25 research outputs found
Crosslinking of surface antigens causes mobilization of intracellular ionized calcium in T lymphocytes.
Superantigen and HLA-DR ligation induce phospholipase-C gamma 1 activation in class II+ T cells
VariabilitĂ© de la composition chimique de lâhuile essentielle des feuilles de Lippia multiflora cultivĂ©es en CĂŽte dâIvoire
Objectif : caractĂ©riser les huiles essentielles des feuilles de Lippia multiflora et dâĂ©tudier la variabilitĂ© de composition chimique de lâhuile essentielle (HE) des feuilles de Lippia multiflora cultivĂ©es en CĂŽte dâIvoire au cours dâune annĂ©eMĂ©thodologie et rĂ©sultats : les 144 Ă©chantillons d'HE ont Ă©tĂ© extraites par hydrodistillation selon le procĂ©dĂ© dĂ©crit par la PharmacopĂ©e EuropĂ©enne 5Ăšme Ă©dition, puis l'analyse a Ă©tĂ© effectuĂ©e au moyen des techniques deChromatographie en phase gazeuse couplĂ©e Ă la spectromĂ©trie de masse (GC-MS) pour l'identification des composĂ©s, couplĂ©e Ă un dĂ©tecteur Ă ionisation de flamme pour leur quantification. Les rĂ©sultats montre que lesphĂ©nols sont prĂ©sents dans la quasi-totalitĂ© des Ă©chantillons Ă©tudiĂ©es, le carvacrol et le thymol sont les plus reprĂ©sentĂ© puisque les HE de Bondoukou en renferment plus de 30 %, tandis que le thymol atteint des teneurs de moins de 10 % dans les HE dâAbidjan et Toumodi. Les monoterpĂšnes et sesquiterpĂšnes sont prĂ©sents dans les huiles Ă©tudiĂ©es.Conclusions et applications de rĂ©sultats : Les rĂ©sultats obtenus ont montrĂ©, dâune part, une variabilitĂ© chimique en fonction de lâorigine gĂ©ographique: les sites dâAbidjan et de Toumodi sont caractĂ©risĂ©s par des compositions similaires en composĂ©s terpĂ©niques aromatiques qui apparaissent trĂšs diffĂ©rentes des Ă©chantillons provenant de Bondoukou. Dâautre part, lâanalyse statistique a aussi Ă©tĂ© conduite afin d'Ă©tudier la variabilitĂ© de la composition chimique en fonction de la date de rĂ©colte pour chacun des 3 sites de culture. Les rĂ©sultats ont permis dâidentifier, pour chacun des sites, la pĂ©riode de rĂ©colte correspondant Ă la teneur maximale en composĂ©s dâintĂ©rĂȘt pharmacologique. Notre travail a donc permis d'une part d'indiquer des compositions d'HE non encore Ă©tudiĂ©es Ă ce jour en CĂŽte dâIvoire et d'autre part de mettre en Ă©vidence des spĂ©cificitĂ©s intra et inter espĂšces. (Variability of the chemical composition of the essential oil of Lippia multiflora leaves grown in Ivory Coast)(Variability of the chemical composition of the essential oil of Lippia multiflora leaves grown in Ivory Coast)Objective: Characterize the essential oils (EO) of Lippia multiflora leaves and study the variability of chemical composition of the essential oil from the Lippia multiflora leaves grown in the Ivory Coast in a yearMethodology and results : 144 samples of EO was extracted by steam distillation according to the process described by the European Pharmacopoeia 5th Edition, then the analysis was carried out using chromatographic techniques in the gas phase coupled with mass spectrometry (GC -MS) for the identification of compounds, coupled with a flame ionization detector for their quantification. The results show that phenols are present in almost all samples studied, carvacrol and thymol are the most represented as Bondoukou the EO contained in more than 30%, while thymol reached levels of less than 10% EO in Abidjan and Toumodi. Monoterpenes and sesquiterpenes are present in the investigated oils.Conclusion and application: The results showed, a chemical variability depending on the geographical origin. Abidjan and Toumodi sites were characterized by similar compositions in aromatic terpene compounds thatappear very different from samples of Bondoukou. On the other hand, the statistical analysis was also conducted to study the variability of the chemical composition depending on the harvest date for each of the three cultural sites. The results were used to identify, for each site, the harvest period corresponding to the maximum content of compounds of pharmacological interest. This work has allowed knowledge of compositionsof EO not yet studied to date in Ivory Coast and also to highlight the specific intra and inter species