CN1790013B - Method for simultaneous determination of protocatechuic acid content and 5-hydroxymethyl furfural content in pulse-activating injection - Google Patents
Method for simultaneous determination of protocatechuic acid content and 5-hydroxymethyl furfural content in pulse-activating injection Download PDFInfo
- Publication number
- CN1790013B CN1790013B CN 200410081501 CN200410081501A CN1790013B CN 1790013 B CN1790013 B CN 1790013B CN 200410081501 CN200410081501 CN 200410081501 CN 200410081501 A CN200410081501 A CN 200410081501A CN 1790013 B CN1790013 B CN 1790013B
- Authority
- CN
- China
- Prior art keywords
- protocatechuic acid
- solution
- hydroxymethyl furfural
- reference substance
- moving phase
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Investigating Or Analysing Biological Materials (AREA)
Abstract
The invention discloses a high effective liquid-phase chromatogram method of original catechin and 5-hydroxymethyl-furfural in the pulse-activating injection, which comprises the following steps: adapting octadecyl silane bonding silica gel as bulking agent, acetonitrile ammonium acetate solution (4mmol/L) and glacial acetic acid (6: 94: 1) as flow-phase; sampling the solution to contrast the original catechin and 5-hydroxymethyl-furfural; using external-scale method to measure the content of sample solution. The invention is fit for normal analysis, which guarantees the safety and efficiencyof pulse-activating injection.
Description
Technical field the invention belongs to the Pharmaceutical Analysis technical field.Be specifically related to a kind of method of measuring protocatechuic acid and 5 hydroxymethyl furfural content in the shengmai injection simultaneously.
The background technology shengmai injection is that red ginseng, the tuber of dwarf lilyturf, the fruit of Chinese magnoliavine etc. three are distinguished the flavor of medicinal materials through the traditional Chinese medicine injection that extracts, purification process is mixed with, and is used for diseases such as miocardial infarction, cardiogenic shock, infectious shock, is widely used clinically.Schisandra chinensis medicinal material in the shengmai injection contains compositions such as protocatechuic acid, malic acid, citric acid.Wherein protocatechuic acid has the reduction myocardial consumption of oxygen, and the oxygen utilization due to the antagonism adrenaline increases, and improves myocardium oxygen-resistant ability, and reducing heart rate improves the lactic acid and the K of ischemic center
+Generation, dwindle the effect of myocardial infarct size, be the effective constituent in this product.
Process for purification about the protocatechuic acid reference substance is not seen bibliographical information as yet, and Chinese Pharmacopoeia Commission does not have the supply of protocatechuic acid reference substance at present yet.Control about 5 hydroxymethyl furfural, bibliographical information is arranged, this material can cause animal striated muscle and visceral lesion, stand as Chinese herbal medicine information center of State Pharmaceutical Administration, the active ingredient of autonomic drug handbook, People's Health Publisher, 1986, p858, but do not see report as yet about the 5 hydroxymethyl furfural limit.The inspection method of 5 hydroxymethyl furfural is in Chinese Pharmacopoeia (version in the 2000) glucose injection: get glucose injection and be diluted to 1% concentration, measure absorbance log at 284nm wavelength place, and must not be greater than 0.32.
Shengmai injection records in the national drug quality standard of China.At present, the quality standard of this product is still perfect inadequately.As the assay of ginsenoside Rg1 and ginsenoside Re in the genseng is only arranged under the assay item, to the control as yet of other flavour of a drug content of effective; And checking under the item that the general inspection project of traditional Chinese medicine injection is only arranged.Use chromatography,, determine to contain in this product protocatechuic acid by comparing with the protocatechuic acid reference substance.By separating in this product a principal component not, and technology such as using NMR, mass spectrum carry out structure to it and identify, determine that this material is a 5 hydroxymethyl furfural.Find also in the research that 5 hydroxymethyl furfural is that sugar and the glucosides constituents in the fruit of Chinese magnoliavine generates in the preparation process of injection.5 hydroxymethyl furfural also has the effect that resists myocardial ischemia when content is low, be effective constituent, but when concentration is higher, then can cause the infringement of animal striated muscle and internal organ, in parenteral solution, must be controlled, but still be difficult at present the control method of two kinds of compositions in the quality standard of this product.Therefore, how effectively controlling the toxic and side effect of traditional Chinese medicine, is the significant problem that Chinese medicine preparation need solve.
