Materials
Chemicals and solvents were purchased from commercial sources. Further purification by standard methods were employed when necessary. 1H NMR and 13C NMR spectra were recorded on a Bruker ARX-400 NMR spectrometer in the indicated solvents (TMS as internal standard): the values of the chemical shifts were expressed in δ values (ppm) and the coupling constants (J) in Hz. HRESIMS data were obtained using Bruker micro-TOFQ-Q mass spectrometer.
General procedures to synthesize 6a-k and 7a-k
The intermediates 4 and 5 were synthesised according to our previous report [29]. A mixture of 4 and HOBt (0.19 mmol), or 5 (0.16 mmol) and HOBt (0.19 mmol) in anhydrous DMF (5 mL) was stirred at room temperature for 0.5 h. After the addition of various types of substituted anilines (0.19 mmol) and EDCI (0.32 mmol) to the solution, the mixture was further stirred at room temperature for another 24 h. Then, the mixture was poured into 30 mL of H2O, and extracted with EtOAc (3 × 20 mL). The organic layer was combined, washed with brine, dried over anhydrous Na2SO4, and concentrated in vacuo. The crude product was purified on silica gel column chromatography eluting with dichloromethane/methanol system (20:1, v/v).
6-((6-(benzyloxy)-2-(4-(benzyloxy)phenyl)-5-hydroxy-4-oxo-4H-chromen-7-yl)oxy)-3,4,5-trihydroxy-N-phenyltetrahydro-2H-pyran-2-carboxamide (6a)
Yellow power, yield: 91%. 1H NMR (DMSO-d6, 400 MHz) δ (ppm): 12.95 (s, 1H, 5-OH), 10.21 (s, 1H, -NH-), 8.09 (d, 2H, J = 9.0 Hz, H-2′, 6′), 7.67 (d, 2H, J = 7.6 Hz, Ar-H), 7.57 (d, 2H, J = 6.9 Hz, Ar-H), 7.50 (d, 2H, J = 6.9 Hz, Ar-H), 7.42 (t, 2H, J = 7.4 Hz, Ar-H), 7.34 (m, 5H, Ar-H), 7.27 (d, 2H, J = 7.6 Hz, Ar-H), 7.23 (d, 2H, J = 9.0 Hz, H-3′, 5′), 7.14 (s, 1H, H-8), 6.95 (s, 1H, H-3), 5.66 (d, 1H, J = 6.0 Hz, H-1′′), 5.50 (d, 1H, J = 5.7 Hz, sugar hydroxyl), 5.40 (d, 1H, J = 5.5 Hz, sugar hydroxyl), 5.28 (s, 1H, sugar hydroxyl), 5.26 (s, 2H, -CH2-), 5.09 (d, 1H, J = 10.8 Hz, -CH2-), 4.98 (d, 1H, J = 10.8 Hz, -CH2-), 4.10 (d, 1H, J = 9.5 Hz, H-5′′), 3.5−3.40 (m, 3H, H-2′′, 3′′, 4′′); 13C NMR (DMSO-d6, 100 MHz) δ (ppm): 182.84, 166.52, 164.24, 162.05, 156.62, 153.27, 152.68, 139.24, 137.99, 136.96, 131.79, 129.19, 129.19, 128.99, 128.99, 128.88, 128.88, 128.58, 128.58, 128.51, 128.33, 128.33, 128.28, 128.28, 124.05, 123.38, 119.64, 119.64, 115.87, 115.87, 106.45, 103.88, 100.72, 94.72, 77.47, 76.88, 74.66, 73.42, 70.79, 70.06; HR-ESI-MS m/z calcd for C41H35NO11 [M + Na]+ 740.2210, found 740.2104.
6-((6-(benzyloxy)-2-(4-(benzyloxy)phenyl)-5-hydroxy-4-oxo-4H-chromen-7-yl)oxy)-N-(3-chlorophenyl)-3,4,5-trihydroxytetrahydro-2H-pyran-2-carboxamide (6b)
Yellow power, yield: 18%. 1H NMR (DMSO-d6, 600 MHz) δ (ppm): 12.95 (s, 1H, 5-OH), 10.35 (s, 1H, -NH-), 8.08 (d, 2H, J = 8.8 Hz, H-2′, 6′), 7.86 (t, 1H, J = 1.8 Hz, Ar-H), 7.57 (d, 2H, J = 7.6 Hz, Ar-H), 7.49 (d, 2H, J = 7.3 Hz, Ar-H), 7.42 (t, 2H, J = 7.3 Hz, Ar-H), 7.37 (m, 4H, Ar-H), 7.32 (m, 1H, Ar-H), 7.29 (d, 1H, J = 8.2 Hz, Ar-H), 7.23 (d, 2H, J = 8.8 Hz, H-3′, 5′), 7.12 (s, 1H, H-8), 7.10 (d, 1H, J = 6.5 Hz, Ar-H), 6.94 (s, 1H, H-3), 5.65 (d, 1H, J = 5.8 Hz, H-1′′), 5.51 (d, 1H, J = 5.6 Hz, sugar hydroxyl), 5.39 (d, 1H, J = 5.3 Hz, sugar hydroxyl), 5.31 (d, 1H, J = 7.6 Hz, sugar hydroxyl), 5.25 (s, 2H, -CH2-), 5.10 (d, 1H, J = 10.8 Hz, -CH2-), 4.99 (d, 1H, J = 11.1 Hz, -CH2-), 4.10 (d, 1H, J = 9.8 Hz, H-5′′), 3.69−3.43 (m, 3H, H-2′′, 3′′, 4′′); 13C NMR (DMSO-d6, 100 MHz) δ (ppm): 182.84, 167.05, 164.27, 162.04, 156.62, 153.29, 152.69, 140.61, 137.99, 136.94, 133.49, 131.81, 130.91, 128.99, 128.99, 128.88, 128.88, 128.58, 128.58, 128.52, 128.33, 128.28, 128.28, 123.81, 123.40, 119.26, 119.26, 118.18, 115.89, 115.89, 106.46, 103.91, 100.67, 94.69, 77.53, 76.73, 74.66, 73.40, 70.90, 70.06; HR-ESI-MS m/z calcd for C41H34ClNO11 [M + Na]+ 774.1820, found 774.1722.
