High-purity magnesium lithospermate B and preparation method therefor
The present invention relates to a method for preparing magnesium lithospermate B. The method is characterized in that: magnesium lithospermate B is extracted or purified from a Salvia miltiorrhiza plant material or a Salvia miltiorrhiza extract in the presence of an added magnesium salt. The present invention also relates to a high-purity magnesium lithospermate B product prepared by the method of the present invention, wherein the content of magnesium lithospermate B is more than 95% by weight.
1. A process for preparing magnesium lithospermate B, comprising:
a) obtaining a Salvia miltiorrhiza liquid extract by extracting a Salvia miltiorrhiza plant material with a first alcohol-water solution, and
b) separating the Salvia miltiorrhiza liquid extract via chromatography on macroporous absorption resin, wherein a second alcohol-water solution and a third alcohol-water solution is used for elution, collecting an eluate containing magnesium lithospermate B; concentrating the eluate to give a concentrated eluate, adjusting the pH value of the concentrated eluate to 3-7, and then extracting with an organic solvent to give a raffinate comprising magnesium lithospermate B;
wherein a magnesium salt is added into at least one of the following: the first alcohol-water solution in a), the Salvia miltiorrhiza liquid extract in b), the second alcohol-water solution in b), or the third alcohol-water solution in b).
2. The process according to claim 1 , wherein the magnesium salt is one or more of the following compounds: MgSO 4 , Mg(Ac) 2 , MgCl 2 , MgBr 2 , MgCO 3 , and Mg(HCO 3 ) 2 .
3. The process according to claim 1 or 2 , wherein the amount of the added magnesium salt is 5-200 mg per 100 g of the Salvia miltiorrhiza plant material or the Salvia miltiorrhiza extract.
4. The process according to claim 3 , wherein the organic solvent is selected from C 3 -C 6 alcohols, C 1 -C 6 alkyl C 1 -C 3 carboxylates, and di(C 1 -C 5 alkyl)ethers.
5. The process according to claim 4 , wherein the organic solvent is one or more selected from the following solvents: n-butyl alcohol, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl t-butyl ether, and diethyl ether.
6. The process according to claim 4 or 5 , further comprising concentrating the raffinate comprising magnesium lithospermate B, follow by alcohol-precipitating, filtrating, and drying to give a magnesium lithospermate B solid.
7. The process according to claim 6 , wherein the solvent used for alcohol-precipitating is ethanol or an aqueous ethanol solution.
8. The process according to claim 1 , wherein the first alcohol-water solution and the second alcohol-water solution are the same or different, and are independently selected from aqueous solutions of C 1 -C 4 alcohol with a concentration of 0-80%.
9. The process according to claim 1 , wherein the third alcohol-water solution is selected from aqueous solutions of C 1 -C 4 alcohol with a concentration of 0-80%.
10. The process according to claim 1 , further comprising concentrating the Salvia miltiorrhiza liquid extract to give a concentrated Salvia miltiorrhiza liquid extract.
11. The process according to any one of claims 1 , 2 , 3 , 4 - 9 , and 10 , wherein the macroporous resin comprises one or more of the following resins: HP20, HPD-80, HPD-100, HPD-100B, HPD-200A, HPD-300, HPD-450, HPD-722, HPD-826, ADS-5, ADS-8, ADS-21, D101, AB-8, and 1300-I.