Bicyclo [3.2.1] octanoid neolignans from Ocotea porosa

Bicyclo [3.2.1] octanoid neolignans from Ocotea porosa

Phytochemistry, Vol. 31, No. 1, pp. 275-277, 1992 Printedin Great Britain. 0031-9422/92 %5.00+00 Q 1991 PergamonPress plc BICYCLO [3.2.1] OCTANOID N...

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Phytochemistry, Vol. 31, No. 1, pp. 275-277, 1992 Printedin Great Britain.

0031-9422/92 %5.00+00 Q 1991 PergamonPress plc

BICYCLO [3.2.1] OCTANOID NEOLIGNANS FROM OCOTEA POROSA* MARCIA ORTIZ M.

MARQUES, MAGNA

C. C. P. GOMES,

MASSAYOSHI YOSHIDA

and OTTO R.

GOTTLIEB

Instituto de Quimica, Universidade de SIo Paulo, 05508 SBo Paulo, SP, Brazil (Received 8 April 1991)

Key Word Index-Ocotea

porosa; Lauraceae; bark; wood; bicycle [3.2.l]octanoid

neolignans.

Abstract-Bark and wood of Ocotea porosa contained eight new bicycle [3.2.l]octanoid neolignans belonging to the rel-(11R,4’S,5’R,7S, 8R)-A”* s’-4’-acetoxy-6’-oxo-8.1’,7.5’-neolignan, the rel-(1’R,4’R,5’R,7R,8S)-A2’*8’-4’-acetoxy-6’oxo-8.1’,7.5’-neolignan and the rel-(lfR,5’S,6’R,7S,8R)-A2’* ” -3’,5’-dioxy-4‘-oxo-8.1’,7.5’-neolignan series.

INTRODUCTION

The great majority of Ocotea species occur in tropical regions of the American continent. Among the few species with a more temperate habitat is 0. porosa, a well known timber. A sample was collected by Prof. K. Kubitzki from a tree known as ‘canela parda’ in the Atlantic forest, municipality of Cunha, State of Sgo Paulo. Partial results on the chemistry of its trunk wood were reported at a time when the botanical classification of the plant was yet unknown [2]. This has since been confirmed as 0. porosa by Dr J. Rohwer. Re-examination of the bark extract gave besides the neolignans la, b, 4a, isolated in the previous study [2] and SC,isolated from 0. veraguensis [3], the new neolignans 2b, 3a, b, Sa and b. Re-examination of the wood extract gave besides the neolignans 2a and 4b, isolated in the previous study [Z], the neolignans 2c, d and !%I.

common feature concerns the trans Ar/Me relationship (‘HNMR 6H,-9 l.lOf0.16) [4]. In contrast, with respect to the C-9/C-6’ relationship, the compounds belong to two series, with C-9 and C-2’ on opposite faces (3a, b) or on the same face (all other compounds), as shown by 13CNMR (6C-9, respectively, 12.5 and 18.00+0.08) [2]. The compounds can also be classified according to their IR carbonyl absorption at 1755.OkO.5 cm- 1 for the pentanone units of 2a-d, 3a and b, at 1729 cn-’ for the hexanone units of 4a and b, at 1690 f 10 cm- ’ for the cc&unsaturated ketone units of 5a-d and at 1742 f 5 cm- ’ for the acetyl units of all compounds except 5a-c [2]. The carbinolic proton at C-2’ of la, b, 5aJ is directed towards the hexacycle, as shown by the absence of H-2’, H-6’ W-coupling and confirmed by 2D HOMOCOSY experiments [2]. All other spectral data (see Experimental) are equally consistent with the structural proposals shown in the formulae.