6-((6-(benzyloxy)-2-(4-(benzyloxy)phenyl)-5-hydroxy-4-oxo-4H-chromen-7-yl)oxy)-N-(4-chlorophenyl)-3,4,5-trihydroxytetrahydro-2H-pyran-2-carboxamide (6c)
Yellow power, yield: 13%. 1H NMR (DMSO-d6, 600 MHz) δ (ppm): 13.00 (s, 1H, 5-OH), 8.11 (d, 2H, J = 8.9 Hz, H-2′, 6′), 7.51 (m, 5H, Ar-H), 7.37 (m, 9H, Ar-H), 7.20 (d, 2H, J = 8.9 Hz, H-3′, 5′), 7.03 (s, 1H, H-8), 6.99 (s, 1H, H-3), 6.47 (d, 1H, J = 4.7 Hz, H-1′′), 5.97 (d, 1H, J = 7.1 Hz, sugar hydroxyl), 5.87 (s, 1H, sugar hydroxyl), 5.24 (s, 2H, -CH2-), 4.94 (s, 2H, -CH2-), 4.83 (t, 1H, J = 4.5 Hz, H-5′′), 4.49−4.19 (m, 3H, H-2′′, 3′′, 4′′); 13C NMR (DMSO-d6, 100 MHz) δ (ppm): 182.89, 172.16, 164.40, 162.04, 155.54, 153.37, 152.53, 137.91, 136.96, 132.00, 128.98, 128.98, 128.98, 128.98, 128.82, 128.82, 128.82, 128.82, 128.63, 128.63, 128.63, 128.63, 128.50, 128.50, 128.41, 128.29, 128.29, 123.34, 115.90, 115.90, 106.59, 103.89, 101.00, 95.19, 74.81, 74.74, 71.05, 70.04, 69.88, 67.49; HR-ESI-MS m/z calcd for C41H34ClNO11 [M + Na]+ 774.1820, found 774.1719.
6-((6-(benzyloxy)-2-(4-(benzyloxy)phenyl)-5-hydroxy-4-oxo-4H-chromen-7-yl)oxy)-3,4,5-trihydroxy-N-(o-tolyl)tetrahydro-2H-pyran-2-carboxamide (6d)
Yellow power, yield: 69%. 1H NMR (DMSO-d6, 400 MHz) δ (ppm): 12.97 (s, 1H, 5-OH), 9.41 (s, 1H, -NH-), 8.08 (d, 2H, J = 8.9 Hz, H-2′, 6′), 7.57 (d, 2H, J = 7.0 Hz, Ar-H), 7.49 (d, 2H, J = 6.9 Hz, Ar-H), 7.41 (t, 3H, J = 7.2 Hz, Ar-H), 7.36 (m, 3H, Ar-H), 7.21 (s, 1H, Ar-H), 7.19 (s, 2H, H-3′, 5′), 7.14 (m, 3H, Ar-H), 7.05 (d, 1H, J = 8.2 Hz, Ar-H), 6.98 (s, 1H, H-3), 5.65 (s, 1H, H-1′′), 5.54 (s, 1H, sugar hydroxyl), 5.41 (d, 1H, J = 6.2 Hz, sugar hydroxyl), 5.28 (d, 1H, J = 7.5 Hz, sugar hydroxyl), 5.24 (s, 2H, -CH2-), 5.10 (d, 1H, J = 10.9 Hz, -CH2-), 5.00 (d, 1H, J = 10.8 Hz, -CH2-), 4.26 (d, 1H, J = 9.8 Hz, H-5′′), 3.68−3.41 (m, 3H, H-2′′, 3′′, 4′′), 2.17 (s, 3H, -CH3); 13C NMR (DMSO-d6, 100 MHz) δ (ppm): 182.87, 167.99, 164.30, 162.03, 156.74, 153.22, 152.75, 137.99, 136.92, 131.81, 128.96, 128.96, 128.96, 128.96, 128.87, 128.87, 128.87, 128.87, 128.57, 128.57, 128.51, 128.51, 128.28, 128.28, 128.28, 128.28, 123.42, 115.85, 115.85, 106.33, 103.81, 100.38, 94.63, 76.92, 76.31, 74.64, 73.39, 71.06, 70.05, 22.37; HR-ESI-MS m/z calcd for C42H37NO11 [M + Na]+ 754.2367, found 774.2275.
6-((6-(benzyloxy)-2-(4-(benzyloxy)phenyl)-5-hydroxy-4-oxo-4H-chromen-7-yl)oxy)-3,4,5-trihydroxy-N-(m-tolyl)tetrahydro-2H-pyran-2-carboxamide (6e)
Yellow power, yield: 49%. 1H NMR (DMSO-d6, 400 MHz) δ (ppm): 12.95 (s, 1H, 5-OH), 10.11 (s, 1H, -NH-), 8.11 (d, 2H, J = 9.0 Hz, H-2′, 6′), 7.57 (d, 2H, J = 6.7 Hz, Ar-H), 7.49 (d, 2H, J = 7.4 Hz, Ar-H), 7.42 (m, 4H, Ar-H), 7.35 (m, 5H, Ar-H), 7.23 (d, 2H, J = 9.0 Hz, H-3′, 5′), 7.14 (t, 2H, J = 6.5 Hz, H-8, Ar-H), 6.95 (s, 1H, H-3), 6.85 (d, 1H, J = 7.6 Hz, Ar-H), 5.65 (d, 1H, J = 5.9 Hz, H-1′′), 5.47 (d, 1H, J = 5.6 Hz, sugar hydroxyl), 5.39 (d, 1H, J = 5.3 Hz, sugar hydroxyl), 5.27 (d, 1H, J = 7.9 Hz, sugar hydroxyl), 5.25 (s, 2H, -CH2-), 5.09 (d, 1H, J = 10.9 Hz, -CH2-), 4.99 (d, 1H, J = 10.9 Hz, -CH2-), 4.10 (d, 1H, J = 9.8 Hz, H-5′′), 3.71−3.40 (m, 3H, H-2′′, 3′′, 4′′), 2.20 (s, 3H, -CH3); 13C NMR (DMSO-d6, 100 MHz) δ (ppm): 182.85, 166.45, 164.24, 162.04, 156.61, 153.26, 152.69, 139.14, 138.37, 138.00, 136.96, 131.80, 128.99, 128.99, 128.88, 128.88, 128.58, 128.58, 128.51, 128.33, 128.27, 128.27, 124.74, 123.41, 120.18, 116.89, 116.89, 115.87, 115.87, 106.44, 103.87, 100.68, 94.72, 77.44, 76.89, 74.67, 73.41, 70.76, 70.07, 21.58; HR-ESI-MS m/z calcd for C42H37NO11 [M + Na]+ 754.2367, found 774.2278.
