NOVEL MANGIFERIN CALCIUM SALTS5THE METHOD FOR ITS
PREPARATION AND ITS USE FIELD OF THE INVENTION
The present invention relates to novel mangiferin calcium and their preparation methods and the use as the insulin sensitizer for diabetes and diabetic complication. BACKGROUND OF THE INVENTION
Insulin resistance (IR) refers to a series of pathologic and clinical syndrome is resulted from that the response of insulin target organs or tissues to the biological effects of insulin lowered or lost. Numerous studies show that insulin resistance exists in the whole process of type 2 diabetes ,it is a marked characteristic of type 2 diabetes. The IR at the core, can lead to hyperglycemia, hypertension, microalbuminuria, inflammation, high fibrinolysis, dyslipidosis, endothelial dysfunction, and atherosclerosis and cardiovascular disease. Therefore, by increasing insulin action, improve insulin receptor sensitivity, research and development of insulin sensitizer in the treatment of diabetes and diabetic complication (Diabetic chronic complications refers to coronary heart disease ^ atherosclerosis Λ cerebrovascular disease and other diabetic macrovascular diseases ^ diabetic nephropathy , diabetic retinopathy and other diabetic microangiopathy, diabetic neuropathy, diabetic foot, diabetic maeulopathy, diabetic cataract, diabetic glaucoma, refractive changes, iris and ciliary body diseases. ) in recent years has become the hotspot.
At present, the most insulin sensitizers that are on the market are expensive or have some adverse reactions, caused by poor compliance of patients. Therefore research and development of insulin sensitizers of low cost ^ high efficiency and low toxicity have important clinical significance and market value.
Mangiferin, a natural polyphenol is from Anemarrhena asphodeloides Bge.or the leaf of Mangifera indical, Anacardiaceae mango tree, the leaf, fruit or bark of Mangifera persiciforma CY Wu et T.L.Ming. , gentian plants Northeast gentian, Swerita musstii Franch, or Pyrrosia clavata(Bak.)Ching.. molecular weight: 422, structural formula: C19H18O11,
Mangiferin is a natural antioxidants. The pharmacological study shows Mangiferin has a variety of biological activity, such as anti-oxidation, anti-tumor, anti-bacterial, anti-viral, hypoglycemic, hypolipidemic, anti-inflammatory, choleretic, immunomodulation, etc.. Mangiferin can lower the blood glucose and lipid levels of diabetic rats or mice by oral or intraperitoneal injection, its potential mechanism for hypoglycemic is by increasing insulin sensitivity [Miura TJchiki H,Hashimoto I,et al.Antidiabetic activity of a xanthone compound , mangiferin.Phytomedicine,2001,8(2):85-87 ] . But mangiferin exists defects in solubility, the bioavailability and absorbability of the body. SUMMARY OF THE INVENTION
In the course of present invention carrying out ,we have obtained a series of salt compounds of mangiferin, which we have applied patent [ application No.CN200710129584.2 ; invention title: mangiferin salts and the method for preparation and their use] . In that patent application we expatiated mangiferin salts can improve the solubility and oral bioavailability of mangiferin .As we research on pharmacology actives of increasing insulin sensitivity for these mangiferin salts , we found surprisedly the mangiferin calcium not only improve the solubility and oral bioavailability of mangiferin, but also increase insulin sensitivity more strongly than mangiferin.
Technology project:
In present invention ,mangiferin calcium have the following characteristics:
(D The chromatography characteristics of the mangiferin calcium is consistent with the standard mangiferin by HPLC.
©There is calcium ion in the structure of the mangiferin calcium.
In present invention ,mangiferin calcium have the general formula ( I ) :
where n is 1 or 2 and m is 1 or 2. When n is 2 and m is 1 ,the mangiferin calcium have general formula ( II ):
Where any one radicel of R1,R2,R3 and R4 is oxygen ion, the other radicels are hydroxyl. The priority elective compound have general formula:
The present invention provides a method for preparation mangiferin calcium:
In present invention, mangiferin monosodium(or monopotassium) is obtained first, then mangiferin monosodium(or monopotassium) reacted with water-solubility calcium salt, and come into being mangiferin calcium . The method for preparation is follow as:
©mangiferin is suspended in menstruum, the solution of alkaline sodium (or potassium) is added slowly into the menstruum while mixing round until the solution is clear , then the reaction solution is filtrated, crystal menstuum is added into the reaction solution, mixing round adequately . A lot of deposition is come into being , the reaction solution is filtrated to get the depositon , the solid substance is heated up no excess 60 °C to dry . The yellow substance is mangiferin monosodium(or monopotassium).
©mangiferin monosodium(or monopotassium) is dissolved into water appropriated concentration, then water-solubility calcium salt solution of appropriated concentration is added slowly into it while mixing round. The reaction solution is mixed round continuely to reacte completely. A lot of deposition is come into being in solution. The reaction solution is filtrated to get the depositon. This deposition is heated up no excess 60 °C to dry. The yellow solid substance is mangiferin calcium.
In the method of preparation as defined above, the mol ratio of mangiferin and alkaline sodium (or potassium) is 1 :0.5-l .0.
In the method of preparation as defined above, the mol ratio of mangiferin
monosodium(or monopotassium) and water-solubility calcium salt is 1 :0.5.
In the method of preparation as defined above, the alkaline sodium (or potassium) is single salt or mixture which is for example sodium carbonate or sodium bicarbonate or potassium carbonate or potassium bicarbonate or sodium acetate or potassium acetate etc. .