RESULTS AND DIXXJSION

EXPERIMENTAL

Routine inspection of ‘H and “CNMR spectra revealed the presence in all 14 isolates from 0. porosa of the structural units ArCHCHMe. OMe. CH,CH =CH, complemented in la and b by C,H,OH . OMe . OAc, in 2a-d, 3a and b by C6H2 ( =0) OMe . OAc, in 4a and b by C,H,( =O)OH. OAc, in Sa by C,H,( =O)(OH),, in 5b and c by C,H,( =O)OH. OMe and in Sd by C,H, (=0) OMe . OAc. Furthermore, this inspection revealed Ar to be represented in la, 4b and 5c by piperonyl (Pi), in lb, 2c, 4a, Sa-c by 3-methoxy-4,5_methylenedioxyphenyl (Mp), in 2a by tri-0-methylpyrogallyl (Tp), in 2b and 3a by guaiacyl (Gu), in 2d by syringyl (Sy) and in 3b by veratryl (Ve). These formulae are consistent with the M,s 416 (la, Zb, 3a,), 446 (lb, 2d), 460 @a), 444 (k, !%I),430 (3b), 432 @a), 402 (4b, Sb), 388 @a) and 372 (SC)determined by EI mass spectrometry. The substituents and the C&-skeletons classify all compounds as bicyclo[3.2.l]octanoid neolignans. Another

* Part 98 in the series ‘The Chemistry of Brazilian Lauraceae’. For Part 97 see ref. [l]. Taken from part of the doctorate thesis submitted by M.O.M.M. to Universidade de EGOPaulo (1990).

Isolation ofconstituentsfrom bark. Dry, powdered bark (900 g) was extracted successively with hexane and CHCl,. The solvents were evapd. The hexane extract (3.1 g) was partitioned between hexane and MeOH-H,O (4: 1). The MeOH soln was evapd and the residue (2 g) submitted to CC (silica gel, pressure). Elution with hexane-EtOAc (3:2) gave 6 frs. Upon careful repeated rechromatography fr. 2 gave la (28 mg), fr. 3 lb (76 mg), fr. 3 2b (12 mg) and fr. 5 4a (24 mg). The CHCI, ext. (3.8 9) was submitted to CC (silica gel, pressure). Elution with CHCl,-EtOAc (9: 1) gave 8 frs. Upon careful repeated rechromatography fr. 5 gave 5c (18 mg) and 5a (22 mgh fr. 6 !% (17 mg) and 3b (14 mg) and fr. 8 3a (14 mg). Isolation ofconstituentsfiom trunk wood. Hexane extract (2 g) [2] was submitted to CC (silica gel, pressure). Elution with C,H,-EtOAc (4: 1) gave 10 frs. Upon careful repeated rechromatography fr. 2 gave 4b (lOmg), fr. 4 Sd (12mg) and 2~ (12 mg), fr. 6 2e (8 mg) and fr. 7 2d (18 mg). rel-(l’R,4’S,5’R,7S,8R)- AZ’*8’-4’-Acetoxy-4-hydroxy-3,3’,5’trimethoxy-6’-oxo-8.1’,7.5’-neolignan, (Zb). Viscous oil. (Found [M]’ m/z 416, C2sH2s07 requires 416). IRv~~~cn-‘: 3466, 1756, 1516, 1464, 1370, 1278, 1236, 1150, 1037, 920. ‘HNMR (200 MHz, CDCl,) 8:6.75-6.85 (m. H,-2, H,-5, H,-6), 2.90 (dd, J =6.2, 1.3 Hz, H-7), 2.73 (dq, J=6.7, 6.2 Hz, H-8), 1.00 (d, J = 6.9 Hz, 3H-9), 4.94 (s, H-2’), 6.04 (s, H-4’), 2.20-2.47 (m, Hz-71,

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M. 0. M. MARQUES et al.

276

OMe

Ar

la lb

AI

Pi up

Ar

Tp

2a 2b

Gu

2C

Mp

2d

sy

3s 3b

GU Ve

OR’

AI

4a 4b

Mp PI

AI

R’

R’

