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Two new triterpenoid saponins from Polygala crotalarioides
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Chinese Chemical Letters 21 (2010) 1107–1110 www.elsevier.com/locate/cclet
Two new triterpenoid saponins from Polygala crotalarioides Yan Hua a,*, Chang Xiang Chen b, Jun Zhou b a
Key Laboratory for Forest Resources Conservation and Use in the Southwest Mountains of China, Ministry of Education, Southwest Forestry University, Kunming 650224, China b State Key Laboratory of Phytochemistry and Plant Resource in West China, Kunming Institute of Botany, Academia Sinica, Kunming 650204, China Received 29 January 2010
Abstract Two new oleanane-type saponins, crotalarioside A (1) and crotalarioside B (2), were isolated from the roots of Polygala crotalarioides. Their structures were elucidated on the basis of spectroscopic and chemical evidence. # 2010 Yan Hua. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved. Keywords: Polygala crotalarioides; Chemical constituents; Oleanane-type saponins
Polygala crotalarioides Buch. Ham. (Polygalaceae) is known to be a folk tonic medicine in Yunnan Wa nationality [1]. Its bioactivities attracted us to investigate its chemical constituents. In the previous paper, we reported structural elucidation of five new xanthones [2,3]. Our continuing phytochemical investigation into the constituents of this plant has resulted in the isolation of two new oleanane-type saponins, crotalarioside A and crotalarioside B. Their structures were elucidated on the basis of spectral analysis.
1. Experimental The dried roots (1 kg) of P. crotalarioides were extracted with 75% EtOH four times under reflux. After removal of the solvent in vacuo, the aqueous solution was passed through a HPD-100 column and the absorbed materials were eluted with water, 75% aqueous ethanol and ethanol, successively. The 75% ethanol eluate was concentrated in vacuo to give a residue (96 g), which was chromatographed on a silica gel (200–300 mesh) column chromatography with CHCl3/MeOH/H2O (7:4:1) to afford 10 fractions (fraction 1–10). Fractions 1–4 were chromatographed on Si gel with CHCl3/MeOH/H2O (7:3:0.5) and then resubjected to Sephadex LH-20 with MeOH to give the total saponins (15 g). The total saponins were passaged over RP-18 eluted with MeOH/H2O (5:5–7:3) to give 4 fractions (fraction A–D). Fraction D was further purified by semi-pre HPLC eluted by CH3CN/0.1% AcOH–H2O solution (24:76) to afford compounds 1 (24 mg) and 2 (10 mg).
* Corresponding author. E-mail address: [email protected] (Y. Hua). 1001-8417/$ – see front matter # 2010 Yan Hua. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved. doi:10.1016/j.cclet.2010.05.005
1108
Y. Hua et al. / Chinese Chemical Letters 21 (2010) 1107–1110
