P. S. Lonkar, V. A. Kumar / Bioorg. Med. Chem. Lett. 14 (2004) 2147–2149
2149
ship. We thank Dr. K. N. Ganesh for his continued
support.
18
16
14
12
10
8
PNA12
PNA11
PNA10
PNA13
PNA14
References and notes
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0
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Figure 3. Percent hyperchromicity verses temperature plots of the
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G.;Cook, P. D.;Egli, M.;Manoharan, M.
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In summary, this communication presents a unique
example of a rationally designed PNA analog that takes
advantage of the conformationally frozen six-membered
ring having substituents in definite preferred orientations
with respect to each other. DNA complementation
studies of the modified PNAs by UV-Tm measurements
indicate that these PNAs form stable PNA2:DNA com-
plexes. The tertiary ring nitrogen is protonable at physi-
ological pH. The additional positive charges in the
backbone may add favorable therapeutic features to the
oligomers as the positive charges in the backbone are
known to aid cellular uptake3. Further work that includes
the synthesis of mixed purine/pyrimidine PNA sequences
incorporating this monomer and synthesis of other ste-
reoisomers is currently underway in our laboratory.
9. (a) Kumar, V. A. Eur. J. Org. Chem. 2002, 2021–2032;(b)
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Supporting information
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14. A preliminary report of this work was presented at XV
IRT Symposium on Nucleosides Nucleotides and Nucleic
Acids, 2002, Leuven, Belgium.
Nucl. Acids
Experimental procedures and characterization for 1–9,
13C and mass spectra of 9, HPLC, ESIMS, and CD
spectra of 10–13, and CD spectra of the complexes of
10–13 with DNA 15. Binding stoichiometry by CD JobÕs
Plot of 13:15.
Acknowledgements
15. Kumar, V. A.;Meena;Pallan, P. S.;Ganesh, K. N. Org.
Lett. 2001, 3, 1269–1272.
V.A.K. thanks DST, New Delhi for financial support.
P.S.L. thanks CSIR, New Delhi for research fellow-
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