Germacranolides from Gutenbergia cordifolia

2706

Short Reports

Anthepseudolide-6-O-acetate (3). Oil, IR v~!$~ cm- I: 1780 MS m/z (rel. int.): 264 (y-lactone), 1750 (OAc), 1690 (C=CCHO). CM-ketene]+ (4),246[M_HOAc]+ (lo), 180(78), 167(91), 149 (100). Antheindurolide A (4). Oil, IR vi!:‘3 cm-‘: 1780 (y-lactone). MS m/z (rel. int.): 266 [M]’ (C15H2204) (l), 210 (5), 108 (51), 99 (lOO), 71 (74). ‘jCNMR (CDCl,, C-l-c-15): 634.6, 76.2, 44.9, 137.6, 123.0, 31.8, 38.2, 70.3, 179.7, 33.5, 134.0, 170.6, 122.1, 15.5, 16.4 (assigned by ‘H- 13C correlation). Antheindurolide B (5). Oil, IR v$F” cm- I: 1780 (y-lactone), 1710 (C=O). MS m/z (rel. int.): 278 [M]’ (0.2) (C,,H,,O,), 178 (lo), 99 (loo), 71 (72). Lactones 6a and 6b. Oil, IR v:!:‘~ cm-‘: 1790 (8-lactone),

Phytochemistry, Vol. 29, No. 8, pp. 2706-2708, Printed in Great Britain

173O(C=O). MS m/z(rel. int.): 156 [M]’ 99 (74), 69 (100).

128 (68).

REFERENCES

1. Saleh, M. M. and Rizk, A. M. (1974) Planta Med. 25, 60. S. M. (1976) Egypt 2. Balbaa, S. I., Zaki, A. Y. and El-Zalabani, J. Pharm. Sci. 16, 323. 3. Holub, M. and Herout, V. (1962) Coil. Czeck. Chem. Commun. 27. 2980. F., Zdero, C. and Grenz, M. (1969) Z’errahedron 4. Bohlmann, Letters 2417. 5. Baruah, R. N., Bohlmann, F. and King. R. M. (1986) Planta Med. 52, 53 I.

0031 9422/90 $3.00 + 0.00 :(T 1990 Pergamon Press plc

1990

GERMACRANOLIDES

(2)(C,H,,O,),

FROM GUTENBERGIA

CORDIFOLIA

C. ZDERO and F. BOHLMANN Institute for Organic Chemistry, Techni$al University of Berlin, D-1000 Berlin 12, F.R.G. (Received 9 Nowmber

Key Word Index---Gutenberyia

cordifolia; Compositae;

1989)

sesquiterpene

lactones;

germacranolides.

Abstract-The aerial parts of Gutenbergia cordifolia gave five known and five new germacranolides. elucidated by high field ‘H NMR spectroscopy.

INTRODUCTION Gutenbergia cordijXa Benth. ex Oliv. var. cordgolia (= Erlangea cordifolia (Benth. ex Oliv.) S. Moore) [lJ has been investigated previously affording some highly oxygenated germacranolides named cordifens [2, 31. A second investigation on G. cordifolia from Rwanda, where no variety was mentioned, gave two very different less oxygenated sesquiterpene lactones, both with a 9/&acetoxy group [4]. We have re-examined material from Kenya; the results are discussed in this paper.

RESULTS AND DISCUSSION The aerial parts of Gutenbergia cordijXa gave the previously isolated lactones 1 and %6 [2], as well as the methacrylate 2 and the angelates 7-10 while cordifolin 54 [2] and cordifolia-P2 [2] were not found. The structure of 2 could be easily deduced from its ‘HNMR spectrum (Table 1) which was close to that of cordifen (1) whose structure was established by X-ray analysis [3]. The typical signals of the angelate residue were replaced by those of methacrylate. As expected some signals, especially those of H-7-H-9 were slightly shifted when compared with those in the spectrum of 1.

