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Iridoids from Scabiosa atropurpurea L. subsp. maritima Arc. (L.)
Biochemical Systematics and Ecology 38 (2010) 253–255
Contents lists available at ScienceDirect
Biochemical Systematics and Ecology journal homepage: www.elsevier.com/locate/biochemsyseco
Iridoids from Scabiosa atropurpurea L. subsp. maritima Arc. (L.) ¨ zgen Alankus-Caliskan a, *, Tamer Karayildirim a, Erdal Bedir b Emre Polat a, O a b
Department of Chemistry, Faculty of Science, Ege University, Bornova, Izmir 35100, Turkey Department of Bioengineering, Faculty of Engineering, Ege University, Bornova, Izmir 35100, Turkey
a r t i c l e i n f o Article history: Received 20 July 2009 Accepted 6 January 2010 Keywords: Scabiosa atropurpurea L. subsp. maritima Iridoids Loganic acid Loganin Sweroside Cantleyoside
1. Subject and source Scabiosa genus is represented by 34 taxa in the flora of Turkey (Davis, 1972), including Scabiosa atropurpurea L. subsp. maritima which has a wide distribution within Turkey. An infusion of the flower heads of S. atropurpurea has been used externally as anti-acneic in the Iberian Peninsula (Angels Bonet et al., 1999). The roots and flowers of S. atropurpurea L. subsp maritima (L.) Arc. were collected from Urla, Izmir, Turkey in June 2002 and identified by Serdar Gokhan Senol. Voucher specimen (EGE 40781) was deposited in the Herbarium of Science Faculty, Ege University, Izmir, Turkey. 2. Previous work Previous phytochemical studies have revealed mainly triterpene saponins (Baykal et al., 1998; Zheng et al., 2004) and iridoids (Horn et al., 2001; Papalexandrou et al., 2003) as the main constituents in members of the genus. No previous phytochemical work has been reported on S. atropurpurea L subsp. maritima. 3. Present study The roots and flowers of the plant were studied apart from each other. Air-dried and grinded flowers of the plant (376 g) were extracted with MeOH (2 3 L) at room temperature. After filtration and removal of the solvent under vacuum, the crude residue was obtained as a gummy mixture (112.38 g).
* Corresponding author. Tel.: þ90 232 388 4000x2369; fax: þ90 232 388 8264. ¨ . Alankus-Caliskan). E-mail address: [email protected] (O 0305-1978/$ – see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.bse.2010.01.004
254
E. Polat et al. / Biochemical Systematics and Ecology 38 (2010) 253–255
The MeOH extract (20 g) was subjected to VLC using silica gel material (Merck 7734, 130 g), employing ether (500 mL), CH2Cl2 (150 mL), EtOAc (500 mL), CHCl3–MeOH–H2O (80.20:2, 50 mL; 61:32:7, 200 mL; 64:50:10, 200 mL), MeOH (100 mL), and three main fractions (Fr. K1,3) were obtained. Fraction K3 (1.99 g) which was eluted with MeOH and CHCl3–MeOH–H2O (64:50:10) was subjected to VLC using reversed-phase material (LiChroprep RP-18, 100 g). Elution was started with H2O (2 100 mL) and then H2O–MeOH mixtures with an increasing amount of MeOH (80:20, 100 mL; 60:40, 300 mL; 40:60, 100 mL; 20:80, 200 mL) yielded 6 fractions (Fr. A1–6). Fraction A3 (476 mg) was fractionated over Sephadex LH-20 (100 g). 41 fractions were collected. Fractions 9–21 (186.9 mg) were combined and rechromatographed over silica gel (50 mg). Elution was performed with CHCl3–MeOH–H2O mixtures (70.30:3, 600 mL; 61:32:7, 600 mL; 64:50:10, 500 ml) to yield 290 fractions. Fractions 75–106 (39.3 mg) were combined and applied to Sephadex LH-20 (40 g) employing with MeOH (150 mL) to afford 38 fractions. Fractions 11–14 (32 mg) were combined and fractionated over reversed-phase material (LiChroprep RP-18, 30 g) using H2O–MeOH (7:3, 100 mL) to give 29 fractions. Fractions 12–16 (7.4 mg) were combined and afforded compound 1 (7.4 mg). Fraction K1 (6 g) was applied to VLC using Al2O3 material (200 g). Elution was started with MeOH (18 100 mL) followed by MeOH-H2O gradient (95:5, 100 mL; 90:10, 100 mL; 80:20, 100 mL; 70:30, 100 mL; 60:40, 100 mL; 50:50, 100 mL). MeOH5–6 (330.4 mg) were combined and fractionated over reversed-phase material (30 g). Elution was performed with H2O (100 mL), H2O–MeOH gradient (97.5:2.5, 400 mL; 95:5, 100 mL) and finally with MeOH (200 mL). MeOH fraction (214.2 mg) was purified on a reversed-phase column (30 g) to give compounds 2 (16.4 mg) and 3 (17.7 mg). Air-dried and grinded roots (925 g) of the plant were extracted with MeOH (2 4.5 L) at 50 C. After filtration of the extract, MeOH phase was evaporated under reduced pressure. The crude extract (110 g) was dissolved in acetone and a solid precipitate was obtained by filtration (58 g). Acetone-soluble fraction was evaporated to dryness (52 g) and an aliquot (3 g) was subjected to column chromatography over reversed-phase material (100 g). Elution was started with H2O (350 mL) and followed by H2O–MeOH gradient (95:5, 100 mL; 92.5:7.5, 350 mL; 90:10, 250 mL; 85:15, 200 mL; 80:20, 300 mL; 75:25, 300 mL; 70:30, 250 mL; 65:35, 250 mL; 60:40, 50 mL; 55:45, 250 mL; 50:50, 200 mL) and MeOH (200 mL) to give 610
O
OR
O
O
H
HO O H 3C
O OH
H O
O
OH
OH
HO
R
1
H
2
CH3
O O
O
O HO
OH
3
HO
HO
OH
HO
OH
Compound
O
O
OCH3
H
O OH
H
O
H
O H3C
O
H
OH
H O
O HO
4 Fig. 1. Loganic acid (1), Loganin (2), Sweroside (3), Cantleyoside (4).
OH OH
E. Polat et al. / Biochemical Systematics and Ecology 38 (2010) 253–255
255
fractions. Fractions 562–610 (343.9 mg) were combined and subjected to silica gel column chromatography (70 g) using CHCl2–MeOH–H2O solvent system (80:20:1, 900 mL) yielding 150 fractions. The fractions 74–80 and 86–124 afforded compound 4 (25.8 mg). Spectral data (1H-NMR, 13C-NMR and HR-ESI-MS) were used to determine the structures of the compounds as loganic acid (1) (Calis et al., 1984; Tomita and Mouri, 1996), loganin (2) (Jensen et al., 1979; Kawai et al., 1988), sweroside (3) (El-Naggar and Beal, 1981; Machida et al., 1995) and cantleyoside (4) (Jensen et al., 1979; El-Naggar and Beal, 1981) (Fig. 1). 4. Chemotaxonomic significance In the present study, we have shown that flowers and roots of S. atropurpurea contain mainly iridoid glycosides. Previous studies have investigated the chemistry of Scabiosa rotata, Scabiosa tschiliensis, Scabiosa hymettia, Scabiosa caucasica, Scabiosa columbaria and Scabiosa variifolia. S. rotata (Baykal et al., 1998) and S. tschiliensis (Zheng et al., 2004) contained saponin glycosides, whereas flavonoids and oleanolic acid were identified in S. caucasica (Garaev et al., 2008), and coumarins, flavonoids and iridoid glycosides were identified from S. hymettia (Christopoulou et al., 2008). Phytochemical studies on S. columbaria (Horn et al., 2001) and S. variifolia (Papalexandrou et al., 2003) afforded only iridoid glycosides (loganin, loganic acid, sweroside, swertiamarin and cantleyoside), which is similar to our results for S. atropurpurea L subsp. maritima. The iridoids loganin (2) and loganic acid (1) were demonstrated to be chemotaxonomic markers of the family Dipsacaceae (Jensen et al., 1979; Horn et al., 2001; Papalexandrou et al., 2003; Christopoulou et al., 2008) which is supported by these results. Among the iridoid containing Scabiosa species, it was noted that at least one seco-iridoid glucoside was present: Sweroside (S. variifolia, S. columbaria and S. atropurpurea subsp. maritima) or swertiamarin (S. hymettia and S. variifolia). Therefore it is suggested that aforesaid seco-iridoids might also be of assistance as chemotaxonomic markers in the Scabiosa genus together with loganin and loganic acid. The studies by Baykal et al. (1998) and Zheng et al. (2004) focused on the saponin glycosides in Scabiosa rather than iridoids. Additionally only flowers of S. caucasica affording oleanolic acid and flavonoids (Garaev et