Sa 5b

Mp

H

H

Mp

Me

H

5c

PI

Me

H

5d

Mp

Me

AC

5.80-5.93 (m, H-8’), 5.14-5.22 (m, H,-9’), 3.85 (s, MeO-3), 3.59 (s, MeO-3’), 3.52 (s, MeO-S’), 1.42 (s, AcO). 13CNMR (20MHz, CD’&) 6:131.7 (C-l), 113.1 (C-2), 146.0 (C-3), 144.6 (C-4), 113.5 (C-5), 122.4 (C-6), 53.1 (C-7), 44.8 (C-8), 18.5 (C-9), 48.4 (C-l’), 103.0 (C-2’), 151.9 (C-3’), 71.4 (C-4’), 87.0 (C-5’), 208.1 (C-6’), 32.6 (C-7’), 133.6 (C-8’), 118.6 (C-9’), 55.9 (MeO-3), 55.3 (MeO-3’), 52.5 (MeO-S), 20.0,169.3 (AcO). EIMS m/z (rel. int.): 416 (6), 375 (15), 251 (30), 210 (lOO), 209 (35), 177 (23), 169 (67), 164 (55), 150 (70), 137 (26), 91 (40), 77 (38). reI-(1’~4’S,SR,7S,8R~Az’,s’~-~cetoxy-3,3’,S-tr~met~xy~,5oil. methylenedioxy-6’-oxo-8.1’,7.5’-neolignan (1). Viscous (Found [M]’ m/z 444, CZ4H,,0s requires 444). IRv$!y cm-‘: 1756, 1509, 1453, 1372, 1234, 1136, 1044, 998. ‘HNMR (200 MHz, CDCI,) 6: 6.51 (s, H-2), 6.53 (s, H-6), 2.89 (d, J =6.1 Hz, H-7), 2.7O(m, H-8), l.OO(d,J=6.9 Hz, H,-9),4.93 (s, H2’), 6.06 (s, H-41, 2.16-2.39 (m, Hz-7’), 5.79-5.92 (m, H-8’), 5.14-5.22 (m, HZ-9’), 3.87 (s, MeO-3), 3.59 (s, MeO-3’), 3.53 (s, MeO-5’), 1.45 (s, AcO), 5.92 (s, CHzO,). 13C NMR (50 MHZ, CDCl,): 133.8 (C-l), 104.0 (C-2), 148.4 (C-3), 134.5 (C-4), 142.8 (C5), 109.7 (C-6), 53.1 (C-7), 44.7 (C-8), 18.7 (C-9), 48.3 (C-l’), 102.6 (C-2’), 151.7 (C-3’), 71.3 (C-4’), 87.0 (C-5’), 208.2(C-6’), 32.5 (C-7’), 133.4 (C-8’), 118.8 (C-9’), 56.6 (MeO-3), 55.3 (MeO-3’), 52.6 (MeO-5’), 20.1,169.4 (AcO), 101.2 (CHzO,). EIMS m/z (rel. int.): ~(6),403(11),361(15),344(30),252(4),251(14),210(100~209 (16h 195(32), 193(54), 192(86), 191(14), 181(8), 165(30), 150(66), 149 (16), 91 (24), 77 (17). rel-(lfR,4’S,5’R,7S,8R) -A”,s’ -4’-Acetoxy&Hydroxy-3,5,3’,5’tetramethoxy-6’-oxo-8.1’,7.5’-neolignan (M). Viscous oil (Found CM]’ m/z 446, C24H3008 requires 446). IRvzT cm-‘: 3478, 1755, 1646, 1571, 1462, 1432, 1371, 1235, 1116, 1041, 921, 836. ‘H NMR (200 MHz, CDCI,) 6: 6.54 (s, H-2, H-6), 2.88 (dd, J =6.3, 1.3 Hz, H-7), 2.70 (dq, J=6.7, 6.3 Hz, H-8), 1.00 (d, J =6.7 Hz, H,-9), 4.92 (s, H-2’), 6.04 (s, H-4’), 2.20-2.43 (m, H,-7’),

