US5324831A
Expired / Lapsed
US
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Phosphoramidite reagent for chemical synthesis of modified DNA
Assignee: United States, AS REPRESENTED BY SECRETARY US Department OF HEALTH AND HUMAN SERVICES
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Filing: 1988-04-06
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Granted: 1994-06-28
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Expires: 2008-04-06
Abstract
Abstract 5,6-dihydro-5-azacytidine phosphoramidite is useful in the synthesis of oligonucleotides and DNA containing dihydro-5-aza- and 5-azacytosine bases. The modified oligonucleotides which contain 5-azacytosine residues at specific sites can be used to determine the mechanism of selective gene activation and the relationship existing between the presence of the triazine base and inhibition of DNA methylation.
Inventors
- 👤 Victor E. Marquez
- 👤 Amanda J. Goddard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:34
CPC Classifications
C; C07; C07H; C07H19/00; C07H19/02; C07H19/04; C07H19/12; C07H21/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
2 words
5,6-dihydro-5-azacytidine phosphoramidite.
Claim 2
Dependent Claim
2 words
5,6-dihydro-5-azacytidine phosphoramidite.
Claim 3
Dependent Claim
33 words
5,6-dihydro-5-azacytidine phosphoramidite with protecting groups on the amino groups of the azacytidine ring and on the 5' hydroxy group, wherein said protecting groups are suitable for use in the phosphoramidite synthesis of polynucleotides.
Claim 4
Dependent Claim
33 words
5,6-dihydro-5-azacytidine phosphoramidite with protecting groups on the amino groups of the azacytidine ring and on the 5' hydroxy group, wherein said protecting groups are suitable for use in the phosphoramidite synthesis of polynucleotides.
Claim 5
Dependent Claim
9 words
A compound selected from the group consisting of: ##STR4##
Claim 6
Dependent Claim
9 words
A compound selected from the group consisting of: ##STR4##
Claim 7
Dependent Claim
71 words
In a method for synthesizing a polynucleotide containing at least one modified cytosine base using the phosphoramidite method, wherein the improvement in said method is that the modified cytosine base is 5-azacytidine and the polynucleotide is prepared by: a) using the phosphoramidite method to synthesize a polynucleotide containing at least one 5,6-dihydro-5-azacytidine base; b) and selectively oxidizing said 5,6-dihydro-5-azacytidine base in the polynucleotide formed in step a) to a 5-azacytidine base.
Claim 8
Dependent Claim
71 words
In a method for synthesizing a polynucleotide containing at least one modified cytosine base using the phosphoramidite method, wherein the improvement in said method is that the modified cytosine base is 5-azacytidine and the polynucleotide is prepared by: a) using the phosphoramidite method to synthesize a polynucleotide containing at least one 5,6-dihydro-5-azacytidine base; b) and selectively oxidizing said 5,6-dihydro-5-azacytidine base in the polynucleotide formed in step a) to a 5-azacytidine base.
Claim 9
Dependent Claim
22 words
The process of claim 4, wherein said selective oxidizing of step b) is carried out with bis(trimethylsilyl)trifluoroacetamide, trimethylsilyl chloride and trimethylsilyl peroxide.
References Cited (Backward Citations)
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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 |