Essential Oils of Seven Brazilian Baccharis Species

Ferracini, V., da Silva, A.G., Paraiba, L.C., Leitao Filho, H.F. and Marsaioli, A.J. (1996). Essential oils of seven Brazilian Baccharis: a prospective approach on their ecolog ical role . In P.D .S. Caligari & D.J.N. Hind (eds). Compositae: Biology & Utilization. Proceedings of the International Compositae Conference, Kew, 1994 . (D.J.N. Hindr Editor-in-Chief), vol. 2. pp. 467-474. Royal Botanic Gardens, Kew.

37. ESSENTIAL OILS OF SEVEN BRAZILIAN BACCHARIS: A PROSPECTIVE APPROACH ON THEIR ECOLOGICAL ROLE V ERA F ERRACINI2 , ARI G. DASILVA\ LOURIYAL C. PARAlBA2 , HERMOGENES F. L EITAO fiLH0 3 AND A NITA J. MARSA IOL1 1 1

lnstituto de Quimica, UNICAMP CP 6154, Campinas 13083-970, SP, BRAZIL ' Embrapa/CNPMA, Jaguariuna, SP, BRAZIL 'lnstituto de Biologia, UNICAMP, SP, BRAZIL

Abstract A description of the habitat and areas where seven Baccharis species (B.caprariifolia male and female, B. dracunculifolia male and female, B. erioclada male and female , B. myriocepha/a , B. platypoda, B. tridentata, B. vincifolia) occur, is presented. The essential oils of the aerial parts were obtained by hydrodistillation and examined by gas chromatography and gas chromatography/mass spectroscopy. The major constituents were identified by mass spectra comparison with those in the Wiley/N BS library and with those of standard commercial, synthetic and isolated compounds. A seasonal and daytime variation in oil composition between female and male plants was observed. The essential oil variation was first correlated to pollination but preliminary field observations showed thi s to be a complex problem and the floral scent was not easily related to a pollination advertisement or vector.

Introduction The genus Baccharis L. from the Compositae occurs in South, Central and North America. The Brazilian Cerrado is one of the richest areas in Baccharis species. Cerrado is the Braz ilian name for a characteristic vegetation of the Central part of Brazil which is intermediate between forest and pasture presenting a great plant diversity. The plants are dioecious with male and fema le capitula appearing on separate plants (Boldt, 1989). Thi s genus has been much investigated from the phytochemical point of view but no systematic work on its essential oil has been reported. It should be mentioned though, that vassoura oil (B. dracunculifolia DC. (Boldt, 1989)) and carqueja oil (B. geniste/loides Pers.) which were produced and used in perfumery, attracted the attention of several research groups including ours (Queiroga eta/., 1990; Mot! & Trka, 1983; Weyerstahl et al., 1990, 1992; Bauer eta/., 1978). This study aims to survey the essential oil composition of several Baccharis naturally occurring in our part of Brazil and to apply this knowledge to interspecific, interspecimen and ecological correlations. The species studied are in Table I .

467

Proc. Int. Comp. Conf. , Kew - Biology & Utilization TABLE I. Details of the material studied *** Entry

I

l 2

3

Collecting site Voucher specimen oil yield (%) I B. caprariifolia Sales6polisUEC-46656 0.05 DC. female S.Paulo (21V/87) B . caprariifolia Sales6polisUEC-46656 O.Q7 (21V/87) DC. male S.Paulo B . dracunculifolia CampinasUEC-47072 0.18 DC. female S.Paulo ( 18/XU/85)

5

6 7 8

9

10

UEC-47072 B. draclllrculifolia Campinas DC. male S.Paulo ( 18/XII/85) B. erioclada Campos de UEC- 1499 Jordao- S.Paulo (23/Y n8) DC. female B. erioclada DC. I Campos de I UEC- 1499 Jordao- S.Paulo. (23/Yn8) I male B. myrioceplrala Jundiaf IUEC-50276 DC. S.Paulo (9/IX/88) B. platypoda DC. Santana do UEC-5 1399 Riacho(2/Y U/89 ) Minas Gerais B. tridemata Yah! Santana do UEC- 5 1400 Riacho(2/Yil/89) Minas Gerais B . vincifolia CampinasUEC Baker S.Paulo

Bohlman et a/., 1973 Bohlman et a/ .. 1973

0. 19

**Queiroga et a/., 1990: Weyerstahl eta/., 1992; Moll & Trka. 1983: Bauer et a/., 1978; Weyerstahl eta/., 1990; *Zdero era/., 1989 *Jarvis eta!.. 199 1

0.30

*Jarvis eta/. , 199 1

I

I 4

References

Plant

0.21

I 0.60 0.49

0. 10

*Jarvi s et a!.. 1987 *Jarvis eta/ .. 1991

*Jarvis eta/., 199 1

0.38

* References concerning phytochemical studies with no emphasis o n the essential oi l. ** Publications concerning essential oi l data. *** Some of the above Baccharis spec ies have recently been rec lassified, for more deta ils see He llwig {1993). Results The GC (gas chromatography) analyses of seven Baccharis (Tables 2 and 3) revealed that the composition of the essential oils is complex with more than I 00 constituents. The identification process relied heavily on some commercial, synthetic and isolated standards mentioned in our