5.7%5.9O(m, H-8’), 5.14-5.22 (m, Hz+‘), 3.85 (s, MeO-3, MeO-5), 3.53 (s, MeO-3’), 3.58 (s, MeO-5’), 1.45 (s, AcO), 5.45 (br, s, HO-4). 13C NMR (20 MHz, CDCl,) 6: 131.0 (C-l), 107.2 (C-2), 153.1 (C3), 134.0 (C-4), 146.5 (C-5), 108.8 (C-6), 53.4 (C-7), 45.0 (C-8), 18.7 (C-9), 48.5 (C-l’), 102.6 (C-2’), 152.0 (C-3’), 71.2 (C-4’), 87.1 (C-5’), 208.0 (C-6’), 32.6 (C-7’), 133.6 (C-8’), 118.7 (C-9’), 56.4 (MeO-3), 56.4 (MeO-5), 55.3 (Me-3’), 52.6 (MeO-S), 20.0, 169.5 (AcO). EIMS m/z (rel. int.): 446 (16), 405 (ll), 363 (15), 252 (7), 251 (30), 210 (96), 209 (21), 195 (36), 194 (lOO), 193 (83), 181 (17), 165 (14), 163 (19), 150 (57), 135 (16), 91 (31), 77 (25). reL(l’R#R,5’R,7R,8S)-A 2’*8’-4’-Acetoxy-4-hydroxy-3,3’,[email protected]’-oxo-8.1’,7.5’-neolignan (3a). Viscous oil (Found [M] + m/z 416, C,,H,,O, requires 416). IR v~~ccm-‘: 3451, 1745, 1653, 1515, 1457, 1434, 1371, 1233, 1034, 923. ‘HNMR (200 MHz, CDCI,) 6: 6.58 (d, J=2.0 Hz, H-2), 6.78 (d, J= 8.0 Hz, H-5), 6.65 (dd, J=8.0,2.0 Hz, H-6), 2.57(d, J=8.OHz, H-7), 1.94 (dq, J=8.0, 6.5 Hz, H-8), 0.94 (d, J=6.5 Hz, H,-9), 4.63 (d, J = 1.1 Hz, H-2’), 6.08 (d, J= 1.2 Hz, H-4’), 2.34-2.47 (m, 2H-7’), 5.84-6.02 (m, H-8’), 5.04-5.20 (m, H,-9’), 3.83 (s, MeO-3), 3.58 (s, MeO-3’), 2.66 (s, MeO-S), 2.08 (s, AcO). ‘%NMR (20 MHz, CDCl,) 6: 130.5 (C-l), 111.7 (C-2), 146.8 (C-3), 145.0 (C-4), 114.0 (C-5), 122.5 (C-6), 51.2 (C-7), 49.3 (C-8), 12.5 (C-9), 49.3 (C-l’), 101.9 (C-2’), 152.6 (C-3’), 76.2 (C-4’), 81.7 (C-S), 208.9 (C-6’), 35.4 (C-7’), 133.8 (C-8’), 118.1 (C-9’), 56.0 (MeO-3), 55.7 (MeO-3’), 52.7 (MeO-S’), 21.0, 170.0 (AcO). EIMS m/z (rel. ink): 416 (l), 375 (IS), 333(16),251(31X 137(3),210(100),209(35), 195(30), 194(20), 181 (16), 180(6), 179(11), 165(27), 164(55), 151(29), lSO(70). 137(26), 91 (41), 77 (38). reL(lfR,4’R,5’R,7R,8S)- A*‘,s’- 4’- Acetoxy-3,4,3’,5’- tetramethoxy-6’-0x0-8.1’,7.S-neo[ignan (3b). Viscous oil. (Found [M]’ m/z 430, C 24H 300 7 requires 430). IR ~2:; cm-‘: 1764, 1746, 1516, 1464, 1370, 1262, 1240, 1144, 1030, 754. ‘H NMR (200 MHz, CDCI,) 6: 6.70 (d, J=2.0, H-2), 6.76 (d, J=8.3 HZ, H-5), 6.63