In the method of preparation as defined above, the water-solubility calcium salt is single salt or mixture which is for example calcium chloride, calcium gluconate , calcium lactate, calcium valerate , calcium glycerophosphate, iodized calcium, etc..
In the method of preparation as defined above, the menstruum is mixture , which water mixed with one or more than two kind of organic solvent for example ethanol or methanol or acetone which can dissolve water at discretion . The ratio of water is 10-90% (v/v).
In the method of preparation as defined above, the crystal menstruum is single organic solvent or mixture which is for example ethanol , acetone , ethyl acetate or chloroform , dichloromethane and the other .
In the invention mangiferin calcium maybe crystal water compounds, crystal water may be 0-9 mol.
The mangiferin calcium can be conducted through appropriate means of purification, such as filters, water rinse, and dry.
The mangiferin calcium in present invention can be obtained by the reaction of mangiferin with alkaline calcium compounds. The method for preparation is follow as:
Mangiferin is dissolved into appropriate solvent, and alkaline calcium compounds are dissolved into appropriate solvent , the alkaline solution is added into the mangiferin solution slowly while mixing round .Appropriate quantity solvent is added into reaction solution ,a mass of yellow deposition appeared . The solution is filtrated to get deposition, the deposition is heated up no excess 60 °C to dry. The yellow green solid substance is calcium salt of mangiferin .
In the method for preparation as defined above, the mol ratio of mangiferin and alkaline calcium compounds is 1 :0.5-2.
In the method for preparation as defined above, the alkaline calcium compound is single or mixture from which is inorganic calcium compounds or organic calcium compounds for example calcium hydroxide, calcium bicarbonate, calcium acetate, calcium propionate, etc. .The priority elective compound is calcium hydroxide .
In the method for preparation as defined above, the solvents is single or mixture
from which is the water solvent, dimethyl sulfoxide (DMSO), methanol, ethanol, acetone and other solvents.
In the process of research, we found phenomenon as follow :
1 ■. The chromatography characteristics of the mangiferin calcium that was prepared by the above two methods is consistent with the standard mangiferin by HPLC.
2^ There is calcium ion in the structure of mangiferin calcium that was prepared by the above two methods detected by titration.
3> The water solution of mangiferin calcium which mangiferin reacted with calcium hydroxide is unstable, it changes much in 2 hours. The reaction of mangiferin with other alkaline calcium like calcium bicarbonate or calcium acetate is difficult because they are alkalescent . The productivity is very low.
4 x If mangiferin and calcium chloride are put together into water several ten days or heated up ten hours along, a little mangiferin calcium come into being in solution ,which can be detected by HPLC, but these substance is too little to have industry value .
5> Mangiferin monosodium(or monopotassium) is come into being first; then mangiferin monosodium(or monopotassium) reacted with water-solubility calcium salt, and come into being mangiferin calcium. The mangiferin calcium which is obtained by this method is stability , and the productivity is high.
According to the analysis and research above all, the method which mangiferin monosodium(or monopotassium) is come into being first, then mangiferin monosodium(or monopotassium) reacted with water-solubility calcium salt, and come into being mangiferin calcium is most excellent in the invention.
Compound identify:
1 , The compound identify of the mangiferin monosodium(or monopotassium): φ the NMR data of mangiferin:
The 1HNMR(DMSOd6) ( δppm ) : the end proton of glucose signal is at 4.60(1 H,d, J=9.8 Hz) ,and it exist a beta-glycoside. Three phenyl proton signal is at 6.37(lH,s),6.86(lH,s) and 7.39(lH,s).
13CNMR(DMSO-d6) (δppm): 162.7(C-I), 108.4(C-2), 164.7(C-3), 94.2(C-4), 157.1 (C-4a), 102.2(C-4b), 103.5(C-5), 154.9(C-6), 144.6(C-7), 108.9(C-8), 112.6(C-8a), 151.7(C-8b), 180.0(C-9) , 73.9(C-I ') , 71.5(C-2') , 79.8(C-3') , 71.1 (C-4') , 82.4(C-5') , 62.4(C-6').
(D the NMR data of the mangiferin monosodium(or monopotassium):
The 1HNMR(DMSO-Ci6) ( δppm ) : the end proton of glucose signal is at 4.60(1 H,d, J=9.8 Hz) ,and it exist a beta-glycoside. Three phenyl proton signal is at 6.05(1 H,s),6.19(lH,s) and 6.95(1 H,s).
13CNMR(DMSOd6) (δppm): 162.4(C-I), 106.95(C-2), 167.6(C-3), 94.7(C-4), 157.1 ( C-4a), 101.7(C-4b), 104.6(C-5), 154.1(C-6), 147.4(C-7), 108.0(C-8), 178.3(C-9) , 74.4(C-I ') , 71.0(C-2') , 80.0(C-3') , 71.0(C-4') , 81.9(C-5') , 61.8(C-6').
Analysis the structural identification data of mangiferin monosodium(or monopotassium): The chemical shift of C-3 and C-7 displace to low-frequency magnetic field markedly in the 13CNMR data compared with mangiferin, The chemical shift of three phenyl proton displace to high-frequency magnetic field markedly in the 1HNMR data compared with mangiferin.
