Diels-Alder reactions of 1,2, 1,4 and 1,6 are easy to occur to form a complex dimeric or trimeric compound. Because the natural chemical structure of the compound is unstable, the quality of the national pharmacopoeia standard product of the ligustilide is not well solved all the time, so that the technical problem of adopting the ligustilide as a quantitative detection index is not applied all the time.

A large number of researches show that the content of ligustilide in the angelica and the ligusticum wallichii medicinal materials is changed remarkably along with different medicinal material planting regions (producing areas), medicinal material storage time and primary processing modes. Because the clinical treatment effect of the medicine (decoction pieces, Chinese patent medicine, Chinese medicine injection and the like) containing the ligustilide can obviously change along with the quality of the Chinese patent medicine and the medicinal decoction pieces, the accurate content of the medicine containing the ligustilide active ingredients, such as angelica, ligusticum wallichii and the like, needs to be quantitatively controlled to meet the basic characteristics of effectiveness, safety and controllability of the medicine.

Although the international standard of Chinese angelica (published in 12 months in 2019) does not limit the content of ligustilide, the british pharmacopoeia (2017 edition) and hong kong pharmacopoeia have already made clear regulations on the content of ligustilide (british: 0.1% or more and hong kong: 0.6% or more), and particularly the hong kong pharmacopoeia only limits the content of ligustilide, and does not control the total amount of volatile oil and the content of ferulic acid, and the limit requirement of the content of ligustilide becomes a necessary situation with the gradual increase of the standard of Chinese angelica medicinal materials in the international range.

CN201810730744.7 discloses a compound of ligustilide obtained by chemical structure derivation and activity screening of ligustilide, which successfully solves the problem of the stabilization of ligustilide. Therefore, the ligustilide can be used as a standard substance, the accurate content of the active component ligustilide in the ligustilide-containing traditional Chinese medicinal materials such as angelica, ligusticum wallichii and the like can be indirectly measured by a chemical conversion method, and the ligustilide-containing traditional Chinese medicinal material can also be applied to the quality control of Chinese patent medicines containing the active component of the ligustilide.

Disclosure of Invention

The invention aims to provide a method for indirectly calculating the accurate content of ligustilide in a traditional Chinese medicinal material or a Chinese medicinal material by measuring the content of the ligustilide by chemical conversion.

Determination of ligustilide content in first, traditional Chinese medicine or Chinese traditional medicine

The method for indirectly calculating the content of the ligustilide in the traditional Chinese medicinal materials or the Chinese patent medicines by measuring the content of the ligustilide in the traditional Chinese medicinal materials or the Chinese patent medicines comprises the steps of extracting and converting the ligustilide in the traditional Chinese medicinal materials or the Chinese patent medicines to convert the ligustilide with an unstable chemical structure in the traditional Chinese medicinal materials or the Chinese patent medicines into the ligustilide with a stable structure, directly measuring the content of the ligustilide in the traditional Chinese medicinal materials or the Chinese patent medicines by an HPLC external standard method, and indirectly calculating by equimolar amount to obtain the content of the ligustilide in the traditional Chinese medicinal materials or the Chinese.

The route of converting ligustilide in the traditional Chinese medicinal materials or the Chinese traditional medicines into the rhizoma ligustici sinense is shown as the following formula:

the invention utilizes the strong electrophilic activity of lactone ring carbonyl functional group in ligustilide chemical structure and amino lone pair electron of cyclopropylamine to produce intermolecular nucleophilic substitution reaction to produce amide transition state, at the same time the enol structure of cyclopentenyl side chain is isomerized to form ketocarbonyl group, the relatively coincidental lone pair electron of amido bond and isomerized ketocarbonyl group produce secondary intramolecular nucleophilic substitution reaction to produce free hydroxyl functional group, at the same time the lactone ring of cyclopropyl ligustilide is undergone two nucleophilic reactions to finally form five-membered cyclic lactam stable structure. Therefore, the detection method converts unstable ligustilide into the stable product of the ligustilide with equal mole through chemical conversion, and can indirectly calculate the content of the ligustilide in the medicinal materials or the medicaments by measuring the amount of the ligustilide generated in the reaction products.

