column chromatography using DCM/MeOH (6/1, 0.1% TEA) to provide the pure products. White powders were
obtained by dissolving the purified compounds in ACN/H2O (3 mL, 1/1) and subsequent lyophilization.
(2S)-2-{[(2S)-1-[(4E,9S,12S,15S)-15-Amino-12-benzyl-11,14-dioxo-2,7-dioxa-10,13-diaza-bicyclo
[15.2.2]heicosa-1(19),4,17,20-tetraene-9-carbonyl]pyrrolidin-2-yl]formamido}-N-(carbamoyl
(1H-indol-3-yl)propanamide (19)
methyl)-3-
The alkenyl bridged compound 19 was obtained from the protected precursor 18 in 94% yield (20 mg). 1H-NMR
(600 MHz, CD3OD): δ = 7.65 (d, J = 8.0 Hz, 1H), 7.36 (d, J = 8.0 Hz, 1H), 7.24-7.19 (m, 5H), 7.14 (s, 1H), 7.13
(overlap, 1H), 7.11 (d, J = 8.4 Hz, 2H), 7.05 (t, J = 7.5 Hz, 1H), 6.86 (d, J = 8.4 Hz, 2H), 5.84 (br, 1H), 5.71 (br,
1H), 4.71 (bs, 2H), 4.63 (t, J = 7.5 Hz, 1H), 4.24 (m, 1H), 4.60 (t, J = 8.0 Hz, 1H), 4.02 (d, J = 11.0 Hz, 1H),
3.84 (d, J = 17.0 Hz, 1H), 3.73 (d, J = 17.0 Hz, 1H), 3.66 (t, J = 11.0 Hz, 1H), 3.57 (m, 1H), 3.35 (overlap, 2H),
3.31 (m, 1H), 3.14 (m, 1H), 3.06 (d, J = 7.5 Hz, 2H), 3.04 (m, 1H), 2.03 (m, 1H), 1.78 (m, 1H), 1.72 (m, 1H),
1.64 (m, 1H). 13C-NMR (150 MHz, CD3OD): δ = 174.2, 174.0, 173.9, 171.9, 171.1, 168.5, 159.3, 138.0, 137.7,
132.3, 130.4, 130.0, 129.1, 128.2, 126.5, 126.0, 123.2, 121.1, 118.5, 117.6, 111.0, 106.5, 70.2, 67.5, 66.9, 60.5,
54.7, 54.3, 53.2, 49.5, 47.6, 41.9, 37.3, 35.2, 28.6, 26.5, 24.6. HPLC-ESI-MS: m/z (%) = 708.4 (100) [M+H]+.
HR-ESI-MS (m/z): calcd. for C43H51N8O8 [M+H]+ 807.3824; found 807.3853.
(2S)-2-{[(2S)-1-[(9S,12S,15S)-15-Amino-12-benzyl-11,14-dioxo-2,7-dioxa-10,13-diaza-
bicyclo[15.2.2]henicosa-1(19),17,20-triene-9-carbonyl]-pyrrolidin-2-yl]formamido}-N-(carbamoylmethyl)-
3-(1H-indol-3-yl)propanamide (20)
Starting material tert-butyl-N-[(9S,12S,15S)-12-benzyl-9-[(2S)-2-{[(1S)-1-[(carbamoyl-methyl)-carbamoyl]-2-
(1H-indol-3-yl)ethyl]carbamoyl}pyrrolidine-1-carbonyl]-11,14-dioxo-2,7-dioxa-10,13-diazabicyclo[15.2.2]-
1
henicosa-1(19),17,20-trie-15-yl]carbamate (18 mg, 26.46 µmol) afforded product 20 (15 mg, 94%). H-NMR
(600 MHz, CD3OD): δ = 7.58 (d, J = 8.6 Hz, 1H), 7.36 (d, J = 8.6 Hz, 1H), 7.18-7.10 (m, 5H), 7.13 (overlap,
2H), 7.08 (overlap, 2H), 7.04 (t, J = 7.5 Hz, 1H), 6.84 (d, J = 7.5 Hz, 2H), 4.64 (t, J = 6.5 Hz, 1H), 4.55 (t, J =
7.5 Hz), 4.44 (t, J = 6.5 Hz, 1H), 4.29 (m, 1H), 4.15 (m, 1H), 4.11 (m, 2H), 3.87 (d, J = 17.0 Hz, 1H), 3.68 (d, J
= 17.0 Hz, 1H), 3.55 (m, 1H), 3.45 (m, 2H), 3.49 (m, 2H), 3.40 (m, 2H), 3.35 (m, 1H), 3.25 (m, 1H), 3.22 (m,
1H), 2.98 (m, 2H), 2.94 (m, 1H), 2.07 (m, 1H), 1.78 (m, 3H), 1.74 (m, 2H), 1.62 (m, 2H). 13C-NMR (150 MHz,
CD3OD): δ = 171.5, 170.3, 170.0, 169.2, 168.9, 155.8, 136.2, 130.1, 129.2, 127.7, 127.5, 126.5, 123.0, 121.3,
118.4, 117.9, 114.9, 110.0, 106.6, 70.5, 69.0, 66.7, 60.5, 54.7, 53.9, 53.5, 51.2, 47.4, 41.9, 38.0, 35.9, 28.7, 26.6,
25.2, 24.5, 24.5. HPLC-ESI-MS: m/z (%) = 809.4 (100) [M+H]+. HR-ESI-MS (m/z): calcd. for C43H52N8O8Na
[M+Na]+ 831.3800; found 831.3819.
