Chantal Menut

Variability in the Chemical Compositions of the Essential Oils of Five Ocimum Species from Tropical African Area

Abstract As part of our research on aromatic plants from Africa, we have analyzed, via GC and CG/MS, the essential oils from fresh leaves of five Ocimum species from tropical Africa: Ocimum basilicum L., O. gratissimum L., O. americanum L. (syn: O. canum Sims), O. lamiifolium Hochst. ex Benth. and O. minimum L. The chemical compositions of O. basilicum, O. gratissimum and O. minimum essential oils could be related to some chemotypes already defined for these three species: linalool- or methyl chavicol-types for the first species, thymol- or eugenol- or ocimenes/far- nesenes-types for the second one; finally, a high content of methyl chavicol (34.3%) and linalool (17.8%) was found in O. minimum oil, similar to that already described for a Brazilian species. On the other hand, an essential oil dominated by 1,8-cineole was described for the first time for a sample of O. americanum. Finally, the oil of O. lamiifolium, which was rich in sabinene, is chemically described for the first time.

Essential Oils from Eugenia Species—Part VII: Sections Phyllocalyx and Stenocalyx

Abstract The chemical composition of the leaf oils obtained by hydrodistillation of eight Eugenia species, collected in southern Brazil, was analyzed by GC and GC/MS. Eugenia speciosa oil is characterized by large amounts of monoterpene hydrocarbons with α-pinene (47.3%) and limonene (23.0%) as major constituents, while E. cuprea oil is composed of 78.6% sesquiterpenes. Spathulenol (12.1%) was the major component, followed by β-caryophyllene (9.2%) and caryophyllene oxide (8.7%). Eugenia arenosa was dominated by the acyclic sesquiterpene, farnesyl acetate (70.4%) and aromadendrene (11.7%). Eugenia brasiliensis, E. multicostata, E. sulcata and E. xiriricana oils possessed very similar chemical compositions. In the monoterpene fraction, α- and β-pinene were the major components (a total of 40.7%, 23.4%, 35.9% and 21.9%, respectively), while for E. pitanga (E)-β-ocimene (10.5%) was the major component. For the sesquiterpene fraction, spathulenol and globulol were the major components (a total of 10.5%, 19.4%, 18.8% and 24.0%, respectively). In contrast, the oil of E. pitanga was characterized in this fraction by germacrene D and bicyclogermacrene (29.3% and 22.4%, respectively).

Aromatic Plants of Tropical West Africa. Part XIV. Chemical and Biological Investigation of Lippia multiflora Mold. Essential Oil from Benina

Abstract The essential oil of the leaves of Lippia multiflora collected in Benin was obtained by hydrodistillation and analyzed by capillary GC and GC/MS. Thirty-six components, representing 96.5% of oil were identified. The sample consisted mainly of monoterpenes. The major constituents were 1,8-cineole (39.9%), sabinene (11.1%), linalool (10.9%) and α-terpineol (10%). The antioxidant and antiradical activities of the oil was found to be low comparatively to that of butylated hydroxytoluene (BHT).

Chemical Composition of the Essential Oils of Eugenia hyemalis and Eugenia stigmatosa. Part VI: Section Biflorae

Abstract Essential oils, which were obtained from the leaves of Eugenia hyemalis Cambess. and Eugenia stigmatosa DC., collected in Southern Brazil, were analyzed by GC and GC/MS. Thirty-three compounds were identified in the analyzed samples. The oil obtained from E. stigmatosa is extremely simple, containing more than 90% of physeteric acid [(Z)-tetradec-5-enoic acid], an olefinic fatty acid, accompanied by its esters and tetradecalactones. The major component of E. hyemalis oil is bicyclogermacrene (37.7%), followed by germacrene D (7.0%) and β-caryophyllene (7.4%).