1- hydroxyl which conclude with 9-carbonyl in molecule can't reacte with alkalescent sodium (or potassium) because its acidity is weak. 3- hydroxyl and 7- hydroxyl can reacte with alkalescent sodium (or potassium) because its acidity is stronger. The acidity of 7- hydroxyl is slightly weaker than the acidity of 3- hydroxyl because 6,7-two hydroxyl conclude each other. When mangiferin reacte with sodium bicarbonate (potassium bicarbonate) (shortened form: bicarbonate route) by mol ratio of 1 :1, the quantity of mangiferin-3-monosodium that the sodium is linked to the position C-3 -hydroxy of mangiferin is more than the quantity of mangiferin-7-monosodium that the sodium is linked to the position C-7- hydroxy of mangiferin. When mangiferin reacte with sodium carbonate (potassium carbonate) (shortened form xarbonate route) by mol ratio of 1 :0.5, the generation opportunities of mangiferin-3-monosodium and mangiferin-7-monosodium is equal because the alkalescence of sodium carbonate (potassium carbonate) is stronger than the alkalescence of sodium bicarbonate (potassium bicarbonate) .
Therefore, we can prepare mangiferin monosodium by the reaction of magiferin and sodium bicarbonate or sodium carbonate.
Based on the above analysis and data, we deduce the mangiferin monosodium is the mixture of mangiferin-3-monosodium and mangiferin-7-monosodium. 2^ the compound identify of the mangiferin calcium: the data of the mangiferin calcium:
ESI-MSm/z: 442[M/2+H] +, 423[Mmgff H]+, we conjecture the molecular weight of the compound is 882 ; IR(KBr)cm' : 341 1 , 3180 ( shoulder , OH ) ,2926,2900,1650,1620(conjugate carbonyl),1474(phenyl).
The 1HNMR(DMSO-Cl6) ( δppm ) : the end proton of glucose signal is at 4.60(1 H,d, J=9.8 Hz) ,and it exist a beta-glycoside. Three phenyl proton signal is at 6.18(lH,s),6.25(lH,s) and 7.05(lH,s).
13CNMR(DMSOd6) (δppm): 162.5(C-I), 106.5(C-2), 166.7(C-3), 94.9(C-4), 157.1 (C-4a), 102.2(C-4b), 104.2(C-5), 154.3(C-6), 148.75(C-7), 107.99(C-8), 178.3(C-9), 74.7(C-I ') , 71.1(C-2') , 80.2(C-3') , 71.1(C-4') , 82.1(C-5') , 61.8(C-6').
Analysis the structural identification data of mangiferin calcium: The chemical shift of C-3 and C-7 displace to low-frequency magnetic field markedly in the 13CNMR data compared with mangiferin. The chemical shift three phenyl proton displace to high-frequency magnetic field markedly in the 1HNMR data compared with mangiferin.
Our research shows that the productivity of mangiferin calcium that was prepared by bicarbonate route significantly lower than by carbonate route. The quantity of mangiferin-3-monosodium is more than the quantity of mangiferin-7-monosodium by bicarbonate route. In the process of reaction from mangiferin monosodium(monopotassium) to mangiferin calcium, because of molecule resistance of space, it is difficult to be obtained that the mangiferin calcium have the following formula:
It is easy to be obtained that the mangiferin calcium have the following formula:
The generation opportunities of mangiferin-3-monosodium and mangiferin-7-monosodium is equal by carbonate route. The productivity of mangiferin calcium that was prepared by carbonate route is significantly higher than
the productivity of mangiferin calcium that was prepared by bicarbonate route.
Based on above analysis and data, we deduce the structure of mangiferin calcium that is prepared through mangiferin monosodium (monopotassium) is follow as:
Mangiferin calcium may be prepared to clinic acceptable formulations with pharmaceutical acceptable auxiliary material .The formulations may be oral formulations or external formulations and injection formulations etc., for example tablets, capsules ,gentle capsules, granules , pills ,oral solution ,oral suspension, gels and powder for injection etc. .
The present invention also provides that mangiferin calciums are used as insulin sensitizers. These insulin sensitizers can also be use as hypoglycemic drugs, hypolipidemic drugs. As insulin sensitizers can be used for prevention and treatment of type 2 diabetes and diabetic chronic complications. Diabetic chronic complications refers to coronary heart disease > atherosclerosis, cerebrovascular disease and other diabetic macrovascular diseases; diabetic nephropathy > diabetic retinopathy and other diabetic microangiopathy; diabetic neuropathy, diabetic foot, diabetic maeulopathy, diabetic cataract, diabetic glaucoma, refractive changes, iris and ciliary body diseases. As hypolipidemic drugs can be used for prevention and treatment hyperlipidemia.
The present invention provides the effective dose range of mangiferin calcium is
10-80 mg/kg/day for the rats when mangiferin calcium is used as insulin sensitizers,
In accordance with the different types of animals dose conversion formula discount to the human body for 100-800mg/day/person by oral administration, three times per day.
Because of the difference between animals and the human body, so the adjustments of the actual clinical application dose and times can be allowed.
The invention is explained in detail in the examples given below which are provided by way of illustration only and therefore should not be construed to limit the scope of the invention.
EXAMPLES
The mangiferin in the invention can buy from market (the factory which have the correspond equipment can produce,for example Guangxi changzhou natural product
Ltd.), mangiferin can separate from Rhizoma Anemarrhenae or leaves of Mangifera indica L. and other plants which have mangiferin . The reagent in present invention like sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, sodium acetate, potassium acetate, calcium bicarbonate, calcium gluconate, ethanol, acetone, ethyl acetate, chloroform, dichloromethane etc. can buy from market. The standard mangiferin buy from China national institute for the control of pharmaceutical and biological products . Example 1 : Preparation of mangiferin
100kg Rhizoma Anemarrhenae are extracted by means of aqueous 80% ethanol two times at the temperature of 80 °C. The combined extracts are evaporated. After the filtration the evaporated extract is placed into macfofeticulaf resin column to adsorb, then the macfofeticulaf resin column is washed with water adequately. Mangiferin is unfixed by aqueous 40% ethanol, the solution is concentrated to obtained the crude mangiferin . The crude mangiferin is recrystallized from a mixture of solvents—dioxane-water to get pure mangiferin . The mangiferin samples is distinguished with mangiferin control ,we acknowledged the samples are mangiferin. The purity of mangiferin is 98.5% detected by HPLC.
