Abstract
Boron-modified nucleic acids comprise a new set of DNA mimics that have potential biological and therapeutic applications. A series of nine dinucleotides containing N7-cyanoborane-2'-deoxyguanosine ((7b)dG) at the 3', 5' or both positions of the phosphodiester linkage have been synthesized using solution phase phosphoramidite chemistry. Fmoc was used as the 5'-protecting group because of incompatibility of the cyanoborane moiety with 5'-DMT cations generated during the deprotection step. The presence of the cyanoborane group was confirmed on the basis of Fab-MS and 1H NMR spectroscopy. The H-8 proton of (7b)dG in the dinucleotides shifted 0.35-0.80 p.p.m. downfield relative to that of unmodified dG. A comparison of the D20 exchange kinetics of the H-8 proton at 60 degrees C showed that H-8 of (7b)dG is very labile relative to unmodified dG, indicating that the N7-cyanoborane modification increases the acidity of the H-8 proton of (7b)dG. These studies illustrate the feasibility of synthesizing boron-containing oligonucleotides which are modified at the N7-guanine to block Hoogsteen pairing in the DNA major groove.
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Selected References
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- Chen J. K., Schultz R. G., Lloyd D. H., Gryaznov S. M. Synthesis of oligodeoxyribonucleotide N3'-->P5' phosphoramidates. Nucleic Acids Res. 1995 Jul 25;23(14):2661–2668. doi: 10.1093/nar/23.14.2661. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cheng D. M., Sarma R. H. Intimate details of the conformational characteristics of deoxyribodinucleoside monophosphates in aqueous solution. J Am Chem Soc. 1977 Oct 26;99(22):7333–7348. doi: 10.1021/ja00464a038. [DOI] [PubMed] [Google Scholar]
- Cook P. D. Medicinal chemistry of antisense oligonucleotides--future opportunities. Anticancer Drug Des. 1991 Dec;6(6):585–607. [PubMed] [Google Scholar]
- Eckstein F. Nucleoside phosphorothioates. Annu Rev Biochem. 1985;54:367–402. doi: 10.1146/annurev.bi.54.070185.002055. [DOI] [PubMed] [Google Scholar]
- Gryaznov S. M., Lloyd D. H., Chen J. K., Schultz R. G., DeDionisio L. A., Ratmeyer L., Wilson W. D. Oligonucleotide N3'-->P5' phosphoramidates. Proc Natl Acad Sci U S A. 1995 Jun 20;92(13):5798–5802. doi: 10.1073/pnas.92.13.5798. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hall I. H., Hall E. S., Chi L. K., Shaw B. R., Sood A., Spielvogel B. F. Antineoplastic activity of boron-containing thymidine nucleosides in Tmolt3 leukemic cells. Anticancer Res. 1992 Jul-Aug;12(4):1091–1097. [PubMed] [Google Scholar]
- Hamblin M. R., Cummins J. H., Potter B. V. Mung bean (Phaseolus aureus) nuclease. A mechanistic investigation of the DNA-cleavage reaction using a dinucleoside phosphorothioate. Biochem J. 1987 Feb 1;241(3):827–833. doi: 10.1042/bj2410827. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lehmann C., Xu Y. Z., Christodoulou C., Tan Z. K., Gait M. J. Solid-phase synthesis of oligoribonucleotides using 9-fluorenylmethoxycarbonyl (Fmoc) for 5'-hydroxyl protection. Nucleic Acids Res. 1989 Apr 11;17(7):2379–2390. doi: 10.1093/nar/17.7.2379. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Li H., Porter K., Huang F., Shaw B. R. Boron-containing oligodeoxyribonucleotide 14mer duplexes: enzymatic synthesis and melting studies. Nucleic Acids Res. 1995 Nov 11;23(21):4495–4501. doi: 10.1093/nar/23.21.4495. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Marcus-Sekura C. J. Techniques for using antisense oligodeoxyribonucleotides to study gene expression. Anal Biochem. 1988 Aug 1;172(2):289–295. doi: 10.1016/0003-2697(88)90447-2. [DOI] [PubMed] [Google Scholar]
- Matsukura M., Shinozuka K., Zon G., Mitsuya H., Reitz M., Cohen J. S., Broder S. Phosphorothioate analogs of oligodeoxynucleotides: inhibitors of replication and cytopathic effects of human immunodeficiency virus. Proc Natl Acad Sci U S A. 1987 Nov;84(21):7706–7710. doi: 10.1073/pnas.84.21.7706. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Miller P. S., Fang K. N., Kondo N. S., Ts'o P. O. Syntheses and properties of adenine and thymine nucleoside alkyl phosphotriesters, the neutral analogs of dinucleoside monophosphates. J Am Chem Soc. 1971 Dec;93(24):6657–6665. doi: 10.1021/ja00753a054. [DOI] [PubMed] [Google Scholar]
- Miller P. S., Yano J., Yano E., Carroll C., Jayaraman K., Ts'o P. O. Nonionic nucleic acid analogues. Synthesis and characterization of dideoxyribonucleoside methylphosphonates. Biochemistry. 1979 Nov 13;18(23):5134–5143. doi: 10.1021/bi00590a017. [DOI] [PubMed] [Google Scholar]
- Porter K. W., Tomasz J., Huang F., Sood A., Shaw B. R. N7-cyanoborane-2'-deoxyguanosine 5'-triphosphate is a good substrate for DNA polymerase. Biochemistry. 1995 Sep 19;34(37):11963–11969. doi: 10.1021/bi00037a038. [DOI] [PubMed] [Google Scholar]
- Sanghvi Y. S., Hoke G. D., Freier S. M., Zounes M. C., Gonzalez C., Cummins L., Sasmor H., Cook P. D. Antisense oligodeoxynucleotides: synthesis, biophysical and biological evaluation of oligodeoxynucleotides containing modified pyrimidines. Nucleic Acids Res. 1993 Jul 11;21(14):3197–3203. doi: 10.1093/nar/21.14.3197. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schroeder S. A., Roongta V., Fu J. M., Jones C. R., Gorenstein D. G. Sequence-dependent variations in the 31P NMR spectra and backbone torsional angles of wild-type and mutant Lac operator fragments. Biochemistry. 1989 Oct 17;28(21):8292–8303. doi: 10.1021/bi00447a006. [DOI] [PubMed] [Google Scholar]
- Sood A., Shaw B. R., Spielvogel B. F., Hall E. S., Chi L. K., Hall I. H. The synthesis and anti-neoplastic activity of N2-isobutyryl-2'-deoxyguanosine-N7-cyanoborane derivatives. Pharmazie. 1992 Nov;47(11):833–838. [PubMed] [Google Scholar]
- Sood A., Spielvogel B. F., Shaw B. R., Carlton L. D., Burnham B. S., Hall E. S., Hall I. H. The synthesis and antineoplastic activity of 2'-deoxy-nucleoside-cyanoboranes in murine and human culture cells. Anticancer Res. 1992 Mar-Apr;12(2):335–343. [PubMed] [Google Scholar]
- Wagner R. W., Matteucci M. D., Lewis J. G., Gutierrez A. J., Moulds C., Froehler B. C. Antisense gene inhibition by oligonucleotides containing C-5 propyne pyrimidines. Science. 1993 Jun 4;260(5113):1510–1513. doi: 10.1126/science.7684856. [DOI] [PubMed] [Google Scholar]