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4.1.25. 5,10,15,20-Tetrakis(5-azido-3-pyridyl)porphyrin (2)
AcOH (450 mL) was heated at 85 °C for 10 min. To the solvent
was added compound 15 (3.66 g, 24.7 mmol) in AcOH (44 mL), fol-
lowed by pyrrole (1.31 mL, 24.7 mmol). The reaction mixture was
stirred at 85 °C for 2 h and cooled to room temperature. The sol-
vent was removed under reduced pressure. The residue was dis-
solved in satd NaHCO3 aq and extracted CH2Cl2. The organic
layer was dried over Na2SO4, then filtered and the solvent was re-
moved under reduced pressure. The residue was purified by col-
umn chromatography [silica, MeOH/CHCl3 (1:49), gradient] and
gel permeation chromatography to give a purple solid (582 mg,
40.5, 43.8, 53.9, 76.7, 77.8, 155.3, 170.9, 176.7; FAB-MS m/z 255
(M+H).
4.1.31. N-Propiolyl-Gly-Gly-Lys-NH2 (16d)
Yield: 96%. 1H NMR (400 MHz, CD3OD) d 1.52–1.37 (m, 2H),
1.78–1.62 (m, 3H), 1.94–1.85 (m, 1H), 2.92 (t, J = 7.1 Hz, 2H), 3.65
(s, 1H), 3.88 (d, J = 3.8 Hz, 2H), 3.91 (d, J = 1.9 Hz, 2H), 4.34 (dd,
J = 9.7, 4.7 Hz, 1H); 13C NMR (125 MHz, CD3OD) d 23.7, 27.9, 32.2,
40.5, 43.8, 43.9, 54.1, 76.8, 77.8, 155.4, 171.7, 171.8, 176.8; FAB-
MS m/z 312 (M+H).
12%). IR (disc)
m
3432, 2109 cmꢁ1
;
1H NMR (400 MHz, CDCl3) d
4.1.32. N-Propiolyl-Gly-Lys-Cit-NH2 (16e)
ꢁ2.86 (s, 2H), 8.19 (s, 4H), 8.83 (d, J = 2.4 Hz, 4H), 8.89 (s, 8H),
9.23 (s, 4H); 13C NMR (125 MHz, CDCl3) d 29.7, 52.7, 115.7,
130.8, 136.1, 138.2, 140.9, 149.8; FAB-MS m/z 783 (M+H).
Yield: quant. 1H NMR (400 MHz, CD3OD) d 1.50–1.41 (m, 1H),
1.60–1.52 (m, 1H), 1.74–1.63 (m, 2H), 1.89–1.81 (m, 2H), 2.92 (t,
J = 7.4 Hz, 2H), 3.13 (t, J = 6.8 Hz, 2H), 3.64 (s, 1H), 3.91 (d,
J = 0.9 Hz, 1H), 3.96 (s, 1H), 4.38–4.32 (m, 1H); 13C NMR
(125 MHz, CD3OD) d 23.5, 27.7, 27.9, 30.2, 32.2, 40.5, 40.5, 43.7,
54.2, 54.5, 76.7, 77.8, 155.3, 171.1, 173.9, 176.8; FAB-MS m/z 412
(M+H).
4.1.26. Manganese(III) 5,10,15,20-tetrakis(5-azido-3-
pyridyl)porphyrin acetate (20)
A mixture of compound 2 (20 mg, 25.6
l
mol) and Mn(OAc)2ꢀ
4H2O (50 mg, 204.4 mol) in AcOH (2 mL) was gradually heated
l
from room temperature to 100 °C for 30 min. The solution was
cooled to room temperature and the solvent was removed under
reduced pressure. The residue was dissolved in 28% NH3 aq and
the solvent was removed under reduced pressure. The residue
was dissolved in MeOH and the solvent was removed under re-
duced pressure twice. The residue was taken up in CHCl3, and
the solution was filtered through Celite. The filtrate was evapo-
rated under reduced pressure, then the residue was dissolved in
AcOH and the solvent was removed under reduced pressure. The
residue was recrystallized from CHCl3/n-hexane to afford a green
solid (20 mg, 86%). FAB-MS m/z 835 (MꢁOAc).
4.1.33. N-Propiolyl-Gly-Cit-Lys-NH2 (16f)
Yield: quant. 1H NMR (400 MHz, CD3OD) d 1.51–1.41 (m, 2H),
1.61–1.52 (m, 2H), 1.76–1.62 (m, 4H), 1.89–1.81 (m, 2H), 2.93 (t,
J = 7.3 Hz, 2H), 3.18–3.10 (m, 2H), 3.63 (s, 1H), 3.88 (d,
J = 16.5 Hz, 1H), 3.95 (d, J = 16.5 Hz, 1H), 4.34–4.29 (m, 2H); 13C
NMR (125 MHz, CD3OD) d 23.7, 27.7, 27.9, 29.7, 32.3, 40.6, 40.6,
43.6, 54.1, 55.0, 76.7, 77.8, 155.3, 162.3, 171.3, 174.3, 176.7; FAB-
MS m/z 412 (M+H).
4.1.34. N-Propiolyl-Glu-Gly-Cit-NH2 (16g)
Yield: quant. 1H NMR (400 MHz, D2O) d 1.39–1.35 (m, 2H),
1.59–1.47 (m, 1H), 1.71–1.62 (m, 1H), 1.87–1.78 (m, 1H), 2.00–
1.91 (m, 1H), 2.32 (t, J = 7.2 Hz, 2H), 2.92 (t, J = 6.9 Hz, 2H), 3.36
(s, 1H), 3.75 (s, 2H), 4.10 (dd, J = 9.5, 4.8 Hz, 1H), 4.21 (dd, J = 8.6,
5.9 Hz, 1H); 13C NMR (125 MHz, D2O) d 27.0, 27.4, 29.9, 31.4,
41.0, 4.2, 54.9, 55.2, 77.0, 79.2, 156.2, 163.0, 172.9, 175.0, 178.2,
178.3; FAB-MS m/z 413 (M+H).
