M. C. de Koning et al. / Tetrahedron 62 (2006) 3248–3258
3257
der Marel, G. A.; van Boom, J. H. Bioconjugate Chem. 2004, 15,
576–582.
4.2. Chiral HPLC
6. de Koning, M. C.; van der Marel, G. A.; Overhand, M. Curr.
Opin. Chem. Biol. 2003, 7, 734–740.
Chiral HPLC experiments were executed using a Chiralcel
OD column at 1 mL/min. A mixture of hexane–i-propyl-
alcohol (92/8, V) containing 0.2% diethylamine was used as
the eluent. The absorption was monitored at 254 nm.
R-Enantiomer of 10: tRZ10.4 min, S-enantiomer of 10:
tRZ7.8 min.
7. Shiraishi, T.; Nielsen, P. E. Nucleic Acids Res. 2004, 32,
4893–4902.
¨
8. Kohler, O.; Jarikote, D. V.; Singh, I.; Parmar, V. S.;
Weinhold, E.; Seitz, O. Pure Appl. Chem. 2005, 77,
327–338.
9. (a) Seitz, O.; Bergmann, F.; Heindl, D. Angew. Chem., Int. Ed.
1999, 38, 2203. (b) Svanvik, N.; Nygren, J.; Westman, G.;
Kubista, M. J. Am. Chem. Soc. 2001, 123, 803. (c) Kuhn, H.;
Demidov, V. V.; Coull, J. M.; Fiandaca, M. J.; Gildea, B. D.;
Frank-Kamenetskii, M. D. J. Am. Chem. Soc. 2002, 124, 1097.
(d) Peterson, K.; Vogel, U.; Rockenbauer, E.; Nielsen, K. V.;
Kolvraa, S.; Bolund, L.; Nexo, B. Mol. Cell. Probes 2004, 18,
117.
For compounds 21 a Chiralpak AD column together with the
eluent isopropanol/hexane 1:1 (1 mL/min) was used:
R-enantiomer of 21: tRZ8.4 min, S-enantiomer of 21:
tRZ15.5 min.
4.3. Thermal denaturation studies
The melting temperature experiments were performed on a
Perkin-Elmer lambda 20 spectrometer using a 1.0 mL
cuvette with 1.0 mM of the two complementary strands in
a phosphate buffered solution. Buffer A was prepared by
mixing appropriate volumes of buffer 1 (200 mm sodium
chloride, 20 mm NaH2PO4 and 0.2 mm EDTA) and buffer 2
(200 mm sodium chloride, 10 mm Na2HPO4 and 0.2 mm
EDTA) until a pH value of 7.0 was obtained (using a
pH-meter for determination of the pH value). The two
complementary strands (dissolved in distilled H2O) were
added to 500 mL of buffer A. Distilled H2O was added to a
total volume of 1000 mL.
10. (a) Challa, H.; Woski, S. A. Tetrahedron Lett. 1999, 40,
419–422. (b) Okamoto, A.; Tanabe, K.; Saito, I. Org. Lett.
2001, 3, 925–928. (c) Ausin, C.; Ortega, J.-A.; Robles, J.;
Grandas, A.; Pedroso, E. Org. Lett. 2002, 4, 4073–4076.
(d) Whitney, A.; Gavory, G.; Balasubramanian, S. Chem.
Commun. 2003, 1, 36–37. (e) Jeon, J. W.; Son, S. J.;
Yoo, C. E.; Hong, I. S.; Suh, J. Bioorg. Med. Chem. 2003,
¨
11, 2901–2910. (f) Kohler, O.; Jarikote, D. V.; Seitz, O.
ChemBioChem 2005, 6, 69–77.
11. (a) Kosynkina, L.; Wang, W.; Liang, T. C. Tetrahedron Lett.
1994, 35, 5173–5176. (b) Duheolm, K. L.; Petersen, K. H.;
Jensen, D. K.; Egholm, M.; Nielsen, P. E.; Buchardt, O.
Bioorg. Med. Chem. Lett. 1994, 4, 1077–1080. (c) Petersen,
K. H.; Buchardt, O.; Nielsen, P. E. Bioorg. Med. Chem. Lett.
1996, 6, 793–796. (d) Haaima, G.; Lohse, A.; Buchardt, O.;
Nielsen, P. E. Angew. Chem., Int. Ed. 1996, 35, 1939–1942.
