Organic & Biomolecular Chemistry
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suspension was filtered and solvents were evaporated. The over 20 min at a flow rate of 1.0 mL min−1). 1H NMR (D2O,
residue was purified by FC (Chex–EtOAc 6 : 4 to 3 : 7 + 1% 400 MHz) δ: 5.29 (br d, J1,2 = 3.7 Hz, 2H, H-1E, H-1E′), 5.26 (d,
Et3N) to give decasaccharide 5 (412 mg, 73%) as a white foam. 1H, J1,2 = 1.6 Hz, H-1), 5.16 (dd, J2,3 = 2.9 Hz, 1H, H-3A), 5.15
[α]2D2 −18 (c 0.34, CHCl3); 1H NMR (Py-d5, 400 MHz) δ: 9.56 (m, (br s, 2H, H-1), 5.06 (d, J1,2 = 1.6 Hz, 1H, H-1), 4.97 (d, J1,2 = 1.3
2H, 2 × NH), 7.69–7.25 (m, 87H, CHPh), 7.00–6.96 (m, 2H, Hz, 1H, H-1), 4.91 (d, J1,2 = 1.4 Hz, 1H, H-1), 4.67 (d, J1,2 = 8.8
CHPh), 6.11 (br s, 1H, H-2A′), 5.77–5.38 (11H, H-1A, H-1A′, H-1B, Hz, 1H, H-1D*), 4.61 (d, J1,2 = 8.2 Hz, 1H, H-1D′*), 4.34–3.44 (m,
H-1B′, H-1C, H-1C′, H-1D′, H-1E, H-1E′, H-2C, H-2C′), 5.32–3.74 49H, H-2A, H-2A′, H-3A′, H-4A, H-4A′, H-5A, H-5A′, H-2B, H-2B′,
(m, 78H, H-2A, H-3A, H-3A′, H-4A, H-4A′, H-5A, H-5A′, H-2B, H-2B′, H-3B, H-3B′, H-4B, H-4B′, H-5B, H-5B′, H-2C, H-2C′, H-3C, H-3C′,
H-3B, H-3B′, H-4B, H-4B′, H-5B, H-5B′, H-3C, H-3C′, H-4C, H-4C′, H-4C, H-4C′, H-5C, H-5C′, H-2D, H-2D′, H-3D, H-3D′, H-4D, H-4D′,
H-5C, H-5C′, H-1D, H-2D, H-3D, H-3D′, H-6aD, H-6bD, H-6aD′, H-5D, H-5D′, H-6aD, H-6aD’, H-6bD, H-6bD′, H-2E, H-2E′, H-3E,
H-2E, H-2E′, H-3E, H-3E′, H-4E, H-4E′, H-5E, H-5E′, H-6aE, H-6bE, H-3E′, H-4E, H-4E′, H-5E, H-5E′, H-6aE, H-6aE′, H-6bE, H-6bE′,
H-6aE′, H-6bE′, OCH2a, OCH2b, CH2Ph), 3.74–3.43 (m, 10H, OCH2), 3.33–3.25 (m, 2H, CH2NH2), 2.30 (s, 3H, C(O)CH3Ac),
H-2D′, H-4D, H-4D′, H-5D, H-5D′, H-6bD′, OCH3, CH2N3a), 2.20, 2.15 (2s, 6H, C(O)CH3NHAc), 1.46–1.34 (m, 18H, H-6A,
3.41–3.33 (m, 1H, CH2N3b), 2.87–2.62 (m, 12H, CH2Lev), 2.44, H-6A′, H-6B, H-6B′, H-6C, H-6C′). 13C NMR (D2O, 100 MHz) δ
2.38 (2s, 6H, C(O)CH3Ac), 2.03, 2.01, 2.00 (3s, 9H, C(O)CH3Lev), (partial): 174.5, 174.2, 173.7 (3C, C(O)CH3), 102.6, 102.4,
1.68 (d, J5,6 = 6.0 Hz, 3H, CH3Rha), 1.55 (d, J5,6 = 5.8 Hz, 3H, 101.4, 101.3, 101.1, 100.8, 100.6 (8C, C-1A, C-1A′, C-1B, C-1B′,
CH3Rha), 1.50 (d, J5,6 = 6.1 Hz, 3H, CH3Rha), 1.46 (s, 3H, CH3Iso), C-1C, C-1C′, C-1E, C-1E′), 97.6 (2C, C-1D, C-1D′), 81.4, 81.0, 79.5,
1.44–1.36 (m, 9H, 3 × CH3Rha), 1.23 (s, 3H, CH3Iso). 13C NMR 76.9, 76.0, 75.6, 72.7, 72.1, 71.9, 71.4, 71.3, 70.8, 70.1, 69.8,
(Py-d5, 100 MHz) δ (partial): 206.1 (C(O)CH2Lev), 206.0 (2 × 69.8, 69.4, 69.3, 69.1, 68.4, 68.1, 65.7, 60.7, 60.6, 55.6, 55.1,
C(O)CH2Lev), 173.1 (COLev), 173.0 (COLev), 172.7 (COLev), 171.9 39.4 (CH2NH2), 22.4, 22.3 (2C, C(O)CH3NHAc), 20.7 (C(O)CH3Ac),
(C(O)CH3Ac), 171.8 (C(O)CH3Ac), 160.2 (CPh), 140.3–139.4 (CPh), 17.9, 16.9, 16.7, 16.6 (6C, C-6A, C-6A′, C-6B, C-6B′, C-6C, C-6C′).