2. Results and discussion Compound 1 was obtained as white powder, and analyzed for C53H82O24 by negative-ion HRFABMS (m/z 1101.3976 [MH] (calcd. for C53H81O24, 1101.3965)). Its IR spectrum exhibited absorption bands for hydroxyl (3424 cm1), carbonyl (1718 and 1737 cm1), and olefinic groups (1631 cm1). The 1H and 13C NMR spectra showed signals due to 30 aglycone carbon signals, including five singlet methyls [dC 33.1 (s), 24.0 (s), 18.4 (s), 17.1 (s), 13.8 (s)], one oxygenated methylene [dC 64.4 (t)], one oxygenated methine [dC 86.1 (d)], two olefinic carbons [dC 139.1 (s), 127.0 (d)], three carboxyl carbons [dC 208.0(s), 180.1 (s), 176.8 (s)]. Also observed were signals of four anomeric carbons and their corresponding anomeric protons [dC 107.4 (d), 104.0 (d), 101.3 (d), 94.8 (d); dH 5.03 (d, 1H, J = 6.8 Hz), 5.13 (d, 1H, J = 7.5 Hz), 6.47 (br s, 1H), 6.06 (d, 1H, J = 8.2 Hz)], indicating a triterpenoid saponin with four sugar moieties. Comparison of the 1H and 13C NMR data of the aglycone unit with those of polygalasaponinXXIII [4] showed that the structures of the two aglycones were very similar. The only difference was the replacement of a methyl group in polygalasaponinXXIII by an oxygenated methine group in 1. Both of the two aglycones were oleanane-type triterpenoids with a ketone quaternary carbon at C-2. Acid hydrolysis of 1 with 1 mol/L HCl furnished four monosaccharides, which may be determined to be D-glucose D-fucose, L-rhamnose and D-xylose, by TLC comparison with authentic samples. This was further confirmed by the 13 C and 1H NMR spectral data of these sugar moieties, which were consistent with those reported [4]. Sugar proton and carbon signals in the spectra were assigned by HMQC, HMBC, and HMQC-TOCSY spectra. In the HMBC spectrum, long-range couplings were observed for H-10 of the glucosyl unit to C-3 of the aglycone, H-100 of the fucosyl unit to C28 of the aglycone, H-1000 of the rhamnosyl unit to C-200 of the fucosyl unit, H 10000 of the xylosyl unit to C-4000 of the rhamnosyl unit. The anomeric configurations of D-glucosyl, D-fucosyl, L-rhamnosyl and D-xylosyl were determined to be b, b, a and b, respectively, from the coupling constants of the anomeric proton signals. On the basis of the above evidence, the structure of 1 was elucidated as 2-oxo-olean-12-ene-27-hydroxy-23, 28-dioic acid 3-O-b-Dglucopyranosyl-28-O-b-D-xylopyranosyl-(1 ! 4)-a-L-rhamnopyranosyl-(1 ! 2)-b-D-fucopyranoside, and was named crotalarioside A (Fig. 1). Compound 2 was obtained as white powder, and analyzed for C59H92O29 by negative-ion HRFABMS (m/z 1263.4251 [MH] (calcd. for C59H91O29, 1263.4236)). Its IR spectrum exhibited absorption bands for hydroxyl
[(Fig._1)TD$IG]
Fig. 1. Structures of compounds 1 and 2.
Y. Hua et al. / Chinese Chemical Letters 21 (2010) 1107–1110
1109
(3425 cm1), carbonyl (1720 and 1737 cm1), and olefinic groups (1630 cm1). Comparison of the 1H and 13C NMR spectral data of 2 with those of 1 showed that the two structures were very similar except that there was an additional glucosyl moiety in compound 2. In the HMBC spectrum, long-range couplings were observed for H 100000 of the additional glucosyl unit to C-300 of the fucosyl unit. The binding sites of the other sugars are identical to compound 1. Based on the above evidence, the structure of 2 can be elucidated as 2-oxo-olean- 12-ene-27-hydroxy-23, 28-dioic acid 3-O-b-D-glucopyranosyl-28-O-b-D-xylopyranosyl-(1 ! 4)-a-L-rhamno-pyranosyl-(1 ! 2)-[b-D-glucopyranosyl(1 ! 3)]-b-D-fucopyranoside, and was named crotalarioside B (Table 1).