Summary of the invention the present invention is directed to the perfect inadequately place of above shengmai injection quality standard, has set up a kind of new method of the content of protocatechuic acid and 5 hydroxymethyl furfural in the hplc simultaneous determination shengmai injection.
The present invention is implemented by following technology path.
1, the preparation of protocatechuic acid reference substance and quality control
Get the protocatechuic acid crude product, add the acetone solution of quintuple after, add carbon dichloride to separating out bulk crystallization, suction filtration with method recrystallization 2 times, is deposited in 80 ℃ of vacuum drying 3 hours, the off-white color crystalline powder.Be the protocatechuic acid highly finished product.
The quality of protocatechuic acid highly finished product is controlled by the following method:
Fusing point: press (appendix VIIC) " melting point determination " first method of Chinese Pharmacopoeia (version in 2000) and measure, sample earlier 80 ℃ of vacuum drying to constant weight, use silicone oil for passing warm liquid, 1.5 ℃/min of heating rate, measurement result is 201～203 ℃, with document basically identical (literature value is 200～202 ℃).The fusing point of this product should be 200～204 ℃
Differentiate: take by weighing discriminating and use the protocatechuic acid reference substance an amount of, dissolve and be diluted to the solution of 0.5mg/ml with moving phase, solution in contrast, it is an amount of to take by weighing the protocatechuic acid highly finished product, with moving phase dissolving and be diluted to the solution of 0.5mg/ml, as sample solution, under the chromatographic condition that related substance is checked, get each 10 μ l sample introduction of two kinds of solution respectively, the retention time of sample solution main peak should be consistent with the retention time of reference substance solution main peak with discriminating.
Related substance is checked: measure according to high performance liquid chromatography (2000 editions VID appendix of Chinese Pharmacopoeia).
The chromatographic condition octadecylsilane chemically bonded silica is a filling agent; Acetonitrile-4mmol/L ammonium acetate solution-glacial acetic acid (4: 96: 1) is a moving phase; Flow velocity is 1.0ml/min; The detection wavelength is 258nm.
The preparation precision of need testing solution takes by weighing at 80 ℃ of drying under reduced pressure an amount of to the protocatechuic acid highly finished product of constant weight, adds moving phase and is made into the solution that every 1ml contains 0.5mg, as need testing solution.
It is an amount of that need testing solution is measured in the preparation of contrast solution, adds moving phase and be made into the solution that every 1ml contains 5 μ g, solution in contrast.
Determination method is accurately drawn each 10 μ l of need testing solution and contrast solution respectively, injects liquid chromatograph, the record chromatogram, and the summation of impurity peak area must not be greater than 1/2 of contrast solution main peak peak area in the need testing solution.
Assay with this product at 80 ℃ of drying under reduced pressure to constant weight, get about 0.15g, accurate claim surely, after ethanol 5ml dissolving, add 45ml and newly boil and put cold water, mixing.With the glass electrode is indicator electrode, and mercurous chloride electrode is a contrast electrode, with NaOH vs (0.1mol/mL) titration, potential method directing terminal.The NaOH vs (0.1mol/L) of every 1ml is equivalent to the protocatechuic acid (C of 15.41mg
7H
6O
4).
This product contains protocatechuic acid should be no less than 99.5%.
2. the content assaying method of protocatechuic acid and 5 hydroxymethyl furfural in the shengmai injection.
The preferred embodiment of the invention is as follows:
(1) chromatographic condition and system suitability test: with the octadecylsilane chemically bonded silica is filling agent; Moving phase is acetonitrile-4mmol/L ammonium acetate solution-glacial acetic acid (4: 96: 1), detects wavelength: 258nm.Number of theoretical plate calculates by the protocatechuic acid peak should be not less than 2500.
