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Saponins from the roots of Hedysarum polybotrys
Biochemical Systematics and Ecology 35 (2007) 389e391 www.elsevier.com/locate/biochemsyseco
Saponins from the roots of Hedysarum polybotrys Yi Liu a, Qing-Ying Zhang a, Yu-Ying Zhao a, Bin Wang a, Li-Qian Hai a, Ya-Ping Ying a, Hu-Biao Chen a,b,* a
Department of Natural Medicines and State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing 100083, PR China b School of Chinese Medicine, Hong Kong Baptist University, Hong Kong Received 8 June 2006; accepted 6 December 2006
Keywords: Hedysarum polybotrys; Leguminosae; Saponin
1. Subject and source Radix Hedysari, the dry roots of Hedysarum polybotrys Hand.-Mazz. (Leguminosae, subfamily Papilionoideae), were purchased from Wudu Micangshan, Gansu Province, which is the major cultivated area, in September 2004 and identified by Prof. Hu-Biao Chen, Department of Natural Medicines, Peking University. A voucher specimen (no. 05021) was deposited at the Herbarium, School of Pharmaceutical Sciences, Peking University (PEM). 2. Previous work The phytochemical investigation of the genus Hedysarum has focused on H. polybotrys Hand.-Mazz., the main medicinal species recorded as Radix Hedysari in the Pharmacopoeia of China (2005). We recently found flavanols in this genus (Liu et al., 2005), and other compounds such as isoflavonones, chalcones, pterocarpans, benzofuranoids (Miyase et al., 1984), coumestans (Hai et al., 2002), lignans (Hai et al., 2003), organic acids, polysaccharides and phenols have been reported. There are reports on the bioactivity of the total saponins from H. polybotrys (Wang et al., 2000), but not on the identification of these saponins. 3. Present study The air-dried and powdered roots (6.7 kg) were extracted consecutively with 95% EtOH and 50% EtOH. The EtOH extract was concentrated under vacuum and the residue was suspended in water. The suspension was extracted successively with EtOAc and n-BuOH. The n-BuOH fraction was subjected to silica gel column chromatography (CHCl3eMeOHeH2O, 8:2:1, v/v/v), Diaion HP-20 column chromatography (eluted with water containing 0, 30, * Corresponding author. Department of Natural Medicines and State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing 100083, PR China. E-mail address: [email protected] (H.-B. Chen). 0305-1978/$ - see front matter Ó 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.bse.2006.12.008
390
Y. Liu et al. / Biochemical Systematics and Ecology 35 (2007) 389e391
R1
R2O CH2OH OH 1.
R1 =
2.
R1 =
3.
R1 =
4.
R1 =O
H
,
R2 =-glc UA Me 2 ara 2 rha
,
R2 =-glc UA 2 ara 2 rha
,
R2 =-glc UA 2 gal 2 rha
,
R2 =-glc UA 2 gal 2 rha
OH H OH H
Fig. 1. Structures of saponins 1e4.
50, 70, 100% MeOH), and semipreparative reversed-phase HPLC (phenomenex ODS column, 1 cm 25 cm, 36% aqueous MeCN, 204 nm) to yield compounds 1e4 (Fig. 1). The structures of compounds 1e4 were identified based on the physical and chemical properties and spectral data (1H, 13C NMR and 2D NMR) as well as by comparison with data in the literature. Compounds 1e4 were determined to be four saponins: soyasaponin II methyl ester (1) (Sakamoto et al., 1992), soyasaponin II (2) (Kitagawa et al., 1976), soyasaponin I (3) (Kubo et al., 1989) and dehydrosoyasaponin I (4) (Miyao et al., 1996). 4. Chemotaxonomic significance In recent years, we sequentially identified steroids, pterocarpins, coumarins (Hai et al., 2002), isoflavonoids, lignanoids (Hai et al., 2003) and alkaloids (Hai et al., 2004) from H. polybotrys. Saponins 1e4 have been isolated from H. polybotrys for the first time in the present study. The isoflavones are of particular interest because they are characteristic constituents differentiating the subfamily Papilionoideae from the other two subfamilies (Mimosoideae and Caesalpinioideae) of Leguminosae (Wu, 1991). In the subfamily Papilionoideae, flavonoids occur as various structural types and are generally distributed. A literature survey also shows that flavonoids, including isoflavones (Miyase et al., 1984; Wang et al., 2001, 2002), flavones (Alaniya, 1983; Chriki and Harborne, 1983; Glyzina and Bykov, 1969), flavanones (Miyase et al., 1984), isoflavans (Miyase et al., 1984) and xanthones (Miyase et al., 1984; Alaniya, 1983; Chriki and Harborne, 1983; Glyzina and Bykov, 1969; Glyzina, 1973; Pan et al., 1984; Wang et al., 2003), are the main classes of compounds isolated from species of the genus Hedysarum. Our phytochemical study on H. polybotrys (Hai et al., 2003) is also in accord with the above results.
