Patent US5324844A successfully refreshed from Google Patents.
US5324844A
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Active carbonates of polyalkylene oxides for modification of polypeptides
Assignee: Viskase Holdings Inc
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Filing: 1992-01-08
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Granted: 1994-06-28
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Expires: 2012-01-08
Abstract
Abstract Poly(ethylene glycol)-N-succinimide carbonate and its preparation are disclosed. Polyethylene glycol (PEG) is converted into its N-succinimide carbonate derivative. This form of the polymer reacts readily with amino groups of proteins in aqueous buffers. The modified proteins have PEG-chains grafted onto the polypeptide backbone by means of stable, hydrolysis-resistant urethane (carbamate) linkages.
Inventors
- 👤 Shmuel Zalipsky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:46
CPC Classifications
C; C07; C07D; C07D207/00; C07D207/46; A; A61; A61K; A61K47/00; A61K47/50; A61K47/51; A61K47/56; A61K47/59; A61K47/60
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
26 words
A polyalkylene oxide having a molecular weight of less than about 20,000, where at least one end group of said polyalkylene oxide is an oxycarbonyl-oxy-N-dicarboximide group.
Claim 2
Dependent Claim
26 words
A polyalkylene oxide having a molecular weight of less than about 20,000, where at least one end group of said polyalkylene oxide is an oxycarbonyl-oxy-N-dicarboximide group.
Claim 3
Dependent Claim
77 words
The polyalkylene oxide of claim 1, having the structure: R.sub.1 --(O--R.sub.2).sub.a --(O--R.sub.3).sub.b --(O--R.sub.4).sub.c --O--CO--O--R.sub.5 wherein R 1 is H--, H 3 C-- or an carbonyl-oxy. N-dicarboximide group; R 2 , R 3 and R 4 are independently selected from the group consisting of straight and branched alkyl groups; R 5 is an N-dicarboximide group; and a is an integer between 1 and 1,000 and b and c are independently zero or an integer between 1 and 1,000.
Claim 4
Dependent Claim
43 words
The polyalkylene oxide of claim 2, wherein R 2 , R 3 and R 4 are independently selected from the group consisting of --CH 2 CH 2 --, --CH 2 CH(CH 3 )-- and --CH 2 CH 2 CH 2 CH 2 --.
Claim 5
Dependent Claim
44 words
The polyalkylene oxide of claim 2, wherein R 1 is a carbonyl-oxy-N-dicarboximide group and R 5 is an N-dicarboximide group and the N-dicarboximide of R 1 and R 5 are independently selected from the group consisting of N-succinimide, N-phthaliide, N-glutarimide, N-tetrahydrophthalimide and N-norborene-2,3-dicarboximide groups.
Claim 6
Dependent Claim
13 words
The polyalkylene oxide of claim 4, wherein R 5 is an N-succinimide group.
Claim 7
Dependent Claim
39 words
The polyalkylene oxide of claim 1, having the structure: ##STR8## wherein R 1 is H 3 C-- or H-- and a is an integer selected so that the molecular weight of said polyalkylene oxide is less than about 20,000.
Claim 8
Dependent Claim
30 words
The polyalkylene oxide of claim 1, having the structure: ##STR9## wherein a is an integer selected so that the molecular weight of said polyalkylene oxide is less than about 20,000.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-06-27 | 1997-12-27 | 1998-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-06-27 | 2001-12-27 | 2002-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-06-27 | 2005-12-27 | 2006-06-28 | $7700.00 | Window Closed / Lapsed |