4.1.27. General procedure for the synthesis of N-propiolyl
peptide (16a–i)
These compounds were synthesized according to the standard
procedures for Fmoc solid-phase peptide synthesis. Fmoc-NH-
SAL-resin was treated with a solution of 20% piperidine/DMF for
15 min. The resin was washed with DMF, then treated with a solu-
tion of Fmoc amino acid (3 equiv), HBTU (3 equiv), HOBtꢀH2O
(3 equiv) and DIPEA (6 equiv) in DMF for 30 min. The Fmoc group
was removed with 20% piperidine/DMF. Propiolic acid (3 equiv)
and EEDQ (3 equiv) were mixed in DMF and transferred to the re-
sin (for reaction overnight). The resin was cleaved, and the product
was purified by RP-HPLC.
4.1.35. N-Propiolyl-Gly-Gly-Glu-NH2 (16h)
Yield: 94%. 1H NMR (400 MHz, D2O) d 1.85–1.75 (m, 1H), 2.03–
1.95 (m, 1H), 2.30 (dt, J = 7.3, 1.7 Hz, 2H), 3.36 (s, 1H), 3.79 (s, 1H),
3.85 (s, 1H), 4.18 (dd, J = 9.6, 4.9 Hz, 1H); 13C NMR (125 MHz, D2O)
d 27.4, 31.4, 43.8, 44.0, 54.1, 76.8, 78.9, 156.6, 172.9, 172.9, 177.3,
178.4; FAB-MS m/z 313 (M+H).
4.1.28. N-Propiolyl-Lys-Gly-Cit-NH2 (16a)
4.1.36. N-Propiolyl-Gly-His-Gly-NH2 (16i)
Yield: 88%. 1H NMR (400 MHz, CD3OD) d 1.54–1.39 (m, 4H),
1.75–1.61 (m, 4H), 1.85–1.78 (m, 2H), 2.89 (t, J = 7.3 Hz, 2H),
3.12–3.05 (m, 2H), 3.61 (s, 1H), 3.85 (s, 2H), 4.32–4.26 (m, 2H);
13C NMR (125 MHz, CD3OD) d 23.6, 27.5, 28.0, 30.2, 31.8, 40.4,
40.5, 43.7, 54.3, 55.4, 77.0, 77.8, 154.9, 162.3, 171.5, 174.1, 176.9;
FAB-MS m/z 412 (M+H).
Yield: 56%. 1H NMR (400 MHz, CD3OD) d 3.14–3.12 (m, 1H),
3.49–3.47 (m, 1H), 3.69 (s, 1H), 3.93–3.85 (m, 4H), 4.74 (dd,
J = 7.0, 5.4 Hz, 1H), 7.37 (d, J = 1.0 Hz, 1H), 8.77 (s, 1H); 13C NMR
(125 MHz, CD3OD) d 27.9, 42.8, 43.8, 53.4, 76.7, 77.8, 119.0,
130.6, 135.0, 155.3, 170.9, 172.2, 174.3; FAB-MS m/z 321 (M+H).
4.1.37. General procedure for the synthesis of peptide–Mn-
porphyrin conjugates (17a–i)
4.1.29. N-Propiolyl-Lys-Gly-Gly-Cit-NH2 (16b)
Yield: 83%. 1H NMR (400 MHz, CD3OD) d 1.57–1.39 (m, 4H),
1.75–1.61 (m, 4H), 1.88–1.79 (m, 2H), 2.89 (t, J = 7.6 Hz, 2H),
3.11–3.07 (m, 2H), 3.62 (s, 1H), 3.85 (d, J = 2.0 Hz, 2H), 3.86 (s,
2H), 4.33–4.27 (m, 2H); 13C NMR (125 MHz, CD3OD) d 23.6, 27.6,
28.0, 30.1, 31.9, 40.4, 40.5, 43.6, 43.9, 54.4, 55.2, 77.1, 77.8,
154.9, 162.3, 171.7, 172.3, 174.2, 176.9; FAB-MS m/z 469 (M+H).
To a mixture of TBTA (5 equiv) and [Cu(CH3CN)4]PF6 (5 equiv)
was added DMSO under an atmosphere of argon, and the mixture
was stirred for 30 min. To the mixture was added a solution of N-
propiolyl peptide (>5 equiv) in DMSO. The mixture was stirred for
30 min, then a solution of compound 20 in DMSO (final concentra-
tion: 6.5 mM compound 20 in DMSO) was added, and stirring was
continued. To the resulting mixture was added CHCl3 and the pre-
cipitate was filtered. The precipitate was purified by RP-HPLC to
give a dark red solid.
4.1.30. N-Propiolyl-Gly-Lys-NH2 (16c)
Yield: quant. 1H NMR (400 MHz, CD3OD) d 1.53–1.36 (m, 2H),
1.73–1.58 (m, 3H), 1.94–1.85 (m, 1H), 2.91 (t, J = 7.4 Hz, 2H), 3.65
(s, 1H), 3.87 (d, J = 16.4 Hz, 1H), 3.94 (d, J = 16.4 Hz, 1H), 4.37 (dd,
J = 9.5, 4.7 Hz, 1H); 13C NMR (125 MHz, CD3OD) d 23.7, 27.9, 32.4,
4.1.38. Compound 17a
Yield: 43%. MALDI-TOF-MS m/z 2481 (MꢁCF3COO+H).