Structures

were

The spectral data of 7 (Table 1) were partly similar to those of 6 [2]. However, several signals differed characteristically. Thus, H-l gave a broadened doublet at 63.19 while the proton under the hydroxy group was a narrowly split singal at 64.13 indicating a quasi-axial orientation of the hydroxy group. Spin decoupling showed that the latter was at C-3 and inspection of a model indicated that the observed couplings required a 3/j’hydroxy group. Thus, lactone 7 was an isomer of 6 with a changed position of the hydroxy group. The corresponding lactone cordifolia-55 (5) with an 3a-acetoxy group showed, as expected, larger couplings. The ‘HNMR spectra of 8 and 9 (Table 1) clearly showed that germacranolides with a Z-configurated 4,5double bond and a hydroxy group at C-l 5 were present. The Za-position of a second hydroxy group followed from the observed couplings of H-l and H-2 and the corresponding chemical shifts required again a l,lO-epoxide. The angelate 8 was a methylene lactone as followed from the doublets at 66.29 and 5.74 while compound 9 obviously was the 11,13-dihydro derivative. The observed coupling J,, 1I favoured a 1 l/j’, 13-dihydro derivative of 8. The aldehyde 10 could not be obtained free from small amounts of a second one. Accordingly, some signals were overlapped. While the stereochemistry at all chiral cen-

Short Reports

2707 EXPERIMENTAL

1 2

R =

Ang

6

RI = OH, Rz = H

R =

Meacr

7

R’=

3

R =

Ang,

4/3,15 epxide

4 5

R = R =

Meacr,

Ang,

4815 epxide 2.3desoxo.3a-acetoxy

8

X

CH1

9

X =

=

H,R1=

OH

10

aMe.H

tres could determined

be established unambigously.

that of a C-4 could Most likely lactone

be

not

10 is

formed by isomerization of 8. Obviously all germacranolides from this species are biogenetically formed from a common precursor. The chemistry of this species shows that most likely this and the previous studied one [2, 33 are the same variety. Table H 1 2u 28

&values)

