Alkaloids from Behria tenuiflora

Letters

C-i, (100.3, 100.3), C-2' (779b 78.9), C-3' (779b769) C-4' (78.8, 78.2), C-5' (76.9, 77.9), C-6' (61.4, 61.4), C-i" (102.0, 102.0),C-2" (72.5, 72.5), C-3" (72.8,72.8), C-4" (74.Ic, 73.9) C-5"(69.5, 69.4),C-6" (18.6, 18.6), c-I',' (102.9, 102.9), C-2" (72.5, 72. 5),C-3" (72.7, 72.8),C-4" (73. 9C, 74.I),C-5" (70.4, 70.4), C-6" (18.5, 18.5). The 13C data underlined in parentheses are from literature (14). Gracillin (3) was crystallized from MeOH as a white powder, m.p. 284—285°C (dec.). [a]13: —80.3° (pyridine; c 0.01). IR (KBr): Vm, = 3420, 2940, 1639, 1454, 1381, 1046, 914 < 900, 815 cm1. FAB-MS: m/z = 885 (M + H), 723 (M + H — Glu), 577 (M + H — Glu

— Rha), 415 (M + H — Glu x 2 — Rha). 1H-NMR (500 MHz, d5-Py): 3 = 0.69 (3H, d,J =6.5 Hz, CH3-27), 0.82 (3H, s, CH3-18), 1.05 (3H, s, CH3-19), 1.13 (3H, d,J= 6.9 Hz, CH3-21), 1.75 (3H, d,J = 6.5Hz, CH3-6" of the outer rhamnose attached to

the C-2' of the inner glucose), 3.95 (IH, m, H-3), 4.94 (1H, d,J = 7.2 Hz, H-i' of the inner glucose), 5.11 (1H, d,J = 1.0Hz, H-I" of the outer glucose attached to the C-4' of the inner glucose),

5.32(iH, hr. d,J 6.0Hz, H-6), 6.39 (1H, d,J= 1.0Hz, H-I" of the rhamnose attached to the C-2' of the inner glucose). 13CNMR: C-2(30.i, 31.6), C-3 (77.9, 78.4), C-23 (31.7,30.0), C-i' (100.0, 99.9), C-2' (77.0, 77.0), C-3' (89.6, 89.2), C-4' (69.6, 69.5), C-5' (77.7, 77.7), C-6 (62.4, 62.3), C-l" (102.2, 102.0),

° Takeda, K., Minato, H., Shimaoka, A., Matsul, Y. (1963)J. Chem. Soc. 4815—4818. Peng,J. P.,Yao,X. S. (1992)Zhongcaoyao 23, 437—445.

12 Nakajina, 0., Hashimoto, Y., Iwasaki, S. (1995) Biol. Pharm. Bull. 18, 903 —906.

13 Watanabe, S., Sanada, S.,lda, Y., Shoji,J. (1983)Chem. Pharm. Bull. 31, 3484—3495. 14 Yang,J.,Jia, Z. J. (1992) Phytochemistry 31, 1349—1351. 15 Yang, C. R. (1986) Yunnan Zhiwu Yanjiu 8,355—358.

Alkaloids from Behria tenuiflora j. Bastida1'3, M. SetIés1, C. Codina1, F. Viladomat1, and J. L. Leon de Ia Luz2 1 Departament de Productes Naturals, Facultat de Farmàcia, Universitat de Barcelona, E-08028 Barcelona, España 2 DivisiOn de Biologla Terrestre — CIBNOR, La Paz, Baja California

del Sur, Mexico Address for correspondence Received: February 20, 1996; Revision accepted: May 16, 1996

C-2" (72.5, 72.2), C-3" (72.8, 72.5), C-4" (74.1,73.9), C-5" (69.6, 69.5),C-6"(18.7, 18.5), C-.1" (104.6, 104.4), C-2" (75.0,

74.8),C-3" (78511 78.4),C-4" (71.5, 714)5(787d 77.7), C-6" (62.4, 62.3). The 13C data underlined in parentheses are from literature (15).

Abstract: The alkaloids shihunine and dihydroshihunine have been isolated from the corms of Behria tenuiflora Greene. The chemotaxonomic value of these alkaloids is discussed.

Behria tenuiflora Greene is a monospecific genus for the Cape

Acknowledgements

Region (Baja California peninsula, Mexico) flora (I). There has

This research was supported by grants from Northeast General

and, up to now, it has been classified as belonging to the

Pharmaceutical Group. We are very grateful to Mrs. Zuohua

monocotyledons families of Amaryllidaceae (1, 2), Liliaceae (3—5) and even into the complex Amaryllidaceae-Allieae (6). Two alkaloids have been isolated from B. tenuflora, and subsequently identified as the pyrrolidine bases shihunine (1) and dihydroshihunine (2). Their structures and biosynthesis (7) are completely different from the Amaryllidaceae alkaloids, which are exclusively found in this plant family (8), and therefore have chemotaxonomical value. From the biological point of view, compound I has been recently shown to be an inhibitor

Wang, Dr. Junpeng Peng, Mr. Baiping Ma and Prof. Chengyu Ma of the Military Academy of Medical Sciences for their kind help in GC analysis of trimethylsilylated of sugars. Thanks are due to Prof. Zherong Jiang in Shenyang Pharmaceutical University for

his identification of the plant material, and to Prof. Congren Yang in Institute of Botany (Kunming City) for providing diosgenin.

References

been a controversy about the systematic position of this taxa

of Na*/K* ATPase in the rat kidney (9).

Richmond, D. V. (1975)Adv. Appl. Microbiol. 19,289—319.

