Jean Marie Bessière

Antibacterial and antioxidant activities of Artemisia annua essential oil

The essential oil of Artemisia annua aerial parts, consisting of camphor (44%), germacrene D (16%), trans-pinocarveol (11%), beta-selinene (9%), beta-caryophyllene (9%) and artemisia ketone (3%), was screened for its antimicrobial activity. The essential oil remarkably inhibited the growth of tested Gram-positive bacteria Enterococcus hirae and both tested fungi. This oil has shown an antioxidant activity equivalent to 18% of the reference compound (alpha-tocopherol).

Essential oils from five southern Brazilian species of Myrcia (Myrtaceae)

Abstract Essential oils from fresh leaves of five Myrcia species collected in the southern region of Brazil were obtained by hydrodistillation and analyzed by GC and GC/MS. Seventy compounds representing 87.5% to 97.0% of the oils were identified. Two samples comprised mainly of monoterpenes with linalool being the most abundant compound in M. acuminatissima oil (22.3%), whereas α- and β-pinenes represented 36.3% of M. bombycina oil. The three other oil samples were found to be rich in sesquiterpenes. The oil of M. fallax contained a high percentage of α-bisabolol (83.8%), while M. glabra oil was characterized by the presence of selinenes (15.2%) and valerianol (13.2%). Finally, the oil of M. multiflora was found to be the most complex with germacrene D (8.7%) and β-caryophyllene (7.5%) being the two major constituents.

Volatile components in okra seed coat

Abstract The volatile compounds in the coat of okra seeds can be released by simple rubbing of the seeds. They were isolated by hexane extraction and steam distillation to give the essential oil (EO) and by head space (HS) condensation. 72 compounds were identified in the study (40 esters and 24 sesquiterpenes and derivatives). The most abundant compound was 2-methylbutyl 2-methylbutanoate which represented 49.6% of the HS and 32% of the EO. Among the sesquiterpenes, germacrene D (11.9% of the EO) and the farnesyl derivatives (7.9% of the EO) were the major compounds. Most of these compounds have not been reported previously to be present in okra.

Antiplasmodial volatile extracts from Cleistopholis patens Engler & Diels and Uvariastrum pierreanum Engl. (Engl. & Diels) (Annonaceae) growing in Cameroon

In a search for alternative treatment for malaria, plant-derived essential oils extracted from the stem barks and leaves of Cleistopholis patens and Uvariastrum pierreanum (Annonaceae) were evaluated in vitro for antiplasmodial activity against the W2 strain of Plasmodium falciparum. The oils were obtained from 500xa0g each of stem barks and leaves, respectively, by hydrodistillation, using a Clevenger-type apparatus with the following yields: 0.23% and 0.19% for C. patens and 0.1% and 0.3% for U. pierreanum (w/w relative to dried material weight). Analysis of 10% (v/v) oil in hexane by gas chromatography and mass spectrometry identified only terpenoids in the oils, with over 81% sesquiterpene hydrocarbons in C. patens extracts and U. pierreanum stem bark oil, while the leaf oil from the latter species was found to contain a majority of monoterpenes. For C. patens, the major components were α-copaene, δ-cadinene, and germacrene D for the stem bark oil and β-caryophyllene, germacrene D, and germacrene B for the leaf oil. The stem bark oil of U. pierreanum was found to contain mainly β-bisabolene and α-bisabolol, while α- and β-pinenes were more abundant in the leaf extract. Concentrations of oils obtained by diluting 1-mg/mL stock solutions were tested against P. falciparum in culture. The oils were active, with IC50 values of 9.19 and 15.19xa0μg/mL for the stem bark and leaf oils, respectively, of C. patens and 6.08 and 13.96xa0μg/mL, respectively, for those from U. pierreanum. These results indicate that essential oils may offer a promising alternative for the development of new antimalarials.

Aromatic Plants of Tropical Central Africa. XXII. Volatile Constituents of Croton aubrevillei J. Léonard and C. zambesicus Muell. Arg.

ABSTRACT The composition of the essential oils obtained by hydrodistillation of the bark of Croton aubrevillei J. Leonard from Central African Republic and leaves of Croton zambesicus Muell. Arg. from Tchad were analyzed by capillary GC and GC/MS. The two samples contained the same major constituents but in different proportions: linalool (34.6% and 9.9%), β-caryophyllene (11.9% and 9.9%). C. zambesicus oil is very different from that previously obtained from the flowering tops of the Saudi Arabian species, which was characterized by much more limonene (38%).

Synthése et caracterisation d'amorceurs azoiques fluorés. Application a l'étude de la reaction de terminaison de chaine lors de la polymérisation radicalaire du styrène

Resume Cette etude presente lapplication dun amorceur azoique porteur de groupements fluores, a la determination de la valeur du pourcentage de recombinaison, lors de la terminaison de la polymerisation du styrene. La determination du taux ponderal de fluor par analyse elementaire et de la longueur de chaine ( DP n ) par CES, permettent dacceder a la valeur du taux de produit recombine, sur un polystyrene resultant dun amorcage par lazoique fluore. Nous avons synthetise deux amorceurs azoiques fluores dont lun a ete utilise pour letude. Les valeurs de sa constante de vitesse de decomposition (kd) et de son coefficient defficacite (f) ont ete calculees.

Chemical composition of essential oils from three southern Brazilian species of Mikania (Asteraceae)

Abstract Samples of essential oils from leaves of Mikania hirsutissima DC, M. involucrata Hook, et Am. and M. laevigata Shultz Bip. ex Baker were analyzed by a combination of capillary gas chromatography and GC/MS. Forty one components have been identified representing 70–95% of the oils content. The oils of M. involucrata and M. laevigata are quite similar and constituted by sesquiterpenes, represented mainly by β-caryophyllene (18.9% and 20.9%), germacrene D (9.9% and 29.8%) and bicyclogermacrene (28.1% and 13.4%). The oil of M. hirsutissima is also characterized by sesquiterpenes, and the major components are ar-curcumene (15.0%) and spathulenol (10.2%), and a small fraction (6.5%) of aliphatic compounds.

Aromatic Plants of French Polynesia. III. Constituents of the Essential Oil of Leaves of Ocimum basilicum L.

Abstract Sweet basil (Ocimum basilicum L.), one of the most popular aromatic plants, shows great variation in both morphology and essential oil components. In this study, the essential oils obtained by hydrodistillation from the leaves of three samples of basil of French Polynesia were investigated for the first time. The main constituents of the oil were (E)-methyl cinnamate (43.4–62.3%) and (Z)-methyl cinnamate (8.1–8.6%).

Volatile Constituents of the Seed Teguments of Abelmoschus esculentus (L.) Moench

Abstract Volatile compounds liberated on rubbing the seeds of okra Abelmoschus esculentus (L.) Moench were identified. These substances were shown to be stored in lenticular formations extending along the surfaces of the seeds. Fractionation of an ethanolic extract of the seed teguments led to identification of more than 40 compounds new to A. esculentus, including a major proportion of aliphatic esters and aldehydes such as undecanal and isododecanal, which are largely responsible for the fragrance of the seeds.