C,Ds

8

9

10

2.59 d

3.19 br d 1.75 ddd 2.35 br d

3.03 br d 1.29 ddd 2.25 br d

2.84 d

2.82 d

3.20 d

3.74 ddd

3.73 ddd

3.75 ddd

4.13 dd

3.67 dd

3.42 4.69 3.19 4.68 1.78 2.50 6.30 5.63 1.43

3.25 4.64 2.61 4.58 1.48 2.26 6.34 5.32 1.02

3.00 dd

5 6 7 8 9u

4.11 4.38 2.95 5.16 1.41 2.57 6.33 6.03 1.58 5.54 5.38 6.03 5.57 1.87

OR

2 and 7-10 (400 MHz, CDCl,,

7

3.98 dt

15

data of compounds

2*

3

98 13 13’ 14

1. ‘H NMR spectral

Air-dried aerial parts (33Og, collected in December 1988 in north western Kenya, border with Uganda, voucher Mungai 2819, deposited in the E.A. Herbarium, Nairobi) were extracted with MeOH-Et,O-petrol (1: 1: 1). The defatted extract was first sepd by CC (silica gel). The polar frs (1: EtO,; 2: EtzO-MeOH (9: 1) and 3: EtzO-MeOH (5: 1) were further sepd by HPLC (RP 8, flow rate, 3 ml mini, ca 100 bar). Fr. 1 gave with MeOH-Hz0 (3: I), 10 mg 2 (R, 2.1 min) and 10 mg 1 (R, 3.7 min). HPLC of fr. 2 (MeOH-Hz0 (3: 1)) gave 10 mg 4 (R, 1.1 min), 30 mg 3 (R2 2.1 min) and 40 mg 1 (R, 3.4 min). Fr. 3 gave by HPLC (MeOH-Hz0 (3: 1)) two mixts (3/l R, 1.7 min; 3/2 R, 2.6 min). TLC of 3/l (silica gel, CHCl,C,H,-Et,O-MeOH (10: 10: 10: l)=Tl) gave 10 mg 3 and two mixts (3/1/l and 3/l/2). HPLC of 3/1/l (MeOH-H,O (13: 7)) gave 10 mg 6 (R, 3.0 min) and HPLC of 3/l/2 (MeOH-H,O (11:9)) afforded 5 mg 8 (R, 12.7 min), 2 mg 9 (R, 14.0 min), 2 mg 10 (R, 15.8 min) and 2 mg 6 (R, 16.2 min). TLC of 3/2 (Tl) gave 2 mg 1 and two mixts (3/2/l and 3/2/2). HPLC of 3/2/l (MeOH-Hz0 (3:2)) gave 2 mg 7 (R, 9.8 min) and 2 mg 5. HPLC of 3/2/2 (MeOH-H,O (13:7)) gave 8 mg 7 (R, 3.9 min). lB,lOa,2cc,3a-Bisegoxy-5B-hydroxy-8a-methacryloyloxy-germacra-4(15),11(13)-dien-12,6c+oIide (2). Crystals, mp 228”. IR v~~~13cm-i: 3600 (OH), 1790 (y-lactone), 1730 (C =CCO,R). CIMS m/z (rel. int.): 363 [M + 1] + (lo), 345 [363 - HzO]’ (33), 277 [363 - RCO,H](30), 259 [277 - H,O] + (100). 8a-AngelDyloxy-18,lOa,4cc,SB-bisepoxy-3B_hydroxygermacr11(13)-en-12,6x-ofide (7). Crystals, mp 168”. IR Y~~~‘~cm-‘: 3570 (OH), 1770 (y-lactone), 1710 (C=CCO,R). MS m/z (rel. int.): 378.168 [M]’ (1) (talc. for Cz,H,,O+ 378.168), 279 [M -OAng]’ (2), 261 [279-H,O]+ (8), 83 [C,,H,CO]+ (lOO), 55 [83-CO] + (87); [a];V73 (CHCI,; c 0.47). 8a-Angeloyloxy-lS,lOa-epoxy-2a,l5-dihydroxygermacra42,11(13)-dien-12,6a-oIide (8). Gum; IR vale” cm-‘: 3600 (OH),

br d d br d ddd br t dd br s br s s

t br s br s dq t

d dd m br d dd d d d s

d dd br dddd dd br dd d d d s

1.46 s

0.99 s

6.15 qq 1.93 dq 1.85 dq

5.73 qq 1.88 dq 1.73 dq

2.82 2.40 5.51 5.25 3.06 5.14 1.63 2.46 6.29 5.74 1.35 4.37 I 4.32 6.08 1.98 1.90

dd t br d t dddd ddd dd dd d d s br d br d qq dq dq

2.78 2.38 5.42 5.14 2.18 5.18 1.56 2.37

dd t br d t ddd ddd dd dd

1.54 m

1.35 s

1.95 m 4.00 t 2.90 dddd 5.30 dt 1.35 dd 2.60 dd 6.14d 5.56 d 1.08 s

4.34 br s

9.71 d

6.16 qq 2.00 dq 1.91 dq

6.18 qq 2.01 dq 1.90 dq

1.37 d

*OH 2.87 d. J [Hz]: Compound 2: 1,2= 8; 2,3 =4.5; 3,15 - 1; 5,6= 10; 7,8 = 10; 8,9a = 11; 8,9fi=4; 9c(,9p= 13; compound 7: 1,2a =11;1,2~-1;2~(,2~=13;2u,3=3.5;2~,3=2.5;5,6=10;6,7=8;7,8=2.5;7,13=3.5;7,13’=3;8,9a=11;9a,9~=13; compounds 8 and 9: 1,2=10; 2,3=5; 2,3’=3,3’=12; 5,6=10; 6,7=9; 7,8=7.5; 7,13=3.5; 7,13’=3; 8,9a=ll; 8,9/l 11; = 1.5; 9a,9/?= 13 (compound 9: 7,11= 12; 11,13 = 7); compound 10: 1,2=9; 2,3 =5; 2,3’= 12; 4,15 =3.5; 5,6=6,7= 7,8=8,9cr=lO.5; 7,13=3; 7,13’=2.5; 8,9~(=10.5; 8,9/l=+ 9a,9B=l3; OAng: 3,4=7; 3,5=4,5=1.5.

Short Reports

2708

1775 (y-lactone), 1715 (C=CCO,R). MS m/z (rel. int.): 378.168 [M] + (0.5) (talc. for Cz0Hz60,: 378.168), 360 [M -H,O] + (0.7), 350 [M-CO]+ (3), 279 [M-OAng]” (4), 278 [M-AngOH]+ (3), 261 [279-HzO]+ (3.5), 231 [261 -CH,O]+ (4.5), 83 [C,H,CO]+ (IOO), 55 [83-CO]’ (66); [~I;~+65 (CHCI,;

-CO]+ (3), 279 [M-OAng]+ -CO] + (72).