Y. Liu et al. / Biochemical Systematics and Ecology 35 (2007) 389e391
391
In addition, lignanoids and alkaloids have been shown to be present in the subfamily Papilionoideae (Wu, 1991). Steroidal saponins and triterpenoid saponins are also obtained from many members of the subfamily Papilionoideae, e.g. methyl protodeltonin in genus Trigonella, glycyrrhetinic acid in genus Glycyrrhiza, and soyasaponin I in genus Astragalus (Wu, 1991). However, saponins, lignanoids and alkaloids have not been found from the genus Hedysarum. The present identification of saponins 1e4 (triterpenoid saponins), along with our former discovery of lignanoids (Hai et al., 2003) and alkaloids (Hai et al., 2004), shows that genus Hedysarum is similar to other genus of the subfamily Papilionoideae in chemical distribution, and this help to support the view that the genus Hedysarum is indeed a natural group belonging to the subfamily Papilionoideae. Acknowledgement This project was supported by the National Natural Science Foundation of China (20432030) and the Changjiang Scholar and Innovative Team in University (985-2-063-112). References Alaniya, M.D., 1983. Khim. Prir. Soedin 5, 646 (in Russian) (CA: 100:82749). China Pharmacopoeia Committee, 2005. China Pharmacopoeia, vol. I. Chemical Industry Press, 104 pp. Chriki, A., Harborne, J.B., 1983. Phytochemistry 22, 2322. Glyzina, G.S., 1973. Khim. Prir. Soedin. 9, 434 (in Russian) (CA: 79:79119h). Glyzina, G.S., Bykov, V.I., 1969. Khim. Prir. Soedin. 5, 322 (in Russian) (CA:72:39767). Hai, L.Q., Liang, H., Zhao, Y.Y., et al., 2002. China J. Chin. Mater. Med. 27, 843. Hai, L.Q., Zhang, Q.Y., Liang, H., et al., 2003. Acta Pharm. Sin. 38, 592. Hai, L.Q., Zhang, Q.Y., Zhao, Y.Y., et al., 2004. China J. Chin. Mater. Med. 29, 432. Kitagawa, I., Yoshikawa, M., Yosioka, I., 1976. Chem. Pharm. Bull. 24, 121. Kubo, T., Hamada, S., Nohara, T., et al., 1989. Chem. Pharm. Bull. 37, 2229. Liu, Y., Zhao, Y.Y., Chen, H.B., et al., 2005. Biochem. Syst. Ecol. 33, 809. Miyao, H., Sakai, Y., Takeshita, T., et al., 1996. Chem. Pharm. Bull. 44, 1222. Miyase, T., Fukushima, S., Akiyama, Y., 1984. Chem. Pharm. Bull. 32, 3267. Pan, J.X., Liu, W., Wang, D., et al., 1984. J. Beijing Med. Sch. 16, 248. Sakamoto, S., Kuroyanagi, M., Ueno, A., et al., 1992. Phytochemistry 31, 1339. Wang, W., You, C.G., Wang, Y., et al., 2000. J. Lanz. Univ. (Natural Sci.) 36, 107. Wang, W., Chen, W., Chen, H.B., et al., 2001. J. Pek. Univ. (Health Sci.) 33, 205. Wang, W., Chen, H.B., Wang, W.M., 2002. Acta Pharm. Sin. 37, 196. Wang, W., An, D.G., Chen, H.B., et al., 2003. J. Asian Nat. Prod. Res. 5, 31. Wu, Z.Y., 1991. Xinghua bencao gangyao, vol. II. Shanghai Science Press, pp. 80e84.
