3
FLAVOUR AND FRAGRANCE JOURNAL, VOL. 11.31-33 (1996) Aromatic Plants of Tropical Central Africa. Part XXVI. * Volatile Constituents of Leaves of Coreopsis barteri Oliv. & Hiern and Coreopsis grandiflora Hogg ex Sweet from Cameroon C. Menut and G. Lamatyi Laboratoire de Chimie Organique Physique, Universitt! de Montpellier 11, Sciences et Techniques du Languedoc. 34095 Montpellier, Cedex 5, France P. H. Amvam Zollo, J. R. Kuiatd and F. Fekam Boyom Faculit! des Sciences, BP 812, Yaoundt!, Cameroon J. M. Bessihe Laboratoire de Phytochimie, ENSCM, 34053 Montpellier, Cedex I, France The chemical composition of essential oils isolated by hydrodistillation of leaves of Coreopsis burteri Oh. & Hiern and Coreopsis grundifIoru Hogg ex Sweet were analysed by capillary G C and GC-MS. Limonene (55.4%) and a-phellandrene (12.9%) were found to be the major constituents of C. burteri oil whereas germacrene-D (42.1%) and myrcene (11.7%) predominate in the volatile extract of C. grundifloru; besides these two terpene hydrocarbons, the latter oil contains minor but significant amounts of two rather unusual compounds: l-phenyl- 1,3,5-heptatriyne (5.2%) and precocene I (0.90/,). KEY WORDS Coreopsis burteri Oh. & Hiern; Coreopsis grundifloru Hogg ex Sweet; Compositae; volatile components; limonene; germacrene-D; l-phenylhepta-1,3,5-triyne INTRODUCTION The genus Coreopsis belongs to the Heliantheae tribe of the Compositae family in which most of the species are used for ornamental purposes.* Coreopsis barteri Oliv. & Hiern, which occurs as a weed in fields and grass lands is an annual herb, glabrous and ramified, growing in the savannah regions with simple serrate upper leaves and golden-yellowflower-heads 1-2 inches across. C. grandiflora is also an annual herb growing up to 30cm in height from an evergreen rhizome; its leaves are alternate and g l a b r ~ u s . ~ The two species are used in folk medicine for the treatment of bums and wounds. Their leaves are mixed with those of Psidium guajava, Bidens pilosa or Vernonia amygdalina to cure malaria.4 *For Part XXV in this series, see Reference 1. tAuthor to whom correspondence should be addressed. Previous chemical investigations on the essential oil of C. grandiflora grown in indicated the presence of l-phenylhepta-l,3,5-triyne, 2- phenyl-5-(a-propyl)-thiophene and some of their derivatives. To the best of our knowledge, no report is available on the volatile constituents of C. barteri. The present article is based on a detailed analysis of the essential oils obtained by hydrodistillation of the leaves of C. barteri and C. grandiflora from Cameroon. EXPERIMENTAL Plant Material and Isolation Procedure Leaves of C. barteri and C. grandijlora were collected in Bafoussam (western area of Camer- oon) in August and September 1991 respectively. The plants were identified at the National Herb- CCC 0882-5734/%1010031-03 0 1996 by John Wiley & Sons, Ltd. Received I9 April 1995 Accepted I June 1995

Aromatic Plants of Tropical Central Africa. Part XXVI.Volatile Constituents of Leaves of Coreopsis barteri Oliv. & Hiern and Coreopsis grandiflora Hogg ex Sweet from Cameroon

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Page 1: Aromatic Plants of Tropical Central Africa. Part XXVI.Volatile Constituents of Leaves of Coreopsis barteri Oliv. & Hiern and Coreopsis grandiflora Hogg ex Sweet from Cameroon

FLAVOUR AND FRAGRANCE JOURNAL, VOL. 11.31-33 (1996)

Aromatic Plants of Tropical Central Africa. Part XXVI. * Volatile Constituents of Leaves of Coreopsis barteri

Oliv. & Hiern and Coreopsis grandiflora Hogg ex Sweet from Cameroon

C. Menut and G. Lamatyi Laboratoire de Chimie Organique Physique, Universitt! de Montpellier 11, Sciences et Techniques du Languedoc. 34095

Montpellier, Cedex 5, France

P. H. Amvam Zollo, J. R. Kuiatd and F. Fekam Boyom Faculit! des Sciences, BP 812, Yaoundt!, Cameroon

J. M. Bessihe Laboratoire de Phytochimie, ENSCM, 34053 Montpellier, Cedex I , France

The chemical composition of essential oils isolated by hydrodistillation of leaves of Coreopsis burteri O h . & Hiern and Coreopsis grundifIoru Hogg ex Sweet were analysed by capillary G C and GC-MS. Limonene (55.4%) and a-phellandrene (12.9%) were found to be the major constituents of C. burteri oil whereas germacrene-D (42.1%) and myrcene (11.7%) predominate in the volatile extract of C. grundifloru; besides these two terpene hydrocarbons, the latter oil contains minor but significant amounts of two rather unusual compounds: l-phenyl- 1,3,5-heptatriyne (5.2%) and precocene I (0.90/,).

