Crystals of L-ornithine and process for producing the same
View Patent ↗The present invention provides crystals of L-ornithine and a process for producing the crystals of L-ornithine including the steps of (i) exposing L-ornithine or a salt thereof, a composition comprising L-ornithine or a salt thereof, or a solution containing L-ornithine, a salt thereof, or the composition to a cation exchange resin to adsorb L-ornithine onto the cation exchange resin; (ii) eluting L-ornithine from the cation exchange resin on which L-ornithine is adsorbed with an aqueous alkaline solution, and removing an alkaline component from the resulting eluate to prepare an aqueous L-ornithine solution; and (iii) mixing the aqueous L-ornithine solution with a hydrophilic organic solvent, and crystallizing L-ornithine from the resulting mixed solution.
1. Isolated crystals of L-ornithine that have an X-ray powder diffraction pattern expressed in terms of the 2θ shown by (i) or (ii):
(i) 4.95, 5.30, 12.15, 14.95, 15.25, 15.95, 17.70, 19.45, 20.00, 20.85, 21.25, 22.00, 22.40, 22.65, 24.05, 24.45, 24.95, 27.15, 28.35, 29.00, 32.25, 33.80, 34.20, 34.95, 35.95, 37.15 and 39.00; or
(ii) 5.25, 12.15, 15.25, 15.90, 17.65, 19.40, 20.85, 22.00, 22.40, 22.60, 24.00, 24.45, 24.90, 27.25, 27.70, 28.35, 28.95, 32.20, 34.10, 34.90, 37.10 and 38.95.
2. A composition, comprising crystals of L-ornithine that have an X-ray powder diffraction pattern expressed in terms of the 2θ shown by (i) or (ii):
(i) 4.95, 5.30, 12.15, 14.95, 15.25, 15.95, 17.70, 19.45, 20.00, 20.85, 21.25, 22.00, 22.40, 22.65, 24.05, 24.45, 24.95, 27.15, 28.35, 29.00, 32.25, 33.80, 34.20, 34.95, 35.95, 37.15 and 39.00; or
(ii) 5.25, 12.15, 15.25, 15.90, 17.65, 19.40, 20.85, 22.00, 22.40, 22.60, 24.00, 24.45, 24.90, 27.25, 27.70, 28.35, 28.95, 32.20, 34.10, 34.90, 37.10 and 38.95.
3. The composition according to claim 2 , wherein the content of L-ornithine crystals is 95% by weight or more.
4. A process for producing crystals of L-ornithine according to claim 1 , comprising, in this order, the steps of:
obtaining a cation exchange resin on which L-ornithine is adsorbed,
eluting L-ornithine from said cation exchange resin with an aqueous alkaline solution, and
removing an alkaline component from the resulting eluate to prepare an aqueous L-ornithine solution.
5. A process for producing crystals of L-ornithine according to claim 1 , comprising the steps of:
mixing an aqueous L-ornithine solution with a hydrophilic organic solvent, and
crystallizing L-ornithine from the resulting mixed solution.
6. A process for producing crystals of L-ornithine according to claim 1 , comprising, in this order, the steps of:
selecting L-ornithine or a salt thereof, or a solution or a composition comprising L-ornithine or a salt thereof;
exposing said L-ornithine, L-ornithine salt, composition or solution to a cation exchange resin to adsorb L-ornithine onto the cation exchange resin;
eluting L-ornithine from the cation exchange resin with an aqueous alkaline solution, and removing an alkaline component from the resulting eluate to prepare an aqueous L-ornithine solution;
mixing the aqueous L-ornithine solution with a hydrophilic organic solvent; and
crystallizing L-ornithine from the resulting mixed solution.
7. The process according to claim 6 , comprising selecting a solution or composition comprising L-ornithine or a salt thereof, wherein said solution or composition is a culture broth of L-ornithine.
8. The process according to claim 4 , 6 or 7 , wherein the aqueous alkaline solution is aqueous ammonia.
9. The process according to any one of claims 4 , 6 or 7 , wherein the step of removing an alkaline component from the resulting eluate is the concentration of the eluate.
10. The process according to any one of claims 5 to 7 , wherein the hydrophilic organic solvent is selected from the group consisting of methanol, ethanol, propanol, isopropyl alcohol, n-butanol, ethylene glycol, acetone, acetonitrile, N,N-dimethylformamide and N,N-dimethylacetamide.
11. The process according to any one of claims 5 to 7 , wherein the hydrophilic organic solvent is methanol or ethanol.
12. A method for purifying L-ornithine, comprising, in this order, the steps of:
exposing L-ornithine to a cation exchange resin to adsorb L-ornithine onto the cation exchange resin,
eluting L-ornithine from the cation exchange resin with an aqueous alkaline solution,
removing an alkaline component from the resulting eluate to prepare an aqueous L-ornithine solution,
mixing the aqueous L-ornithine solution with a hydrophilic organic solvent,
crystallizing L-ornithine from the resulting mixed solution, and
thereby obtaining crystals of L-ornithine described in claim 1 .
13. The process according to claim 8 , wherein the step of removing an alkaline component from the resulting eluate is the concentration of the eluate.
14. The process according to claim 8 , wherein the hydrophilic organic solvent is selected from the group consisting of methanol, ethanol, propanol, isopropyl alcohol, n-butanol, ethylene glycol, acetone, acetonitrile, N,N-dimethylformamide and N,N-dimethylacetamide.
15. The process according to claim 9 , wherein the hydrophilic organic solvent is selected from the group consisting of methanol, ethanol, propanol, isopropyl alcohol, n-butanol, ethylene glycol, acetone, acetonitrile, N,N-dimethylformamide and N,N-dimethylacetamide.
16. The process according to claim 8 , wherein the hydrophilic organic solvent is methanol or ethanol.
17. The process according to claim 9 , wherein the hydrophilic organic solvent is methanol or ethanol.