Compound identify:
The ΗNMR(DMSO-d6) ( δppm ) : the end proton of glucose signal is at 4.60(lH,d, J=9.8 Hz) ,and it exist a beta-glycoside. Three phenyl proton signal is at 6.37(lH,s),6.86(lH,s) and 7.39(lH,s).
13CNMR(DMSO-d6) (δppm): 162.7(C-I), 108.4(C-2), 164.7(C-3), 94.2(C-4), 157.1 (C-4a), 102.2(C-4b), 103.5(C-5), 154.9(C-6), 144.6(C-7), 108.9(C-8), 112.6(C-8a), 151.7(C-8b), 180.0(C-9) , 73.9(C-I') , 71.5(C-2') , 79.8(C-3') , 71.1(C-4') , 82.4(C-5') , 62.4(C-6')o
13CNMR data of mangiferin in reference document ( YF Hong, GY Han. ISOLATION AND STRUCTURE DETERMINATION OF XANTHONE GLYCOSIDES OF ANEMARRHENA ASPHODELOIDES . ACTA PHARMACEUTICA SINICA, 1997; 32 (6): 473-475]:
The 1HNMR(DMSO-d6) (δppm) : the end proton of glucose signal is at 4.60(1 H,d, J=9.8 Hz) ,and it exist a beta-glycoside. Three phenyl proton signal is at 6.46(lH,s), 6.95(lH,s)fP 7.50(lH,s).
I3CNMR(DMSO-d6) (δppm): 161.6(C-I), 107.3(C-2), 163.6(C-3), 93.9(C-4), 156.1 ( C-4a) , 101.2(C-4b) , 102.5(C-5) , 153.6(C-6) , 143.7(C-7),108.1(C-8),
118.7(C-8a),150.7(C-8b),179.0(C-9) , 73.0(C-I ') , 70.5(C-2') , 78.8(C-3') , 70.3(C-4') , 81.3(C-5') , 61.4(C-6')»
The compound that we prepared is consistent with the compound that is reported in the reference document, It is mangiferin. Example 2: Preparation of mangiferin monosodium
Mangiferin 42.2(0. lmol) is suspended in the mixture of water 1800ml and ethanol 600ml in reactor, mixing round adequately. Sodium bicarbonate 8.4g(0.1mol) is dissolved in water ,the concentration is 0.5%( w/v) . The solution of sodium bicarbonate is added slowly into the mangiferin suspended solution while mixing round until the solution is clear , then the reaction solution is filtrated, appropriate quantity ethanol-ethyl acetate(l :1.5 v/v) is added into the reaction solution, mixing round adequately . A lot of deposition is come into being, the reaction solution is filtrated to get the depositon, the solid substance is heated up no excess 60°C to dry . The yellow substance is mangiferin monosodium. Its weight is 31.2g, the productivity is 74%. The purity of mangiferin monosodium is 98.6% detected by HPLC. Example 3: Preparation of mangiferin monosodium
Mangiferin 42.2(0. lmol) is suspend in the mixture of water 1800ml and ethanol 900ml in reactor ,mixing round adequately. Sodium carbonate 5.30g(0.05mol) is dissolved in water , the concentration is 0.5%( w/v ) . The solution of sodium carbonate is added slowly into the mangiferin suspended solution while mixing round until the solution is clear , then the reaction solution is filtrated, appropriate quantity actone is added into the reaction solution, mixing round adequately . A lot of deposition is come into being , the reaction solution is filtrated to get the depositon, the solid substance is heated up not excess 60°C to dry .the yellow substance is mangiferin monosodium. Its weight is 31.4g, the productivity is 74.5%. The purity of mangiferin monosodium is 98.5% detected by HPLC. Example 4: Preparation of mangiferin monopotassium
Mangiferin 42.2(0. lmol) is suspended in the mixture of water 200ml and methanol 1800ml in reactor, mixing round adequately. Potassium carbonate 6.9g(0.05mol) is dissolved in water ,the concentration is 0.2%( w/v ) . The solution of potassium carbonate is added slowly into the mangiferin suspended solution while mixing round until the solution is clear, then the reaction solution is filtrated, appropriate quantity ethanol- chloroform (4:1 v/v) is added into the reaction solution, mixing round adequately . A lot of deposition is come into being, the reaction solution is filtrated to get the depositon, the solid substance is heated up no excess
60 °C to dry. The yellow substance is mangiferin monopotassium. Its weight is 3 Ig, the productivity is 73.4%. The purity of mangiferin monopotassium is 98.6% detected by HPLC. Example 5: Preparation of mangiferin monopotassium
Mangiferin 42.2(0. lmol) is suspended in the mixture of water 1000ml and methanol 1000ml in reactor ,mixing round adequately. Potassium bicarbonate 10.0g(0. lmol) is dissolved in water , the concentration is 0.1 %( w/v) . The solution of potassium bicarbonate is added slowly into the mangiferin suspended solution while mixing round until the solution is clear , then the reaction solution is filtrated, appropriate quantity ethanol-dichloroform (7: 1 v/v) is added into the reaction solution, mixing round adequately . A lot of deposition is come into being , the reaction solution is filtrated to get the depositon, the solid substance is heated up no excess 60 °C to dry .The yellow substance is mangiferin monopotassium . Its weight is 31.7g, the productivity is 75%. The purity of mangiferin monopotassium is 98.7% detected by HPLC. Example 6: Preparation of mangiferin monosodium
Mangiferin 42.2(0. lmol) is suspended in the mixture of water 1800ml and methanol 900ml in reactor ,mixing round adequately. Sodium carbonate 5.30g(0.05mol) is dissolved in water , the concentration is 5%( w/v) . The solution of sodium carbonate is added slowly into the mangiferin suspended solution while mixing round until the solution is clear , then the reaction solution is filtrated, appropriate quantity ethyl acetate is added into the reaction solution, mixing round adequately . A lot of deposition is come into being , the reaction solution is filtrated to get the depositon, the solid substance is heated up no excess 60°C to dry .The yellow substance is mangiferin monopotassium . Its weight is 32.3g, the productivity is76.5%. The purity of mangiferin monopotassium is 98.5% detected by HPLC. Example 7: Preparation of mangiferin calcium
