Molecules 2015, 20, 21494–21500
standard. ESI-MS and HR-EI-M-TOF-MS were measured on a Bruker HTC/Esquire spectrometer
and a Bruker Daltonics Flex spectrometer, respectively. GC analysis was carried out on an HP-5890 II
system (Gentech Scientific, Alto, CA, USA) equipped with a FID detector and a HP-20M capillary
column (25 m ˆ 0.32 mm ˆ 0.3 µm). Column chromatography was performed with silica gel
(Qingdao Marine Chemical Industry Factory, Qingdao, China) and Sephadex LH-20 (GE Healthcare
Bio-Sciences AB, Fairfield, CT, USA) and reversed-phase C18 silica gel (40–60 µm, Merck, Darmstadt,
Germany). TLC was performed with silica gel GF254 (Qingdao Marine Chemical Industry Factory).
Fractions were monitored by TLC and spots were visualized by heating after spraying with 5% H2SO4
in ethanol.
3.2. Plant Material
The whole plant of P. Sibirica L. Var megalopha Fr. were collected in Yongshan, Yunnan Province,
People’s Republic of China. A voucher specimen (HUA002) was identified by Prof. Fan Du
(Southwest Forestry University) and was deposited at the College of Forestry, Southwest
Forestry University.
3.3. Extraction, Isolation and Characterization
The 75% ethanol extract of the whole plant of Polygala sibirica L. var megalopha Fr. (5.0 kg),
was chromatographed over a D101 macroporous resin, eluted successively with a gradient of
H2O, 35% EtOH, 65% EtOH, 95% EtOH. The 65% EtOH eluate was subjected to silica gel
column chromatography and eluted with CHCl3–MeOH (50:1Ñ0:1) to afford thirteen fractions
(Fr.1ÑFr.13). Fr.8 (56 g) was chromatographed on a silica gel column and RP-C18 to yield eleven
fractions (Fr.8-1ÑFr.8-11). Fr.8-7 (35 mg) was purified by Sephadex LH-20 with CHCl3–MeOH
(1:1) and semi-preparative HPLC with a mixture of acetonitrile and water (34:66, v/v) to give
compound 1 (20 mg). Fr.8-5 (4.654 g) was repeatedly subjected to silica gel column and Sephadex
LH-20 chromatography to yield five fractions (Fr.8-5AÑFr.8-5E). Fr.8-5C (40.8 mg) was purified by
semi-preparative HPLC with a mixture of acetonitrile and water (29:71, v/v) to afford 2 (4.6 mg) and
3 (4.3 mg).
20
Polygalin H (1). Yellow amorphous power; rαsD ´89 (c 0.0011, MeOH); UV (CH OH) λ
(log ε):
max
3
343 (0.17), 273 (0.19), 258 (0.19), 209 (0.45); IR (KBr) νmax: 3440, 2926, 1613, 1512, 1484, 1354, 1263,
1213, 1142, 1078, 1024 cm´1; for 1H- and 13C-NMR, see Table 2; MALDI-TOF/TOF-MS: m/z 691.1077
[M + Na]+ (calcd. for 691.1640, C30H36O17Na+).
20
Polygalin I (2). Yellow amorphous power; rαsD ´89 (c 0.0011, MeOH); UV (CH OH) λ
(log ε):
max
3
343 (0.17), 273 (0.19), 258 (0.19), 209 (0.45); IR (KBr) νmax: 3441, 2925, 1609, 1510, 1484, 1351, 1258,
1212, 1180, 1077, 1024 cm´1; for 1H- and 13C-NMR, see Table 2; MALDI-TOF/TOF-MS: m/z 675.1942
[M + Na]+ (calcd. for 675.1901, C30H36O16Na+).
20
˝
Polygalin D (3). Yellow needles (MeOH); m.p. 251–253 C; rαsD ´47 (c 0.51, MeOH); UV (CH3OH)
λ
max (log ε) nm: 268 (4.12), 355 (3.98); IR (KBr) cm´1: 3410, 2943, 1657, 1601, 1497, 1353, 1218 and 1025.
HRESIMS (positive) m/z: 647.1587 (calcd. for C28H32O16, 647.1588]; H-NMR (DMSO-d6, 600 MHz)
δH: 7.82 (1H, dd, J = 9.0, 2.0 Hz, H-6 ), 7.59 (1H, d, J = 2.0 Hz, H-2 ), 7.03 (1H, d, J = 9.0 Hz, H-5 ),
1
1
1
1
1
6.72 (1H, d, J = 2.5 Hz, H-8), 6.38 (1H, d, J = 2.5 Hz, H-6), 3.88 (3H, s, 4 -OMe), 3.87 (3H, s, 7-OMe),
5.63 (1H, d, J = 8.0 Hz ,Glc-H-1); 13C-NMR (DMSO-d6, 150 MHz) δ: 177.8 (s, C-4), 165.1 (s, C-7), 161.0
1
1
1
(s,C-5), 156.2 (s, C-9), 155.7 (s, C-2), 150.1 (s, C-4 ), 145.0 (s, C-3 ), 133.7 (s, C-3), 122.5 (s, C-6 ), 121.8
1
1
1
(s, C-1 ), 115.5 (s, C-2 ), 111.1 (s, C-5 ), 108.6 (d, Api-C-1), 105.0 (s, C-10), 98.5 (d, Glc-C-1), 97.8 (s, C-6),
92.1 (s, C-8), 79.2 (s, Api-C-3), 77.5 (d, Glc-C-2), 77.0 (d, Glc-C-3, 5), 76.1 (d, Api-C-2), 73.9 (t, Api-C-4),
70.2 (d, Glc-C-4), 64.2 (t, Api-C-5), 60.8 (t, Glc-C-6), 56.1 (q, 7-OMe), 55.6 (q, 4 -OMe).
1
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