J. Agric. Food Chem. 1996, 44, 1829
−1832
1829
Essen tia l Oil Com p osition a n d Allelop a th ic Effect of th e Br a zilia n
La m ia cea e Hesper ozygis r in gen s (Ben th .) Ep lin g a n d Hesper ozygis
†
r h od od on Ep lin g
‡
,§
‡
§
‡
Gilsane L. von Poser, Chantal Menut,* Maria E. Toffoli, Pierre V e´ rin, Marcos Sobral,
∇
§
‡
J ean-Marie Bessi e` re, G e´ rard Lamaty, and Am e´ lia T. Henriques
Curso de P o´ s-Gradua c¸ a˜ o em Ci eˆ ncias Farmac eˆ uticas - UFRGS, Av. Ipiranga 2752,
9
0610-000 Porto Alegre, RS, Brazil, Laboratoire de Chimie Organique Physique,
Universit e´ de Montpellier II, Sciences et Techniques du Languedoc,
3
4095 Montpellier Cedex 5, France, and Laboratoire de Phytochimie, ENSCM,
4053 Montpellier Cedex 5, France
3
Samples of Hesperozygis ringens (Benth.) Epling and Hesperozygis rhododon Epling essential oils
were analyzed by a combination of analytical techniques: capillary gas chromatography, liquid/
solid chromatography, GC/MS coupling, and NMR spectroscopy. Twenty-four components have been
identified representing altogether more than 95% of the oil content. The oil of H. ringens is
constituted mainly by pulegone (79.2%) accompanied by several oxygenated derivatives (pulegone
oxides, 1.2%; 8-hydroxy-p-menth-3-one, 1.3%; and 8-hydroxy-p-menth-4-en-3-one, 3.7%); that of H.
rhododon contains menthone and pulegone as main compounds in almost comparable amounts
(
43.4% and 29.6%, respectively). Tests carried out on lettuce seeds using alcoholic extracts of the
two species showed significant antigerminating properties mainly for H. ringens. The same activity
was observed with its essential oil.
Keyw or d s: Hesperozygis ringens (Benth.) Epling; Hesperozygis rhododon Epling; Lamiaceae;
essential oil composition; pulegone; menthone
The subfamily Nepetoideae of the Lamiaceae is
characterized by the presence of a high content of
essential oils (Cantino and Sanders, 1986), several of
them being commercially important sources of raw
material for personal care, food, and cosmetic industries;
the most common Lamiaceae oils are those obtained
from the genera Mentha, Rosmarinus, Thymus, and
Lavandula (Heinrich, 1992; Lawrence, 1992).
Hesperozygis Epling is a genus with about six species,
five of them restricted to southeastern Brazil (Pereira
and Pereira, 1973) and one cited for Mexico (Cantino
and Sanders, 1986). Hesperozygis ringens is a woody
herb native in rocky fields of southeastern Rio Grande
do Sul; although it occurs sparsely in the region, it is
the dominant species in the sites where it exists, a
feature that may indicate some allelopathic action. The
plant is employed for its antiparasitic properties and is
known by the vernacular name “espantapulga” (a name
that literally means “to keep fleas away”). Hesperozygis
rhododon is a shrub that grows in rocky fields at the
top of mountains along the Serra do Mar formation in
the states of Paran a´ and S a˜ o Paulo; no dominance was
observed in the site of collection, although the species
was very frequent. Neither vernacular name nor popu-
lar use are known.
EXPERIMENTAL PROCEDURES
P la n t Ma ter ia l. Samples of Hesperozygis species were
collected in 1993 in Ca c¸ apava do Sul, Rio Grande do Sul, and
Quatro Barras, Paran a´ , Brazil. The plants were identified by
M. Sobral, and voucher specimens were deposited at the
herbarium of the Universidade Federal do Rio Grande do Sul
(ICN).
P r ep a r a tion of Essen tia l Oils. Fresh leaves were sub-
jected to hydrodistillation for 5 h using a Clevenger-type
apparatus.
Ga s-Liqu id Ch r om a togr a p h y. The compounds were
first tentatively identified by peak enrichment and their GC
retention indices on two fused silica gel capillary columns (25
m × 0.25 mm i.d. coated with OV-101, film thickness 0.25 µm;
25 m × 0.22 mm i.d. coated with Carbowax 20 M, film
thickness 0.25 µm), using a chromatograph (Shimadzu GC-
1
4A) equipped with a Shimadzu C-R4A Chromatopac integra-
tor. Detector and injector temperatures were set at 250 and
10 °C, respectively; the oven temperature was programmed
2
-
1
from 50 to 200 °C at 5 °C min , with nitrogen as carrier gas.
The percentage compositions were obtained from electronic
integration measurements using flame ionization detection
without taking into account relative response factors.
Ga s-Liqu id Ch r om a togr a p h y/Ma ss Sp ectr om etr y. All
the samples were then analyzed by GC/MS, using a Hewlett-
Packard capillary GC quadrupole MS system (Model 5970)
fitted with a 25 m × 0.23 mm i.d. fused silica gel column coated
with DB-1, film thickness 0.25 µm; temperature was pro-
grammed as follows: 60 °C (1 min), 60-250 °C (5 °C min ).
Helium was used as carrier gas at a flow rate of 0.9 mL min
the mass spectrometer was operated at 70 eV.
The aim of this work is to compare the essential oil
chemical composition of the two species and verify the
allelopathic potential of them.
-
1
-
1
;
The identification of nearly all compounds was based on a
comparison of retention indices and mass spectra with those
of commercial samples and with literature data (Stenhagen
et al., 1974; Adams, 1989; J ennings and Shibamoto, 1980); four
of them were compared to authentic samples obtained by
isolation or hemisynthesis, and their identification was con-
firmed on the basis of their NMR data.
†
Part IV of Aromatic Plants from Brazil. For part
III, see von Poser et al., 1994.
*
Author to whom correspondence should be ad-
dressed (fax 67 14 38 88).
‡
UFRGS.
Universit e´ de Montpellier II.
ENSCM.
§
Isola tion . 8-Hydroxy-p-menth-4-en-3-one (26). 26 was
isolated by liquid/solid chromatography of H. ringens essential
∇
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© 1996 American Chemical Society