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- Characterization of volatiles from Moroccan propolis samplesPublication . EL-GEUNDOUZ, Soukaina; Lyoussi, Badiaa; Miguel, Maria Graca; Figueiredo, A. CristinaThe volatiles from 24 propolis samples collected from different geographical locations in Morocco were evaluated. Propolis volatiles isolated by hydrodistillation and analyzed by gas chromatography (GC) and gas chromatography–mass spectrometry (GC-MS). Cluster analysis based on propolis samples’ volatile chemical composition defined two main uncorrelated clusters. Cluster I, with 23 of the 24 samples analyzed, included three subgroups, Ia, Ib1 and Ib2, dominated by βeudesmol (11–30%), cedrol (7–40%) and n-tricosane (6–34%), respectively. Cluster II included just one sample, with ar-curcumene (32%) as the main component. The results obtained contributed to increase the knowledge on the chemical composition and variability of Moroccan propolis samples. The volatile profile of these samples was distinct from those of Algeria, Canary Islands and Ethiopia, the sole African propolis volatiles studied so far.
- Growth, photosynthetic pigments, phenolic content and biological activities of Foeniculum vulgare Mill., Anethum graveolens L. and Pimpinella anisum L. (Apiaceae) in response to zincPublication . MAJDOUB, Nesrine; EL-GEUNDOUZ, Soukaina; Rezgui, Marwa; Carlier, Jorge; Clara Costa, Maria; Ben Kaab, Leila Bettaieb; Miguel, Maria GracaThe effect of zinc (Zn) on phenols, antioxidant activities (free radicals' scavenging activities, inhibition of lipid peroxidation, chelating activity and reducing power), and enzyme inhibition activities of acetylcholinesterase, lipoxygenase and tyrosinase of anise, dill and two cultivars of fennel [Latina" (F-L) and "Doux de Florence" (F-DF)] aqueous extracts was evaluated for the first time. At the same time, growth and photosynthetic pigment contents were also estimated. A significant decrease in all growth parameters, such as plant height, fresh and dry weights of aerial parts and roots was statistically proved in the presence of 2 mM Zn. An enhancement of Zn accumulation was observed, particularly in aerial part. Exposure to 2 mM Zn induced quantitative changes in the phenols of all tested extracts. In fennel extracts, a decrease of phenol content was observed when treated with Zn, whereas an increase was found in dill and anise extracts submitted to Zn treatment. All samples, either in the presence or absence of Zn, showed antioxidant activity, independent on the tested assay, with the exception of the cultivar F-DF (treated and non-treated), which was unable to scavenge NO radicals. Zn-treated dill and anise presented usually higher antioxidant activity. Concerning inhibitory activities against acetylcholinesterase, lipoxygenase and tyrosinase enzymes, both treated and non-treated F-DF did not inhibit acetylcholinesterase activity. Zinc-treated F-DF was also unable to inhibit lipoxygenase activity. The remaining species presented capacity for inhibiting those enzymes and tyrosinase as well, but their abilities varied in response to Zn excess.