Journal of Chemical Crystallography
144.74, 136.26, 134.41, 130.88, 130.83, 129.09, 128.89,
121.68, 120.68, 119.10, 117.70. HRMS (ESI) m/z: calcd for
C15H12O2 for [M+1]+, calculated 225.0837, found 225.0883.
135.13, 133.70, 130.85, 130.17, 129.42, 129.34, 128.84,
127.76, 121.01, 113.51, 68.42, 35.00, 32.43, 28.39, 24.89.
HRMS (ESI) m/z: calcd for C20H21BrO2 [M+H]+ 372.0798,
found 372.0796.
Synthesis of 1–5
Compound 5: pale yellow crystals; yield: 75%. m.p. 74–76
℃. 1H NMR (500 MHz, DMSO) δ 7.77–7.67 (m, 2H), 7.53 (s,
1H), 7.52–7.50 (m, 2H), 7.49 (s, 1H), 7.46–7.42 (m, 3H), 7.17
(d, J=8.1 Hz, 1H), 7.08–7.03 (m, 1H), 4.09 (t, J=6.0 Hz, 2H),
3.35 (t, J=6.8 Hz, 2H), 1.73–1.65 (m, 2H), 1.60–1.53 (m, 2H),
1.40–1.32 (m, 2H), 1.33–1.23 (m, 2H). 13C NMR (125 MHz,
DMSO) δ 192.46, 157.84, 142.21, 135.12, 133.71, 130.87,
130.19, 129.43, 129.31, 128.83, 127.73, 120.98, 113.46, 68.50,
35.29, 32.47, 29.11, 27.77, 25.33. HRMS (ESI) m/z: calcd for
C21H23BrO2 [M+Na]+ 408.0773, found 408.0780.
1,2-Dibromoethane (8.2 g, 40.5 mmol) was added dropwise
to a solution of 2′-hydroxychalcone (2 g, 13.5 mmol) and
K2CO3(3.7 g, 27 mmol) in acetone (50 mL) at room tem-
perature. The reaction mixture was stirred for 4–5 h. Com-
pletion of reaction was monitored by TLC analysis. After
completion of the reaction, the product was extracted with
ethyl acetate (3 × 50 mL) and dried with anhydrous Na2SO4.
The product was then separated by silica gel column chro-
matography to obtain compound 1 as pale-yellow oil with a
yield of 80%. 1H NMR (500 MHz, DMSO) δ 7.79–7.74 (m,
2H), 7.63–7.59 (m, 2H), 7.59–7.56 (m, 1H), 7.55–7.52 (m,
1H), 7.46–7.40 (m, 3H), 7.19 (d, J = 8.4 Hz, 1H), 7.13–7.07
(m, 1H), 4.50–4.45 (m, 2H), 3.83–3.79 (m, 2H). 13C NMR
(125 MHz, DMSO) δ 191.96, 156.95, 142.69, 135.13,
133.78, 130.86, 130.51, 129.39, 129.35, 129.08, 127.43,
121.61, 113.66, 68.95, 31.73. HRMS (ESI) m/z: calcd for
C17H15BrO2 [M + H]+ 330.0255, found 330.0257.
Structure Determination
The crystal data for 4 and 5 were integrated using the pro-
program SADABS [23]. The structures were solved by direct
methods and refned on F2by full-matrix least squares using
SHELXTL-2014 software [24]. All non-hydrogen atoms were
syntheses. The hydrogen atoms bound to carbon were placed
in calculated positions and refined using a riding model.
Crystallographic data and refnement information are given
Compounds 2, 3, 4, and 5 were synthesized following the
procedure described for 1. Pale yellow crystals of 4 and 5,
suitable for X-ray difraction analysis, were obtained from
ethyl acetate and acetone (V/V=1:1) with yields of 80 % and
75%, respectively.
1
Compound 2: pale yellow oil; yield: 83%. H NMR
In Vitro α‑Glucosidase Inhibitory Activity Study
(500 MHz, DMSO) δ 7.77–7.70 (m, 2H), 7.56–7.51 (m,
3H), 7.46 (s, 1H), 7.45–7.42 (m, 3H), 7.20 (d, J=8.2 Hz,
1H), 7.11–7.05 (m, 1H), 4.20 (t, J = 5.8 Hz, 2H), 3.56 (t,
J=6.7 Hz, 2H), 2.29–2.19 (m, 2H). 13C NMR (125 MHz,
DMSO) δ 192.46, 157.30, 142.71, 134.96, 133.63, 130.95,
130.17, 129.46, 129.44, 128.92, 127.43, 121.27, 113.49,
66.46, 32.31, 31.47. HRMS (ESI) m/z: calcd for C18H17BrO2
[M+H]+ 344.0485, found 344.0482.
The inhibition activity of these compounds on α-glucosidase
activity was evaluated using a micro determination model
based on the reaction of α-glucosidase and 4-nitrophenyl-α-d-
gluocpynoaside (PNPG). The test compounds were dissolved
in DMSO and phosphate bufer (PB) to prepare the required
distributing (10, 20 mmol/L) concentration. Specifcally,
α-glucosidase from Saccharomyces cerevisiae was assayed
using a 0.01 M phosphate bufer at pH 6.8 and 10 mM PNPG
as the substrate. The concentration of the enzymes was 1 U/
mL in each experiment. PB (160 μL), various concentrations
of the derivatives (10 μL), and α-glucosidase (10 μL) were
added to 96-well polystyrene plates, and the plates were incu-
bated at 37 °C for 20 min. After 20 min preincubation, 20 μL
of PNPG solution were added to the mixture. The reaction was
carried out at 37 °C for 10 min. The absorbance was measured
at 405 nm using a multiscanner. Acarbose was used as the
positive control in this study. The percentage of enzyme inhibi-
tion was determined by the following equation:
1
Compound 3: pale yellow oil; yield: 85%. H NMR
(500 MHz, DMSO) δ 7.76–7.69 (m, 2H), 7.54 (s, 1H),
7.53–7.50 (m, 2H), 7.49 (s, 1H), 7.46–7.43 (m, 3H), 7.19
(d, J=8.1 Hz, 1H), 7.10–7.01 (m, 1H), 4.13 (t, J=6.0 Hz,
2H), 3.42 (t, J=6.5 Hz, 2H), 1.94–1.87 (m, 2H), 1.86–1.79
(m, 2H). 13C NMR (125 MHz, DMSO), 157.65, 142.41,
135.06, 133.66, 130.88, 130.17, 129.45, 129.35δ 192.42,
128.89, 127.62, 121.06, 113.52, 67.73, 34.97, 29.50, 27.93.
HRMS (ESI) m/z: calcd for C19H19BrO2 [M+H]+ 358.0641,
found 358.0640.
Compound 4: pale yellow crystals; yield: 80%; m.p. 58–60
℃; 1H NMR (500 MHz, DMSO) δ 7.76–7.69 (m, 2H), 7.53
(s, 1H), 7.52–7.50 (m, 2H), 7.49 (s, 1H), 7.47–7.41 (m, 3H),
7.18 (d, J=8.2 Hz, 1H), 7.09–7.03 (m, 1H), 4.10 (t, J=5.8,
2H), 3.33 (t, J=5.3 Hz, 2H), 1.76–1.65 (m, 4H), 1.50–1.41 (m,
2H). 13C NMR (125 MHz, DMSO) δ 192.49, 157.79, 142.23,
(
)
Inhibition(%) = ΔAcontrol − ΔAsample ∕ΔAcontrol × 100
1 3