Aromatic Plants of Tropical West Africa. Part XV. Chemical and Biological Evaluation of Leaf Essential Oil of Commiphora africana from Benin

Abstract The essential oil from leaves of Commiphora africana collected in Benin was analyzed by capillary GC and GC/MS. The essential oil was characterized by a majority of sesquiterpenoid constituents with bisabolane skeleton among them bisabolone (38.4%) and β-sesquiphellandrene (19.1%) were the most abundant. The radical scavenging activity of the oil was found to be low comparatively to that of butylated hydroxytoluene (BHT).

Aromatic Plants of Tropical Central Africa. Part XLVI. Essential Oil Constituents of Cassia alata (L.) from Gabon

Abstract The essential oil obtained by hydrodistillation of leaves of Cassia alata collected in Gabon was analyzed using capillary GC and GC/MS. Forty-four compounds representing 95.2% of the oil were identifi ed among them linalool (23.0%), borneol (8.6%) and pentadecanal (9.3%) were major constituents. The antioxidant activity of the oil was found to be low compared to that of butylated hydroxytoluene (BHT).

Aromatic Plants of Tropical West Africa. XIII. Chemical Composition of the Leaf Oil of Laggera pterodonta (DC.) Sch. Bip. ex Oliv. from Benin

Abstract The essential oil obtained by hydrodistillation from leaves of Laggera pterodanta Sch. Bip. ex Oliv. was analyzed by GC and GC/MS. Twenty-three components were identified, of which 2,5-dimethoxy-p-cymene (30.5%), 10-epi-δ-eudesmol (24.6%) and juniper camphor (7.5%) were the most significant.

Volatile constituents of Eugenia mattosii legr (Myrtaceae)

Abstract The volatile constituents of the fresh leaves of Eugenia mattosii (Myrtaceae) were isolated by hydrodistillation and analyzed by GC and GC/MS. The oil from this species showed that it comprised only sesquiterpenes: β-elemene (16.1%), β-caryophyllene (12.4%), bicyclogermacrene (17.5%) and α-cadinol (11.2%), being the major components.

Aromatic Plants of Tropical Central Africa XXXVIII: Chemical Composition of the Essential Oils from Four Aframomum Species Collected in Cameroon (1)

Abstract The essential oils isolated by hydrodistillation from the leaves or seeds of Aframomum citratum (Pereira) K. Schum., Aframomum hanburyi K. Schum., A. letestuanum Gagnepain and A. pruinosum Gagnepain (Zingiberaceae) grown in Cameroon were analyzed by GC and GC/MS. The leaf oils obtained from A. citratum and A. hanburyi were characterized by being rich in monoterpene hydrocarbons, dominated by pinenes. The major volatile components from seeds of the four species were oxygenated components belonging to the acyclic terpene class, such as geraniol (70.0%) in the case of A. citratum, (E,E)-farnesol (27.3%) and linalool (19.0%) for A. hanburyi, while A. letestuanum and A. pruinosum contained a main proportion of (E)-nerolidol (67.0% and 91.7%, respectively) in their seeds oils.

Antifungal Activity of the Essential Oil of Cymbopogon citratus (Poaceae) Against Phaeoramularia angolensis

Abstract The essential oil of Cymbopogon citratus grown in Ngaoundere- Cameroon was extracted by hydrodistillation with a yield of 0.4 % (w/w). The chemical analysis, carried out by gas chromatography and gas chromatography coupled with mass spectrometry revealed that the extract is rich in geranial (32.2 %), myrcene (27.0 %) and neral (25.7 %), also the chemical composition of the fractions was determined. The antifungal activity was evaluated by incorporation technique. We have observed that citral, considered as a reference compared to fractions, is very active against P. angolensis with a Minimal inhibitory concentration (MIC) of 400 ppm. Also, oil fractions 10 and 11 which are very rich in neral and geranial presented comparable efficacy with MIC of 500 ppm slightly more potent than the crude extract which presented an identical MIC to that of a reference fungicide (600 ppm). On the other hand, until 5000 ppm, no MIC was obtained with fraction 4 of this same extract. From the results achieved, the antifungal activity of the essential oil of C. citratus may be mainly due to the presence of neral and geranial. This essential oil could constitute an alternative to synthetic fungicides mostly used for Citrus fruit crops, due to high neral and geranial contents.