Table 1 1 H and 13C NMR spectral data of 1 and 2 (400 and 500 MHz, C5D5N, d). Position
1 dC
1 2 3
54.8 t 208.0 s 86.1 d
4 5
58.4 s 52.4 d
6 7 8 9 10 11 12 13 14 15 16 17 18
21.0 t 33.8 t 40.7 s 48.5 d 43.6 s 23.5 t 127.0 d 139.1 s 47.0 s 24.3 t 24.0 t 48.0 s 42.0 d
19 20 21 22 23 24
45.4 t 30.8 s 33.3 t 32.3 t 180.1 s 13.8 q
25 26 27
17.1 q 18.4 q 64.4 t
28 29
176.8 s 33.1 q
0.76 (s, 3H)
30
24.0 q
0.89 (s, 3H)
Glc-10
104.0 d
5.13 (d, 1H, J = 7.5 Hz)
20 30 40 50
75.1 78.6 71.4 78.1
1 dH
d d d d
1 HMBC
5.66 (s, 1H)
Glc-C-10 , C-1, C-5, C-23, C-24
2.74 (br d, 1H, J = 10.7 Hz)
C-1, C-7, C-23, C-24, C-25
5.74 (t-like, 1H)
C-9, C-11, C-14,
3.20 (dd, 1H, J = 14.0, 3.8 Hz)
C-12, C-16, C-20, C-28
1.51 (s, 3H) 0.96 (s, 3H) 1.03 (s, 3H) 3.83 (d, 1H, J = 12.0 Hz), 4.07 (d, 1H, J = 12.0 Hz)
C-3, C-4, C-5, C-23 C-1, C-5, C-9 C-7, C-9, C-14 C-8, C-13, C-14, C-15
C-19, C-21, C-19, C-21,
C-20, C-30, C-20, C-29,
C-3, Glc-C-30 , Glc-C-50
2 dC
2 dH
2 HMBC
54.8 t 207.9 s 85.7 d
5.65 (s, 1H)
Glc-C-10 , C-1, C-5, C-23, C-24
58.4 s 52.4 d
2.75 (m, 1H)
C-1, C-7, C-23, C-24, C-25
5.73 (t-like, 1H)
C-9, C-14,
3.20 (dd, 1H, J = 14.0, 4.0 Hz)
C-12, C-16, C-20, C-28
1.50 (s, 3H)
C-3, C-5, C-23
0.96 (s, 3H) 1.05 (s, 3H) 3.82 (d, 1H, J = 12.0 Hz), 4.06 (d, 1H, J = 12.0 Hz)
C-1, C-5, C-9 C-7, C-9, C-14 C-8, C-13, C-15
176.8 s 33.1 q
0.77 (s, 3H)
24.0 q
0.90 (s, 3H)
C-19, C-21, C-19, C-21,
103.9 d
5.12 (d, 1H, 7.5 Hz)
21.0 t 33.9 t 40.7 s 48.5 d 43.7 s 23.6 t 127.0 d 139.1 s 47.0 s 24.3 t 24.0 t 48.1 s 42.0 d
45.5 t 30.8 s 33.5 t 32.3 t 180.4 s 14.0 q 17.1 q 18.4 q 64.4 t
75.0 78.6 71.4 78.1
d d d d
C-20, C-30, C-20, C-29,
C-3, Glc-C-30 , Glc-C-50
1110
Y. Hua et al. / Chinese Chemical Letters 21 (2010) 1107–1110
Table 1 (Continued ) Position 0
1 dH
1 dC
1 HMBC 0
2 dC
2 HMBC
2 dH a
a
Glc-C-40 , Glc-C-50
6
62.6 t
4.29 (dd, 1H, J = 2.0, 5.0 Hz), 4.45a
Glc-C-4 , Glc-C-50
62.6 t
4.30 , 4.47
Fuc-100
94.8 d
6.06 (1H, d, J = 8.2 Hz)
C-28, Fuc-C-300 , Fuc-C-500
94.8 d
6.05 (d, 1H, J = 8.1 Hz)
C-28, Fuc-C-300 , Fuc-C-500
1.40 (d, 3H, J = 6.2 Hz)
Fuc-C-400 , Fuc-C-500
6.42 (br s, 1H)
Fuc-C-200 , Rha -C-3000 , Rha -C-5000
1.68 (d, 3H, J = 6.1 Hz)
Rha -C-4000 , Rha -C-5000 ,
5.02 (d, 1H, J = 6.8 Hz)
Rha -C-4000 , xyl-C-30000 , xyl-C-50000
5.09 ((d, 1H, J = 7.5 Hz))
Fuc-C-300 , Glc-C-300000 , Glc-C-500000
4.28a, 4.46a
Glc-C-400000
200 300 400 500 600 Rha-1000
2000 3000 4000 5000 6000 xyl-10000
20000 30000 40000 50000
74.0 76.8 73.3 72.6 17.0
d d d d q
101.3 d
71.9 72.6 85.1 68.3 18.6
d d d d q
107.4 d
76.2 78.7 70.9 67.5
1.49 (3H, d, J = 6.2 Hz)
Fuc-C-400 , Fuc-C-500
6.47 (br s, 1H)
Fuc-C-200 , Rha -C-3000 , Rha -C-5000
1.67 (d, 3H, J = 6.0 Hz)
Rha -C-4000 , Rha -C-5000 ,
5.03 (d, 1H, J = 6.8 Hz)
Rha -C-4000 , xyl-C-30000 , xyl-C-50000
d d d t
Glc-100000 200000 300000 400000 500000 600000 a
72.7 85.5 72.4 72.1 16.9
d d d d q
101.2 d
72.1 72.4 84.9 68.4 18.7
d d d d q
107.4 d
76.2 78.7 70.9 67.4
d d d t