Key to Tables 2 & 3. R I = retention index obtained follow ing Van den Dool & Kratz ( 1963) and arranged in o rder of e lution of the components in a HP-ULTRA- 1 capillary column. Rib= Retention index compared to that of Jennings & Shibamoto ( 1980) Rlis =retention index compared to that of isolated standard whi ch were further characte ri zed by IR, proton and carbon- 13 NMR; Rlss =retention index compared to that of a synthetic standard reported in Queiroga et a/. ( 1990). Rlcs = retention index compared to that of a commercial standard. *Compounds I, 2, 3, 4 and 5 were detected in the commercial B . dracwrculifolia oi l but never in the recently obtained volatiles from fresh plant hydrodstillation.

468

37. Essential oils of seven Brazilian Baccharis

T AB LE

2. Percentage oil composition of three female and male Baccharis plants.

B. caprarifolia

Method

9

d

B. dracunculus

I

9

d

0.07 1.1 8

0.23 0.1 3

3.76

1.90

B. erioclada

I

I d

9

MONOTERPENES

a -thujene a -pinene sabinene ~-pinene ~-myrcene

a-phellandrene 8-3-carene a -terpinene limonene y-terpinene a -terpinolene a-terpineol

1.2 1.08

0.17 0.08 0.77

~-elemene

a-gurjunene ~-caryo phy llene

calarene aromadendrene humulene alloarimadendrene cabreuva ox. I cabreuva ox. 2 ~-selinene ~-cadinene

-

r---

Rlis,MS Rlss,MS

21.44 1-

1.1 6 0.09

I-

1-

2.05 1.15 1.87

0.74 0.85 0.12 0.18 5.85

4.65

0.14 0.93

0.55 1.42

0.40 2.54

SESQUITERPENES Rlb,MS Rlb,MS Rlcs,MS 0.33 Rlb,MS 2.06 0.65 1.23 1 - -Rics,MS 0.45 Rlcs,MS 15.73 17.09 5.40 Rlcs,MS 0.44 Rlcs,MS 1.63 -Rlcs,MS 3.94 1.76 1.55 Rlcs,MS 0.37 0.92 MS MS - 1-Rlb,MS 9.90 Rlss,MS 1.20 _ Rib,MS 0.97 0.90 Rlb,MS 5.35 2.96 5.07 Rlb,MS MS MS - - 1.33 Rlss,MS Rlis,MS 8.85 0.43 20.80 Rlis,MS 8.41 2.58 4.54 Rlcs, MS Rlss,MS 4.65 7.02 2.46 1.34 Rlss,MS 2.55 3.76 - r2.55 0.45 0.86 1- Rlcs, MS

a--cubebene a-y langene a-copaene

0.18 0.26

8.45

-

--1-{Ics,MS Rlb,MS Rlcs,MS Rlb,MS Rlb,MS Rlcs,MS Rlcs,MS

trans-geraniol

a-muurolene y-cadinene 8-cadinene isohumbertio l 3 isohumbertiol 4 epiglobulol nerolido l spathulenol caryophyllene ox.5 globu lol viridiflorol guaiol Unknown M+ 222 a-cadinol Unknown M+240-1 5 annodendrenod iol Unknown M+238

i

Rlb,MS Rlcs,MS Rlb,MS Rlcs,MS Rlb,MS Rlb,MS

-

f-

15. 16 0.37 1.89 3.45

0.16 2.68 0.14 0.52 1.55

0.55

0.23

0.22 1.14 0.28

0.38 0.67 0.39 0.99 0.24 0.62 10.7 5.~ 4.21 r---

1.06 2.25 0.83

11.00 0.98 0.48

0. 15 3.54 0.42

1.09 0.3 1

t

0.55 1.92

-

1.02 4.55

3.58

I 12.02 3.79

1.92 6.61

2.26 1.1 2 0.83

1.02 2.27 1.32

1--

t

1.81

4.73

2.55

3.01

1.30

2.03

0.26

1.86

1.1 9

1.1 9

4.55 12.57

- ---

-

1.46 3.38 0.36

--

2.15 2.5 I

I 469

..

Proc. Tnt. Compositae Conf., Kew - Biology & Utilization TABLE 3. Percentage composition of the volati les of four Baccharis species.

