Patent ID: 8354524

Claim:
A selenium-containing compound having the structure of formula I: wherein: (a) R 1 is a nucleic acid base selected from the group consisting of cytosine and 2-selenocytosine; or is a protected nucleic acid base selected from the group consisting of protected cytosine and 2-selenocytosine; (b) R 2 is H, HO, alkyl-O, TBDMS-O, TOM-O group, ACE-O group, orthoester group, diselenide, or alkyl-Se; (c) R 3 is H, HO, alkyl-O, TBDMS-O, diselenide, alkyl-Se, phosphoramidite, phosphoroselenoamidite, phosphate, a 5′ linked nucleotide, a 5′ linked seleno-nucleotide, a 5′ linked oligonucleotide, a 5′linked seleno-oligonucleotide, a 5′ linked nucleic acid chain, or a 5′ linked seleno-nucleic acid chain, wherein any phosphorus atom of a bridging phosphate of the 5′ linked seleno-nucleotide, the 5′ linked seleno-oligonucleotide, or the 5′ linked seleno-nucleic acid chain is bonded to non-selenium atoms; (d) R 4 is H, HO, HSe, diselenide, alkyl-Se, alkyl-O, DMTr-O, TBDMS-O, (alkyl-O) 3 Si—O, phosphate, diphosphate, diphosphoroselenoate, triphosphate, triphosphoroselenoate, a 3′ linked nucleotide, a 3′ linked seleno-nucleotide, a 3′ linked oligonucleotide, a 3′ linked seleno-oligonucleotide, a 3′ linked nucleic acid chain, or a 3′ linked seleno-nucleic acid chain, wherein any phosphorus atom of a bridging phosphate of the 3′ linked seleno-nucleotide, the 3′ linked seleno-oligonucleotide, or the 3′ linked seleno-nucleic acid chain is bonded to non-selenium atoms; and (e) X is an oxygen atom or a selenium atom; wherein at least one of R 1 , R 2 , or X comprises at least one selenium atom, and wherein alkyl is a saturated or unsaturated, branched or unbranched hydrocarbon group having between 1 and 24 carbon atoms.