J. M. Bessière

Aromatic Plants from Brazil. II. The Chemical Composition of Some Eugenia Essential Oils

ABSTRACT Essential oils were obtained from the leaves of six Eugenia species collected from different areas of Brazil and were analyzed by GC and GC/MS. Forty-four compounds representing 89.6–95.7% of the oils were identified. Only Eugenia schuechiana and E. plicato-costata showed considerable amounts of monoterpenes: among them, α-pinene was the most abundant (13.2 and 20.9%). In all analyzed samples, bicyclic sesquiterpenes were present, particularly the selinene group (41%) in E. uniflora; another group of hydrocarbon and oxygenated sesquiterpenes, this time with the aromadendrene nucleus, was found in all samples in different amounts. The oils of E. rostrifolia and E. involucrata were found to be especially rich in sesquiterpene hydrocarbons (77.7% and 84.4%), with considerable amounts of viridiflorene (>30%); β-caryophyllene and its oxide are the main components of the essential oil of E. schuechiana and E. plicato-costata (31.9% and 26.9%), while E. uniflora and E. tinguyensis were characterized by ...

Óleos voláteis de espécies de Myrcia nativas do Rio Grande do Sul

Essential oils from M. richardiana, M. arborescens, M. selloi, M. oligantha, M. rostrata, M. lajeana, M. obtecta, M. pubipetala and M. hatschbachii were obtained by hydrodistillation and analyzed by GC and GC/MS. Sixty-seven compounds have been identified ranging from 90-99% of the oil contents. All analyzed species were rich in cyclic sesquiterpenes (66-99%), mainly those from the cadinane, caryophyllane and germacrane cyclization pathway, among them b-caryophyllene, germacrene D, bicyclogermacrene, d-cadinene, spathulenol, caryophyllene oxide, globulol and a-cadinol. The acyclic sesquiterpene series was well represented by M. lajeana (32.1%), with 25,3% of (E)-nerolidyl acetate.

Aromatic plants of tropical west Africa. XI. Chemical composition, antioxidant and antiradical properties of the essential oils of three Cymbopogon species from Burkina Faso.

Abstract The essential oils isolated by hydrodistillation from the leaves or the flowering stalks of Cymbopogon citratus (DC) Stapf., C. giganteus Chiov. and C. proximus Stapf. syn. C. schoenanthus (L.) Spreng. subsp. proximus (A. Rich.) Maire & Weiller from Burkina Faso were analyzed by GC and GC/MS. The main constituents of the oil of C. citratus were geranial (44.6%), neral (330%) and myrcene (10.7%). The oil of C. giganteus contained limonene (17.3%) and a set of monoterpene alcohols: trans-p-mentha-l(7),8-dien-2-ol (17.0%), cis-p-mentha-l(7),8-dien-2-ol (16.5%), trans-p-mentha-2,8-dien-l-ol (13.8%) and cis-p-mentha-2,8-dien-l-ol (9.3%). The main component of the leaf and flower oils of C. proximus was piperitone (59.1% and 55.6%, respectively). The essential oils of the three Cymbopogon species were also studied concerning their antioxidant and antiradical activity. Their properties were very low, compared to the two commercially used antioxidants tested (BHT and 5-tocopherol). C. proximus showed the strongest antioxidant activity (Antioxidant Value = 1.54), followed by C. giganteus (A.V. = 1.04) and C. citratus (A.V.=0.11). On die other hand, the oil of C. citratus was estimated to present the highest antiradical power, followed by C. proximus and C. giganteus.

Chemical composition of peel and leaf essential oils of Citrus medica L. and C. limonimedica Lush.

Five peel oils and six leaf oils of different varieties of citrons (Citrus medica and C. limonimedica) were obtained from fruits and leaves collected on trees submitted to the same pedoclimatic and cultural conditions. Their composition was investigated by capillary GC, GC–MS and Carbon-13 NMR. Three chemotypes: limonene, limonene/γ-terpinene and limonene/geranial/neral were observed for peel oils while leaf oils exhibited the limonene/geranial/neral composition. Copyright

2-Methyl-6-Methylene-7-Octen-4-One, a constituent of Lippia multiflora essential oil

Abstract The essential oils of Lippia multiflora from different regions of the Congo were analysed by GC and GC-MS; their chemical compositions are quite different from those previously described for this species. 2-Methyl-6-methylene-7-octen-4-one (ipsenone) was identified as a component of these oils. This is the first time that this ketonic terpenoid has been found in the plant kingdom.