6-((6-(benzyloxy)-2-(4-(benzyloxy)phenyl)-5-hydroxy-4-oxo-4H-chromen-7-yl)oxy)-3,4,5-trihydroxy-N-(p-tolyl)tetrahydro-2H-pyran-2-carboxamide (6f)
Yellow power, yield: 68%. 1H NMR (DMSO-d6, 400 MHz) δ (ppm): 12.94 (s, 1H, 5-OH), 10.09 (s, 1H, -NH-), 8.09 (d, 2H, J = 9.0 Hz, H-2′, 6′), 7.57 (d, 2H, J = 7.3 Hz, Ar-H), 7.55 (d, 2H, J = 8.5 Hz, Ar-H), 7.50 (d, 2H, J = 7.2 Hz, Ar-H), 7.42 (t, 2H, J = 7.6 Hz, Ar-H), 7.36 (m, 3H, Ar-H), 7.32 (d, 1H, J = 7.2 Hz, Ar-H), 7.23 (d, 2H, J = 9.0 Hz, H-3′, 5′), 7.12 (s, 1H, H-8), 7.07 (d, 2H, J = 8.4 Hz, Ar-H), 6.94 (s, 1H, H-3), 5.62 (s, 1H, H-1′′), 5.45 (s, 1H, sugar hydroxyl), 5.34 (s, 1H, sugar hydroxyl), 5.24 (s, 1H, sugar hydroxyl), 5.26 (s, 2H, -CH2-), 5.09 (d, 1H, J = 10.9 Hz, -CH2-), 4.99 (d, 1H, J = 10.9 Hz, -CH2-), 4.08 (d, 1H, J = 9.7 Hz, H-5′′), 3.69−3.41 (m, 3H, H-2′′, 3′′, 4′′), 2.22 (s, 3H, -CH3); 13C NMR (DMSO-d6, 100 MHz) δ (ppm): 182.84, 166.29, 164.24, 162.05, 156.63, 153.27, 152.68, 138.00, 136.96, 136.76, 132.95, 131.80, 129.55, 129.55, 128.99, 128.99, 128.88, 128.88, 128.58, 128.58, 128.52, 128.33, 128.33, 128.30, 128.30, 123.40, 119.63, 119.63, 115.87, 115.87, 106.44, 103.88, 100.70, 94.70, 77.46, 76.88, 74.66, 73.42, 70.80, 70.08, 20.90; HR-ESI-MS m/z calcd for C42H37NO11 [M + Na]+ 754.2367, found 774.2272.
6-((6-(benzyloxy)-2-(4-(benzyloxy)phenyl)-5-hydroxy-4-oxo-4H-chromen-7-yl)oxy)-3,4,5-trihydroxy-N-(2-hydroxyphenyl)tetrahydro-2H-pyran-2-carboxamide (6g)
Yellow power, yield: 20%. 1H NMR (DMSO-d6, 600 MHz) δ (ppm): 12.97 (s, 1H, 5-OH), 9.96 (s, 1H, -NH-), 9.19 (s, 1H, Ar-OH), 8.05 (d, 2H, J = 9.1 Hz, H-2′, 6′), 7.57 (d, 2H, J = 7.3 Hz, Ar-H), 7.48 (d, 2H, J = 7.3 Hz, Ar-H), 7.41 (t, 2H, J = 7.3 Hz, Ar-H), 7.35 (m, 5H, Ar-H), 7.22 (s, 2H, H-3′, 5′), 7.20 (s, 1H, H-8), 6.94 (s, 1H, H-3), 6.90 (m, 1H, Ar-H), 6.85 (m, 1H, Ar-H), 6.75 (t, 1H, J = 8.3 Hz, Ar-H), 5.64 (d, 1H, J = 5.8 Hz, H-1′′), 5.49 (d, 1H, J = 5.2 Hz, sugar hydroxyl), 5.36 (d, 1H, J = 5.5 Hz, sugar hydroxyl), 5.33 (d, 1H, J = 7.7 Hz, sugar hydroxyl), 5.23 (s, 2H, -CH2-), 5.10 (d, 1H, J = 10.8 Hz, -CH2-), 4.99 (d, 1H, J = 10.9 Hz, -CH2-), 4.38 (d, 1H, J = 9.7 Hz, H-5′′), 3.58−3.40 (m, 3H, H-2′′, 3′′, 4′′); 13C NMR (DMSO-d6, 100 MHz) δ (ppm): 182.86, 166.80, 164.33, 162.01, 156.65, 153.25, 152.76, 147.05, 138.04, 136.92, 131.80, 128.98, 128.98, 128.89, 128.89, 128.59, 128.59, 128.53, 128.53, 128.34, 128.34, 126.58, 124.66, 123.41, 120.67, 119.49, 115.87, 115.87, 115.38, 106.43, 103.92, 100.08, 94.64, 76.92, 76.03, 74.73, 73.39, 71.45, 70.07; HR-ESI-MS m/z calcd for C41H35NO12 [M + Na]+ 756.2159, found 756.2080.