(e) Gangamani, B. P.; Kumar, V. A. Tetrahedron 1996, 52,
15017–15030. (f) Lagriffoule, P.; Wittung, P.; Eriksson, M.;
The samples were heated to 70 8C and cooled to 5 8C before
initiating the experiment with a ramp of 1 8C/min.
The melting temperature Tm was determined as the
local maximum of the first derivative of the melting curve
(A260 vs temperature).
´
Jensen, K. K.; Norden, B.; Buchardt, O.; Nielsen, P. E. Chem.
Eur. J. 1997, 3, 912–919. (g) Puschl, A.; Sforza, S.;
Haaima, G.; Dahl, O.; Nielsen, P. E. Tetrahedron Lett. 1998,
39, 4707–4710. (h) Wu, Y.; Xu, J.-C. Tetrahedron 2001, 57,
8107–8114.
References and notes
12. Englund, E. A.; Appella, D. H. Org. Lett. 2005, 7,
3465–3467.
1. Hanvey, J. C.; Peffer, N. J.; Bisi, J. E.; Thomson, S. A.;
Cadilla, R.; Josey, J. A.; Ricca, D. J.; Hassman, C. F.; Bonham,
M. A.; Au, K. G.; Carter, S. G.; Bruckenstein, D. A.;
Boyd, A. L.; Noble, S. A.; Babiss, L. E. Science 1992, 258,
1481–1485.
13. The original native chemical ligation reaction was carried out
between peptide fragments: Dawson, P. E.; Muir, T. W.;
Clark-Lewis, I.; Kent, S. B. H. Science 1994, 266, 776–779.
14. For synthesis of PNA-thioesters and their use in chemical
ligations, see: (a) de Koning, M. C.; Filippov, D. V.;
Meeuwenoord, N.; Overhand, M.; van der Marel, G. A.; van
Boom, J. H. Tetrahedron Lett. 2002, 43, 8173–8176. (b) de
Koning, M. C.; Filippov, D. V.; van der Marel, G. A.; van
Boom, J. H.; Overhand, M. Tetrahedron Lett. 2003, 44,
7597–7600. (c) de Koning, M. C.; Filippov, D. V.; van der
Marel, G. A.; van Boom, J. H.; Overhand, M. Eur. J. Org.
Chem. 2004, 4, 850–857. (d) de Koning, M. C.; van der Knaap,
M.; Petersen, L.; van den Elst, H.; van der Marel, G. A.;
Overhand, M.; Filippov, D. V. Synlett 2005, 4, 595–598.
15. (a) Brown, S. C.; Thomson, S. A.; Veal, J. M.; Davis, D. G.
Science 1994, 265, 777. (b) Eriksson, M.; Nielsen, P. E. Nat.
Struct. Biol. 1996, 3, 410.
2. Nielsen, P. E. Curr. Opin. Biotechnol. 1992, 10, 71–75.
3. Soomets, U.; Hallbrink, M.; Langel, U. Front. Biosci. 1999, 4,
D782–D786.
4. (a) Buchardt, O.; Egholm, M.; Berg, R. H.; Nielsen, P. E.
Trends Biotechnol. 1993, 11, 384–386. (b) Nielsen, P. E.;
Egholm, M.; Berg, R. H.; Buchardt, O. Nucleic Acids Res.
1993, 21, 197–200. (c) Corey, D. R. Trends Biotechnol. 1997,
15, 224. (d) Lansdorp, P. M.; Verwoerd, N. P.; van de Rijke,
F. M.; Dragowska, V.; Little, M.-T.; Dirks, R. W.; Raap, A. L.;
Tanke, H. J. Hum. Mol. Genet. 1996, 5, 685. (e) Carlsson, C.;
Jonsson, M.; Norden, B.; Dulay, M. T.; Zare, R. N.;
Noolandi, J.; Nielsen, P. E.; Tsui, L.-C.; Zielenski, J. Nature
(London) 1996, 380, 207.
5. (a) Verheijen, J. C.; Deiman, B. A. L. M.; Yeheskiely, E.; van der
Marel, G. A.; van Boom, J. H. Angew. Chem., Int. Ed. 2000, 39,
369–372. (b) Petersen, L.; de Koning, M. C.; van Kuik-Romeijn,
P.; Weterings, J.; Pol, C. J.; Platenburg, G.; Overhand, M.; van
16. Hyrup, B.; Egholm, M.; Nielsen, P. E.; Wittung, P.;
Norden, B.; Buchardt, O. J. Am. Chem. Soc. 1994, 116, 7964.
17. In fact, during the preparation of this manuscript, a paper
appeared from O. Seitz and C. Dose, in which a similar ligation