105.7 d 75.3 78.6 71.6 78.1 62.5
d d d d t
Overlapping with other signals.
Acknowledgments The authors are grateful to the Analytical Group of the Laboratory of Phytochemistry, Kunming Institute of Botany, Chinese Academy of Sciences, for the spectral measurements. References [1] [2] [3] [4]
B.X. Xiang, P.F. Zhang, Y.H. Xiang, Guizhou Sci. 13 (1995) 24. Y. Hua, J. Zhou, C.X. Chen, Chin. Chem. Lett. 17 (2006) 773. Y. Hua, C.X. Chen, J. Zhou, J. Asian Nat. Prod. Res. 9 (2007) 273. D.M. Zhang, T. Miyase, M. Kuroyanagi, Chem. Pharm. Bull. 44 (1996) 173.
Chinese Chemical Letters 21 (2010) 1107–1110 www.elsevier.com/locate/cclet
Two new triterpenoid saponins from Polygala crotalarioides Yan Hua a,*, Chang Xiang Chen b, Jun Zhou b a
Key Laboratory for Forest Resources Conservation and Use in the Southwest Mountains of China, Ministry of Education, Southwest Forestry University, Kunming 650224, China b State Key Laboratory of Phytochemistry and Plant Resource in West China, Kunming Institute of Botany, Academia Sinica, Kunming 650204, China Received 29 January 2010
Abstract Two new oleanane-type saponins, crotalarioside A (1) and crotalarioside B (2), were isolated from the roots of Polygala crotalarioides. Their structures were elucidated on the basis of spectroscopic and chemical evidence. # 2010 Yan Hua. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved. Keywords: Polygala crotalarioides; Chemical constituents; Oleanane-type saponins
Polygala crotalarioides Buch. Ham. (Polygalaceae) is known to be a folk tonic medicine in Yunnan Wa nationality [1]. Its bioactivities attracted us to investigate its chemical constituents. In the previous paper, we reported structural elucidation of five new xanthones [2,3]. Our continuing phytochemical investigation into the constituents of this plant has resulted in the isolation of two new oleanane-type saponins, crotalarioside A and crotalarioside B. Their structures were elucidated on the basis of spectral analysis.
1. Experimental The dried roots (1 kg) of P. crotalarioides were extracted with 75% EtOH four times under reflux. After removal of the solvent in vacuo, the aqueous solution was passed through a HPD-100 column and the absorbed materials were eluted with water, 75% aqueous ethanol and ethanol, successively. The 75% ethanol eluate was concentrated in vacuo to give a residue (96 g), which was chromatographed on a silica gel (200–300 mesh) column chromatography with CHCl3/MeOH/H2O (7:4:1) to afford 10 fractions (fraction 1–10). Fractions 1–4 were chromatographed on Si gel with CHCl3/MeOH/H2O (7:3:0.5) and then resubjected to Sephadex LH-20 with MeOH to give the total saponins (15 g). The total saponins were passaged over RP-18 eluted with MeOH/H2O (5:5–7:3) to give 4 fractions (fraction A–D). Fraction D was further purified by semi-pre HPLC eluted by CH3CN/0.1% AcOH–H2O solution (24:76) to afford compounds 1 (24 mg) and 2 (10 mg).