KEY WORDS Coreopsis burteri O h . & Hiern; Coreopsis grundifloru Hogg ex Sweet; Compositae; volatile components; limonene; germacrene-D; l-phenylhepta-1,3,5-triyne

INTRODUCTION

The genus Coreopsis belongs to the Heliantheae tribe of the Compositae family in which most of the species are used for ornamental purposes.* Coreopsis barteri Oliv. & Hiern, which occurs as a weed in fields and grass lands is an annual herb, glabrous and ramified, growing in the savannah regions with simple serrate upper leaves and golden-yellow flower-heads 1-2 inches across. C. grandiflora is also an annual herb growing up to 30cm in height from an evergreen rhizome; its leaves are alternate and g labr~us .~

The two species are used in folk medicine for the treatment of bums and wounds. Their leaves are mixed with those of Psidium guajava, Bidens pilosa or Vernonia amygdalina to cure malaria.4

*For Part XXV in this series, see Reference 1. tAuthor to whom correspondence should be addressed.

Previous chemical investigations o n the essential oil of C. grandiflora grown in indicated the presence of l-phenylhepta-l,3,5-triyne, 2- phenyl-5-(a-propyl)-thiophene and some of their derivatives. To the best of our knowledge, no report is available on the volatile constituents of C. barteri.

The present article is based on a detailed analysis of the essential oils obtained by hydrodistillation of the leaves of C. barteri and C. grandiflora from Cameroon.

EXPERIMENTAL

Plant Material and Isolation Procedure Leaves of C. barteri and C. grandijlora were

collected in Bafoussam (western area of Camer- oon) in August and September 1991 respectively. The plants were identified at the National Herb-

CCC 0882-5734/%1010031-03 0 1996 by John Wiley & Sons, Ltd.

Received I9 April 1995 Accepted I June 1995

Page 2: Aromatic Plants of Tropical Central Africa. Part XXVI.Volatile Constituents of Leaves of Coreopsis barteri Oliv. & Hiern and Coreopsis grandiflora Hogg ex Sweet from Cameroon

32 C. MENUT E T A L .

Table 1 . Percentage composition of essential oils of Coreopsis barteri O h . & Hiern and C. grandiflora Hogg ex Sweet leaves from Cameroon

Compounds RI' C. barteri C. grandiflora

Monoterpene hydrocarbons a-Pinene Camphene Sabinene P-Pinene Myrcene a-Phellandrene Limonene (E)-p-Ocimcnc y-Terpinene Oxygenated monoterpenoids 1.8-Cineole Terpinen-4-01 Bornyl acetate Sesquiterpene hydrocarbons a-Copaene P-Elemene P-Cedrene P-Caryophyllene P-Copaene a-Humulene Germacrene-D a-Muurolene Bicyclogermacrene Farneseneb y-Cadinene 8-Cadinene Oxygenated sesquiterpenoids a-Cadinol T-Muurolol Precocene I 1-Phenylhepta-1.3.5-triyne

934 944 968 974 98 1

loo0 1024 1039 1045

1024 1170 1278

1384 1394 1423 1429 1431 1461 1487 1498 1500 1504 1506 1518

1627 1641

1445 1698

78.6 2.1

<o. 1 5.5

<o. 1 0.4

12.9 55.4 2.3

<o. 1 1.2 1 .o 0.2

15.2 0.6 0.4 0.4 2.5

1.6 7.8 0.3

<o. 1

0.3 1.3 3.5 1.7 1.8

-

-

-

- -

27.0 8.7 2.6

<0.1 1.2

11.7 <o.1

2.8 <o. 1 <O.l

1 .o <o. 1 <0.1

1 .o 57.1 <0.1

0.7 1.2 1.4 1 . 1 0.8

42.1

1.2 4.8 1 .o 2.8 6.7 3.1 3.6 0.9 5.2

-

Retention indices on OV-101 column ' Correct isomer not characterized.

arium of Yaounde where voucher specimens were deposited.