(6-((6-(benzyloxy)-2-(4-(benzyloxy)phenyl)-5-hydroxy-4-oxo-4H-chromen-7-yl)oxy)-3,4,5-trihydroxy-N-(4-hydroxyphenyl)tetrahydro-2H-pyran-2-carboxamide (6h)
Yellow power, yield: 22%. 1H NMR (DMSO-d6, 600 MHz) δ (ppm): 12.94 (s, 1H, 5-OH), 9.94 (s, 1H, -NH-), 9.18 (s, 1H, Ar-OH), 8.09 (d, 2H, J = 8.8 Hz, H-2′, 6′), 7.57 (d, 2H, J = 7.2 Hz, Ar-H), 7.50 (d, 2H, J = 7.3 Hz, Ar-H), 7.45 (d, 2H, J = 8.9 Hz, Ar-H), 7.42 (t, 2H, J = 7.8 Hz, Ar-H), 7.37 (m, 3H, Ar-H), 7.31 (d, 1H, J = 7.3 Hz, Ar-H), 7.23 (d, 2H, J = 8.8 Hz, H-3′, 5′), 7.12 (s, 1H, H-8), 6.95 (s, 1H, H-3), 6.66 (d, 2H, J = 8.9 Hz, Ar-H), 5.61 (d, 1H, J = 6.0 Hz, H-1′′), 5.42 (d, 1H, J = 5.5 Hz, sugar hydroxyl), 5.34 (d, 1H, J = 5.4 Hz, sugar hydroxyl), 5.24 (s, 1H, sugar hydroxyl), 5.26 (s, 2H, -CH2-), 5.10 (d, 1H, J = 11.0 Hz, -CH2-), 4.99 (d, 1H, J = 10.8 Hz, -CH2-), 4.05 (d, 1H, J = 9.6 Hz, H-5′′), 3.67−3.41 (m, 3H, H-2′′, 3′′, 4′′); 13C NMR (DMSO-d6, 100 MHz) δ (ppm): 182.85, 165.79, 164.24, 162.06, 156.64, 153.94, 153.26, 152.68, 137.99, 136.94, 131.80, 130.98, 128.99, 128.99, 128.88, 128.88, 128.58, 128.58, 128.54, 128.54, 128.34, 128.34, 123.39, 121.26, 121.26, 115.86, 115.86, 115.51, 115.51, 106.44, 103.88, 100.72, 94.73, 77.43, 76.94, 74.66, 73.42, 70.81, 70.11; HR-ESI-MS m/z calcd for C41H35NO12 [M + Na]+ 756.2159, found 756.2056.
6-((6-(benzyloxy)-2-(4-(benzyloxy)phenyl)-5-hydroxy-4-oxo-4H-chromen-7-yl)oxy)-3,4,5-trihydroxy-N-(2-methoxyphenyl)tetrahydro-2H-pyran-2-carboxamide (6i)
Yellow power, yield: 23%. 1H NMR (DMSO-d6, 400 MHz) δ (ppm): 12.99 (s, 1H, 5-OH), 9.19 (s, 1H, -NH-), 8.14 (d, 1H, J = 7.0 Hz, Ar-H), 8.04 (d, 2H, J = 9.0 Hz, H-2′, 6′), 7.58 (d, 2H, J = 7.0 Hz, Ar-H), 7.48 (d, 2H, J = 7.0 Hz, Ar-H), 7.36 (m, 8H, Ar-H), 7.22 (s, 1H, H-8), 7.18 (d, 2H, J = 9.2 Hz, H-3′, 5′), 6.96 (s, 1H, H-3), 6.90 (t, 1H, J = 7.0 Hz, Ar-H), 5.68 (d, 1H, J = 5.6 Hz, H-1′′), 5.57 (d, 1H, J = 4.8 Hz, sugar hydroxyl), 5.40 (s, 1H, sugar hydroxyl), 5.34 (d, 1H, J = 7.5 Hz, sugar hydroxyl), 5.25 (s, 2H, -CH2-), 5.11 (d, 1H, J = 10.9 Hz, -CH2-), 5.00 (d, 1H, J = 10.9 Hz, -CH2-), 4.39 (d, 1H, J = 9.8 Hz, H-5′′), 3.70 (s, 3H, -OCH3), 3.61−3.43 (m, 3H, H-2′′, 3′′, 4′′); 13C NMR (DMSO-d6, 100 MHz) δ (ppm): 180.68, 171.94, 164.34, 161.98, 159.84, 158.66, 153.70, 149.01, 144.73, 137.99, 136.91, 128.99, 128.99, 128.88, 128.88, 128.59, 128.59, 128.30, 124.70, 122.89, 120.91, 120.91, 120.53, 115.87, 115.87, 111.56, 111.56, 106.45, 103.87, 100.15, 93.29, 76.91, 75.56, 74.73, 73.43, 71.37, 70.11, 56.24; HR-ESI-MS m/z calcd for C42H37NO12 [M + Na]+ 770.2316, found 770.2237.
6-((6-(benzyloxy)-2-(4-(benzyloxy)phenyl)-5-hydroxy-4-oxo-4H-chromen-7-yl)oxy)-3,4,5-trihydroxy-N-(3-methoxyphenyl)tetrahydro-2H-pyran-2-carboxamide (6j)
Yellow power, yield: 25%. 1H NMR (DMSO-d6, 400 MHz) δ (ppm): 12.95 (s, 1H, 5-OH), 10.18 (s, 1H, -NH-), 8.08 (d, 2H, J = 9.0 Hz, H-2′, 6′), 7.57 (d, 2H, J = 7.0 Hz, Ar-H), 7.50 (d, 2H, J = 7.0 Hz, Ar-H), 7.37 (m, 8H, Ar-H), 7.22 (d, 2H, J = 9.2 Hz, H-3′, 5′), 7.17 (d, 1H, J = 8.10 Hz, Ar-H), 7.13 (s, 1H, H-8), 6.95 (s, 1H, H-3), 6.62 (m, 1H, Ar-H), 5.65 (s, 1H, H-1′′), 5.50 (s, 1H, sugar hydroxyl), 5.38 (s, 1H, sugar hydroxyl), 5.28 (d, 1H, J = 7.9 Hz, sugar hydroxyl), 5.24 (s, 2H, -CH2-), 5.10 (d, 1H, J = 10.9 Hz, -CH2-), 4.99 (d, 1H, J = 10.9 Hz, -CH2-), 4.09 (d, 1H, J = 9.8 Hz, H-5′′), 3.68 (s, 3H, -OCH3), 3.55−3.41 (m, 3H, H-2′′, 3′′, 4′′); 13C NMR (DMSO-d6, 100 MHz) δ (ppm): 182.83, 166.59, 164.26, 162.04, 159.94, 156.63, 153.28, 152.69, 140.40, 138.00, 136.95, 131.82, 129.99, 128.99, 128.99, 128.88, 128.88, 128.57, 128.57, 128.51, 128.51, 128.28, 128.28, 123.40, 115.86, 115.86, 111.99, 109.52, 106.46, 105.53, 103.90, 100.74, 94.71, 77.54, 76.86, 74.67, 73.43, 70.78, 70.07, 55.43; HR-ESI-MS m/z calcd for C42H37NO12 [M + Na]+ 770.2316, found 770.2228.