131.1–128.1 (CHPh), 114.7 (CHPh), 102.6, 102.4, 102.2, 101.1, HR-ESI-TOF-MS m/z 1710.6890 [M
+
H]+ (calcd for
100.4, 100.4, 99.3, 98.5, 98.1, 98.0 (C-1A, C-1A′, C-1B, C-1B′, C-1C, C68H116N3O46, 1710.6830).
C-1C′, C-1D, C-1D′, C-1E, C-1E′) 99.9 (C(CH3)2), 82.7, 82.6, 82.3,
2-Aminoethyl α-L-rhamnopyranosyl-(1→2)-α-L-rhamnopyra-
81.8, 81.2, 80.9, 80.3, 79.9, 79.7, 79.4, 78.8, 78.6, 76.9, 76.3, nosyl-(1→3)-[α-D-glucopyranosyl-(1→4)]-α-L-rhamnopyranosyl-
76.2, 76.0, 76.0, 75.8, 75.6, 75.4, 75.0, 74.3, 74.1, 74.0, 73.9, (1→3)-(2-acetamido-6-O-acetyl-2-deoxy-β-D-glucopyranosyl)-
73.8, 73.6, 72.9, 72.7, 72.4, 72.0, 71.9, 71.0, 70.3, 69.9, 69.8, (1→2)-(3-O-acetyl-α-L-rhamnopyranosyl)-(1→2)-α-L-rhamnopyr-
69.7, 69.6, 69.3, 68.6, 68.5, 68.2, 67.9 (C-2A, C-2A′, C-3A, C-3A′, anosyl-(1→3)-[α-D-glucopyranosyl-(1→4)]-α-L-rhamnopyranosyl-
C-4A, C-4A′, C-5A, C-5A′, C-2B, C-2B′, C-3B, C-3B′, C-4B, C-4B′, C-5B, (1→3)-2-acetamido-2-deoxy-β-D-glucopyranoside (2). A solution
C-5B′, C-2C, C-2C′, C-3C, C-3C′, C-4C, C-4C′, C-5C, C-5C′, C-3D, of decasaccharide 39 (24.3 mg, 7.3 µmol) in DCE–MeOH
C-3D′, C-4D, C-4D′, C-5D, C-5D′, C-6D, C-2E, C-2E′, C-3E, C-3E′, (13 mL, 1 : 12 v/v) containing conc. HCl (1.2 µL, 2 equiv.) was
C-4E, C-4E′, C-5E, C-5E′, C-6E, C-6E′, 18 × CH2Ph), 63.0 (C-6D′), passed through a 20% Pd(OH)2/C cartridge (CatCart®30) using
59.6 (C-2D′), 58.3 (C-2D), 55.5 (OCH3), 51.6 (CH2N3), 38.6, 38.5, a H-Cube™ continuous flow hydrogenation system in the
38.5 (3C, CH2Lev), 29.9 (3C, C(O)CH3Lev), 29.2, 29.1, 29.0 (3C, “Full-H2” mode (30 °C, 1.0 mL min−1). After 5 runs, the car-
CH2Lev), 24.4, 24.2 (2C, C(O)CH3Ac), 19.8, 19.8, 19.5, 19.5, 19.1 tridge was rinsed with MeOH and H2O. Following concen-
(2C), 19.0, 18.9 (8C, 6 CH3Rha, 2 CH3Iso). HR-ESI-TOF-MS m/z tration under reduced pressure, the solution was freeze-dried.