Aromatic plants of Tropical Central Africa. Part XXVII.Comparative Study of the Volatile Constituents of Five Annonaceae Species Growing in Cameroon

Nine essential oils were isolated from five Annonaceae species growing in Cameroon. The samples were analysed by GC and GC-MS. The volatile oils obtained from seeds of Monodora myristica (Gaertn.) Dunal and Monodora brevipes Benth., those from leaves and fruits of Annona senegalensis. Pers. var. senegalensis and that from fruits of Cananga odorata (Lam.) Hook. Fil. et Thoms. were mainly monoterpenic, the major components being α-phellandrene or sabinene and mycrene. The leaf essential oil of M. brevipes contained approximately equal amounts of monoterpenes and sesquiterpenes, with two major components with an acyclic structure: (Z)-β- ocimene and (E),(E) α-farnesene. Finally, the oils from leaves of M. myristica, Annona muricata L. and C. odorata contained mostly sesquiterpenes, the major constituent being β-caryophyllene.

Aromatic Plants of Tropical West Africa. X. Volatile Constituents of Zanthoxylum zanthoxyloides Lam. Leaves and Fruit Pericarps from Benin

Abstract The essential oils of leaves and fruit pericarps of Zanthoxylum zanthoxyloides were analyzed by GC and GC/MS. The leaf oil contained only monoterpene hydrocarbons (98.2%); among them, α-pinene (26.5%), myrcene (30.0%) and (E)-β-ocimene (31.9%) were most predominant. The composition of the fruit oil is more diverse, with 85.5% of monoterpenoids and a fairly large proportion of oxygenated compounds (30.9%), among which linalool (11.3%) and geranial (9.5%) were the most abundant. Both the leaf and fruit oils contained fairly large amounts of (E)-β-ocimene 31.9% and 41.5%, respectively.

Isoprene related esters, significant components of Pandanus tectorius

Isopentenyl and dimethylallyl acetates and cinnamates have been found in large amounts in an essential oil obtained from the ripe fruit of Pandanus tectorius, their identification has been confirmed by synthesis. This is the first time that these esters, apart from one, have been found in the plant kingdom and, generally speaking, that monoterpene precursors predominate in an essential oil.

Composition of the essential oils from the leaves of two varieties of Aspilia africana (Pers.) C. D. Adams from Cameroon

Four essential oil samples obtained by hydrodistillation from the leaves of Aspilia africana var. africana and a corresponding sample of A. africana var. ambigua were analysed by GC and GC–MS. The two varieties were poor in essential oil content (<0.1%). The qualitative composition of the essential oils was found to be quite similar, irrespective of the area and date of plant collection. Marked differences were, however, observed in the quantitative composition of the oils from the two varieties. As far as A. africana var. africana is concerned, two oil samples from Bafoussam were rich in sesquiterpenes (88% and 94%) with germacrene-D (45% and 54%) as the major component, while two oil samples from Yaounde contained mainly monoterpenes (63% and 48%) with α-pinene (39% and 27%) as the most abundant component. The variety A. africana var. ambigua afforded an essential oil rich in monoterpenes (54%) with limonene (23%) and α-pinene (22%) as predominating components. Finally, the insect antijuvenile hormone precocene I was found to be present in all samples of the two varieties. Copyright

Two chromene derivatives from Calyptranthes tricona

Two alpha-monomethyl chromene derivatives were isolated from the leaf essential oil of Calyptranthes tricona from Brazil which were characterized by 1H- and 13C-NMR. Besides these components, which represent about half of the oil, classical terpenoid structures could be identified, among which cis-beta-farnesene is the most abundant (26.6%). A biosynthetic pathway could be proposed to explain the formation of the chromene derivatives in the plant.