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US4259441A
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Process for resolving D, L-leucine
Assignee: Albemarle Corp
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Filing: 1979-09-17
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Granted: 1981-03-31
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Expires: 1999-09-17
Abstract
Abstract Production of optically pure D-leucine and L-leucine ester by treating a racemic mixture of N-acyl-D,L-leucine ester with a proteolytic enzyme and separating the resulting N-acyl-L-leucine and N-acyl-D-leucine ester from the solution with subsequent removal of the N-acyl and ester groups to provide L-leucine and D-leucine, respectively.
Inventors
- 👤 Dennis P. Bauer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:12
CPC Classifications
C; C12; C12P; C12P13/00; C12P13/04
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
89 words
A process for resolving a racemic mixture of D,L-leucine, said process comprising the steps of (a) acylating a racemic mixture of D,L-leucine to form a mixture of N-acyl-D,L-leucine, (b) esterifying the resultant N-acyl-D,L-leucine to form a mixture of N-acyl-D,L-leucine ester, (c) subjecting the resultant mixture of N-acyl-D,L-leucine esters to the action of a proteolytic enzyme selected from the group consisting of microbially derived serine proteinases, (d) separating the unreacted N-acyl-D-leucine ester from the resulting N-acyl-L-leucine, and (e) recovering D-leucine and L-leucine from the separate N-acyl-D-leucine ester and N-acyl-L-leucine, respectively.
Claim 2
Dependent Claim
89 words
A process for resolving a racemic mixture of D,L-leucine, said process comprising the steps of (a) acylating a racemic mixture of D,L-leucine to form a mixture of N-acyl-D,L-leucine, (b) esterifying the resultant N-acyl-D,L-leucine to form a mixture of N-acyl-D,L-leucine ester, (c) subjecting the resultant mixture of N-acyl-D,L-leucine esters to the action of a proteolytic enzyme selected from the group consisting of microbially derived serine proteinases, (d) separating the unreacted N-acyl-D-leucine ester from the resulting N-acyl-L-leucine, and (e) recovering D-leucine and L-leucine from the separate N-acyl-D-leucine ester and N-acyl-L-leucine, respectively.
Claim 3
Dependent Claim
14 words
The process of claim 1 wherein the acyl group contains from 1-9 carbon atoms.
Claim 4
Dependent Claim
14 words
The process of claim 2 wherein the ester group contains from 1-10 carbon atoms.
Claim 5
Dependent Claim
19 words
The process of claim 1 wherein the proteolytic enzyme is a microbially derived serine proteinase which is subtilisin Carlsberg.
Claim 6
Dependent Claim
15 words
The process of claim 1 wherein the mixture of N-acyl-D,L-leucine ester comprises N-acetyl-D,L-leucine methyl ester.
Claim 7
Dependent Claim
55 words
The process according to claim 1 in which said step (c) is further characterized by subjecting an aqueous solution of a racemic mixture of N-acetyl-D,L-leucine methyl ester to the action of a proteolytic enzyme selected from the group consisting of microbially derived serine proteinases at a pH in the range of from 5 to 10.
Claim 8
Dependent Claim
37 words
The process according to claim 6 which is carried out at a pH in the range from about 5 to about 7.5 and at a temperature in the range from about 10° C. to about 60° C.
Claim 9
Dependent Claim
15 words
The process according to claim 7 further characterized by the serine proteinase being subtilisin Carlsberg.
Claim 10
Dependent Claim
27 words
The process according to claim 8 wherein the proteinase is subtilisin Carlsberg and the temperature is in the range from about 20° C. to about 40° C.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-03-30 | 1984-09-29 | 1985-03-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-30 | 1988-09-29 | 1989-03-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-30 | 1992-09-29 | 1993-03-31 | $7700.00 | Window Closed / Lapsed |