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Journal of the Mexican Chemical Society
versão impressa ISSN 1870-249X
J. Mex. Chem. Soc vol.56 no.2 Ciudad de México Abr./Jun. 2012
Article
Orizabolide, a New Withanolide from Physalis orizabae
Emma Maldonado,1* Rodrigo Gutiérrez,1 Ana L. PérezCastorena,1 and Mahinda Martínez2
1 Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, Coyoacán, 04510, D. F., México. *emmaldon@unam.mx. Telephone +52 555624412.
2 Facultad de Ciencias Naturales, Universidad Autónoma de Querétaro, Avenida de las Ciencias s/n, Col. Junquilla 76230, Querétaro, Qro., México.
Received August 29, 2011.
Accepted February 8, 2012.
Abstract
A new withanolide, orizabolide (1), together with the known flavonoid rutin (2) were isolated from the aerial parts of Physalis orizabae. Structural elucidation of these compounds was carried out by interpretation of their spectroscopic data.
Key words: Solanaceae, Physalis orizabae, withanolide, orizabolide, rutin.
Resumen
Una nueva withanólida, orizabólida (1), junto con el conocido flavonoide rutina (2) fueron aislados de las partes aéreas de Physalis orizabae. La elucidación estructural de estos compuestos se llevó a cabo por interpretación de sus datos espectroscópicos.
Palabras clave: Solanaceae, Physalis orizabae, withanólida, orizabólida, rutina.
Physalis is a genus of the Solanaceae family with ca. 90 species, most of them endemic to Mexico [1]. These plants are a recognized source of withasteroids, which are ergostane type steroids with a lactone or lactol at the C17 side chain. These compounds usually exhibit significant biological activities [24]. Nevertheless, withasteroids are not the only constituents of Physalis species; they also contains ceramides [5], sucrose esters [6,7], amides, homoergostanes [7], labdane diterpenes [7,8], and flavonoids [610]. The flavonoids isolated from Physalis are flavones and flavonols, which usually are present as glycosides. As a continuation of our studies on this genus we have investigated Physalis orizabae Dunal, an herbaceous, perennial plant, growing in Western and Central Mexico [11], which is used to treat diarrhea and gallbladder disease [12]. This study led to the isolation and structural elucidation of the new withanolide, orizabolide (1), and the known flavonoid rutin (2) which was present in a high concentration in this plant.
Results and Discussion
Orizabolide (1) was isolated as colorless crystals. Its ESIMS showed a pseudomolecular ion peak at m/z 567 [M + Na]+, which together with the 13C NMR spectrum exhibiting 30 signals allow to propose the molecular formula C30H40O9 [13]. The IR spectrum showed the absorption for hydroxyl group at 3369 cm1, and a broad band at 1710 cm1, whose second derívate indicated the presence of ester (1734 cm1), α,βunsaturatedδlactone (1711 cm1), α,βunsaturated ketone (1686 cm1), and double bonds (1659 cm1). The 13C NMR spectrum exhibited two signals corresponding to an acetyl group (5 171.2 and 21.0). The above mentioned and the 1H NMR signals at 5 5.76 (ddd, J = 10, 3, 1.5 Hz, H2), 6.85 (ddd, J = 10, 5, 2.5 Hz, H3), 3.32 (br d, J = 21.5 Hz, H4a), 2.86 (br dd J = 21.5, 5 Hz, H4b), and 5.61 (dt, J = 6, 2 Hz, H6), allowed to propose that 1 was an acetyl withanolide possessing a 2,5dien1one system in rings A/B. The presence of the dienone was supported by the carbon signals at ô 204.1 (C1), 128.2 (C2), 146.4 (C3), 34.0 (C4), 136.5 (C5), and 125.8 (C6), and confirmed by the HMBC correlations of H4b with C2, C3, C5, C6, and C10 (5 51.5), of H6 with C4, C7 (5 26.48), C8 (5 38.5), and C10, and those of H319 (5 1.19 s) with C1, C5, C9 (5 36.9), and C10. The presence of an α,βunsaturatedδlactone was evident from the NMR signals for a δlactone carbonyl (δ 166.4, C26), two olefinic carbons (δ 153.4, C24 and δ 121.6, C25), a methylene (δh 3.23 and 2.39, δc 29.7, CH223), an oxymethyne (δH 4.92, δC 82.1, CH22), a methyl (δH 1.82, δC 11.9, CH327), and an oxymethylene (δH 4.41 and 4.28, δC 61.7, CH228). These assignations were based on the correlations of H27 with C24, C25 and C26, and those of H28 with C23, C24 and C25, observed in the HMBC spectrum. The oxygenated function bonded to C28 was an hydroxyl group, whose proton signal appeared at δ 4.18 and showed interactions with both C28 protons in the COSY spectrum, and with C24 in the HMBC spectrum. The multiplicity of H22 (dd, J = 13, 3 Hz) and its HMBC correlations with an oxygenated non protonated carbon (δ 79.7, C20) and with a methyl carbon (δ 19.4, CH321) established the presence of an hydroxyl group at C20. Two additional signals for oxygenated nonprotonated carbons were observed at δ 88.9 and 81.7. The first signal was attributed to C17 on the basis of its correlations, in the HMBC spectrum, with H321, H215 (5 1.61), H216 (5 2.66, 1.72), H218 (δ 4.38), and OH (δ 3.93). The last signal was assigned to a 17OH group by its correlations, in the HMBC spectrum, with C13 (δ 58.2), C16 (δ 37.9), C17, and C20. Signal at δ 81.7 was assigned to C14 on the basis of the observed HMBC correlations with H215, H16β (5 1.72) and H218. The acetoxy group was bonded to CH218, as indicated by the chemical shifts of this methylene (δC 65.2, δH 4.38, 2H) and the correlations of H218 with the acetoxy carbonyl (δ 171.2), and with C12 (δ 26.53), C13, C14, and C17. The configuration of C22 was established as R on the basis of the H22 coupling constants (J = 13, 3 Hz) [14]. The βorientation of the 17OH group was deduced from its NOESY correlations with H218 and H16β. On the other hand, the NOESY correlations of H218 with H8β, H11β (δ 1.43), and H15 are only possible if the hydroxyl group at C14 is αoriented, since Dreiding models of the C14 epimer, indicated two possible conformations: In the first one, with ring C in a chair conformation, NOE of H218 with H8β and H11β, but no with H15β should be observed. On the contrary, in the second one, ring C adopts a twist boat conformation, in which H218 should show NOE only with H15β. Supporting these assumptions, the chemical shifts of C9C17 signals of 1 are similar to those of the quite related compounds physacoztolide D [8] and physachenolide A, whose structure was confirmed by Xray diffraction analysis [15].
The flavonoid glycoside rutin (2) was also isolated from this plant and identified by comparison of its physical and spectroscopic data, and those of its decaacetyl derivative, with those in the literature [1618]. The presence of large amounts of rutin in this plant is interesting due to its relevant biological activities. It is an inhibitor of rat intestinal αglucosidases [19], and shows, among others, antioxidant, antigastric, antiHelicobacter pilori, and hepatoprotective activities [2022].
Experimental Section
General Experimental Procedures. Melting points are uncorrected. Column chromatography (CC) was performed on silica gel 60 (Merck G) and assisted with vacuum. TLC was carried out on precoated MachereyNagel Sil G/UV254 plates of 0.25 mm thickness. Preparative TLC was carried out on precoated MachereyNagel Sil G/UV254 plates of 2.0 mm thickness. Optical rotation was measured on a UVVis Shimadzu U160 polarimeter. The IR spectra were recorded on a FTIR Bruker Tensor 27 spectrometer. 1H and 13C NMR spectra were recorded on a Varian Unity Plus 500 spectrometer, with TMS as internal standard. ESIMS were recorded on an ESI Ion trap Bruker Esquire 6000 mass spectrometer.
Plant Material. Aerial parts of Physalis orizabae Dunal were collected in Ocoyoacac, State of México, México, on August 2006. A voucher specimen of the plant (EMJ8) was identified by Dr. Mahinda Martínez and deposited at the Herbarium of the Universidad Autónoma de Querétaro.
Extraction and Isolation. Dried and ground leaves, flowers and stems of P. orizabae (284.8 g) were extracted with Me2CO and then with MeOH. These extracts showed similar profiles by TLC; therefore, they were combined (60.94 g) and partitioned between EtOAcH2O to obtain 17.9 g of the EtOAc fraction. A yellow solid (5.34 g) was filtered off from the aqueous fraction. The EtOAc fraction was fractioned by CC (column A) eluted with mixtures of hexaneEtOAc of increasing polarity. Fractions eluted with hexaneEtOAc 3:2 to 2:3 were combined (2.08 g). They were discolored with activated charcoal and purified by column chromatography eluted with hexaneMe2CO 4:1 to 1:1. Fractions eluted with hexaneMe2CO 3:1 (187 mg) were submitted to column chromatography (CH2Cl2Me2CO 4:1), followed by preparative TLC (hexaneEtOAc 1:4; 3 runs) and crystallization (EtOAchexane) to obtain compound 1 (12.7mg). Compound 2 (3.97 g) was obtained by crystallization of the yellow solid obtained from the aqueous phase. Acetylation of 2 (74.5 mg) in the usual manner gave 96.9 mg of its decaacetyl derivative.