Fractions of 250 g of fresh leaves were submitted to hydrodistillation using the same experimental procedure as that followed for Bidens pilosu leaves:' hydrodistillation for 12 hours using the apparatus described in the French Pharmacopoeia in order to minimize the loss of l-phenylhepta- 1,3,5-triyne. The oils obtained were dried over anhydrous sodium sulphate and subjected to in- strumental analysis.

Identification of Oil Components GC analyses were performed on two fused-

silica capillary columns (25 m x 0.32 mm coated with OV-101 or Carbowax 20M); the oven tem- perature was programmed from 50°C to 200°C at 5Wmin.

GC-MS analyses were carried out on a Hewlett-Packard capillary GC-quadrupole MS system (Model 5970) fitted with a 25 m x 0.23 mm i.d. fused-silicacolumncoated withDB-1, using the same gas-chromatographic parameters. Authentic reference compounds, as well as ublished mass spectra and retention indices8-'8were used as basis for the identification of the oil components.

RESULTS AND DISCUSSION

The hydrodistillation of leaves of C. barteri and C. grandifloru gave pale yellowish mobile oils in 0.12% (w/w) and 0.10% (w/w) yields respectively.

The compounds identified in the two essential oils are listed in Table 1 according to their chemical classes. The two samples have different chemical

Page 3: Aromatic Plants of Tropical Central Africa. Part XXVI.Volatile Constituents of Leaves of Coreopsis barteri Oliv. & Hiern and Coreopsis grandiflora Hogg ex Sweet from Cameroon

VOLATILE LEAF CONSTITUENTS OF COREOPSIS SPECIES 33

characteristics although the amount of oxygen- ated components is very low in both cases (<8%).

The oil from C. barteri contained mainly mono- terpenoids (79.8%) with limonene (55.4%) and a-phellandrene (12.9%) as major components. That from C. grandiflora is rich in sesquiterpen- oids (63.8%) with germacrene-D (42.1%) as the main constituent; it is of interest to note the pre- sence, in the latter mixture, of l-phenylhepta- 1,3,5-triyne in a sizeable amount (5.2%) accom- panied by0.9 % of precocene I (ageratochromene).

This observation is not surprising since the genus Coreopsis belongs to the same tribe (Heliantheae) as Bidens p i l ~ s a , ~ the essential oil of which contains also a significant amount of the polyacetylene compound (12.0-32.3%) and less than 1% of precocene 1.

This latter compound was found in abundance accompanied by precocene 11, in species of the Ageratum and Eupatorium genera (Eupatoriae tribe), a tribe which has been placed next to the Heliantheae by P. Proksch and E. Rodriguez;" it would be interesting to check whether other species of the Heliantheae tribe contain in their volatile extracts these compounds which have been considered to be specific to the Eupatoriae tribe.

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REFERENCES

Part XXV. C. Eyele MvC-Mba, C. Menut. G. Lamaty, P. H. Amvam Zollo, F. Tchoumbougnang and J. M. Bessitre, 1. Essent. Oil Res., (1995) (in press). S . A. Ghazanfar, Savannah Plants, An Illustrated Guide, p. 127, Macmillan, Basingstoke (1989). J. Hutchinson and J. M. Dalziel, Flora of West Tropical Africa, Vol. 2 , 2nd edn. p. 239, Crown Agents, London (1%3). M. Biholong, Contribution h I'Ctude de la more du Cameroun: les AstCracCes, p. 104, Thtse de doctorat d'universitt, UniversitC de Bordeaux I11 (1986). J. S. Sorensen and N. A. Sarensen, Acta Chem. Scand., 12, 771 (1958). J. S. Wrensen and N . A. Sirensen, Acta Chem. Scand., 12, 765 (1958). P. H. Amvam Zollo, J. R. KuiatC, C. Menut, G. Lamaty, J. M. Bessitre, J. C. Chalchat and R. P. Garry, Flav. Fragr. 1., 10, 97 (1995). E. Von Sydow, K. Anjou and G. Karlsson, Arch. of Mass Spectral Data, 1, 392 (1970). R. P. Adams, Identification of Essential Oils by Ion Trap Mass Spectrometry, Academic Press, New York (1989). W. Jennings and T. Shibarnoto, Qualitative Analysis of Flavor and Fragrance Volatiles by Gloss Capillary Gar Chromatography, Academic Press, New York (1980). P. Proksch and E. Rodriguez, Phyrochemistry, 22, 2335 (1983).