al., 2008) were studied phytochemically. Thus, it is not logical to speculate that chemotaxonomic markers of the Dipsacaceae family (loganin, loganic acid and their derivatives) were not represent in the species of Scabiosa they studied. Consequently, based on the presence of marker iridoids and seco-iridoids, our study on S. atropurpurea subsp. maritima provided evidence for Dipsacaceae family as being very close phylogenetic relative of Oleaceae, Gentianacae, Loganiacea and Hernandiaceae families in accordance with Jensen and Nielsen’s proposition (Jensen et al., 1979). Acknowledgements The authors are grateful Dr. Serdar Gokhan Senol for their helpful assistance in the collection and identification of the plant material. References Angels Bonet, M., Parada, M., Selga, A., Valles, J., 1999. J. Ethnopharmacol. 68, 145. Baykal, T., Panayir, T., Tasdemir, D., Sticher, O., Calis, I., 1998. Phytochemistry 48, 867. Calis, I., Lahloub, M.F., Sticher, O., 1984. Helv. Chim. Acta 67, 160. Christopoulou, C., Graikou, K., Chinou, I., 2008. Chem. Biodivers. 5, 318. Davis, P.H., 1972. Flora of Turkey and the East Aegean Islands. University Press, Edinburg. El-Naggar, L.J., Beal, J.L., 1981. Iridoids. A review. J. Nat. Prod 43, 647. Garaev, E.A., Movsumov, I.S., Isaev, M.I., 2008. Chem. Nat. Compd. 44, 520. Horn, M.M., Drewes, S.E., Brown, N.J., Munro, O.Q., Meyer, J.J.M., Mathekga, A.D.M., 2001. Phytochemistry 57, 51. Jensen, S.R., Lyse-Petersen, S.E., Nielsen, B.J., 1979. Phytochemistry 18, 273. Kawai, H., Kuroyanagi, M., Veno, A., 1988. Chem. Pharm. Bull. 36, 3664. Machida, K., Asano, J., Kikuchi, M., 1995. Phytochemistry 39, 111. Papalexandrou, A., Magiatis, P., Perdetzoglou, D., Skaltsounis, A.L., Chinou, I.B., Harvala, C., 2003. Biochem. Syst. Ecol 31, 91. Tomita, H., Mouri, Y., 1996. Phytochemistry 42, 239. Zheng, Q., Koike, K., Han, L., Okoda, H., Nikaido, T., 2004. J. Nat. Prod 67, 604.
Contents lists available at ScienceDirect
Biochemical Systematics and Ecology journal homepage: www.elsevier.com/locate/biochemsyseco
Iridoids from Scabiosa atropurpurea L. subsp. maritima Arc. (L.) ¨ zgen Alankus-Caliskan a, *, Tamer Karayildirim a, Erdal Bedir b Emre Polat a, O a b
Department of Chemistry, Faculty of Science, Ege University, Bornova, Izmir 35100, Turkey Department of Bioengineering, Faculty of Engineering, Ege University, Bornova, Izmir 35100, Turkey
a r t i c l e i n f o Article history: Received 20 July 2009 Accepted 6 January 2010 Keywords: Scabiosa atropurpurea L. subsp. maritima Iridoids Loganic acid Loganin Sweroside Cantleyoside
1. Subject and source Scabiosa genus is represented by 34 taxa in the flora of Turkey (Davis, 1972), including Scabiosa atropurpurea L. subsp. maritima which has a wide distribution within Turkey. An infusion of the flower heads of S. atropurpurea has been used externally as anti-acneic in the Iberian Peninsula (Angels Bonet et al., 1999). The roots and flowers of S. atropurpurea L. subsp maritima (L.) Arc. were collected from Urla, Izmir, Turkey in June 2002 and identified by Serdar Gokhan Senol. Voucher specimen (EGE 40781) was deposited in the Herbarium of Science Faculty, Ege University, Izmir, Turkey. 2. Previous work Previous phytochemical studies have revealed mainly triterpene saponins (Baykal et al., 1998; Zheng et al., 2004) and iridoids (Horn et al., 2001; Papalexandrou et al., 2003) as the main constituents in members of the genus. No previous phytochemical work has been reported on S. atropurpurea L subsp. maritima. 3. Present study The roots and flowers of the plant were studied apart from each other. Air-dried and grinded flowers of the plant (376 g) were extracted with MeOH (2 3 L) at room temperature. After filtration and removal of the solvent under vacuum, the crude residue was obtained as a gummy mixture (112.38 g).