Saponins from the roots of Hedysarum polybotrys Yi Liu a, Qing-Ying Zhang a, Yu-Ying Zhao a, Bin Wang a, Li-Qian Hai a, Ya-Ping Ying a, Hu-Biao Chen a,b,* a
Department of Natural Medicines and State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing 100083, PR China b School of Chinese Medicine, Hong Kong Baptist University, Hong Kong Received 8 June 2006; accepted 6 December 2006
Keywords: Hedysarum polybotrys; Leguminosae; Saponin
1. Subject and source Radix Hedysari, the dry roots of Hedysarum polybotrys Hand.-Mazz. (Leguminosae, subfamily Papilionoideae), were purchased from Wudu Micangshan, Gansu Province, which is the major cultivated area, in September 2004 and identified by Prof. Hu-Biao Chen, Department of Natural Medicines, Peking University. A voucher specimen (no. 05021) was deposited at the Herbarium, School of Pharmaceutical Sciences, Peking University (PEM). 2. Previous work The phytochemical investigation of the genus Hedysarum has focused on H. polybotrys Hand.-Mazz., the main medicinal species recorded as Radix Hedysari in the Pharmacopoeia of China (2005). We recently found flavanols in this genus (Liu et al., 2005), and other compounds such as isoflavonones, chalcones, pterocarpans, benzofuranoids (Miyase et al., 1984), coumestans (Hai et al., 2002), lignans (Hai et al., 2003), organic acids, polysaccharides and phenols have been reported. There are reports on the bioactivity of the total saponins from H. polybotrys (Wang et al., 2000), but not on the identification of these saponins. 3. Present study The air-dried and powdered roots (6.7 kg) were extracted consecutively with 95% EtOH and 50% EtOH. The EtOH extract was concentrated under vacuum and the residue was suspended in water. The suspension was extracted successively with EtOAc and n-BuOH. The n-BuOH fraction was subjected to silica gel column chromatography (CHCl3eMeOHeH2O, 8:2:1, v/v/v), Diaion HP-20 column chromatography (eluted with water containing 0, 30, * Corresponding author. Department of Natural Medicines and State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing 100083, PR China. E-mail address: [email protected] (H.-B. Chen). 0305-1978/$ - see front matter Ó 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.bse.2006.12.008
390
Y. Liu et al. / Biochemical Systematics and Ecology 35 (2007) 389e391
R1
R2O CH2OH OH 1.
R1 =
2.
R1 =
3.
R1 =
4.
R1 =O
H
,
R2 =-glc UA Me 2 ara 2 rha
,
R2 =-glc UA 2 ara 2 rha
,
R2 =-glc UA 2 gal 2 rha
,
R2 =-glc UA 2 gal 2 rha
OH H OH H
Fig. 1. Structures of saponins 1e4.
50, 70, 100% MeOH), and semipreparative reversed-phase HPLC (phenomenex ODS column, 1 cm 25 cm, 36% aqueous MeCN, 204 nm) to yield compounds 1e4 (Fig. 1). The structures of compounds 1e4 were identified based on the physical and chemical properties and spectral data (1H, 13C NMR and 2D NMR) as well as by comparison with data in the literature. Compounds 1e4 were determined to be four saponins: soyasaponin II methyl ester (1) (Sakamoto et al., 1992), soyasaponin II (2) (Kitagawa et al., 1976), soyasaponin I (3) (Kubo et al., 1989) and dehydrosoyasaponin I (4) (Miyao et al., 1996). 4. Chemotaxonomic significance In recent years, we sequentially identified steroids, pterocarpins, coumarins (Hai et al., 2002), isoflavonoids, lignanoids (Hai et al., 2003) and alkaloids (Hai et al., 2004) from H. polybotrys. Saponins 1e4 have been isolated from H. polybotrys for the first time in the present study. The isoflavones are of particular interest because they are characteristic constituents differentiating the subfamily Papilionoideae from the other two subfamilies (Mimosoideae and Caesalpinioideae) of Leguminosae (Wu, 1991). In the subfamily Papilionoideae, flavonoids occur as various structural types and are generally distributed. A literature survey also shows that flavonoids, including isoflavones (Miyase et al., 1984; Wang et al., 2001, 2002), flavones (Alaniya, 1983; Chriki and Harborne, 1983; Glyzina and Bykov, 1969), flavanones (Miyase et al., 1984), isoflavans (Miyase et al., 1984) and xanthones (Miyase et al., 1984; Alaniya, 1983; Chriki and Harborne, 1983; Glyzina and Bykov, 1969; Glyzina, 1973; Pan et al., 1984; Wang et al., 2003), are the main classes of compounds isolated from species of the genus Hedysarum. Our phytochemical study on H. polybotrys (Hai et al., 2003) is also in accord with the above results.