Neolignans from Ocotea porosa (dd,J= 8.3,2.0 Hz,H-6),2.59 (d,J=8.3 Hz,H-7), 1.97(dq,J=8.3, 6.5 Hz, H-8), 0.96 (d, J=6.5 Hz, H,-9), 4.63 (d, J= 1.3 Hz, H-2’), 6.09 (d, J = 1.5 Hz, H-4’), 2.34-2.41 (m, Hz-7’), 5.88-6.09 (m, H-8’), 5.05-5.16 (m. Hz-9’), 3.84 (s, MeO-3), 3.82 (s, MeO-4), 3.58 (s, MeO-3’), 2.66 (s, MeO-53, 2.08 (s, AcO). WNMR (50 MHZ, CDCl,) S: 130.9 (C-l), 110.6 (C-2), 148.1, (C-3, C-4), 112.1 (C-5), 121.7 (C-6), 51.8 (C-7), 49.2 (C-8), 12.5 (C-9), 49.2 (C-l’), 101.9 (C2’), 152.4 (C-3’), 78.2 (C-4’), 81.7 (C-5’), 208.9 (C-6’), 35.3 (C-7’), 133.8 (C-8’), 118.1 (C-9’), 55.8 (MeO-3, MeO-4), 55.7 (M&-3’), 52.5 (MeO-S), 21.0, 110.1 (AcO). EIMS m/z (rel. int.): 430 (13), 389 (17), 347 (39), 251 (39), 210 (lOO), 178 (85),165 (18), 163 (26), 150 (51), 101 (14), 91 (14X 11 (10). reI-(l’R,5’S$‘R,7S,8R)-A *‘**‘-3’,6’-Dihydroxy-3,5’-dimethoxy -4,5-methylenedioxy-4’-oxo-8.1’,l.5’-neolignan @a). Viscous oil. (Found [Ml’ m/z 388, CZ,Hz407 requires 388). IRvziT cm-‘: 3461, 1680, 1513, 1463, 1452, 1372, 1233, 1108, 1092, 926. ‘HNMR (80 MHz, CDCI,) 6: 6.40 (s, H-2, H-6), 3.33 (d, J =7.0 Hz, H-7), 2.20-2.40 (m, H-8), 1.26 (d, J=l.O Hz, H,-9), 6.24 (s, H-2’), 4.00 (s, H-6’), 2.2-2.4,2.62.8 (m, Hz-7’), 5.67-5.86 (m, H-8’), 5.15-5.38 (m, Hz-9’), 3.82 (s, MeO-3), 3.40 (s, MeO-5’), 5.87 (s, CH,Oz). ‘“CNMR (20 MHz, CDCI,) 6: 132.2 (C-l), 102.9 (C-2), 148.8 (C-3), 135.0 (C-4), 147.9 (C-5), 108.6 (C-6), 58.8 (C-7), 47.9 (C-8), 17.2 (C-9), 49.0 (C-l’), 127.3 (C-2’), 151.0 (C-3), 193.8 (C-4’), 87.6 (C-S), 19.5 (C-6’), 34.4 (C-l’), 134.2 (C-8’), 118.6 (C-9’), 56.5 (MeO-3), 54.5 (MeO-5’), 101.3 (CHzOz). EIMS m/z (rel. int.): 388 (7), 193 (14), 192 (lOO), 119 (4), 167 (9), 165 (5), 155 (8),135 (20), 91 (5), 77 (3). reI-(l’R,5’S$R,7S,8R)-A 2’v8’-6’-Hydroxy-3,5’-dimebhoxy-4,5methylenedioxy-4’-oxo-8.1’,7.5’-neolignan (Sb). Viscous oil. (Found [M]’ m/z 402, C,,H,,O, requires 402). IR v~\‘cm-‘: 3491,1694,1632,1619,1511,1455,1371,1317,1235,1200,1137, 1109, 924. ‘H NMR (200 MHz, CDCI,) 8: 6.26 (d, J = 1.6, H-2), 6.27(d,J=1.6Hz,H-6),3.32(d, J=6.5 Hz,H-1),2.19-2.44(m,H8), 1.25 (4 J = 7.0 Hz, H,-9), 6.12 (s, H-2’), 3.99 (s, H-6’), 2.19-2.44, 2.67-2.82(m, Hz-7’), 5.7’+5.96(m, H-8’), 5.165.34(m, Hz-g’), 3.80 (s, MeO-3), 3.64 (s, MeO-3’), 3.39 (s, MeO-5’), 5.89, 5.99 (2d, J = 1.6 Hz, CHzO,). “CNMR (20 MHz, CDCI,) 6: 132.2 (C-l), 102.6 (C-2), 148.7 (C-3), 134.4 (C-4), 143.1 (C-5), 108.8 (C-6), 58.1 (C-7), 48.2 (C-8), 17.3 (C-9), 48.8 (C-l’), 125.3 (C-2’), 152.4 (C-3’), 191.9 (C-4’), 95.5 (C-5’), 78.8 (C-6’), 34.6 (C-73, 134.3 (C-8’), 118.6 (C-9’), 56.4 (MeO-3), 55.3 (MeO-3’), 54.4 (MeO-S), 101.2 (CHzO,). EIMS m/z (rel. ink): 402 (30), 210 (40), 209 (4), 194 (15), 193(16x192(65), 182(12),181(30),169(100), 165(30),164(9),153 (lo), 135 (30), 91 (56), 77 (40). rel-(lfR,5’S,6’R,7S,8R)-A 2’s8’-6’-Hydroxy-3’, S-dimethoxy-3,4methylenedioxyA’-oxo-8.1’,7.5’-neolignan (k). Viscous oil.