* Corresponding author. Tel.: þ90 232 388 4000x2369; fax: þ90 232 388 8264. ¨ . Alankus-Caliskan). E-mail address: [email protected] (O 0305-1978/$ – see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.bse.2010.01.004
254
E. Polat et al. / Biochemical Systematics and Ecology 38 (2010) 253–255
The MeOH extract (20 g) was subjected to VLC using silica gel material (Merck 7734, 130 g), employing ether (500 mL), CH2Cl2 (150 mL), EtOAc (500 mL), CHCl3–MeOH–H2O (80.20:2, 50 mL; 61:32:7, 200 mL; 64:50:10, 200 mL), MeOH (100 mL), and three main fractions (Fr. K1,3) were obtained. Fraction K3 (1.99 g) which was eluted with MeOH and CHCl3–MeOH–H2O (64:50:10) was subjected to VLC using reversed-phase material (LiChroprep RP-18, 100 g). Elution was started with H2O (2 100 mL) and then H2O–MeOH mixtures with an increasing amount of MeOH (80:20, 100 mL; 60:40, 300 mL; 40:60, 100 mL; 20:80, 200 mL) yielded 6 fractions (Fr. A1–6). Fraction A3 (476 mg) was fractionated over Sephadex LH-20 (100 g). 41 fractions were collected. Fractions 9–21 (186.9 mg) were combined and rechromatographed over silica gel (50 mg). Elution was performed with CHCl3–MeOH–H2O mixtures (70.30:3, 600 mL; 61:32:7, 600 mL; 64:50:10, 500 ml) to yield 290 fractions. Fractions 75–106 (39.3 mg) were combined and applied to Sephadex LH-20 (40 g) employing with MeOH (150 mL) to afford 38 fractions. Fractions 11–14 (32 mg) were combined and fractionated over reversed-phase material (LiChroprep RP-18, 30 g) using H2O–MeOH (7:3, 100 mL) to give 29 fractions. Fractions 12–16 (7.4 mg) were combined and afforded compound 1 (7.4 mg). Fraction K1 (6 g) was applied to VLC using Al2O3 material (200 g). Elution was started with MeOH (18 100 mL) followed by MeOH-H2O gradient (95:5, 100 mL; 90:10, 100 mL; 80:20, 100 mL; 70:30, 100 mL; 60:40, 100 mL; 50:50, 100 mL). MeOH5–6 (330.4 mg) were combined and fractionated over reversed-phase material (30 g). Elution was performed with H2O (100 mL), H2O–MeOH gradient (97.5:2.5, 400 mL; 95:5, 100 mL) and finally with MeOH (200 mL). MeOH fraction (214.2 mg) was purified on a reversed-phase column (30 g) to give compounds 2 (16.4 mg) and 3 (17.7 mg). Air-dried and grinded roots (925 g) of the plant were extracted with MeOH (2 4.5 L) at 50 C. After filtration of the extract, MeOH phase was evaporated under reduced pressure. The crude extract (110 g) was dissolved in acetone and a solid precipitate was obtained by filtration (58 g). Acetone-soluble fraction was evaporated to dryness (52 g) and an aliquot (3 g) was subjected to column chromatography over reversed-phase material (100 g). Elution was started with H2O (350 mL) and followed by H2O–MeOH gradient (95:5, 100 mL; 92.5:7.5, 350 mL; 90:10, 250 mL; 85:15, 200 mL; 80:20, 300 mL; 75:25, 300 mL; 70:30, 250 mL; 65:35, 250 mL; 60:40, 50 mL; 55:45, 250 mL; 50:50, 200 mL) and MeOH (200 mL) to give 610