6-((6-(benzyloxy)-2-(4-(benzyloxy)phenyl)-5-hydroxy-4-oxo-4H-chromen-7-yl)oxy)-3,4,5-trihydroxy-N-(4-methoxyphenyl)tetrahydro-2H-pyran-2-carboxamide (6k)
Yellow power, yield: 27%. 1H NMR (DMSO-d6, 400 MHz) δ (ppm): 12.96 (s, 1H, 5-OH), 10.05 (s, 1H, -NH-), 8.09 (d, 2H, J = 9.0 Hz, H-2′, 6′), 7.57 (d, 2H, J = 9.3 Hz, Ar-H), 7.49 (d, 2H, J = 7.1 Hz, Ar-H), 7.43 (d, 2H, J = 7.1 Hz, Ar-H), 7.36 (m, 4H, Ar-H), 7.32 (d, 2H, J = 7.1 Hz, Ar-H), 7.23 (d, 2H, J = 9.2 Hz, H-3′, 5′), 7.12 (s, 1H, H-8), 6.95 (s, 1H, H-3), 6.85 (d, 2H, J = 9.3 Hz, Ar-H), 5.65 (brs, 1H, H-1′′), 5.47 (brs, 1H, sugar hydroxyl), 5.40 (brs, 1H, sugar hydroxyl), 5.28 (d, 1H, J = 7.5 Hz, sugar hydroxyl), 5.25 (s, 2H, -CH2-), 5.10 (d, 1H, -CH2-), 4.99 (d, 1H, -CH2-), 4.07 (d, 1H, J = 9.8 Hz, H-5′′), 3.69 (s, 3H, -OCH3), 3.54−3.40 (m, 3H, H-2′′, 3′′, 4′′); 13C NMR (DMSO-d6, 100 MHz) δ (ppm): 182.84, 166.08, 164.27, 162.05, 156.64, 155.81, 153.28, 152.68, 137.99, 136.94, 132.41, 131.82, 128.99, 128.88, 128.88, 128.58, 128.58, 128.52, 128.52, 128.32, 128.32, 123.40, 121.15, 121.15, 115.87, 115.87, 114.27, 114.27, 113.97, 106.44, 103.90, 100.69, 94.70, 77.48, 76.87, 74.66, 73.43, 70.88, 70.09, 55.59; HR-ESI-MS m/z calcd for C42H37NO12 [M + Na]+ 770.2316, found 770.2224.
3,4,5-trihydroxy-6-((5-hydroxy-6-methoxy-2-(4-methoxyphenyl)-4-oxo-4H-chromen-7-yl)oxy)-N-phenyltetrahydro-2H-pyran-2-carboxamide (7a)
Yellow power, yield: 62%. 1H NMR (DMSO-d6, 400 MHz) δ (ppm): 12.92 (s, 1H, 5-OH), 10.22 (s, 1H, -NH-), 8.09 (d, 2H, J = 8.9 Hz, H-2′, 6′), 7.67 (d, 2H, J = 7.8 Hz, Ar-H), 7.29 (d, 2H, J = 7.8 Hz, Ar-H), 7.15 (d, 2H, J = 9.0 Hz, H-3′, 5′), 7.11 (s, 1H, H-8), 7.06 (m, 1H, Ar-H), 6.96 (s, 1H, H-3), 5.61 (d, 1H, J = 5.7 Hz, H-1′′), 5.49 (d, 1H, J = 5.6 Hz, sugar hydroxyl), 5.36 (d, 1H, J = 5.2 Hz, sugar hydroxyl), 5.21 (d, 1H, J = 7.6 Hz, sugar hydroxyl), 4.08 (d, 1H, J = 9.6 Hz, H-5′′), 3.89 (s, 3H, -OCH3), 3.77 (s, 3H, -OCH3), 3.50−3.39 (m, 3H, H-2′′, 3′′, 4′′); 13C NMR (DMSO-d6, 100 MHz) δ (ppm): 182.86, 166.52, 164.30, 162.99, 156.49, 153.06, 152.60, 139.24, 133.04, 129.20, 129.20, 128.89, 128.89, 124.06, 123.17, 119.73, 119.73, 119.65, 115.05, 106.49, 100.80, 94.82, 77.45, 76.79, 73.29, 70.79, 60.83, 56.12; HR-ESI-MS m/z calcd for C29H27NO11 [M + Na]+ 588.1584, found 588.1502.
N-(3-chlorophenyl)-3,4,5-trihydroxy-6-((5-hydroxy-6-methoxy-2-(4-methoxyphenyl)-4-oxo-4H-chromen-7-yl)oxy)tetrahydro-2H-pyran-2-carboxamide (7b)
Yellow power, yield: 29%. 1H NMR (DMSO-d6, 400 MHz) δ (ppm): 12.92 (s, 1H, 5-OH), 10.39 (s, 1H, -NH-), 8.08 (d, 2H, J = 8.7 Hz, H-2′, 6′), 7.85 (s, 1H, Ar-H), 7.57 (m, 1H, Ar-H), 7.32 (t, 1H, J = 8.1 Hz, Ar-H), 7.14 (d, 2H, J = 8.7 Hz, H-3′, 5′), 7.12 (m, 1H, Ar-H), 7.10 (s, 1H, H-8), 6.95 (s, 1H, H-3), 5.61 (d, 1H, J = 5.8 Hz, H-1′′), 5.50 (d, 1H, J = 5.4 Hz, sugar hydroxyl), 5.36 (d, 1H, J = 5.0 Hz, sugar hydroxyl), 5.24 (d, 1H, J = 7.5 Hz, sugar hydroxyl), 4.08 (d, 1H, J = 9.8 Hz, H-5′′), 3.88 (s, 3H, -OCH3), 3.78 (s, 3H, -OCH3), 3.51−3.38 (m, 3H, H-2′′, 3′′, 4′′); 13C NMR (DMSO-d6, 100 MHz) δ (ppm): 182.84, 167.01, 164.33, 162.97, 156.47, 153.07, 152.59, 140.61, 133.49, 133.07, 130.91, 128.88, 128.88, 128.25, 127.63, 123.81, 123.20, 119.24, 118.19, 115.06, 115.06, 106.50, 103.82, 100.79, 94.79, 77.49, 76.65, 73.28, 70.87, 60.82, 56.10; HR-ESI-MS m/z calcd for C29H26ClNO11 [M + Na]+ 622.1194, found 622.1096.