(2) preparation of reference substance solution respectively precision take by weighing protocatechuic acid reference substance and each about 10mg of 5 hydroxymethyl furfural reference substance, put respectively in the 10ml measuring bottle, add the moving phase dissolving and be diluted to scale, get protocatechuic acid stock solution and 5 hydroxymethyl furfural stock solution respectively.Precision is measured protocatechuic acid stock solution 1ml and 5 hydroxymethyl furfural stock solution 2ml, puts in the 100ml measuring bottle, adds moving phase and is diluted to scale, in contrast product solution.
(3) the preparation precision of need testing solution is measured shengmai injection 10m, puts in the 25ml measuring bottle, adds moving phase and is diluted to scale, shakes up.
(4) assay method respectively precision measure each 10 μ l of reference substance solution and need testing solution, inject liquid chromatograph, with peak area by external standard method result of calculation, promptly.
Description of drawings
1. the chromatogram that mixes reference substance solution
2. the chromatogram of shengmai injection negative control
3. the chromatogram of shengmai injection
Embodiment:
1. instrument and reagent
Day island proper Tianjin LC-10AT VP high performance liquid chromatograph, Tianjin, island LC-10AT VP infusion pump, SPD-10A VP UV-detector, Class-VP chromatographic work station.
Discriminating protocatechuic acid reference substance (chemical reference substance, Nat'l Pharmaceutical ﹠ Biological Products Control Institute, 809-9201).
Protocatechuic acid crude product (Long Huaxueshijichang of Chengdu section).
5 hydroxymethyl furfural reference substance (Acros Organics, content 98%).
Acetonitrile, methyl alcohol (chromatographically pure, Fisher company), ultrapure water (southwestern physics Institute), ammonium acetate, glacial acetic acid (analyze pure, the Long Huaxueshijichang of Chengdu section), other reagent of using in this experiment be analyze pure.
2. assay method
Chromatographic condition: use Luna 5u C18 (2) post (150 * 4.6mm ID); Acetonitrile-4mmol/L ammonium acetate solution-glacial acetic acid (4: 96: 1), flow velocity, 0.7mL/min; Detect wavelength: 258nm; Column temperature: 35 ℃.
The preparation of reference substance solution precision respectively takes by weighing protocatechuic acid reference substance and each about 10mg of 5 hydroxymethyl furfural reference substance, puts respectively in the 10mL volumetric flask, with moving phase dissolving and be diluted to scale.Get protocatechuic acid stock solution and 5 hydroxymethyl furfural stock solution respectively.Precision is measured in protocatechuic acid stock solution 1mL and 5 hydroxymethyl furfural stock solution 2mL to the 100mL volumetric flask, adds moving phase and is diluted to scale, in contrast product solution liquid.
The preparation precision of need testing solution is measured in shengmai injection 10ml to the 25ml volumetric flask, adds moving phase and is diluted to scale, shakes up.
Determination method precision is respectively measured reference substance solution and each 10 μ L of need testing solution, injects liquid chromatograph, presses external standard method result of calculation with peak area, promptly.
In the above conditions, the chromatogram of reference substance solution, need testing solution and negative control solution is seen accompanying drawing.
Chromatographic system employment and suitability test (E ﹠ ST): calculate with protocatechuic acid, record the number of theoretical plate 8.9 * 10 of chromatographic column
3, 5 hydroxymethyl furfural, protocatechuic acid and front and back chromatographic peak reach baseline separation, and the tailing factor at 5 hydroxymethyl furfural peak is 1.2, and the tailing factor at protocatechuic acid peak is 1.1, and peak shape is symmetry substantially.
The analytical approach checking:
Specificity: from accompanying drawing as can be seen, the negative control of preparation is noiseless to measuring.
Linearity and range: after measured, the 5 hydroxymethyl furfural sample size returns sample size (μ g) with peak area between 0.05～0.8 μ g, and regression equation is: A=1.612 * 10
6X-6.945 * 10
3, r=0.9999, protocatechuic acid sample size return sample size (μ g) with peak area between 0.025～0.4 μ g, and regression equation is: A=2.117 * 10
6X-1.027 * 10
6, r=0.9999, peak area and sample size are good linear relationship.