FIG. 1 is a typical HPLC chromatogram of ligustilide and Cyclopropaneligusticum. Wherein A is liquid chromatogram of methanol extract of radix Angelicae sinensis detected by HPLC at 330nm wavelength, and ligustilide chromatogram peak at tR = 20 min. tR = 12 min no spectral peak appeared. B is a liquid chromatogram of the angelica methanol extract detected by HPLC under the wavelength of 232 nm, and a ligustilide chromatographic peak is at a position with tR = 20 min, which shows that the ligustilide also has ultraviolet absorption under the wavelength, but no chromatographic peak appears at the position with tR = 12 min, and shows that the wavelength is not interfered by other impurities in the angelica methanol extract as the quantitative detection wavelength of the ligustilide. C is a liquid chromatogram of the angelica methanol/cyclopropylamine reaction solution detected by HPLC at the wavelength of 330nm, and a ligustilide chromatographic peak does not appear at the position of tR = 20 min, which shows that the compound has completely reacted. And no chromatographic peak appears at the time of tR = 12 min, which indicates that the generated C.cycloartesian has no ultraviolet absorption at the wavelength, and no other analogs of ligustilide appear at the position to influence the accurate determination of the C.cycloartesian. D. The liquid chromatogram of the angelica methanol/cyclopropylamine reaction solution detected by HPLC at the wavelength of 232 nm shows that no ligustilide chromatographic peak appears at the position of tR = 20 min, which indicates that the reaction is complete. tR = 12 min is the chromatographic peak of the cyclopropanoic ligusticum, and the separation degree of other adjacent chromatographic peaks is good, so that the chromatographic peak can be used for quantitative detection.

FIG. 2 is a graph of the UV absorption spectra of C.galoshimurium and ligustilide recorded in a DAD detector. Wherein A is UV pattern of ligustilide with maximum absorption wavelength at 205 nm, 280 nm and 330 nm. B. Is a UV picture of the genus Cyclopropaneligusticum, and has maximum absorption wavelengths at 232 nm and 292 nm respectively.

The specific method for detecting the content of ligustilide in the traditional Chinese medicinal materials or the Chinese traditional medicines comprises the following steps:

the method I comprises the following steps: firstly, organic solvent and cyclopropylamine are adopted to extract and/or react ligustilide in traditional Chinese medicinal materials or Chinese patent medicines synchronously, so that the degradation of the ligustilide in the extraction and reaction processes is prevented, the fixation of the ligustilide is accelerated by ultrasonic-assisted treatment, and the dissolution of the fixed ligustilide in plant cells is promoted; and finally, after the reaction system is fully eluted, transferred, diluted and quantified by using a solvent, the content of the ligustilide in the medicine is indirectly obtained by calculating the equimolar amount. The specific process comprises the following steps:

(1) preparation of a test solution: pulverizing the Chinese medicinal materials and sieving with a No. four pharmacopoeia sieve; adding traditional Chinese medicine powder and cyclopropylamine into an organic solvent, and heating at 0-60 ℃ (preferably 31℃)) Performing electromagnetic stirring extraction/reaction in a water bath for 5-20 min (preferably 15 min); ultrasonic extracting for 2-10 min (preferably 5 min), and electromagnetic stirring extracting/reacting in water bath at 0-60 deg.C (preferably 31 deg.C) for 30-90 min (preferably 60 deg.C)min）After the reaction product is filtered, eluting the reaction product with an organic solvent for three times, and combining the elution solutions; diluting until the concentration of the Cyclopropylate ligusticum is 80-400 mug/mL, and taking the diluted solution as a test solution; adding the medicinal material powder into an organic solvent according to the proportion of 0.05 g/mL-0.5 g/mL (preferably 0.1 g/mL); the mass-volume ratio of the traditional Chinese medicine powder to the cyclopropylamine is 0.1 g/mL-0.77 g/mL (preferably 0.208 g/mL);

(2) determining the content of rhizoma ligustici wallichii in the test solution by an HPLC external standard method: chromatographic conditions for measuring the content of the ligusticum ciprofloxacin by an HPLC external standard method are as follows: the mobile phase consists of methanol and water, the volume ratio of the methanol to the water is 35:65, the sample amount is as follows: 20 μ L. Flow rate: 1 mL/min; measuring wavelength: 200-400 nm (preferably 232 nm);

(3) the content of ligustilide in the medicine is indirectly obtained by calculating the equimolar amount.