N-(4-chlorophenyl)-3,4,5-trihydroxy-6-((5-hydroxy-6-methoxy-2-(4-methoxyphenyl)-4-oxo-4H-chromen-7-yl)oxy)tetrahydro-2H-pyran-2-carboxamide (7c)
Yellow power, yield: 26%. 1H NMR (DMSO-d6, 400 MHz) δ (ppm): 12.92 (s, 1H, 5-OH), 10.32 (s, 1H, -NH-), 8.08 (d, 2H, J = 8.8 Hz, H-2′, 6′), 7.70 (d, 2H, J = 8.8 Hz, Ar-H), 7.34 (d, 2H, J = 9.1 Hz, Ar-H), 7.15 (d, 2H, J = 9.1 Hz, H-3′, 5′), 7.09 (s, 1H, H-8), 6.95 (s, 1H, H-3), 5.60 (d, 1H, J = 5.8 Hz, H-1′′), 5.49 (d, 1H, J = 5.6 Hz, sugar hydroxyl), 5.35 (d, 1H, J = 5.1 Hz, sugar hydroxyl), 5.24 (d, 1H, J = 7.5 Hz, sugar hydroxyl), 4.07 (d, 1H, J = 9.7 Hz, H-5′′), 3.89 (s, 3H, -OCH3), 3.77 (s, 3H, -OCH3), 3.48−3.37 (m, 3H, H-2′′, 3′′, 4′′); 13C NMR (DMSO-d6, 100 MHz) δ (ppm): 182.85, 176.63, 166.88, 164.41, 163.01, 156.50, 154.24, 152.65, 138.16, 133.20, 129.09, 129.09, 128.89, 128.89, 127.61, 123.26, 121.34, 121.34, 115.10, 115.10, 106.53, 103.86, 100.83, 94.84, 77.51, 76.70, 73.32, 70.93, 60.83, 56.13; HR-ESI-MS m/z calcd for C29H26ClNO11 [M + Na]+ 622.1194, found 622.1085.
3,4,5-trihydroxy-6-((5-hydroxy-6-methoxy-2-(4-methoxyphenyl)-4-oxo-4H-chromen-7-yl)oxy)-N-(o-tolyl)tetrahydro-2H-pyran-2-carboxamide (7d)
Yellow power, yield: 33%. 1H NMR (DMSO-d6, 400 MHz) δ (ppm): 12.95 (s, 1H, 5-OH), 9.43 (s, 1H, -NH-), 8.08 (d, 2H, J = 8.7 Hz, H-2′, 6′), 7.18 (m, 2H, Ar-H), 7.12 (d, 3H, J = 9.0 Hz, H-3′, 5′, H-8), 7.05 (m, 1H, Ar-H), 6.98 (s, 1H, H-3), 6.87 (m, 1H, Ar-H), 5.60 (d, 1H, J = 3.7 Hz, H-1′′), 5.53 (s, 1H, sugar hydroxyl), 5.36 (s, 1H, sugar hydroxyl), 5.20 (d, 1H, J = 7.2 Hz, sugar hydroxyl), 4.24 (d, 1H, J = 9.6 Hz, H-5′′), 3.86 (s, 3H, -OCH3), 3.78 (s, 3H, -OCH3), 3.50−3.39 (m, 3H, H-2′′, 3′′, 4′′), 2.19 (s, 3H, -CH3); 13C NMR (DMSO-d6, 100 MHz) δ (ppm): 182.87, 166.71, 164.31, 162.99, 156.60, 153.06, 152.65, 136.20, 133.08, 127.74, 127.74, 126.41, 124.95, 119.59, 115.05, 115.05, 106.48, 103.81, 100.70, 94.81, 76.90, 76.44, 73.29, 70.95, 60.83, 56.10, 18.07; HR-ESI-MS m/z calcd for C30H29NO11 [M + Na]+ 602.1541, found 602.1647.
3,4,5-trihydroxy-6-((5-hydroxy-6-methoxy-2-(4-methoxyphenyl)-4-oxo-4H-chromen-7-yl)oxy)-N-(m-tolyl)tetrahydro-2H-pyran-2-carboxamide (7e)
Yellow power, yield: 83%. 1H NMR (DMSO-d6, 400 MHz) δ (ppm): 12.91 (s, 1H, 5-OH), 10.14 (s, 1H, -NH-), 8.11 (d, 2H, J = 9.0 Hz, H-2′, 6′), 7.16 (m, 3H, Ar-H), 7.12 (d, 3H, J = 9.0 Hz, H-3′, 5′, H-8), 6.96 (s, 1H, H-3), 6.88 (d, 1H, J = 7.6 Hz, Ar-H), 5.61 (d, 1H, J = 5.8 Hz, H-1′′), 5.47 (d, 1H, J = 5.5 Hz, sugar hydroxyl), 5.35 (d, 1H, J = 5.1 Hz, sugar hydroxyl), 5.20 (d, 1H, J = 7.5 Hz, sugar hydroxyl), 4.08 (d, 1H, J = 9.6 Hz, H-5′′), 3.88 (s, 3H, -OCH3), 3.77 (s, 3H, -OCH3), 3.49−3.37 (m, 3H, H-2′′, 3′′, 4′′), 2.21 (s, 3H, -CH3); 13C NMR (DMSO-d6, 100 MHz) δ (ppm): 182.86, 166.42, 164.28, 162.97, 156.47, 153.04, 152.61, 148.93, 138.37, 133.01, 129.13, 129.13, 124.75, 123.19, 117.03, 115.06, 115.05, 106.48, 103.79, 100.77, 94.81, 77.40, 76.80, 73.27, 70.72, 60.82, 56.11, 21.59; HR-ESI-MS m/z calcd for C30H29NO11 [M + Na]+ 602.1541, found 602.1649.
