Chemical Composition of the Essential Oil of Aristolochia gibertii Hooker from Paraguay

Journal of Essential Oil Research: JEOR, Nov/Dec 2004 by Canela, Nancy, Ferro, Esteban, Alvarenga, Nelson, Vila, Roser, Ca�igueral, Salvador

Abstract

The chemical composition of the essential oils from leaves and stems of Aristolochia gibertii Hooker collected in Paraguay was investigated by GC and GC/MS. The composition of both oils consisted mainly of sesquiterpenes and a small percentage of monoterpenes; 46 constituents being identified in total. The major component was bieyclogermacrene (26.8% in leaves and 15.0% in stems) followed by (E)-nerolidol (17.5% in leaves and 7.1% in stems), limonene (0.4% in leaves and 11.1% in stems), germacrene D (8.5% in leaves and 7.3% in stems) and spathulenol (3.4% in leaves and 7.3% in stems).

Key Word Index

Aristolochia gibertii, Aristolochiaceae, essential oil composition, bicyclogermacrene, (E)-nerolidol, limonene.

Plant Name

Aristolochia gibertii Hooker, Aristolochiaceae.

Source

Leaves and stems oiAristolochia gibertii were collected in December 2000 in the Campus of the Universidad Nacional de Asunci�n, San Lorenzo, Paraguay. A voucher specimen (M. Ort�z 1.455) was deposited in the Herbarium of the Departamento de Bot�nica, Facultad de Ciencias Qu�micas, Universidad Nacional de Asuncion, Paraguay.

Plant Part

The essential oil was obtained from air-dried leaves and stems by hydrodistillation in a Clevenger-type apparatus according to the European Pharmacopoeia method (1). The oil yield was 0.14% (v/w) for the leaves and 0.10% (v/w) for the stems, based on fresh material.

Previous Work

Aristolochia gibertii Hooker is a climbing shrub that can be found widely distributedin Brazil (Rio de Janeiro, Ilha Grande), Paraguay (Asunci�n, Cordillera and Central Departments) and Argentina (northeast, including Formosa and Chaco Provinces) (2). Previous studies on the oil composition of other plants of the genus showed different composition patterns: A. zenkeri (3) and A. ringens (4) showed mainly monoterpenes, whereas A. elegans (5), A. melanoglossa (6), A. macroura (T) and A. triangularis (8) showed sesquiterpenes as major components. More recently, the composition of the oil from A. gibertii from Argentina has been reported with bicyclogermacrene and limonene being the major constituents (9).

Present Work

Identification of the oil components was made from their retention indices (RI), determined in relation to a homologous series of fatty acid methyl esters on two stationary phases, and from their mass spectra, which were compared with those given in the literature (10,11) and those obtained from authentic samples.

GC analysis was carried out using a Hewlett-Packard gas Chromatograph model 6890 equiped with a flame ionization detector and fused silica capillary columns with two different stationary phases: Carbowax (Supelcowax 10) and methyl silicone (Supelco SPB-I), (30 m � 0.25 mm, 0.25 �m film thickness). Analytical conditions were as follows: injection temperature 250�C, detector temperature 270�C, split ratio 1:60. Oven temperature was programmed from 60�-220�C (4�C/min), using helium as carrier gas at a working flow rate of 1 mL/min. Quantitative data were obtained from FID area values from the two columns. GC/ MS analysis was performed with an HP 6890 gas Chromatograph coupled to an HP 5971A mass selective spectrometer. GC/MS operating conditions were: columns, Supelcowax 10 (30 m � 0.25 mm, 0.25 �m film thickness) and methyl silicone SPB-I (30 m � 0.25 �m film thickness); oven temperature programmed from 60�-220�C at a rate of 4�C/inin. Mass spectra were taken every 5 s over m/z 35-400, using an ionizing voltage of 70 eV

Results are listed in Table I. In total, 46 constituents were identified - more than 80% of each sample. The leaf oil of A. gibertii was mainly constituted by sesquiterpenes (ca. 80% of the total oil). In contrast, monoterpenes showed a low percentage (0.6%). The major compounds were the sesquiterpenes bicyclogermacrene (26.8%), (E)-nerolidol (17.5%) and germacrene D (8.5%).

The oil from stems was also characterized by a high proportion of sesquiterpenes (ca. 60% of the total oil), whereas monoterpenes reached 22.4%. Main constituents were bicyclogermacrene (15.0%), limonene (11.2%), spathulenol (7.3%) and germacrene D (7.3%).

Acknowledgements

This work was developed in the framework of the CYTED project IV-6 "Flora Aromitica Latinoamericana. " N. Canela thanks CYTED for the support of a study trip.

References

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4. J.E. Larrahondo and C. Acevedo, Terpenoids of Aristo/ochia ringens. An. As. Quim. Argent., 78, 355-358 (1990).

5. R. Vila, M. Mundina, L. Muschietti, H.A. Priestap, A.L. Bandoni, T. Adzet and S. Cafligueral, Volatile constituents of leaves, roots and stems from Aristolochia elegans. Phytochemistry, 46, 1127-1129 (1997).

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