Mangiferin monosodium 4.44g(0.01mol) that is prepared by the method of example 2 is dissolved into 500ml water, calcium chloride 0.55g(0.005mol) is dissolved in 150ml water, calcium chloride solution is added slowly into mangiferin monosodium solution while mixing round . mixing round until it reacte completely . A lot of deposition is come into being in solution. The reaction solution is chilled in 4°C more than 3 hours, then filtrated to get the depositon .The deposition is heated up no excess 60°C to dry. The yellow solid substance is mangiferin calcium. Its weight is 2.7g, the productivity is 61.4%. The purity of mangiferin calcium is 98.8% detected
n
by HPLC.
Example 8: Preparation of mangiferin calcium
Mangiferin monosodium 4.44g(0.01mol) that is prepared by the method of example 3 is dissolved into 500ml water, calcium chloride 0.55g(0.005mol) is dissolved in 150ml water, calcium chloride solution is added slowly into mangiferin monosodium solution while mixing round , mixing round until it reacte completely. A lot of deposition is come into being in solution. The reaction solution is chilled in 4°C more than 3hours, then filtrated to get the depositon .this deposition is heated up no excess 60°C to dry. The yellow solid substance is mangiferin calcium. Its weight is 3.4g, the productivity is 77.2%. The pure of mangiferin calcium is 98.3% detected by HPLC. Example 9: Preparation of mangiferin calcium mangiferin potassium 4.6g(0.01mol) that is prepared by the method of example 4 is dissolved into 300ml water, calcium chloride 0.55g(0.005mol) is dissolved in 300ml water, calcium chloride solution is added slowly into mangiferin potassium solution while mixing round , mixing round until it reacte completely. A lot of deposition is come into being in solution. The reaction solution is chilled in 4 "C more than 3hours , then filtrated to get the depositon . This deposition is heated up no excess 60°C to dry. The yellow solid substance is mangiferin calcium. Its weight is 3.5g, the productivity is 76.3%. The pure of mangiferin calcium is 98.6% detected by HPLC. Example 10: Preparation of mangiferin calcium mangiferin potassium 4.6g(0.01mol) that is prepared by the method of example 5 is dissolved into 300ml water, calcium chloride 0.55g(0.005mol) is dissolved in 300ml water, calcium chloride solution is added slowly into mangiferin potassium solution while mixing round , mixing round until it reacte completely. A lot of deposition is come into being in solution. The reaction solution is chilled in 4°C more than 3hours , then filtrated to get the depositon . This deposition is heated up no excess 60°C to dry. The yellow solid substance is mangiferin calcium. Its weight is 2.9g, the productivity is 63%. The pure of mangiferin calcium is 98.4% detected by HPLC. Example 11 : Preparation of mangiferin calcium
Mangiferin monosodium 4.44g(0.01mol) that is prepared by the method of example 3 is dissolved into 1000ml water, calcium gluconate 2.15g(0.005mol) is dissolved in 150ml water, calcium gluconate solution is added slowly into mangiferin
monosodium solution while mixing round . mixing round until it reacte completely . A lot of deposition is come into being in solution. The reaction solution is chilled in 4°C more than 3hours, then filtrated to get the depositon .The deposition is heated up no excess 60 °C to dry. The yellow solid substance is mangiferin calcium. Its weight is
3.18g, the productivity is 71.7%. The purity of mangiferin calcium is 98% detected by
HPLC.
Example 12: Preparation of mangiferin calcium mangiferin 4.2g(0.01mol) is dissolved into 50ml DMSO, calcium hydroxide 0.37g(0.005mol) is dissolved in 8Og glycerol, calcium hydroxide solution is added slowly into mangiferin solution while mixing round, mixing round until it reacte completely. Appropriate quantity ethanol is added into the reaction solution, mixing round adequately. A lot of deposition is come into being in solution. The reaction solution is filtrated to get the depositon . This deposition is heated up no excess 600C to dry. The yellow green solid substance is mangiferin calcium. Its weight is 3.8g, the productivity is 90.4%. The purity of mangiferin monopotassium is 71.2% detected by HPLC. Example 13: Preparation of mangiferin calcium mangiferin 4.2g(0.01mol)is dissolved into 80ml DMSO, calcium hydroxide 1.48g(0.02mol) is dissolved in 20Og glycerol, calcium hydroxide solution is added slowly into mangiferin solution while mixing round , mixing round until it reacte completely. Appropriate quantity ethanol is added into the reaction solution, mixing round adequately . A lot of deposition is come into being in solution. The reaction solution is filtrated to get the depositon. This deposition is heated up no excess 60 °C to dry. The yellow green solid substance is mangiferin calcium. Its weight is 3.83g, the productivity is 91.2%. The purity of mangiferin monopotassium is 63.8% detected by HPLC. Example 14: Preparation of mangiferin calcium capsules
The formulation is as follow : mangiferine calcium 40Og carboxymethyl cellulose 300 g pregelatinized starch 300 g the total is 10000 capsules.
