Analysis of the Essential Oil of the Aerial Parts of the Medicinal Plant Aristolochia indica Linn . ( Aristolochiaceae ) from South-India

The essential oil of the aerial parts of Aristolochia indica Linn. (Anstolochiaceae) from South-India was analyzed by gas chromatographicspectroscopic (GC-FID and GC-MS) and olfactoric methods to identify those compounds responsible for the characteristic odor as well as partly for the folk medicinal use of this plant. Especially sesquiand monoterpenes were found to be dominating constituents of this essential oil, such as: P-caryophyllene, ahumulene, ishwarone, caryophyllene oxide I, ishwarol, ishwarane and aristolochene as well as linalool and a-terpinolene. The odor impression of the sample is described and the possible biological activity of some single volatiles shortly discussed.


Introduction
In continuation of a scientific cooperation on the analysis of volatiles of medicinal plant used in Indian folk medicine the essential oil of the aerial parts of Aristolochia indica was investigated.
Aristolochia indzca Linn., commonly known as ,,Indian birthwort" [I], belongs to a family of plants (Aristolochiaceae) which comprises nearly eighteen genera and over six hundred species of mostly perennial climbing shrubs [5]. The genus, Aristolochia, known to contain about 500 species, is distributed mainly in subtropical and tropical regions of the world. Of the many species of this genus, only five or six have been subjected to careful chemical analysis. In some papers dealing with the chemical composition of this plant, used in Indian folk medicine as an emrnenagogue and as an abortifacient [I], especially sesqui-, di-and triterpenes were found to be dominant and of high importance for the above mentioned biological effects [1, [5][6][7][8][16][17][18], but studies only of the volatiles from Aristolochia indica could not be found upto now.

Results and discussion
The essential oil of the aerial parts of Aristolochia indica was olfactorically evaluated as follows: Smoky, leather-like, woody-earthy with weak greencaryophyllene-terpinene and floral-fruity side-notes.

)
The identified main compounds b-caryophyllene, a-humulene, caryophyllene oxide I, linalool and a-terpinolene are well-known natural products possessing antimicrobial effects [9,12,14]. So this essential oil of A. indica from South-India may be used as a powerful medicine in this field.

3.) Additional p-caryophyllene and linalool (concentration of both compounds
together about 60%) show sedative effects [12] and an application as mild sedative seems to be effective.
In conclusion we can report, that the essential oil of the aerial parts of

Essential Oil Extractions:
The aerial parts of Aristolochia indica (100g) were cut into small pieces and ground into a paste using an electric gnnder. This paste was distilled by steam for 2.5 hours. The distillate was extracted with diethyl ether (100mL for 2-times) and dried over anhydrous sodium sulphate. After the removal of the solvent a yield of O.15g light green essential oil of A. irzdica was obtained.

Olfactoric evaluations:
lop1 of a solution of the essential oil in dichloromethane were placed on a commercial odor-strip (Dragoco Co.) and its odor characterized by professional perhmers.

Gas Chromatography:
GC analyses were carried out using a Shimadzu GC-14A with FID and the integrator C-R6A-Chromatopac and a Varian GC-3700 with FID and the integrator C-R 1 B-Chromatopac (Shimadzu Co.

Gas chromatography -Mass spectrometv:
The samples were analyzed by the GC-MS systems Shimadzu GC-17A with QPSOOO and the data system Compaq-ProLinea (class5k-software), Shimadzu GC-17A with QP5050 and data system Pentium-II (BOhm Co., class5ksoftware), Hewlett-Packard GC-HP5890 with HP-5970MSD and PC-Pentium