Compounds a -thujene a-pinene sabinene ~-pinene ~-mircene

a-phellandrene o-3-carene a-terpinene limonene rt-terpinene a-terpinolene a -terpineol trans-geraniol a-cubebene a-ylangene a-copaene ~-elemene

a-gurjunene ~-caryophyllene

calarene aromadendrene humulene alloaromdendrene cabreuva ox. I cabreuva ox. 2 ~-selinene ~-cadinene

a-muurolene rY-cadinene 0-cadinene isohumbertiol 3 isohumbertiol 4 ~piglobulol

)lerolidol spathulenol aryophyllene ox.5 globulol viridiflorol guaiol Unknown M+ 222 a-cadionol !Unknown M+240-15 !aromadendranediol Unknown M+238

470

Rl' 1117 1123 1147 1152 1156 1167 1172 I 177 1184 1203 12 19 1234 1325 1409 1428 1432 1445 1463 1475 1481 1495 1505 1508 1512 1529 1537 1541 1554 1567 1579 1588 1611 1619 1627 1638 1641 1645 1652 1663 1691 1707 1735 1744 1760

B . myri. B . plat. MONOTERPENES

B. trid.

B. vine.

0.82

0.60

0. 11

0.40

0.15 1.38

0.35

SESQUITERPENES 1.01

0.09

3.41

0.03

4.98

0.08 0.04 0.10 0,02 0,02 0.05 0,02

0.98 1.31 0.56 8.66 0.46 0.56 2.1 8 1.11

0,02

0.62

0.07

Rlb,MS RJcs,MS Rlb,MS Rlcs,MS Rlb,MS Rlb,MS Rlcs,MS Rfb,MS I Rlcs,MS Rlb,MS Rlb,MS Rlcs,MS Rlcs,MS ·-

0.22 0.15 0.047 1.03 0.05

1.78 1.08 1.29

Rlb,MS Rlb,MS Rlcs,MS Rlb,MS Rlcs,MS Rlcs,MS Rlcs,MS Rlcs,MS Rfcs,MS Rfcs,MS MS MS Rlb,MS Rlss,MS Rlb,MS Rlb,MS Rlb,MS MS MS Rlss,MS Rlis,MS Rfis,MS Rlcs,MS Rlss,MS Rfss,MS RTcs,MS

1.29

Rli s,MS

0.04 0.65

0.68

Rl ss,MS

2.86 1.57 0.24 4.52

0.15 0.23 0.82

1.76 1.03 0.22

0.49 0.66 0.28

2.23

1.90 0.43 0.53

9.44

3.45 ·- - 1.60

0.54 6.49 8.88

9.01 9.44

0.36 8.76

0.06 4 .65 8.60

3. 19 4.78

2.45 0.82 0.91 1.8 I 2.28

2.70 0.71 2.36 1.00 3.09 0.06 1.60 1.44

1.58

Method

37. Essential oils of seven Brazilian Baccharis

0,1

D

Male

•

female

FIG. I. Seasonal monoterpene/sesquiterpene variation in female and male B. dracunculifolia volatiles

first publication (Queiraga, et al., 1990). Several constituents are present in trace amounts and about 15-20 components contribute to more than 1-2% of the total oil and are present in most species. There is a neat variation of oxygen containing mono and sesquiterpenes from one species to the other but more data are necessary to draw any taxonomic conclusions. Compounds I ,2,3,4 (Weyerstahl et a!., 1990; Weyerstahl et a/., 1992) and 5 (Schneider & Agrawal, 1986) were found in the commercial B. dracunculifolia oil but were not detected in fresh plant hydrodistilled oils. These compounds might be artifacts connected with the oil oxidation. A synthetic pathway was undertaken to obtain several standards possessing a cadinane skeleton in order to identify the three unknown constituents detected in B. dracunculifo/ia, B. myriocepha/a and B. platypoda and will be reported elsewhere. The most striking fact was the variation observed among the female and male specimens of the same species (Table 2). The monoterpene/sesquiterpene ratio was higher in the female plants. It was first suggested that stress might be responsible for this variation. As one plant might be closer to a water source or growing in a different soil than the other. B. dracunculifolia was therefore submitted to water stress and 104 M aqueous magnesium chloride solution stress for 72 h before hydrodistillation. A monoterpene/sesquiterpene ratio decrease and a total oil yield increase of 100% was observed for the plant material submitted to water and aqueous magnesium chloride stress. Our second experiment proposed to analyse B. dracunculifolia essential oil of a female plant and a male plant during 12 months (Fig. I). The seasonal variation of the monoterpene/sesquiterpene ratio revealed that higher ratios were closely related to the low rainfall levels and to a low oil yield (samples collected in March, June

471

..

Proc. Int. Compositae Conf. , Kew -B iology & Utilizati on a nd August 1993) and lower ratios were related to high rainfall levels (November 93, Jan uary and March 94) and to high oil yield. These results were analogous to our stress experi ments but major differences were observed between the male and female plants during the flowering season. The obvious conclusion, at this point, was that the first observed female/ma.le plant oil variation was probably related to the inflorescences and not to unaccounted stress conditions. From a daytime (8 am , .II am, 2 pm and 5 pm) moni toring of female and male plants (Fig. 2) we could observe that the inflorescences are mainly responsible for monoterpene/sesquiterpene variation with a noticeable inversion occurring at about 10 am. Further support was obtained studying a population of ten female and te n male plants of B. dracun.culifolia growing in a very restricted area of the University campus. These results were reproduced. It is easy to assume and expect a clear assoc iation of fl oral scents and advertiseme nt for po llinators, and dioecy obviously reinforces this assumpti on, if the needs of tra nsporting po lle n from male to female flower is regarded. Contrasting pro files of

0.3

0.25

0.2

0.15

0. 1

---------=

=

0.05

~

Male leaves

~

Female leaves

----