Mangiferine calcium is obtained by the method of example 8 which is shattered into exiguous powder, mangiferine calcium and pregelatinized starch and carboxymethyl cellulose are put into together mixing round uniformity . Appropriate bond is spray in the powder to make soft material , which is cranked out granule . The
granule is dried and then is put into capsules, 10000 capsules are prepared . There is
40mg mangiferin calcium in every capsule.
Example 15 : Preparation of mangiferin calcium tablets
The formulation is as follow : mangiferine calcium 500g microcrystalline cellulose 200 g starch 300 g
The total is 10000 tablets. mangiferine calcium is obtained by the method of example 8 which is shattered into exiguous powder, mangiferine calcium and starch and microcrystalline cellulose are put into together mixing round uniformity . Appropriate bond is spray in the powder to make soft material ,which is cranked out granule . the granule is dried and then tablets are pressed by tablet pressed machine .10000 tablets are prepared . There is 50mg mangiferin calcium in every tablet. Example 16: Preparation of mangiferin calcium granule
The formulation is as follow : mangiferin calcium lOOg carboxymethyl cellulose 300 g pregelatinized starch 300 g xylose 500g
The total is 100Og.
Mangiferin calcium is prepared by the method of example 8. which is shattered into exiguous powder, mangiferin calcium and pregelatinized starch and carboxymethyl cellulose and xylose are put into together mixing round uniformity . Appropriate bond is spray in the powder to make soft material ,which is cranked out granule . The granule is dried .100Og granule is prepared . there is lOOmg mangiferin calcium in every gram. Example 17: Preparation of mangiferin calcium gel
The formulation is as follow : mangiferine calcium 1 Og tween80 2g carbomer940 1 Og sodium hydroxide 4g ethanol 80g
The surplus is distilled water
The total is 100Og.
Mangiferin calcium is prepared by the method of example 8.Carbomer940 and Tween80 are mixed into water (solution 1), sodium hydroxide is dissolved in 100ml water and added into solution 1, Gel matrix is obtained. Mangiferine calcium exiguous powder is dissolved in mixture of water and ethanol (solution 2) .solution 2 is added into gel matrix and mixed uniformity .The gel is Plus distilled water to 1000 g, mixing uniformity .That is mangiferin calcium gel.
Example 18: Preparation of mangiferin calcium powder for injection The formulation is as follow : mangiferine calcium 1Og mannitol 4Og the surplus is distilled water The total is 2000ml.
Mangiferin calcium is prepared by the method of example δ.Mannitol is added into 1500ml water for injection in appropriate containers, Activated carbon for injiection is added into the solution and heated up to 80°C while mixing round 30min,then the solution is filtrated by microporous membrane of 0.22μm (solution 1). Mangiferine calcium exiguous powder is dissolved in solution 1, Plus water for injection to 2000ml, then the solution is filtrated by Microporous Membrane of 0.22μm, the solution is separated into bottles , every bottle have lOmg mangiferin calcium, all samples are freezed-drying. Stopers are pushed down after Freeze-drying, the bottles are airproof by covers, then stickers are pasted and packed up.That is mangiferin calcium powder for injection. Mangiferin calcium detected by HPLC:
Apparatus: Angilent 1100 HPLC (American Agilent Co.),include G1312Adual pump G 1313 A Auto-Sampler.
Chromatographic conditions:
Chromatographic column : discover ODS column (250mmχ6mm,5μm);
The mobile phase: Acetonitrile-0.1%H3PO4 water (13:87 v/v)
Velocity of flow :1.0 ml/min.
Detection Wavelength :254nm.
Column temperature: 30 °C mangiferin calcium powder weighed up accurately is put into distilled water and dissolved , then the solution is determined in proper capacity. The tested samples solution is obtained.
Standard mangiferin powder weighed up accurately is put into methanol and dissolved , then the solution is determined in proper capacity. The standard samples solution is obtained.
The tested samples solution and the standard samples solution are detected by HPLC separately. The data are recorded and calculated.
The chromatography characteristics of the mangiferin calcium that was prepared by the method of example 8 is consistent with the standard mangiferin by HPLC. The purity of mangiferin calcium is 98.3%.
The chromatography characteristics of the mangiferin calcium that was prepared by the method of example 12 is consistent with the Standard mangiferin by HPLC. The purity of mangiferin calcium is 71.2%. The content of calcium ion in mangiferin calcium is determined by titration:
25 mg mangiferin calcium powder weighed up accurately is put into 20 ml distilled water and dissolved in taper glass bottle .then 3ml Buffer solution of NH3-NH4Cl(pH=10)is added into the solution,a few eriochrome black T is added into the solution. Standard EDTA solution (0.0297mol/L) is added into the solution until the solution color changed from wine red to yellow green. The content of calcium ion is calculated according to the volume of standard EDTA solution that is consumed by the sampIe.The results of four times experiments follow as:
Mangiferin calcium Mangiferin calcium
(by the method for preparation of example 8) (by the method for preparation of example
28.2 1.31 27.5 1.31
25.5 1.18 26.5 1.25
27.5 1.28 29.5 1.37
The mol ratio of mangiferin ion and calcium ion is 2: 1 according to the above calculation. The solubility of calcium:
5mg mangiferin powder which is weighed up accurately is put into 50ml distilled water , the solution is shaked acutely 30 second every 5 minutes .The mangiferin can't dissolved in 30 minutes .The water solubility of mangiferin is less than O.lmg/ml . Mangiferin is hardly solubility substance in water.