Orizabolide (1). Pale yellowish crystals, mp 174176 °C; [α] D + 38 ° (c 0.21, MeOH); IR (KBr): vmax 3369, 1710 cm1 (second derivate: 1734, 1711, 1686, 1659 cm1); 1H and 13C NMR: Table 1; ESIMS m/z: 567.3 [M + Na]+.
Acknowledgements
Authors thank to Héctor Ríos, Ángeles Peña, Elizabeth Huerta, Rocío Patiño, Eréndira García, Carmen Márquez, Luis Velasco, and Javier Pérez for technical assistance. We thank to CONACyT for financial support to this work (Project 34993N).
References
1. Martínez, M. Revision of Physalis Section Epeteiorhiza (Solanaceae). Anales del Instituto de Biología, Universidad Nacional Autónoma de México, Serie Botánica 1998; 69, 71117. [ Links ]
2. Ray, A. B.; Gupta, M. Withasteroids, a growing group of naturally occurring steroidal lactones, in: Prog. Chem. Org. Nat. Prod., Vol. 63, Herz, W.; Kirby, G. W.; Moore, R. E; Steglich, W., Tamm, Ch. Eds., Springer Verlag, Wien. 1994, 1106. [ Links ]
3. Tomassini, T. C. B.; Barbi, N. S.; Ribeiro, I. M.; Xavier, D. C. D. Quim. Nova 2000, 23, 4757. [ Links ]
4. Maldonado, E.; Amador, S.; Martínez, M.; PérezCastorena, A. L. Steroids, 2010, 75, 346349. [ Links ]
5. Su, B. N.; Misico, R.; Park, E. J.; Santarsiero, B. D.; Mesecar, A. D. ; Fong, H. H. S.; Pezzuto, J. M.; Kinghorn, A. D. Tetrahedron 2002, 58, 34533466. [ Links ]
6. Maldonado, E.; Torres, F. R.; Martínez, M.; PérezCastorena, A. L. J. Nat. Prod. 2006, 69, 15111513. [ Links ]
7. PérezCastorena, A. L.; Martínez, M.; Maldonado, E. J. Nat. Prod, 2010, 73, 12711276. [ Links ]
8. PérezCastorena, A. L.; Oropeza, R. F.; Martínez, M.; Maldonado, E. J. Nat. Prod, 2006, 69, 10291033. [ Links ]
9. Sahai, M.; Neogi, P. J. Indian Chem. Soc. 1984, 61, 170171. [ Links ]
10. Ismail, N.; Alam, M. Fitoterapia 2001, 72, 676679. [ Links ]
11. Vargas Ponce, O.; Martínez y Díaz, M.; Dávila Aranda, P. La familia Solanaceae en Jalisco. El género Physalis. Colección Flora de Jalisco. México. Universidad de Guadalajara 2003. [ Links ]
12. Santiaguillo, H. J. F.; Blas, Y. S. Rev. Geo. Agric. 2009, 43, 8186. [ Links ]
13. Orizabolide (1) is a labile compound. It was not possible to obtain its HRMS. [ Links ]
14. Minguzzi, S.; Barata, L. E. S.; Shin, Y. G.; Jonas, P. F.; Chai, H. B.; Park, E. J.; Pezzuto, J. M.; Cordell, G. A. Phytochemistry 2002, 59, 635641. [ Links ]
15. Maldonado, E.; Torres, F. R.; Martínez, M.; PérezCastorena, A. L. Planta Med. 2004, 70, 5964 [ Links ]
16. Kazuma, K.; Noda, N.; Suzuki, M. Phytochemistry 2003, 62, 229237. [ Links ]
17. ElSeedi, H. R.; Sobaih, S. A. M. Rev. Latinoamer. Quím. 1999, 27, 1721. [ Links ]
18. Nishida, R.; Ohsugi, T.; Fukami, H.; Nakahima, S. Agric. Biol. Chem. 1990, 54, 12651270. [ Links ]
19. Jo, S. H.; Ka, E. H.; Lee, H. S.; Apostolidis, E.; Jang, H. D.; Kwon, Y. I. Int. J. Appl. Res. Nat. Prod. 2010, 2, 5260. [ Links ]
20. Slimestad, R.; Verheul, M. J. Agric. Food Chem. 2011, 59, 31803185. [ Links ]
21. Jeong, C. S. Biomol. Ther. 2009, 17, 199204. [ Links ]
22. Kanchana, A.; Heleena, S. A.; Ayyappan S. R. J. Pharm. Res. 2010, 3, 19911996. [ Links ]