* Corresponding author. E-mail address: [email protected] (Y. Hua). 1001-8417/$ – see front matter # 2010 Yan Hua. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved. doi:10.1016/j.cclet.2010.05.005
1108
Y. Hua et al. / Chinese Chemical Letters 21 (2010) 1107–1110
2. Results and discussion Compound 1 was obtained as white powder, and analyzed for C53H82O24 by negative-ion HRFABMS (m/z 1101.3976 [MH] (calcd. for C53H81O24, 1101.3965)). Its IR spectrum exhibited absorption bands for hydroxyl (3424 cm1), carbonyl (1718 and 1737 cm1), and olefinic groups (1631 cm1). The 1H and 13C NMR spectra showed signals due to 30 aglycone carbon signals, including five singlet methyls [dC 33.1 (s), 24.0 (s), 18.4 (s), 17.1 (s), 13.8 (s)], one oxygenated methylene [dC 64.4 (t)], one oxygenated methine [dC 86.1 (d)], two olefinic carbons [dC 139.1 (s), 127.0 (d)], three carboxyl carbons [dC 208.0(s), 180.1 (s), 176.8 (s)]. Also observed were signals of four anomeric carbons and their corresponding anomeric protons [dC 107.4 (d), 104.0 (d), 101.3 (d), 94.8 (d); dH 5.03 (d, 1H, J = 6.8 Hz), 5.13 (d, 1H, J = 7.5 Hz), 6.47 (br s, 1H), 6.06 (d, 1H, J = 8.2 Hz)], indicating a triterpenoid saponin with four sugar moieties. Comparison of the 1H and 13C NMR data of the aglycone unit with those of polygalasaponinXXIII [4] showed that the structures of the two aglycones were very similar. The only difference was the replacement of a methyl group in polygalasaponinXXIII by an oxygenated methine group in 1. Both of the two aglycones were oleanane-type triterpenoids with a ketone quaternary carbon at C-2. Acid hydrolysis of 1 with 1 mol/L HCl furnished four monosaccharides, which may be determined to be D-glucose D-fucose, L-rhamnose and D-xylose, by TLC comparison with authentic samples. This was further confirmed by the 13 C and 1H NMR spectral data of these sugar moieties, which were consistent with those reported [4]. Sugar proton and carbon signals in the spectra were assigned by HMQC, HMBC, and HMQC-TOCSY spectra. In the HMBC spectrum, long-range couplings were observed for H-10 of the glucosyl unit to C-3 of the aglycone, H-100 of the fucosyl unit to C28 of the aglycone, H-1000 of the rhamnosyl unit to C-200 of the fucosyl unit, H 10000 of the xylosyl unit to C-4000 of the rhamnosyl unit. The anomeric configurations of D-glucosyl, D-fucosyl, L-rhamnosyl and D-xylosyl were determined to be b, b, a and b, respectively, from the coupling constants of the anomeric proton signals. On the basis of the above evidence, the structure of 1 was elucidated as 2-oxo-olean-12-ene-27-hydroxy-23, 28-dioic acid 3-O-b-Dglucopyranosyl-28-O-b-D-xylopyranosyl-(1 ! 4)-a-L-rhamnopyranosyl-(1 ! 2)-b-D-fucopyranoside, and was named crotalarioside A (Fig. 1). Compound 2 was obtained as white powder, and analyzed for C59H92O29 by negative-ion HRFABMS (m/z 1263.4251 [MH] (calcd. for C59H91O29, 1263.4236)). Its IR spectrum exhibited absorption bands for hydroxyl
[(Fig._1)TD$IG]
Fig. 1. Structures of compounds 1 and 2.