3,4,5-trihydroxy-6-((5-hydroxy-6-methoxy-2-(4-methoxyphenyl)-4-oxo-4H-chromen-7-yl)oxy)-N-(p-tolyl)tetrahydro-2H-pyran-2-carboxamide (7f)
Yellow power, yield: 52%. 1H NMR (DMSO-d6, 400 MHz) δ (ppm): 12.92 (s, 1H, 5-OH), 10.14 (s, 1H, -NH-), 8.10 (d, 2H, J = 9.0 Hz, H-2′, 6′), 7.56 (d, 2H, J = 8.4 Hz, Ar-H), 7.12 (d, 2H, J = 9.0 Hz, H-3′, 5′), 7.10 (s, 1H, H-8), 7.08 (d, 2H, J = 8.4 Hz, Ar-H), 6.97 (s, 1H, H-3), 6.88 (d, 1H, J = 7.6 Hz, Ar-H), 5.61 (d, 1H, J = 5.7 Hz, H-1′′), 5.48 (d, 1H, J = 5.4 Hz, sugar hydroxyl), 5.36 (d, 1H, J = 5.2 Hz, sugar hydroxyl), 5.20 (d, 1H, J = 7.5 Hz, sugar hydroxyl), 4.06 (d, 1H, J = 9.6 Hz, H-5′′), 3.90 (s, 3H, -OCH3), 3.77 (s, 3H, -OCH3), 3.48−3.38 (m, 3H, H-2′′, 3′′, 4′′), 2.22 (s, 3H, -CH3); 13C NMR (DMSO-d6, 100 MHz) δ (ppm): 182.53, 166.27, 164.30, 163.00, 156.50, 153.06, 152.60, 136.76, 132.96, 129.55, 129.55, 128.90, 128.90, 123.19, 119.73, 119.64, 11964, 115.06, 115.06, 106.48, 103.81, 100.82, 77.44, 76.80, 73.30, 70.77, 60.82, 56.13, 20.90; HR-ESI-MS m/z calcd for C30H29NO11 [M + Na]+ 602.1541, found 602.1649.
3,4,5-trihydroxy-6-((5-hydroxy-6-methoxy-2-(4-methoxyphenyl)-4-oxo-4H-chromen-7-yl)oxy)-N-(2-hydroxyphenyl)tetrahydro-2H-pyran-2-carboxamide (7g)
Yellow power, yield: 33%. 1H NMR (DMSO-d6, 400 MHz) δ (ppm): 12.94 (s, 1H, 5-OH), 10.06 (s, 1H, -NH-), 9.20 (s, 1H, Ar-OH), 8.05 (d, 2H, J = 8.8 Hz, H-2′, 6′), 7.19 (s, 1H, H-8), 7.13 (d, 2H, J = 9.0 Hz, H-3′, 5′), 6.95 (s, 1H, H-3), 6.88 (m, 2H, Ar-H), 6.75 (m, 1H, Ar-H), 5.61 (brs, 1H, H-1′′), 5.48 (brs, 1H, sugar hydroxyl), 5.33 (d, 1H, J = 4.7 Hz, sugar hydroxyl), 5.28 (d, 1H, J = 7.3 Hz, sugar hydroxyl), 4.36 (d, 1H, J = 9.7 Hz, H-5′′), 3.86 (s, 3H, -OCH3), 3.79 (s, 3H, -OCH3), 3.57−3.51 (m, 3H, H-2′′, 3′′, 4′′); 13C NMR (DMSO-d6, 100 MHz) δ (ppm): 182.87, 166.80, 164.40, 162.94, 156.53, 153.04, 152.67, 147.07, 132.08, 128.88, 128.88, 126.71, 124.46, 119.34, 115.08, 115.08, 106.48, 103.84, 100.19, 94.80, 76.82, 76.03, 73.28, 71.48, 60.84, 56.09; HR-ESI-MS m/z calcd for C29H27NO12 [M + Na]+ 604.1533, found 604.1444.
3,4,5-trihydroxy-6-((5-hydroxy-6-methoxy-2-(4-methoxyphenyl)-4-oxo-4H-chromen-7-yl)oxy)-N-(4-hydroxyphenyl)tetrahydro-2H-pyran-2-carboxamide (7h)
Yellow power, yield: 27%. 1H NMR (DMSO-d6, 400 MHz) δ (ppm): 12.91 (s, 1H, 5-OH), 10.01 (s, 1H, -NH-), 9.22 (s, 1H, Ar-OH), 8.09 (d, 2H, J = 8.9 Hz, H-2′, 6′), 7.47 (d, 2H, J = 8.9 Hz, Ar-H), 7.14 (d, 2H, J = 8.9 Hz, H-3′, 5′), 7.11 (s, 1H, H-8), 6.95 (s, 1H, H-3), 6.66 (d, 2H, J = 8.8 Hz, Ar-H), 5.59 (brs, 1H, H-1′′), 5.43 (brs, 1H, sugar hydroxyl), 5.31 (d, 1H, J = 4.8 Hz, sugar hydroxyl), 5.18 (d, 1H, J = 7.5 Hz, sugar hydroxyl), 4.05 (d, 1H, J = 9.7 Hz, H-5′′), 3.89 (s, 3H, -OCH3), 3.77 (s, 3H, -OCH3), 3.66−3.58 (m, 3H, H-2′′, 3′′, 4′′); 13C NMR (DMSO-d6, 100 MHz) δ (ppm): 182.85, 165.76, 164.29, 162.99, 156.50, 153.96, 153.03, 143.29, 127.13, 127.13, 124.63, 124.63, 119.42, 115.51, 115.51, 110.26, 110.26, 106.48, 103.78, 100.85, 94.90, 77.37, 76.89, 73.34, 70.79, 60.82, 56.11; HR-ESI-MS m/z calcd for C29H27NO12 [M + Na]+ 604.1533, found 604.1437.
3,4,5-trihydroxy-6-((5-hydroxy-6-methoxy-2-(4-methoxyphenyl)-4-oxo-4H-chromen-7-yl)oxy)-N-(2-methoxyphenyl)tetrahydro-2H-pyran-2-carboxamide (7i)
Yellow power, yield: 30%. 1H NMR (DMSO-d6, 400 MHz) δ (ppm): 12.95 (s, 1H, 5-OH), 9.20 (s, 1H, -NH-), 8.14 (d, 1H, J = 7.6 Hz, Ar-H), 8.03 (d, 2H, J = 8.7 Hz, H-2′, 6′), 7.18 (s, 1H, H-8), 7.09 (d, 2H, J = 9.0 Hz, H-3′, 5′), 7.02 (t, 2H, J = 8.0 Hz, Ar-H), 6.94 (s, 1H, H-3), 6.89 (t, 1H, J = 6.8 Hz, Ar-H), 5.64 (d, 1H, J = 5.1 Hz, H-1′′), 5.55 (d, 1H, J = 5.1 Hz, sugar hydroxyl), 5.37 (d, 1H, J = 4.7 Hz, sugar hydroxyl), 5.28 (d, 1H, J = 7.0 Hz, sugar hydroxyl), 4.38 (d, 1H, J = 9.7 Hz, H-5′′), 3.85 (s, 3H, -OCH3), 3.80 (s, 3H, -OCH3), 3.75 (s, 3H, -OCH3), 3.60−3.41 (m, 3H, H-2′′, 3′′, 4′′); 13C NMR (DMSO-d6, 100 MHz) δ (ppm): 182.83, 166.83, 164.33, 162.91, 156.53, 153.08, 152.67, 148.97, 133.13, 128.80, 128.80, 127.37, 124.71, 123.16, 120.90, 115.01, 115.01, 111.54, 106.49, 103.86, 100.22, 94.76, 76.81, 75.88, 73.24, 71.36, 60.81, 56.26, 56.04; HR-ESI-MS m/z calcd for C30H29NO12 [M + Na]+ 618.1690, found 618.1597.