2 Gunji, S., Arima, K., Beppu, T. (1983) Agric. Biol. Chem. 47, 2061 —2069.

Bruno,W. (1968) Planta 79, 77—83. Imai, S., Fujioka, S., Murata, E., Goto, M., Kawasaki, T., Yamauchi, T. (1967) Takeda Kenkyusho Nempo 26,76—82. Tsuruo, T., Oh-hara, T., lida, H., Tsukagoshi, S., Sato, Z., Mats uda, I.,

Iwasaki, S., Okuda, S., Shimizu, F., Sasagawa, K., Fukami, M.,

I

CH3

00e

la

lb

H3

OOH

2

Fukuda, K., Arakawa, M. (1986) Cancer Res. 46,381—385.

Kobayashi, H., Sunaga, R., Furihata, K., Morisaki, N., Iwasaki, S. (1995)J. Antibiotics 48,42—52. Tschesche, R., Pandey, V. B. (1978) Phytochemistry 17, 1781—1782.

Compound 1, C12H13N02 (HR-MS), crystallized from CHCI3 as colorless needles, with m. p. 78—80°C and optically inactive be-

Kawasaki, 1., Yamauchi, 1. (1962) Chem. Pharm. Bull. 10,

cause it is a racemic mixture (Ia, ib), was identified as

703 —708.

shihunine by spectral comparison with reported data. This al-

Li, 1. L, Wu, C. X.,Jiang, T. D., Zhang, Y. X., Fan, X. (1981) Fenxi Huaxue 9,295—298.

Planta Medica 62 (1996)575—577 © GeorgThien1eVerlatuttgart New York

Downloaded by: University of Utrecht. Copyrighted material.

inner glucose), 5.32 (1H, br. d,J = 6.0 Hz, H-6), 5.79 (1H, d,J 1.0 Hz, H-I" of the rhamnose attached to the C-4' of the inner glucose), 6.32 (IH, d,J = 1.0Hz, H-I" of the rhamnose attached to the C-2' of the inner glucose). 13C-NMR (125 MHz, d5-Py):

Planta Med. 62(1996) 575

576 Planta Med. 62 (1996)

Letters

Table 1 1H-NMR (500 MHz) spectral data for compounds 1 and 2 (TMS as mt. standard).

proton

1b

2

proton'

8

8

2

—

1a

compound 6

2 3

—

2.30—2.45

m

4

2.04—2.19

m

3a 3/3

4a 4/3

5a 5/3

7 8 9 10 NMe

3.34 3.06 7.40 7.64 7.51

7.84 2.09

5a

ddd (9, 8.5,4)

dt dt

(9,7.5)

5/3

(7.5, 1.5) ddd (7.5, 7.5, 1.5) ddd (7.5, 7.5, 1.5) dt (7.5, 1.5)

6' 5' 4' 3'

s

NMe

3.33

brs

2.41

m

4.19

brt(8)

7.35 7.66 7.66 8.08 3.08

m m m m s

3.61

brt

2.20—2.31

m m m m

2.38 2.20—2.31

2.07 3.58 2.73 7.15

7.34 7.41

8.09 2.50

(8.5)

brt

(9.5) (9.5) dd (7.5, 1.5) ddd (7.5, 7.5, 1.5) ddd (7.5, 7.5, 1.5) dd (7.5, 1.5) q

s

Coupling constants in parentheses are in Hz. Solvents la: CDCI3, ib: CD300, 2: CDCI3 + drops CD3OD.

compound

1a

carbon

6 111.7

2 3

4 5 6 7 8 9 10 11

12

NMe

39.3 20.7 53.6 146.8 122.5 134.0 130.0 125.2 128.9 169.2 32.1

ib-

2

carbon*

8

6

2 3

184.9 42.6 20.6 61.5 132.6 125.7 132.6 132.6

4 5

1'

6' 5'

4' 3' 2' CO NMe

131.1

137.4 171.0 37.1

73.3 31.8 21.8 54.5 132.3 131.1

130.3 129.5 133.4 136.8 172.5 37.3

Table 2 13C-NMR spectral data for compounds 1 and 2.

m

s/d

t t t s

d d d d s s

q

Carbon multiplicities were established by DEPT pulse sequence. The C-2 multiplicity was s for both forms of compound 1 and d for compound 2. Solvents la: CDCI3, lb: CD3OD, 2: CDCI + drops CD3OD * Carbon numeration for compounds lb and 2.

kaloid has been previously isolated only from Dendrobium lohohense, D. pierardii (Orchidaceae), and Banisteriopsis caapi (Malpighiaceae) (10—12). Spectroscopic measurements showed that 1, when crystalline or dissolved in non-polar sol-

vents, has the structure of a phthalide-pyrrolidine alkaloid (la). However, when it is dissolved in MeOH, the alkaloid is

converted into the betaine form (lb), which can be retransformed into the original form by evaporating the solvent. The IR spectrum (in Cd4) showed a strong ester carbonyl band at 1763 cm1, and the El-MS fragmentation pattern showed a parent peak at m/z = 203 and the base ion at nh/z = 158, formed by decarboxylation of the phthalide ring. Although the 1H-NMR (200MHz, CDCI3) spectrum was reported before (12), some

doubts about assignments were still present. For this reason, unambiguous assignment was performed by 2D NMR

methods (see Table 1), On the contrary, only a reversal of the pair C-9/C-10 of 13C-NMR assignments was required (7), taking into account the HMQC and HMBC experiments (see Table 2).

Furthermore, NMR spectra of the betaine form (ib) were also carried out, and included in Tables 1 and 2.

Compound 2, which crystallized from MeOH, should be regarded as a product from hydrogenation of 1, and has been isolated only once before, from B. caapi (12). Its El-MS showed a parent peak at m/z = 205 (