Guaianolides from Kaunia lasiophthalma

Phytochemistry,Vol. 29, No. 4, pp. 1219-1225, 1990.

0031-9422/90 $3.00 + 0.00 © 1990 Pergamon Press pie

Printed in Great Britain.

GUAIANOLIDES FROM K A U N I A LASIOPHTHALMA ADRIANA N. DE GUTIERREZ, EMMA E. SIGSTAD, C]~SAR A. N. CATALAN, ALICIA B. GUTII~RREZ* a n d WERNER HERZ* Instituto de Quimica Org~inica, Facultad de Bioquimica, Quimica y Farmacia, Universidad Nacional de Tucum~in, Ayacucho 491, S.M. de Tucum:in 4000, Argentina; *Department of Chemistry, The Florida State University, Tallahassee, FL 32306, U.S.A.

(Received 13 June 1989) Key Word Index--Kaunia lasiophthalma; Compositae; guaianolides; sesquiterpene lactones; structural elucidation.

A b s t r a c t - - E x t r a c t i o n o f t h e aerial p a r t s o f Kaunia lasiophthalma afforded six k n o w n a n d 13 n e w guaianolides. R e v i s i o n s in the s t e r e o c h e m i s t r y o f several k n o w n g u a i a n o l i d e s are suggested.

INTRODUCTION T h e S o u t h A m e r i c a n g e n u s Kaunia ( C o m p o s i t a e , Eup a t o r i e a e , s u b t r i b e O x y l o b i n a e ) includes 14 species previously p l a c e d in t h e t r a d i t i o n a l c o n c e p t o f Eupatoriurn [1]. Earlier w o r k o n the c h e m i s t r y o f three species revealed the p r e s e n c e o f t h y m o l derivatives a n d relatively simple g u a i a n o l i d e s [2, 3]. W e n o w r e p o r t the results o f o u r s t u d y o f K. lasiophthalma, a species native to s o u t h e r n Bolivia a n d n o r t h w e s t e r n A r g e n t i n a . I s o l a t e d f r o m the aerial p a r t s were a large n u m b e r o f 8 - u n s u b s t i t u t e d guaianolides. T h e s e include 8 - d e o x y c u m a m b r i n B (1) [3-5], dehydroleucodin (2a) I-5, 6], 2-oxo-8-

d e o x y l i g u s t r i n (3) 1,7], 2 - o x o l u d a r t i n (4) I-2] as well as l a c t o n e s 2b, c, 5, 6, 7a--e, a n d 8 a - 1 3 m o s t o f w h i c h are new.

RESULTS AND DISCUSSION W e begin with the n e w l a c t o n e s 2b a n d 2c ( 3 - c h l o r o and 3-hydroxydehydroleucodin) whose t H NMR spectra (Table 5) r e s e m b l e d t h a t o f 2a e x c e p t for t h e a b s e n c e o f the H-3 frequency, t h u s l e a d i n g to the s t e r e o c h e m i s t r y d e p i c t e d in the formulae. I n t h e case o f 2b, s u b s t i t u t i o n o f

Table 1. t a C N M R spectra of compounds 2b, c and 7b, d, e (67.89MHz, CDCI3)*

C

2b

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

128.75 187.30 136.88 160.54 51.23 84.13 52.91 24.28 37.23 154.74 138.23 168.68 119.09 22.36 17.35 OAc

1' 2' Y 4' 5'

-----

2e s s s s dt df d~ tt tt s s s tt qt qt

128.94 184.77 133.55 152.26 48.44 85.83 52.73 24.38 37.06 153.61 138.74 169.12 118.56 22.27 14.02 -------

s s s s d d d d t s s s t q q

7b

7b~

7d

7e

132.21 s 74.40 d t 64.10 d 64.70 s 52.70 d t 80.94 d 54.10 d t 24.89 t t 34.97 t t 143.51 s 138.89 s 168.91 s 118.18 t t 22.30 q t 19.15 q f 170.83s 20.66 q t ------

132.60s 74.62 d t 64.24 d t 64.74 s 52.20 d t 80.90 d t 54.08 d t 24.98 t t 35.07 t t 143.26 s 139.36 s 168.93 s 117.91 t t 22.33 q 19.36 q t 170.91 s 20.74 q t ------

132.51 s 74.34 d t 64.22 d 64.54 s 52.22 d# 81.06 d 54.22 d t 25.00it 34.99 t t 142.31 s 139.03 s 168.95 s 118.13 t t 22.51 q t 19.17 q t