Y. Hua et al. / Chinese Chemical Letters 21 (2010) 1107–1110
1109
(3425 cm1), carbonyl (1720 and 1737 cm1), and olefinic groups (1630 cm1). Comparison of the 1H and 13C NMR spectral data of 2 with those of 1 showed that the two structures were very similar except that there was an additional glucosyl moiety in compound 2. In the HMBC spectrum, long-range couplings were observed for H 100000 of the additional glucosyl unit to C-300 of the fucosyl unit. The binding sites of the other sugars are identical to compound 1. Based on the above evidence, the structure of 2 can be elucidated as 2-oxo-olean- 12-ene-27-hydroxy-23, 28-dioic acid 3-O-b-D-glucopyranosyl-28-O-b-D-xylopyranosyl-(1 ! 4)-a-L-rhamno-pyranosyl-(1 ! 2)-[b-D-glucopyranosyl(1 ! 3)]-b-D-fucopyranoside, and was named crotalarioside B (Table 1).
Table 1 1 H and 13C NMR spectral data of 1 and 2 (400 and 500 MHz, C5D5N, d). Position
1 dC
1 2 3
54.8 t 208.0 s 86.1 d
4 5
58.4 s 52.4 d
6 7 8 9 10 11 12 13 14 15 16 17 18
21.0 t 33.8 t 40.7 s 48.5 d 43.6 s 23.5 t 127.0 d 139.1 s 47.0 s 24.3 t 24.0 t 48.0 s 42.0 d
19 20 21 22 23 24
45.4 t 30.8 s 33.3 t 32.3 t 180.1 s 13.8 q
25 26 27
17.1 q 18.4 q 64.4 t
28 29
176.8 s 33.1 q
0.76 (s, 3H)
30
24.0 q
0.89 (s, 3H)
Glc-10
104.0 d
5.13 (d, 1H, J = 7.5 Hz)
20 30 40 50
75.1 78.6 71.4 78.1
1 dH
d d d d
1 HMBC
5.66 (s, 1H)
Glc-C-10 , C-1, C-5, C-23, C-24
2.74 (br d, 1H, J = 10.7 Hz)
C-1, C-7, C-23, C-24, C-25
5.74 (t-like, 1H)
C-9, C-11, C-14,
3.20 (dd, 1H, J = 14.0, 3.8 Hz)
C-12, C-16, C-20, C-28
1.51 (s, 3H) 0.96 (s, 3H) 1.03 (s, 3H) 3.83 (d, 1H, J = 12.0 Hz), 4.07 (d, 1H, J = 12.0 Hz)
C-3, C-4, C-5, C-23 C-1, C-5, C-9 C-7, C-9, C-14 C-8, C-13, C-14, C-15
C-19, C-21, C-19, C-21,
C-20, C-30, C-20, C-29,
C-3, Glc-C-30 , Glc-C-50
2 dC
2 dH
2 HMBC
54.8 t 207.9 s 85.7 d
5.65 (s, 1H)
Glc-C-10 , C-1, C-5, C-23, C-24
58.4 s 52.4 d
2.75 (m, 1H)
C-1, C-7, C-23, C-24, C-25
5.73 (t-like, 1H)
C-9, C-14,
3.20 (dd, 1H, J = 14.0, 4.0 Hz)
C-12, C-16, C-20, C-28
1.50 (s, 3H)
C-3, C-5, C-23
0.96 (s, 3H) 1.05 (s, 3H) 3.82 (d, 1H, J = 12.0 Hz), 4.06 (d, 1H, J = 12.0 Hz)
C-1, C-5, C-9 C-7, C-9, C-14 C-8, C-13, C-15
176.8 s 33.1 q