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(Found [Ml’ m/z 372, CzlH,,Os requires 312). IRvELt cm-‘: 3490, 1694, 1611, 1491, 1458, 1371, 1239, 1037, 930. ‘HNMR (200 MHz, CDCI,) 6: 6.54 (d, J = 1.3 Hz, H-2), 6.48 (d, J = 8.5 Hz, H-5), 6.67 (dd, J=8.5, 1.3Hz, H-6), 3.32 (d, J=6.5Hz, H-l), 2.17-2.45 (m. H-8), 1.25 (d, J = 6.9 HZ, H,-9), 6.12 (s, H-2’), 3.98 (s, H-6’), 2.17-2.45, 2.70-2.81 (m, Hz-?“), 5.72-5.89 (m, H-Q, 5165.30 (m, Hz-9’), 3.64 (s, MeO-31, 3.38 (s, MeO-5’), 5.82 (s, C&O,). “CNMR (50 MHz, CDCI,) 6: 131.7 (C-l), 108.1 (C-2), 147.4 (C-3), 146.4 (C-4), 109.0 (C-5), 121.7 (C-6), 58.2 (C-7), 47.7 (C-8), 17.2 (C-9), 48.6 (C-l’), 124.5 (C-2’), 152.2(C-3’), 192.0 (C-4’), 95.4 (C-s), 78.5 (C-6’), 34.6 (C-7’), 134.6 (C-8’), 119.2 (C-9’), 55.2 (MeO-3’), 54.3 (MeO-S), 100.8 (CHzO,). EIMS m/z (rel. int.): 372 (ll), 210 (16), 195 (11), 180 (42), 169 (lOO), 162 (25), 135 (31), 91 (29), 77 (64). rel-(1’R,5’S,6’R,7S,8R)-A2’~s’-6’-Acetoxy-3,3’,5’-trimethoxy4,5-methylenedioxy-4’-oxo-8.1’,7.5’-neobgnan (sa). Viscous oil. (Found [M]’ m/z 444, Cz4H2s0s requires 444). IRv$ cm-‘: 1748, 1704, 1633, 1512, 1453, 1314, 1228, 1140, 1093, 929. ‘H NMR (200 MHz, CDCI,) 6: 6.21 (d, J = 1.6 Hz, H-2), 6.27 (d, J = 1.6 Hz, H-6), 3.32 (d, J =7.0 Hz, H-l), 2.28-2.45 (m, H-8), 1.26 (d, J = 1.0 Hz, H,-9), 6.16 (s, H-2’), 5.32 (s, H-6’), 2.28-2.45 (m, H7’), 5.16-5.91 (m, H-8’), 5.17-5.26 (m, Hz-9’),3.84 (s, MeO-3), 3.67 (s, MeO-3’), 3.27 (s, MeO-53, 2.25 (s, AcO), 5.90, 5.91 (2d, J = 1.6 Hz, CH,O,). 13CNMR (20 MHz, CDCl,) 6: 131.1 (C-l), 102.1 (C-2b 148.4 (C-3), 133.1 (C-4), 143.1 (C-5), 109.0 (C-6), 59.0 (C-7), 47.9 (C-8), 17.1 (C-9), 48.0 (C-l’), 124.5 (C-2’), 152.3 (C-3’), 192.0 (C-4’), 94.1 (C-5’), 78.6 (C-6’), 35.0 (C-7’), 133.1 (C-S), 119.2 (C-9’), 56.5 (MeO-3), 55.4 (MeO-3’), 54.9 (MeO-5’), 20.9, 172.0 (AcO), 101.2 (CH,O,). EIMS m/z (rel. int.): 444 (ll), 371 (3), 210 (lOO), 194 (4), 193 (9), 192 (33), 181 (8), 119 (9), 165 (9), 151(5), 91 (14), 77 (11). Acknowledgement--The cial support.

authors wish to thank CNPq for finan-

REFERENCES 1. Marques, M. 0. M., Yoshida, M. and Gottlieb, 0. R (1991) Phytochemistry 31,360. 2. Gomes, M. C. C. P., Yoshida, M., Gottlieb, 0. R., Martinez V., J. C. and Gottlieb, H. EL(1983) Phytochemistry 22, 269. 3. Dodson, C. D., Stermitz, F. R., Castro C., 0. and Janzen, D. H. (1981) Phytochemistry 26, 2037. 4. Dias, S. M. C., Fernandes, J. B., Maia, J. G. S., Got&b, 0. R. and Gottlieb, H. E. (1986) Phytochemistry 25, 213.