Precision: record in the need testing solution, the RSD of 5 hydroxymethyl furfural and protocatechuic acid withinday precision is respectively 0.6% and 0.4%, and the RSD of day to day precision is respectively 0.2% and 1.1%.
Accuracy: the average recovery rate that records 5 hydroxymethyl furfural is 99.5%, and RSD is 0.6%, and the average recovery rate that records protocatechuic acid is 101.3%, and RSD is 1.7%,
Durability: this law is at Luna C18 post, and on the different brands chromatographic columns such as Tianjin, island ODS post, the separating effect basically identical illustrates that the durability of this law is good.
3. measurement result
The content that records several shengmai injections by above method is as follows:
| Lot number | 5 hydroxymethyl furfural content (mg/ml) | Protocatechuic acid content (mg/ml) |
| 0501 | 0.0653 | 0.0212 |
| 0102 | 0.0761 | 0.0128 |
| 1103 | 0.126 | 0.0176 |
| 0801 | 0.115 | 0.0242 |
Claims (2)
1. method of measuring protocatechuic acid and 5 hydroxymethyl furfural content in the shengmai injection simultaneously is characterized in that this method may further comprise the steps:
(1) to the preparation and the method for detecting purity of protocatechuic acid reference substance:
A, use acetone and methylene chloride carry out recrystallization to the protocatechuic acid crude product, and carry out drying under reduced pressure under 80 ℃, get the protocatechuic acid highly finished product;
The assay method of B, protocatechuic acid highly finished product purity: use high effective liquid chromatography for measuring, with octadecylsilane chemically bonded silica is filling agent, acetonitrile-4: 96: 1 systems of 4mmol/L ammonium acetate solution-glacial acetic acid are moving phase, the detection wavelength is 258nm, and need testing solution and contrast solution adopt the moving phase preparation;
Wherein, the preparation of need testing solution: precision takes by weighing at 80 ℃ of drying under reduced pressure an amount of to the protocatechuic acid highly finished product of constant weight, adds moving phase and is made into the solution that every 1ml contains 0.5mg, as need testing solution;
The preparation of contrast solution: it is an amount of to measure need testing solution, adds moving phase and is made into the solution that every 1ml contains 5 μ g, solution in contrast;
C, protocatechuic acid highly finished product Determination on content method: use volumetric determination protocatechuic acid highly finished product content, the sampling amount of sample is 0.15g, sample is earlier with behind the dissolve with ethanol, adding newly boils again puts cold water dilution, NaOH vs titration with 0.1mol/L, with the glass electrode is indicator electrode, and mercurous chloride electrode is a contrast electrode, uses the potential method directing terminal;
(2) to the content assaying method of protocatechuic acid in the shengmai injection and 5 hydroxymethyl furfural:
A, use high performance liquid chromatography are carried out assay to protocatechuic acid in the shengmai injection and 5 hydroxymethyl furfural simultaneously, with octadecylsilane chemically bonded silica is filling agent, acetonitrile-4: 96: 1 systems of 4mmol/L ammonium acetate solution-glacial acetic acid are moving phase, and the detection wavelength is 258nm;
The reference substance solution that B, shengmai injection need testing solution and protocatechuic acid reference substance and 5 hydroxymethyl furfural reference substance are formed adopts the moving phase preparation, the shengmai injection need testing solution is diluted to 2.5 times volume with moving phase, use external standard method, calculating, promptly;
Wherein, the preparation of shengmai injection need testing solution: precision is measured shengmai injection 10ml, puts in the 25ml measuring bottle, adds moving phase and is diluted to scale, shakes up;
The preparation of the reference substance solution that protocatechuic acid reference substance and 5 hydroxymethyl furfural reference substance are formed: precision takes by weighing protocatechuic acid reference substance and each 10mg of 5 hydroxymethyl furfural reference substance respectively, put respectively in the 10ml measuring bottle, add the moving phase dissolving and be diluted to scale, get protocatechuic acid stock solution and 5 hydroxymethyl furfural stock solution respectively; Precision is measured protocatechuic acid stock solution 1ml and 5 hydroxymethyl furfural stock solution 2ml, puts in the 100ml measuring bottle, adds moving phase and is diluted to scale, in contrast product solution.