50mg mangiferin calcium powder which is obtained by the method for preparation of example 8 and weighed up accurately is put into 50ml distilled water ,the solution is shaked acutely 30 second every 5 minutes,The mangiferin calcium can dissolve in 30 minutes. lOOmg mangiferin calcium powder which is obtained by the method for preparation of example 8 and weighed up accurately is put into 50ml distilled water , the solution is shaked acutely 30 second every 5 minutes. The mangiferin calcium can not dissolve completely in 30 minutes.
The water solubility of mangiferin calcium is more than lmg/ml . Mangiferin is tiny solubility substance in water. The Pharmacokinetics of mangiferin and mangiferin calcium after oral
administration
1 > the confect of drug solution
Mangiferin is suspended in Carboxymethyl cellulose sodium solution which concentration is one percent,the mangiferin concentration is 1 Omg/mL,which is sample A.
Mangiferin calcium is suspended in Carboxymethyl cellulose sodium solution which concentration is one percent, the mangiferin concentration is 1 Omg/mL,which is sample B. The mangiferin calcium is obtained by the method for preparation of example 8.
2> oral administrated project
All rats were fasted for 16 hours, free drinking water. The rats are oral administrated separately sample A and sample B, which dose is 100mg/kg . The rats were taken whole blood in 5 minutes before oral administrated and 15 min ,30 min,45 min,60 min,90 min, 120 min, 180 min,240 min,300 min,360 min,480 min after oral administrated. Serum is separated from these blood samples.
3 - Serum Sample treatment
Serum Samples are extracted accurately 0.2ml into centrifuge tubes separately, then 40μL cold trichloroactic acid solution which concertration is ten percent is added into centrifuge tubes separately. The samples are whorled 3 minutes , then centrifuged 12000 r / min for 10 minutes , 120μI the up layer solution are extracted from centrifuge tubes and put into sample bottles separately. All the samples are detected by HPLC.
Apparatus: Angilent 1100 HPLC (American Agilent Co.),include G1312A dual pump Gl 313 A Auto-Sampler.
Chromatographic conditions:
Chromatographic column : discover ODS column (250mmx6mm,5μm);
The mobile phase: Acetonitrile-0.1%H3PO4 water (13:87 v/v)
Velocity of flow :1.0 ml/min.
Detection Wavelength :254nm.
Column temperature: 30°C
4, Results:
According to the data (Table 1 ) ,the pharmacokinetics data of oral administrated mangiferin calcium is better than oral administrated mangiferin . The bioavailability of mangiferin calcium is better than mangiferin.
Table 1 The Pharmacokinetics parameter of mangiferin calcium and mangiferin parameter mangiferin mangiferin calcium
Cmax/μg/ml 14.8±0.5 48.3±0.6
Ti/2β (min) 45.7±8.3 61.4±7.7
AUC0-oo/μg.h/ml 1864.1±275.2 3469.2±359.3
Efficacy in STZ model
K Materials
Mangiferin calcium are prepared in accordance with the method of preparation of example 12. Mangiferin are prepared in accordance with the method of preparation of example 1. Rosiglitazone Hydrochloride tablets were purchased from Zhejiang wanma pharmaceutical Co., Ltd. Mangiferin and mangiferin calcium salts were suspended with 3 %o sodium carboxymethyl cellulose.
Normal female wistar rats(SPF, 3 months age, 180— 20Og) were purchased from Hainan provincial peoples hospital experimental Animal Center. The animals were kept in a room temperature(25~28°C) with free access of food and water. A light-dark cycle(6 a.m and 6 p.m)was strictly enforced. High fat chow is composed of 55% basic chow, 2% protein, 16% fat, 27%white sugar. 2> Method
Model: After the rats were fasted for 12 hours, the rats are injected 30-35mg/kg streptozotocin (STZ) solution once by tail vein. STZ solution is prepared to 2% concentration with 0.1 mmol / L, pH 4.4 citrate - sodium citrate buffer before use. The model rats were weighed ^ taked out tail vein blood > tested blood glucose when the Model is done after 14 days after fasting for 12 hours, then injected 20% glucose solution (2mg/kg) by intraperitoneal, determined blood glucose in 0.5h, Ih, 2h. The rats whose glucose tolerance were abnormal were bringed into experiments. Normal wistar rats were fed normal chow, model rats were fed high fat chow.
Experimental group: normal wistar rats group(n=10); after Diabetes model is succeed, the rats were randomly divided into 7 groups: Diabetes model group(n = 10 ); mangiferin groups (20> 40 ^ 80mg/kg,each 10 rats) ; mangiferin calcium groups ( 10> 20> 40mg/kg,each 10 rats) ; Rosiglitazone Hydrochloride group[3mg/kg, n = 10] o Test samples or vehicle control was given orally for 8 weeks.Diabetes model group and normal group were given vehicle.