3,4,5-trihydroxy-6-((5-hydroxy-6-methoxy-2-(4-methoxyphenyl)-4-oxo-4H-chromen-7-yl)oxy)-N-(3-methoxyphenyl)tetrahydro-2H-pyran-2-carboxamide (7j)
Yellow power, yield: 34%. 1H NMR (DMSO-d6, 400 MHz) δ (ppm): 12.91 (s, 1H, 5-OH), 10.21 (s, 1H, -NH-), 8.04 (d, 2H, J = 8.7 Hz, H-2′, 6′), 7.36 (t, 1H, J = 1.8 Hz, Ar-H), 7.21 (m, 2H, Ar-H), 7.10 (d, 2H, J = 9.0 Hz, H-3′, 5′), 7.08 (s, 1H, H-8), 6.91 (s, 1H, H-3), 6.62 (m, 1H, Ar-H), 5.63 (d, 1H, J = 5.2 Hz, H-1′′), 5.50 (d, 1H, J = 5.2 Hz, sugar hydroxyl), 5.38 (d, 1H, J = 4.4 Hz, sugar hydroxyl), 5.23 (d, 1H, J = 7.4 Hz, sugar hydroxyl), 4.09 (d, 1H, J = 9.7 Hz, H-5′′), 3.86 (s, 3H, -OCH3), 3.78 (s, 3H, -OCH3), 3.68 (s, 3H, -OCH3), 3.49−3.44 (m, 3H, H-2′′, 3′′, 4′′); 13C NMR (DMSO-d6, 100 MHz) δ (ppm): 182.86, 166.57, 164.33, 162.99, 159.96, 156.50, 153.06, 152.61, 140.40, 133.07, 130.00, 128.90, 128.90, 123.21, 115.06, 115.06, 112.01, 109.52, 106.51, 105.54, 103.83, 100.85, 94.83, 77.48, 76.79, 73.30, 70.76, 60.83, 56.11, 55.44; HR-ESI-MS m/z calcd for C30H29NO12 [M + Na]+ 618.1690, found 618.1604.
3,4,5-trihydroxy-6-((5-hydroxy-6-methoxy-2-(4-methoxyphenyl)-4-oxo-4H-chromen-7-yl)oxy)-N-(4-methoxyphenyl)tetrahydro-2H-pyran-2-carboxamide (7k)
Yellow power, yield: 20%. 1H NMR (DMSO-d6, 400 MHz) δ (ppm): 12.92 (s, 1H, 5-OH), 10.07 (s, 1H, -NH-), 8.07 (d, 2H, J = 8.7 Hz, H-2′, 6′), 7.58 (d, 2H, J = 9.0 Hz, Ar-H), 7.13 (d, 2H, J = 9.0 Hz, H-3′, 5′), 7.09 (s, 1H, H-8), 6.94 (s, 1H, H-3), 6.85 (d, 2H, J = 9.2 Hz, Ar-H), 5.59 (d, 1H, J = 5.4 Hz, H-1′′), 5.45 (d, 1H, J = 5.2 Hz, sugar hydroxyl), 5.33 (d, 1H, J = 5.0 Hz, sugar hydroxyl), 5.22 (d, 1H, J = 7.4 Hz, sugar hydroxyl), 4.05 (d, 1H, J = 9.7 Hz, H-5′′), 3.88 (s, 3H, -OCH3), 3.78 (s, 3H, -OCH3), 3.69 (s, 3H, -OCH3), 3.50−3.39 (m, 3H, H-2′′, 3′′, 4′′); 13C NMR (DMSO-d6, 100 MHz) δ (ppm): 182.84, 166.07, 164.33, 162.98, 156.51, 155.84, 153.07, 152.60, 132.41, 128.88, 128.88, 123.20, 121.18, 121.18, 115.05, 115.05, 114.28, 114.28, 106.50, 103.82, 100.84, 94.86, 77.44, 76.81, 73.33, 70.88, 60.82, 56.11, 55.60; HR-ESI-MS m/z calcd for C30H29NO12 [M + Na]+ 618.1690, found 618.1597.
Cell proliferation assay against HL-60 and THP-1 cells
The antiproliferative activities of all the tested compounds against HL-60 and THP-1 cells were performed by MTT method [35, 36]. Two tumor cells in logarithmic growth were seeded to each well and incubated for 24 h at 37 oC in a humidified atmosphere of 5% CO2. Compounds were dissolved in DMSO before being diluted in the growth medium. Cells were further incubated for 72 h, at the end of the incubation time, fresh medium containing 0.5 mg/mL of MTT were added. Plates were incubated for another 4 h at 37 oC, the media was removed and formazan crystals formed in the cells were dissolved in 200 µL of DMSO. Optical density was measured at 570 nm with DMSO as blank using a Bio-Rad microplate reader (Model 680). In these experiments, the negative reference was 0.1% DMSO, scutellarin and 5-FU were used as the positive references.
Cell viability assay in PC 12 cells
Cytoprotective activity of scutellarin and target compounds on H2O2-induced PC12 cell injury was investigated by an MTT assay. PC12 cells were incubated in 96-well microplates (3.5 × 105 cell/well in 100 µL) for 24 h, then pretreated with the compounds and diluted in phosphate buffered saline (PBS)) for 6 h, and then treated with 400 µM H2O2 for 4 h at 37 C. The controls were exposed to the same solvent. After treatment with 4 mg/mL of MTT for 4 h and DMSO for 10 min, the absorbance was read at 570 nm on a microplate reader. Cell viability was expressed as a percent of the control culture value.