O
OR
O
O
H
HO O H 3C
O OH
H O
O
OH
OH
HO
R
1
H
2
CH3
O O
O
O HO
OH
3
HO
HO
OH
HO
OH
Compound
O
O
OCH3
H
O OH
H
O
H
O H3C
O
H
OH
H O
O HO
4 Fig. 1. Loganic acid (1), Loganin (2), Sweroside (3), Cantleyoside (4).
OH OH
E. Polat et al. / Biochemical Systematics and Ecology 38 (2010) 253–255
255
fractions. Fractions 562–610 (343.9 mg) were combined and subjected to silica gel column chromatography (70 g) using CHCl2–MeOH–H2O solvent system (80:20:1, 900 mL) yielding 150 fractions. The fractions 74–80 and 86–124 afforded compound 4 (25.8 mg). Spectral data (1H-NMR, 13C-NMR and HR-ESI-MS) were used to determine the structures of the compounds as loganic acid (1) (Calis et al., 1984; Tomita and Mouri, 1996), loganin (2) (Jensen et al., 1979; Kawai et al., 1988), sweroside (3) (El-Naggar and Beal, 1981; Machida et al., 1995) and cantleyoside (4) (Jensen et al., 1979; El-Naggar and Beal, 1981) (Fig. 1). 4. Chemotaxonomic significance In the present study, we have shown that flowers and roots of S. atropurpurea contain mainly iridoid glycosides. Previous studies have investigated the chemistry of Scabiosa rotata, Scabiosa tschiliensis, Scabiosa hymettia, Scabiosa caucasica, Scabiosa columbaria and Scabiosa variifolia. S. rotata (Baykal et al., 1998) and S. tschiliensis (Zheng et al., 2004) contained saponin glycosides, whereas flavonoids and oleanolic acid were identified in S. caucasica (Garaev et al., 2008), and coumarins, flavonoids and iridoid glycosides were identified from S. hymettia (Christopoulou et al., 2008). Phytochemical studies on S. columbaria (Horn et al., 2001) and S. variifolia (Papalexandrou et al., 2003) afforded only iridoid glycosides (loganin, loganic acid, sweroside, swertiamarin and cantleyoside), which is similar to our results for S. atropurpurea L subsp. maritima. The iridoids loganin (2) and loganic acid (1) were demonstrated to be chemotaxonomic markers of the family Dipsacaceae (Jensen et al., 1979; Horn et al., 2001; Papalexandrou et al., 2003; Christopoulou et al., 2008) which is supported by these results. Among the iridoid containing Scabiosa species, it was noted that at least one seco-iridoid glucoside was present: Sweroside (S. variifolia, S. columbaria and S. atropurpurea subsp. maritima) or swertiamarin (S. hymettia and S. variifolia). Therefore it is suggested that aforesaid seco-iridoids might also be of assistance as chemotaxonomic markers in the Scabiosa genus together with loganin and loganic acid. The studies by Baykal et al. (1998) and Zheng et al. (2004) focused on the saponin glycosides in Scabiosa rather than iridoids. Additionally only flowers of S. caucasica affording oleanolic acid and flavonoids (Garaev et al., 2008) were studied phytochemically. Thus, it is not logical to speculate that chemotaxonomic markers of the Dipsacaceae family (loganin, loganic acid and their derivatives) were not represent in the species of Scabiosa they studied. Consequently, based on the presence of marker iridoids and seco-iridoids, our study on S. atropurpurea subsp. maritima provided evidence for Dipsacaceae family as being very close phylogenetic relative of Oleaceae, Gentianacae, Loganiacea and Hernandiaceae families in accordance with Jensen and Nielsen’s proposition (Jensen et al., 1979). Acknowledgements The authors are grateful Dr. Serdar Gokhan Senol for their helpful assistance in the collection and identification of the plant material. References Angels Bonet, M., Parada, M., Selga, A., Valles, J., 1999. J. Ethnopharmacol. 68, 145. Baykal, T., Panayir, T., Tasdemir, D., Sticher, O., Calis, I., 1998. Phytochemistry 48, 867. Calis, I., Lahloub, M.F., Sticher, O., 1984. Helv. Chim. Acta 67, 160. Christopoulou, C., Graikou, K., Chinou, I., 2008. Chem. Biodivers. 5, 318. Davis, P.H., 1972. Flora of Turkey and the East Aegean Islands. University Press, Edinburg. El-Naggar, L.J., Beal, J.L., 1981. Iridoids. A review. J. Nat. Prod 43, 647. Garaev, E.A., Movsumov, I.S., Isaev, M.I., 2008. Chem. Nat. Compd. 44, 520. Horn, M.M., Drewes, S.E., Brown, N.J., Munro, O.Q., Meyer, J.J.M., Mathekga, A.D.M., 2001. Phytochemistry 57, 51. Jensen, S.R., Lyse-Petersen, S.E., Nielsen, B.J., 1979. Phytochemistry 18, 273. Kawai, H., Kuroyanagi, M., Veno, A., 1988. Chem. Pharm. Bull. 36, 3664. Machida, K., Asano, J., Kikuchi, M., 1995. Phytochemistry 39, 111. Papalexandrou, A., Magiatis, P., Perdetzoglou, D., Skaltsounis, A.L., Chinou, I.B., Harvala, C., 2003. Biochem. Syst. Ecol 31, 91. Tomita, H., Mouri, Y., 1996. Phytochemistry 42, 239. Zheng, Q., Koike, K., Han, L., Okoda, H., Nikaido, T., 2004. J. Nat. Prod 67, 604.