Measurements:
Determination of insulin sensitivity(Glucose infusion rate): Using glucose clamp technique, in accordance with Konglingdong' method [KONG Ling-dong, ZHU
Liang-zheng , SONG Ju-min, etc al. Intervention Effects of Tiaozhi Jiangtang Tablet on Insulin Resistance in Rats with Diabetes Mellitus Type 2. Chinese Journal of Integrated Traditional and Western Medicine,2006,26:76-79] in the treatment of eight weeks.
Determination of plasma glucose and lipid: Rats were taken whole blood after killed, then serum was separated, determined plasma glucose(GLU), insulin(INS), triglycerides(TG) and free fatty acids(FFA).
GLU and TG levels were determined using GF-D800 semi-auto chemist which was purchased from Shandong Gaomi Caihong Analytical Instrument Co., Ltd. Free fatty acids were determined using copper colorimetric determination. The kits for Determination of free fatty acids were purchased from Nanjing Jiancheng Bioengineering Institute. Insulin: radioimmunoassay(RIA), γ counter counts, insulin RIA Kit was purchased from Shandong Weifang City three-dimensional (3 V) Biological compny.
Statistics: The results have been calculated as mean±SD ( X±SD) and compareisons of the data have been done by t-test.
3x Results
20mg/kg mangiferin does not significantly improve GLU > TGx FFAx INSN Glucose infusion rate in diabetic rats. 10mg/kg mangiferin calcium can significantly improves GLU > TGx FFAN INS > Glucose infusion rate in diabetic rats and has a significant dose-effect relationship(Table 2).
These results suggest that mangiferin calcium can improve the solubility x oral bioavailability and pharmacological activity of mangiferin because the effective doses of mangiferin calcium are greatly reduced than mangiferin. Efficacy in GK model K Materials
Mangiferin calcium are prepared in accordance with the method of preparation of example 8. Mangiferin are prepared in accordance with the method of preparation of example 1. Rosiglitazone Hydrochloride tablets were purchased from Zhejiang wanma pharmaceutical Co., Ltd. Mangiferin and mangiferin calcium were suspended with 3 %o sodium carboxymethyl cellulose before use.
Goto-Kakizaki rats(GK) ( 16 weeks age, $c?) were purchased from Shanghai SLAC laboratory animal Co., Ltd.o The animals were kept in IVC cages with temperature(22°C). There are two rats in each cage. 2> Method
Experimental group: GK rats group(n=10); mangiferin groups (2Ox 4Ox 80mg/kg,each 10 rats) ; mangiferin calcium groups ( 1Ox 20Λ 40mg/kg,each 10 rats) ;
Rosiglitazone Hydrochloride group[3mg/kg, n = 10]o Test samples or vehicle control was given orally for 30 days.GK rats group were given vehicle.
Measurements:
The blood specimens were taken by abdominal aorta at the end of the test. Plasma glucose(GLU), insulin(INS), triglycerides(TG), total cholesterol (TC), high density lipoprotein(HDL), low density lipoprotein(LDL) were determined.
GLl-K TC TG, HDL and LDL levels were determined using GF-D800 semi-auto chemist which was purchased from Shandong Gaomi Caihong Analytical Instrument Co., Ltd. Insulin: radioimmunoassay(RIA), γ counter counts, insulin RIA Kit was purchased from Shandong Weifang City three-dimensional (3V) Biological company.
Statistics: The results have been calculated as mean±SD ( X±SD) and compareisons of the data have been done by t-test. 3, Results
20mg/kg mangiferin does not significantly improve GLU, TC, TG, HDL and LDL and INS in diabetic GK rats. 40mg/kg mangiferin improves TG, HDL and LDL in diabetic GK rats. 10mg/kg mangiferin calcium can significantly improves TCHDL and LDL in diabetic GK rats. 20mg/kg mangiferin calcium can significantly improves GLU, TC, TG, HDL and LDL and INS in diabetic GK rats (Table3 ) .
These results suggest that mangiferin calcium can improve the solubility, oral bioavailability and pharmacological activity of mangiferin because the effective doses of mangiferin calcium are greatly reduced than mangiferin.
Table 2.Effect of the samples in STZ rats
Glucose infusion rate
Groups GLU(mmol/L) INS(μ IU/ml) TG(mmol/L) FFA(μmol/L)
(mg/kg-min)
Normal group 6.37±0.39** 20.67±4.39** 1.38±0.1 l" 1.08±0.12" 26.25±4.24**
Model group 11.43±0.42 37.39±3.56 3.62±0.37 1.88±0.2(T 14.46±3.87**
Mangiferin group(20mg/kg) 10.56±0.38 33.42±3.79 3.42±0.41 1.79±0.24 15.75±3.69
Mangiferin group(40mg/kg) 8.45±0.23* 28.13±3.74* 2.82±0.22* 1.56±0.19* 18.32±3.89*
Mangiferin group(80mg/kg) 7.05±0.44" 24.35±3.46** 1.82±0.32** 1.29±0.34** 23.65±3.67**
Mangiferin calcium group(10mg/kg) 8.01±0.32* 27.63±3.46* 2.49±0.18* 1.54±0.23* 17.56±3.45*
Mangiferin calcium group(20mg/kg) 7.31±0.22** 23.57±3.68** 1.93±0.36** 1.28±0.14** 24.37±3.75**
Mangiferin calcium group(40mg/kg) 6.91±2.02" 20.53±4.42** 1.49±0.28** 1.13±0.18** 26.36±3.58**
Rosiglitazone group 7.49±2.18** 19.87±4.2f* 1.44±0.16" 1.25±0.13** 24.75±3.69**
Table 1 : compared with model group: *p<0.05» **p<0.01 o
Table 2: compared with GK group: *P<0.05; **P<0.01 ; ***P<0.001.