132.51 s 74.47 d 64.29 d 64.59 s 52.12 d 81.05 d 54.21d 25.00t~ 35.02 t 142.10 s 138.17 s 168.11 s 118.11 t 22.33 q 19.17 q

177.09 34.10 19.06 18.91

167.93 128.17 138.17 14.33 11.98

* Multiplicities determined by DEPT pulse sequence. t Identified by heteronuclear decoupling. $ Run in CDCI3-C6D6(2: 1). § Assignments may be interchanged. 1219

s df q~ qt

s§ s d q q

Guaianolides

MS m/z (rel. int.) 263 ([M+ I]‘, 63.2), 245 (lOO), 227 (10.5), 217 (5.9) 139 (12.1). ‘HNMR spectrum in Table 5. (lS,2S,5R,6S,7S,lOS)-l,lO-Epoxy-2-hydroxygua~u-3, 11 (13)dien-6, 12-olide( l@, lo/&epoxy-2a-hydroxykaunioIide) (12). Gum; IR v$T cm-‘: 3437,1768,1648, 1257,1141,998,965. El MS m/z (rel. int.) 262 ([Ml’, 6.0). 247 (30.4) 244 (12.0), 229 (13.1), 216 (18.4), 215 (11.5), 201 (26.2) 191 (11.8) 189 (14.7), 188 (18.6). 187 (17.4) 185 (14.2), 183 (12.5), 175 (14.1) 174 (16.0), 173 (31.1), 172 (26.4) 172 (11.4), 167 (15.2). 95 (100). PC1 MS m/z (rel. int.) 263 ([M+l]+, 46.4) 245 (100) 227 (16.4). ‘HNMR spectrum in Table 6. (1S,2R,5R,6S,7S,10S)-1,10-Epoxy-2-hydroxyguaia-3,11(13)dien-6,12-olide( l/I,lOfi-epoxy-2/I-hydroxykauniolide) (13). Mp 126127” (without recrystallization). IR vkf; cm-‘: 3453, 1772, 1713,1667, 1256, 1138, 1021, 1001. UV $$~” nm: 221, ‘H NMR spectrum in Table 6. The material decomposed before MS could be run.

from Kaunia

6.

7. 8. 9. 10.

Acknowledgements-Work in Tucuman was supported by grants from Consejo National de Investigaciones Cientificas y Tecnicas (CONICET) and Consejo de Investigaciones de la Universidad de Tucuman.

REFERENCES

1. King,

R. M. and

Robinson,

Eupatorieae

(Asteraceae),

Monographs

in Systematic

H. (1987) The Genera OS the Missouri Botanical Gardens Botany, Vol. 22, pp. 448450.

11. 12. 13. 14. 15.

1225

Bohlmann, F., Kramp, W., Gupta, R. K., King, R. M. and Robinson, H. (1981) Phytochemistry 20. 2375. Bohlmann, F., Trinks, C., Jakupovic, J., King, R. M. and Robinson, H. (1984) Planta Med. 50, 284. Irwin, M. A. and Geissman, T. A. (1969) Phytochemistry 8, 305. Sosa, V. E., Oberti, J. C., Gil, R. R., Ruveda, E. A., Goedken, V. L., Gutiirrez, A. B. and Herz, W. (1989) Phytochemistry za, 1925. de Heluani, C. S., de Lampasona, M. P., Catalan, C. A. N., Goedken, V. L., Gutitrrez, A. B. and Herz, W. (1989) Phytochemistry 28, 1931. Zdero, C., Bohlmann, F., King, R. M. and Robinson, H. (1988) Phytochemistry 27, 2835. Gil, R. R., Pastoriza, J. A., Oberti, J. C., Gutierrez, A. B. and Herz, W. (1989) Phytochemistry 28, 2841. Irwin, M. A. and Geissman, T. A. (1973) Phytochemistry 12, 863. Kalsi, P. S., Kaur, G., Sharma, S. and Talwar, K. (1984) Phytochemistry 23, 2855. Bohlmann, F., Hartono, L., Jakupovic, J. and Huneck, S. (1985) Phytochemistry 24, 1003. Bohlmann, F., Zdero, C., King, R. M. and Robinson, A. (1984) Phytochemistry 23, 1187. Ando, M., Akahane, A., Yamaoka, H. and Takase, K. (1982) J. Org. Chem. 47, 3909. Fischer, N. H., Olivier, E. J. and Fischer, H. D. (1979) Progr. Chem. Org. Nat. Prod. 38, 47. Seaman, F. C. (1982) Bat. Rev. 48, 123.