(2), 83 [C,H,COJ’(lOO),

55 [83

Acknowledgements-WC thank Mr G.M. Mungai (E.A. Herbarium, Nairobi) for providing us with the plant material.

c 0.80). 8a-Angeloyloxy-l/?,lOa-epoxy-2a,lS-dihydroxy-1

lbH-germacr-4Z-en-12,6a-oIide (9). Gum; IR vale” cm-‘: 3600 (OH), 1775 (y-lactone), 1705 (C=CCO,R). MS m/z (rel. int.): 380.184 [M]’ (l)(calc. for C,,HzBO,: 380.184), 362 [M-H,O]+ (1.5), 352 [M -CO]’ (Z), 281 [M-OAng]+ (4.5), 280 [M-AngOH]+ (2.5), 252 [280-CO] + (12), 83 [C,H,CO] + (100). 8a-Angeloyloxy-lS,lOa-epoxy-2a-hydroxy-l5-oxo-germucr11(13)-en-12,6a-okde (10). Gum; IR v:!:‘~ cm-‘: 3600 (OH), 1770 (y-lactone), 1720 (CxCCO,R, CHO). MS m/z (rel. int.): 378.168 [M]’ (0.3) (talc. for C 20H 260 7: 378.168). 350 [M

Phytochemistry, Vol. 29, No. 8, pp. 2708-2709, Printedin Great Britain.

REFERENCES 1. Jeffrey, C. (1988) Kew Bull. 43. 252. 2. Begley, M. J., Crombie, L., Crombie, W. M. L., Gatuma, A. K. and Maradufu, A. (1984) J. Chem. Sot., Perkin I 819. 3. Begley, M. .I.. Crombie, L., Crombic, W. M. L., Gatuma. A. K. and Maradufu, A. (1981) J. Chem. Sot., Perkin I 2702. 4. Fujimoto, Y., Kinoshita, T., lkekawa, N. and Mungarulire. J. (1987) Phytochemistry 26, 2593.

0031 9422/90 $3.00+0.00

1990.

‘i’: 1990 PergamonPressplc

A RESIN ACID FROM PINUS SYLVESZXZS NEEDLES LIONEL BURATTI, JEAN-PIERRE ALLAIS and

Institut

de Chimie des Substances

Naturelles,

CNRS,

MICHEL

Avenue de la Terrasse;

BARBIER

91198 Gif sur Yvette Cedex. France

(Received in revised form 15 January 1990)

Key Word Index--Pinus syluestris; Pinaceae;

needles; resin acid; 12-oxo-8-hydroxy

abiet-13(14)-enoic

acid.

Abstract-In the course of a systematic search for resin acids in Pinus sylvestris, a new diterpene acid (12-0x0-8hydroxy abiet-13 (14)-enoic acid) was isolated and identified. This product, previously described from synthetic works was unknown from natural sources.

INTRODUCTION

The study of the relationships existing between the dietary acceptability of the resin acids present in the foliage of Pinus sylvestris for the sawfly Diprion pini (Hym., Diprionidae) led us [ 1) to the isolation of I5 diterpene acids from the needles. These products, previously reported from P. sylvestris [2] or related conifer species were: abietic acid, dehydroabietic acid, neoabietic acid, levopimaric acid, palustric acid, A’. “-isopimaric acid, sandaracopimaric acid, dihydroabietic acid pinifolic acid, dehydropinifolic acid, agatholic acid and 13oxopodocarp-8(14)-enoic acid [3-141. The isolation and structure elucidation of a new diterpene acid (1) found during the course of this study are reported. We were unable to establish any deterrent effect for 13-0x0podocarp-8(14)-enoic acid on Diprion pini [l] as previously reported [ 15, 161 for Neodiprion rugifrons and N. swainei.

1

R =

1-I

2

R =

Me

RESULTS AND DISCUSSION

Pinus sylvestris foliage collected from lo-year-old trees from an experimental plantation of the INRA at Olivet,