Method II: firstly, completely extracting ligustilide in the medicine powder by adopting an organic solvent, then adding cyclopropylamine into the ligustilide extract to carry out ligustilide chemical conversion reaction, diluting a conversion reaction system after the reaction is finished, quantifying, and directly measuring the content of the ligustilide by an HPLC external standard method; the content of ligustilide in the medicament is indirectly calculated through equimolar amount and/or correction coefficient. The specific process comprises the following steps:

(1) preparation of a test solution: pulverizing Chinese medicinal materials or Chinese traditional medicines, sieving with a No. four pharmacopoeia sieve, adding the medicinal powder into organic solvent, and ultrasonic extracting to obtain ligustilide extract; adding cyclopropylamine into ligustilide extract, and stirring at room temperature to completely convert ligustilide; the reaction solution was directly used as a test solution. Wherein the organic solvent is one or more of methanol, ethanol, acetonitrile, petroleum ether, diethyl ether, acetone, ethyl acetate and the like, preferably methanol), and the medicinal powder is added into the organic solvent according to the proportion of 0.012-0.02 g/mL (preferably 0.016 g/mL); the volume of the ligustilide extracting solution for chemical conversion is 0.5 mL, and the addition amount of the cyclopropylamine is 0.1 mL-0.5 mL (preferably 0.3 mL); the power of ultrasonic extraction is 100W-500W, 50 Hz (preferably 500W), the ultrasonic temperature is 10 ℃ to 55 ℃ (preferably 40 ℃), the extraction time is 15 min to 60min (preferably 30 min), the reaction temperature is 0 ℃ to 40 ℃ (preferably 25 ℃), and the reaction time is 0.5 h to 2 h (preferably 1.5 h);

(2) determining the content of rhizoma ligustici wallichii in the test solution by an HPLC external standard method: chromatographic conditions for measuring the content of the ligusticum ciprofloxacin by an HPLC external standard method are as follows: the mobile phase consists of methanol and water, the volume ratio of the methanol to the water is 35:65, the sample amount is as follows: 20 μ L. Flow rate: 1 mL/min; measuring wavelength: 200-400 nm (preferably 232 nm);

(3) the content of ligustilide in the medicine is indirectly obtained through calculation of equimolar amount and/or correction coefficient, and the range of the correction factor is 1.017-1.065, preferably 1.041.

In the method II, a procedure of extraction and conversion is adopted, so that degradation of ligustilide and incomplete chemical conversion reaction are inevitably caused in the process, and systematic errors caused by degradation and accurate measurement in the ligustilide extraction process are eliminated by repeatedly investigating and introducing correction factors. Experiments show that the content of ligustilide is indirectly calculated and determined according to the content of the cyclopropanoic ligustilide (the mol number is multiplied by a correction factor), wherein the correction factor is 1.041.

The above Chinese medicinal materials comprise radix Angelicae sinensis, rhizoma Ligustici Chuanxiong, and rhizoma Ligustici with large amount of ligustilide active ingredients; the Chinese medicinal composition comprises ligustilide as active component, such as radix Angelicae sinensis pill, radix Angelicae sinensis bellyache pill, concentrated radix Angelicae sinensis pill, rhizoma Ligustici Chuanxiong pill, SHUNAOXING dripping pill, SUXIAOJIUXIN pill, GUANXINNING, etc.

Secondly, research on high performance liquid chromatography (HPLC-DAD) methodology of ligustilide content in angelica sinensis

The method for indirectly calculating the content of ligustilide in the Chinese medicinal material or the Chinese patent medicament by measuring the content of the ligustilide is researched by taking the Chinese medicinal material angelica as an example.

1. Preparation of reference stock solution

Accurately weighing 0.05001 g of rhizoma Ligustici Chuanxiong reference substance, dissolving chromatographic methanol in 50mL volumetric flask, refrigerating at 5 deg.C, taking out when using, and standing to room temperature for normal use.

2. Preparation of test solution

Taking a proper amount of angelica sinensis, crushing by a crusher, sieving by a fourth pharmacopoeia sieve, precisely weighing 0.5000 g of medicinal powder, placing the medicinal powder into a 50mL single-neck round-bottom flask with a plug, adding 2.4 mL of cyclopropylamine and 2.6 mL of methanol, carrying out electromagnetic stirring (rotating speed of 2400 r/min) extraction/reaction for 15 min, placing the round-bottom flask into an ultrasonic extractor for ultrasonic treatment for 5 min, continuing to carry out electromagnetic stirring extraction/reaction on an extraction/reaction product for 60min, stopping stirring, carrying out suction filtration on a reactant, eluting the medicinal powder with 10 mL/10 mL/10 mL of methanol for three times, combining the methanol solution, and fixing the volume to a 50mL volumetric flask to serve as a sample solution.