0.77 (s, 3H)
24.0 q
0.90 (s, 3H)
C-19, C-21, C-19, C-21,
103.9 d
5.12 (d, 1H, 7.5 Hz)
21.0 t 33.9 t 40.7 s 48.5 d 43.7 s 23.6 t 127.0 d 139.1 s 47.0 s 24.3 t 24.0 t 48.1 s 42.0 d
45.5 t 30.8 s 33.5 t 32.3 t 180.4 s 14.0 q 17.1 q 18.4 q 64.4 t
75.0 78.6 71.4 78.1
d d d d
C-20, C-30, C-20, C-29,
C-3, Glc-C-30 , Glc-C-50
1110
Y. Hua et al. / Chinese Chemical Letters 21 (2010) 1107–1110
Table 1 (Continued ) Position 0
1 dH
1 dC
1 HMBC 0
2 dC
2 HMBC
2 dH a
a
Glc-C-40 , Glc-C-50
6
62.6 t
4.29 (dd, 1H, J = 2.0, 5.0 Hz), 4.45a
Glc-C-4 , Glc-C-50
62.6 t
4.30 , 4.47
Fuc-100
94.8 d
6.06 (1H, d, J = 8.2 Hz)
C-28, Fuc-C-300 , Fuc-C-500
94.8 d
6.05 (d, 1H, J = 8.1 Hz)
C-28, Fuc-C-300 , Fuc-C-500
1.40 (d, 3H, J = 6.2 Hz)
Fuc-C-400 , Fuc-C-500
6.42 (br s, 1H)
Fuc-C-200 , Rha -C-3000 , Rha -C-5000
1.68 (d, 3H, J = 6.1 Hz)
Rha -C-4000 , Rha -C-5000 ,
5.02 (d, 1H, J = 6.8 Hz)
Rha -C-4000 , xyl-C-30000 , xyl-C-50000
5.09 ((d, 1H, J = 7.5 Hz))
Fuc-C-300 , Glc-C-300000 , Glc-C-500000
4.28a, 4.46a
Glc-C-400000
200 300 400 500 600 Rha-1000
2000 3000 4000 5000 6000 xyl-10000
20000 30000 40000 50000
74.0 76.8 73.3 72.6 17.0
d d d d q
101.3 d
71.9 72.6 85.1 68.3 18.6
d d d d q
107.4 d
76.2 78.7 70.9 67.5
1.49 (3H, d, J = 6.2 Hz)
Fuc-C-400 , Fuc-C-500
6.47 (br s, 1H)
Fuc-C-200 , Rha -C-3000 , Rha -C-5000
1.67 (d, 3H, J = 6.0 Hz)
Rha -C-4000 , Rha -C-5000 ,
5.03 (d, 1H, J = 6.8 Hz)
Rha -C-4000 , xyl-C-30000 , xyl-C-50000
d d d t
Glc-100000 200000 300000 400000 500000 600000 a
72.7 85.5 72.4 72.1 16.9
d d d d q
101.2 d
72.1 72.4 84.9 68.4 18.7
d d d d q
107.4 d
76.2 78.7 70.9 67.4
d d d t
105.7 d 75.3 78.6 71.6 78.1 62.5
d d d d t
Overlapping with other signals.
Acknowledgments The authors are grateful to the Analytical Group of the Laboratory of Phytochemistry, Kunming Institute of Botany, Chinese Academy of Sciences, for the spectral measurements. References [1] [2] [3] [4]
B.X. Xiang, P.F. Zhang, Y.H. Xiang, Guizhou Sci. 13 (1995) 24. Y. Hua, J. Zhou, C.X. Chen, Chin. Chem. Lett. 17 (2006) 773. Y. Hua, C.X. Chen, J. Zhou, J. Asian Nat. Prod. Res. 9 (2007) 273. D.M. Zhang, T. Miyase, M. Kuroyanagi, Chem. Pharm. Bull. 44 (1996) 173.