2. the method for measuring protocatechuic acid and 5 hydroxymethyl furfural content in the shengmai injection simultaneously according to claim 1, it is characterized in that: the described protocatechuic acid highly finished product of steps A are for getting the protocatechuic acid crude product in (1), after adding the acetone solution of quintuple, add carbon dichloride to separating out bulk crystallization, suction filtration with method recrystallization 2 times, is deposited in 80 ℃ of vacuum drying 3 hours, get the off-white color crystalline powder, be the protocatechuic acid highly finished product.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200410081501 CN1790013B (en) | 2004-12-16 | 2004-12-16 | Method for simultaneous determination of protocatechuic acid content and 5-hydroxymethyl furfural content in pulse-activating injection |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200410081501 CN1790013B (en) | 2004-12-16 | 2004-12-16 | Method for simultaneous determination of protocatechuic acid content and 5-hydroxymethyl furfural content in pulse-activating injection |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1790013A CN1790013A (en) | 2006-06-21 |
| CN1790013B true CN1790013B (en) | 2010-06-16 |
Family
ID=36788010
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200410081501 Active CN1790013B (en) | 2004-12-16 | 2004-12-16 | Method for simultaneous determination of protocatechuic acid content and 5-hydroxymethyl furfural content in pulse-activating injection |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1790013B (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102466658B (en) * | 2010-11-12 | 2014-10-15 | 天津天士力之骄药业有限公司 | Measurement method of content of 5-hydroxymethylfurfural (5-HMF) in injection |
| CN102206600B (en) * | 2011-04-11 | 2012-09-05 | 黑龙江大学 | Bacillus subtilis for producing protocatechuric acid |
| CN103675046B (en) * | 2012-09-10 | 2016-05-25 | 安徽大学 | A kind of detection method of protocatechuic acid |
| CN103728410A (en) * | 2013-12-05 | 2014-04-16 | 天津昭鑫电材科技有限公司 | Measuring method for furfuraldehyde content of mixed solvent |
| CN104931594B (en) * | 2014-03-20 | 2018-08-03 | 天津天士力之骄药业有限公司 | The detection method of content of 5 hydroxymethyl furfural in a kind of Schisandra chinensis |
| CN106153737A (en) * | 2015-03-23 | 2016-11-23 | 天津药物研究院有限公司 | A kind of detect the method for glucose degradation thing in buprenorphin hydrochloride injection |
| CN105911198B (en) * | 2016-06-07 | 2018-03-09 | 云南中烟工业有限责任公司 | A kind of pretreating device of chaff aldehyde material detection and application |
| CN110361457A (en) * | 2018-03-26 | 2019-10-22 | 北京哈三联科技有限责任公司 | The HPLC detection method of 5 hydroxymethyl furfural content in medical product |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1182589A (en) * | 1997-11-13 | 1998-05-27 | 中国药科大学 | Medical use of 5 -hydroxymethyl -2 -furol |
| CN1264040A (en) * | 1999-08-11 | 2000-08-23 | 河北省药品检验所 | Method for detecting protocatechuic aldehyde in red sage root |
-
2004
- 2004-12-16 CN CN 200410081501 patent/CN1790013B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1182589A (en) * | 1997-11-13 | 1998-05-27 | 中国药科大学 | Medical use of 5 -hydroxymethyl -2 -furol |
| CN1264040A (en) * | 1999-08-11 | 2000-08-23 | 河北省药品检验所 | Method for detecting protocatechuic aldehyde in red sage root |
Non-Patent Citations (6)
| Title |
|---|
| 张清波等.HPLC测定熟地黄中5-羟甲基糠醛的含量.中国药品标准2 4.2001,2(4),33-34. |
| 张清波等.HPLC测定熟地黄中5-羟甲基糠醛的含量.中国药品标准2 4.2001,2(4),33-34. * |
| 蔡梅等.高效液相色谱法测定香丹注射液中丹参素和原儿茶醛的含量.海峡药学16 3.2004,16(3),54-55. |
| 蔡梅等.高效液相色谱法测定香丹注射液中丹参素和原儿茶醛的含量.海峡药学16 3.2004,16(3),54-55. * |