3. Drawing of quantitative detection standard curve of ligusticum sinense

Preparing 1000 microgram/mL solution from Huanyuan lovage control solution and chromatographic methanol, sequentially diluting the solution in a multiple ratio to prepare series solutions of 500 microgram/mL, 250 microgram/mL, 125 microgram/mL, 62.5 microgram/mL, 31.25 microgram/mL, 15.625 microgram/mL, 7.813 microgram/mL and 3.906 microgram/mL, precisely absorbing 20 microgram L of each concentration solution, feeding samples, automatically integrating at an Agilent chromatographic work station, and recording Huanyuan lovage chromatographic peak area (y). Linear regression and fitting are carried out by taking the concentration (X) of the ligusticum sinense control solution as an independent variable and the peak area (Y) of a chromatographic peak as a dependent variable, so that the linear regression equation is Y = 31.807X + 74.987, and the complex correlation coefficient R = 0.9999. The concentration of the ligusticum ciprofloxacin within the range of 15.313-980 mug/mL has a good linear relation with the peak area.

4. Determination of lowest detection limit and lowest quantitative limit of ligusticum clypearia

According to the detection signal and noise ratio (S/N) of the chromatographic sample of the ligusticum sinense with the liquid chromatogram being 3, the lowest detection limit of the compound is determined as follows: 0.244 mug/mL, and determining that the quantitative limit is 0.976 mug/mL when the signal-to-noise ratio (S/N) is more than 10.

5. Precision of the method

Accurately sucking 20 mu L of the control solution of the ligusticum cyclopropylense, and continuously feeding samples for 6 times, wherein the RSD of the area of the ligusticum cyclopropylense is 0.803%, which indicates that the precision of the measurement method and the instrument of the ligusticum cyclopropylense is good.

6. Method stability

And (3) feeding the reacted test solution every 2 h, measuring the sample to 8 h, measuring the chromatogram of the rhizoma ligustici sinense, and calculating the content of the ligustilide, wherein the result is shown in table 1, and the result shows that the content of the test solution is kept stable within 8 h.

7. Reproducibility of the method

Aiming at the reliability of the method, 6 parts of angelica medicinal material powder is accurately weighed to carry out parallel experiments, and the result shows that the content of ligustilide in the angelica medicinal material is 1.556 +/-0.080 (%) and the relative standard deviation RSD (%) is 0.549 under the determination method, the determination method has high reliability and good reproducibility.

8. Method sample adding recovery rate

According to the quality standard analysis method verification guiding principle in the fourth edition of Chinese pharmacopoeia, experiments of 80%, 100% and 120% sample adding recovery rate of ligusticum cycloprophyllum are designed, and the results are shown in table 2. The recovery rate is 95-105%, and the relative standard deviation is less than 3%, which indicates that the method has good accuracy.

In conclusion, the unstable ligustilide is converted into the stable product of the ligustilide with equal mole through chemical conversion, the content of the ligustilide in the medicinal materials or the medicaments is indirectly calculated through measuring the amount of the ligustilide generated in the reaction products, the reliability and the accuracy of detecting the content of the ligustilide are effectively improved, and the method has good stability and reproducibility. The direct aim of effectively controlling the quality of the medicine is achieved by the application of the method.

Drawings

FIG. 1 is a typical HPLC chromatogram of ligustilide and Cyclopropaneligusticum.

FIG. 2 is a graph of the UV absorption spectra of C.galoshimurium and ligustilide recorded in a DAD detector.

FIG. 3 shows the measurement results of ligustilide content in angelica samples from different origins.

FIG. 4 shows the result of quantitative determination of samples of Angelica sinensis origin in different growing areas of Gansu province by UPLC technique and external standard method with ligustilide as reference.

FIG. 5 is a statistical analysis of ligustilide content in Angelica sinensis origin samples (collected in 11-12 months in 2019 and measured in 5-6 months in 2020).

FIG. 6 chemical transformation method for determining ligustilide content of commercial radix Angelicae sinensis (purchased and determined in 6 months in 2020).

FIG. 7 content of ligustilide in commercial Angelica sinensis (purchased in 6 months in 2019 and measured in 6 months in 2020) stored for 1.5 years measured by chemical transformation method.

Detailed Description

The method for indirectly calculating the content of ligustilide in the traditional Chinese medicinal materials or the Chinese patent medicines by measuring the content of the ligusticum sinense is further explained by the specific embodiment.