(S)-Methyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole-3-carboxylate (22)
To a solution of L-Trp-OMe*HCl (800 mg, 3.14 mmol) in MeOH/H2O (10 mL, 10/1) was added dropwise 36%
formaldehyde (24 mg, 0.27 mmol) in MeOH (2 mL). After stirring at room temperature for 16 h, the reaction
mixture was concentrated under reduced pressure to dryness. The residue was dissolved in H2O (10 mL) and
neutralized with NaHCO3. The aqueous solution was extracted with EtOAc (3x50 mL), the combined organic
phases were washed with brine solution (2x20 mL) and dried over Na2SO4. Removal of the solvent and
subsequent flash chromatography (EtOAc/EtOH, 20/1) of the residue yielded tetrahydro-β-carboline 22 (400 mg,
55%) as a white solid. Rf = 0.12 (AcOEt/EtOH, 20/1). 1H-NMR (400 MHz, CDCl3): δ = 7.98 (s, 1H, NH), 7.5
(d, J = 7.5 Hz, 1H), 7.3 (d, J = 7.9 Hz, 1H), 7.18 (dt, J = 1.5 Hz, J = 7.1 Hz, 1H), 7.12 (dt, J = 0.9 Hz, J = 7.2
Hz, 1H), 4.1 (s, 2H), 3.83 (overlap, 1H), 3.82 (s, 3H), 3.14 (dd, J = 4.7 Hz, J = 15.2 Hz, 1H), 2.95 (dd, J = 9.6
Hz, J = 15.2 Hz, 1H). 13C-NMR (100 MHz, CDCl3): δ = 173.8, 135.9, 131.9, 127.2, 121.7, 114.5, 117.8, 110.7,
107.3, 55.9, 52.1, 42.1, 25.4. IR (KBr) ν (cm-1): 3176.8 (NH), 1733.5 (CO). HPLC-ESI-MS: m/z (%) = 231
(100) [M+H]+. HR-ESI-MS (m/z): calcd. for C13H15N2O2 [M+H]+ 231.1134; found 231.1137.
Methyl-(3S)-2-[(2S)-1-[(4E,9S,12S,15S)-12-benzyl-15-{[(tert-butoxy)carbonyl]amino}-11,14-dioxo-2,7-
dioxa-10,13-diazabicyclo[15.2.2]henicosa-1(19),4,17,20-tetraene-9-carbonyl]pyrrolidine-2-carbonyl]-
1,2,3,4,9-pentahydropyrido[3,4-b]indole-3-carboxylate (23)
To a solution of macrocycle 17 (40 mg, 60.17 µmol) and carboline 22 (18 mg, 78.23 µmol) in DMF (1.5 mL)
HATU (29.7 mg, 78.23 µmol) and DIPEA (50 µL, 241 µmol) were added. After stirring at room temperature for
18 h, the solvent was removed and the crude residue was purified by silica gel column chromatography using
EtOAc as eluent to afford product 23 (41 mg, 78%). Rf = 0.21 (EtOAc). 1H-NMR (400 MHz, CDCl3): δ = 7.37
(d, J = 8.2 Hz, 1H), 7.27 (d, J = 8.2 Hz, 1H), 7.22-7.13 (m, 5H), 7.11 (overlap, 1H), 7.05 (overlap, 1H), 6.98 (d,
J = 8.0 Hz, 2H), 6.68 (d, J = 8.0 Hz, 2H), 5.66 (m, 1H), 5.56 (m, 1H), 5.05 (d, J = 17.1 Hz, 1H), 5.02 (m, 1H),
4.81 (t, J = 7.0 Hz, 1H), 4.76 (overlap, 1H), 4.72 (d, J = 14.2 Hz, 1H), 4.60 (m, 2H), 4.42 (t, J = 6.5 Hz, 1H),
4.21 (bs, 1H), 4.05 (m, 1H), 3.84 (m, 1H), 3.74 (br, 1H), 3.60 (m, 1H), 3.54 (s, 3H), 3.38 (m, 1H), 3.32 (m, 1H),
3.30 (overlap, 1H), 2.93 (m, 2H), 2.90 (overlap, 1H), 2.80 (m, 1H), 2.73 (m, 1H), 2.27 (m, 1H), 2.11 (m, 1H),
1.97 (m, 2H), 1.44 (s, 9H). 13C-NMR (100 MHz, CDCl3): δ = 172.3, 171.5, 170.1, 169.6, 168.5, 156.3, 155.2,
136.5, 135.9, 130.7, 130.0, 129.5, 129.3, 128.5, 126.9, 121.8, 119.4, 118.0, 115.4, 111.1, 105.6, 70.5, 68.0, 66.8,
57.7, 55.5, 54.1, 52.3, 50.7, 50.2, 47.4, 42.2, 37.8, 37.6, 28.3, 27.9, 24.3, 22.1. IR (KBr) ν (cm-1): 3421.3,