1840.38 [M + 2H]2+ (calcd for C211H245N5O52, 1840.33).
2-Aminoethyl α-L-rhamnopyranosyl-(1→2)-α-L-rhamnopyra-
The residue (13 mg) was purified by RP-HPLC (Kromasil 5 µm
C18 100 Å 10 × 100 mm semi-preparative column, 0–20% linear
nosyl-(1→3)-[α-D-glucopyranosyl-(1→4)]-α-L-rhamnopyranosyl- gradient of CH3CN in 0.04% aq. TFA–0.05% aq. formic acid
(1→3)-(2-acetamido-2-deoxy-β-D-glucopyranosyl)-(1→2)-(3-O- over 20 min at a flow rate of 5.5 mL min−1) to give decasacchar-
acetyl-α-L-rhamnopyranosyl)-(1→2)-α-L-rhamnopyranosyl- ide 2 (5.9 mg, 48%) as a white amorphous powder. HPLC
(1→3)-[α-D-glucopyranosyl-(1→4)]-α-L-rhamnopyranosyl-(1→3)- (210 nm): Rt = 8.15 min (Kromasil 5 µm C18 100 Å 4.6 ×
2-acetamido-2-deoxy-β-D-glucopyranoside (1). A solution of 250 mm analytical column; 0–50% linear gradient of CH3CN
decasaccharide 38 (20 mg, 6.1 µmol) in EtOH–AcOH (3.3 mL, in 0.01 N aq. TFA over 20 min at a flow rate of 1.0 mL min−1).
10 : 1 v/v) was passed through
a
10% Pd/C cartridge 1H NMR (D2O, 400 MHz) δ: 5.30–5.27 (m, 2H, H-1E, H-1E′), 5.19
(CatCart®30) using a H-Cube™ continuous flow hydrogen- (br s, 1H, H-1), 5.17 (d, J = 2.8 Hz, H-3A), 5.14 (br s, 2H, H-1),
ation system in the “Full-H2” mode (60 °C, 0.5 mL min−1). 5.06 (br s, 1H, H-1), 4.97 (br s, 1H, H-1), 4.91 (br s, 1H, H-1),
After 8 h, the cartridge was rinsed with EtOH–H2O (30 mL, 4.67 (d, J1,2 = 8.5 Hz, 1H, H-1D*), 4.63 (d, J1,2 = 8.5 Hz, 1H,
1 : 1 v/v) and solvents were evaporated to dryness. The residue H-1D′*), 4.49 (d, J6a,6b = 11.9 Hz, H-6aD’), 4.39 (dd, J5,6b = 4.3
(14 mg) was purified by RP-HPLC (Kromasil 5 µm C18 100 Å Hz, 1H, H-6bD′), 4.34–3.46 (m, 47H, H-2A, H-2A′, H-3A′, H-4A,
10 × 100 mm semi-preparative column, 0–20% linear gradient of H-4A′, H-5A, H-5A′, H-2B, H-2B′, H-3B, H-3B′, H-4B, H-4B′, H-5B,
CH3CN in 0.04% aq. TFA–0.05% aq. formic acid over 20 min at H-5B′, H-2C, H-2C′, H-3C, H-3C′, H-4C, H-4C′, H-5C, H-5C′, H-2D,
a flow rate of 5.5 mL min−1) to give decasaccharide 1 (5.2 mg, H-2D′, H-3D, H-3D′, H-4D, H-4D′, H-5D, H-5D′, H-6aD, H-6bD,
50%) as a white amorphous powder. HPLC (210 nm): Rt = H-2E, H-2E′, H-3E, H-3E′, H-4E, H-4E′, H-5E, H-5E′, H-6aE, H-6aE′,
7.4 min (Kromasil 5 µm C18 100 Å 4.6 × 250 mm analytical H-6bE, H-6bE′, OCH2), 3.34–3.26 (m, 2H, CH2NH2), 2.30, 2.24
column; 0–50% linear gradient of CH3CN in 0.01 N aq. TFA (2s, 6H, C(O)CH3Ac), 2.20, 2.15 (2s, 6H, C(O)CH3NHAc),
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Org. Biomol. Chem., 2014, 12, 4218–4232 | 4229