Y. Liu et al. / Biochemical Systematics and Ecology 35 (2007) 389e391
391
In addition, lignanoids and alkaloids have been shown to be present in the subfamily Papilionoideae (Wu, 1991). Steroidal saponins and triterpenoid saponins are also obtained from many members of the subfamily Papilionoideae, e.g. methyl protodeltonin in genus Trigonella, glycyrrhetinic acid in genus Glycyrrhiza, and soyasaponin I in genus Astragalus (Wu, 1991). However, saponins, lignanoids and alkaloids have not been found from the genus Hedysarum. The present identification of saponins 1e4 (triterpenoid saponins), along with our former discovery of lignanoids (Hai et al., 2003) and alkaloids (Hai et al., 2004), shows that genus Hedysarum is similar to other genus of the subfamily Papilionoideae in chemical distribution, and this help to support the view that the genus Hedysarum is indeed a natural group belonging to the subfamily Papilionoideae. Acknowledgement This project was supported by the National Natural Science Foundation of China (20432030) and the Changjiang Scholar and Innovative Team in University (985-2-063-112). References Alaniya, M.D., 1983. Khim. Prir. Soedin 5, 646 (in Russian) (CA: 100:82749). China Pharmacopoeia Committee, 2005. China Pharmacopoeia, vol. I. Chemical Industry Press, 104 pp. Chriki, A., Harborne, J.B., 1983. Phytochemistry 22, 2322. Glyzina, G.S., 1973. Khim. Prir. Soedin. 9, 434 (in Russian) (CA: 79:79119h). Glyzina, G.S., Bykov, V.I., 1969. Khim. Prir. Soedin. 5, 322 (in Russian) (CA:72:39767). Hai, L.Q., Liang, H., Zhao, Y.Y., et al., 2002. China J. Chin. Mater. Med. 27, 843. Hai, L.Q., Zhang, Q.Y., Liang, H., et al., 2003. Acta Pharm. Sin. 38, 592. Hai, L.Q., Zhang, Q.Y., Zhao, Y.Y., et al., 2004. China J. Chin. Mater. Med. 29, 432. Kitagawa, I., Yoshikawa, M., Yosioka, I., 1976. Chem. Pharm. Bull. 24, 121. Kubo, T., Hamada, S., Nohara, T., et al., 1989. Chem. Pharm. Bull. 37, 2229. Liu, Y., Zhao, Y.Y., Chen, H.B., et al., 2005. Biochem. Syst. Ecol. 33, 809. Miyao, H., Sakai, Y., Takeshita, T., et al., 1996. Chem. Pharm. Bull. 44, 1222. Miyase, T., Fukushima, S., Akiyama, Y., 1984. Chem. Pharm. Bull. 32, 3267. Pan, J.X., Liu, W., Wang, D., et al., 1984. J. Beijing Med. Sch. 16, 248. Sakamoto, S., Kuroyanagi, M., Ueno, A., et al., 1992. Phytochemistry 31, 1339. Wang, W., You, C.G., Wang, Y., et al., 2000. J. Lanz. Univ. (Natural Sci.) 36, 107. Wang, W., Chen, W., Chen, H.B., et al., 2001. J. Pek. Univ. (Health Sci.) 33, 205. Wang, W., Chen, H.B., Wang, W.M., 2002. Acta Pharm. Sin. 37, 196. Wang, W., An, D.G., Chen, H.B., et al., 2003. J. Asian Nat. Prod. Res. 5, 31. Wu, Z.Y., 1991. Xinghua bencao gangyao, vol. II. Shanghai Science Press, pp. 80e84.