| 许育梅等.RP-HPLC法测定五味子中原儿茶酸的含量.中草药35 7.2004,35(7),817-819. |
| 许育梅等.RP-HPLC法测定五味子中原儿茶酸的含量.中草药35 7.2004,35(7),817-819. * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1790013A (en) | 2006-06-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102466658B (en) | Measurement method of content of 5-hydroxymethylfurfural (5-HMF) in injection | |
| CN101502616B (en) | Method for measuring content of Bletilla striata medicinal materials | |
| Chang et al. | Simultaneous determination of four phenolic acids and seven alkaloids in rat plasma after oral administration of traditional Chinese medicinal preparation Jinqi Jiangtang Tablet by LC-ESI–MS/MS | |
| CN1790013B (en) | Method for simultaneous determination of protocatechuic acid content and 5-hydroxymethyl furfural content in pulse-activating injection | |
| CN110297061B (en) | Method for determining contents of chlorogenic acid, caffeic acid and luteolin in Ixeris denticulata by one-test-multiple-evaluation method | |
| CN101968467A (en) | Quality control method for edaravone and edaravone-containing preparation | |
| CN114527202A (en) | Method for determining salt forming rate of methylergometrine maleate raw material | |
| CN101504393B (en) | HPLC measuring method for d-biotin and its impurity content | |
| CN103424476A (en) | Method for simultaneously determining four water-soluble components in polydanshinolic acid | |
| CN102204999A (en) | Method for measuring content of luteolin in callicarpa nudiflora preparation | |
| CN105424834B (en) | Detect 2-Pyrrolidone and formic acid method in PVP K30 simultaneously | |
| CN101816715A (en) | Method for measuring content of Danshensu in shenshuaining capsules by utilizing HPLC method | |
| CN105004803B (en) | The liquid-phase chromatography method of multiple impurity in a kind of separation determination tolvaptan | |
| CN104833754B (en) | A kind of attached sweet drug detection method | |
| CN116818963A (en) | One-measurement-multiple-evaluation-level detection method for five chemical components in corydalis saxicola bunting | |
| CN102662022A (en) | Pharmacokinetics measurement method for oral bulleyaconitine A tablets of rat | |
| CN111721855B (en) | Method for determining related substances of pharmaceutical preparation containing acetaminophen, dextromethorphan hydrobromide and doxylamine succinate | |
| CN103364501B (en) | The detection method of the adulterated pigment gold orange II in safflower | |
| CN102166216A (en) | Lactulose oral solution and quality control method thereof | |
| CN101320026B (en) | Quality detection method of novel healing formulation | |
| CN111707766A (en) | Detection method of furotriptan succinate tablet | |
| CN103808848A (en) | High-performance liquid chromatography for detecting content of neosperidin dihydrochalcone | |
| CN106855542A (en) | Method of the high performance liquid chromatography detection metadoxine about material | |
| Sharma et al. | Analytical method validation and method development for simultaneous estimation for ornidazole and diloxanide furoate in pharmaceutical solid dosage form | |
| CN108398493A (en) | A kind of quality determining method of centella medicinal material and its extract and preparation |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C56 | Change in the name or address of the patentee | ||
| CP01 | Change in the name or title of a patent holder |
Address after: 625000 No. 116 West South Street, Sichuan, Ya'an Patentee after: Huarun 39 (Ya'an) Pharmaceutical Co., Ltd. Address before: 625000 No. 116 West South Street, Sichuan, Ya'an Patentee before: Sanjiu Pharmaceutical Industry Co., Ltd., Ya'an City |