[Show abstract][Hide abstract] ABSTRACT: A qualitative analysis of flavonoids has been carried out for Vicia eristalioides Maxt., V. kalakhensis Khatt., Maxt. and Bisby, V. narbonensis L. and V. galilaea Plitm. et Zoh in two different vegetative phases. Free aglycones were consistently absent and there was no evidence of flavone glycosides, whereas kaempferol and quercetin glycosides were present in different amounts, according to the species. The flavonoid patterns of the four species were compared and differences were present among them and also within the same species during the two vegetative phases. The results indicate that flavonoid data may be used in the study of the organisation and evolution in Narbonensis complex.
[Show abstract][Hide abstract] ABSTRACT: A qualitative and quantitative analysis of flavonoids has been carried out for first time in Vicia eristalioides Maxt. and in Vicia kalakhensis Khatt., Maxt. Bisby. Free aglycones were consistently absent from both species while kaempferol derivatives were pre dominant in V. kalakhensis; a more complex mixture of flavonoid glycosides,(kaempferoland quercetin glycosides) was present in V. eristalioides. Therer was no evidence of flavones glycosides.The flavonoid patterns of V. kalakhensis and V. eristalioides were compared with that of V. narbonensis which is considered to be the ancestor of the Narbonensis complex. The results indicate that qualitative and quantitative flavonoid data may be used in the study of the organization and evolution of the Narbonensis complex.
[Show abstract][Hide abstract] ABSTRACT: Evaluation and identification of wild olive genetic resources allowed us to select new olive varieties and to recognize Tunisian grove richness and diversity. Five new olive cultivars were previously selected among populations of wild olive plants on the basis of agronomic and chemical evaluations. Their virgin olive oils were analysed for their fatty acid composition, quality indices (Free acidity, PV and UV characteristics) and oxidative stability. They were then submitted to solid phase microextraction (SPME) and their volatile compositions were determined.Forty five compounds were isolated and characterized by GC–MS, representing 85%–98% of the total amount. The presence of some of these compounds in virgin olive oil had not been previously reported. The volatile compounds identified were mainly (E)-3-hexen-1-ol, (E)-2-hexen-1-ol, tricosane and β-selinene. Results demonstrated that the profiles of oleaster oils were distinctly different from those of European and Tunisian oils. All results indicate that there is a wide variability in the chemical and aroma characteristics of the selected oleaster virgin olive oils.
[Show abstract][Hide abstract] ABSTRACT: In order to identify new crop suitable for indigo production in Italy, seasonal variation in productivity of indigo precursors was studied in woad (Isatis tinctoria L., Family Cruciferae) and in dyer's knotweed (Polygonum tinctorium Ait., Family Polygonaceae), grown in central Italy under temperate climate. Indigo precursors, indoxyl-3-ketogluconate (isatan B) and indoxyl-β-d-glucoside (indican), were measured in leaves by HPLC analysis under well watered versus rain fed field conditions, and the amount of indigo derived by stoichiometric calculations.Woad showed lower indigo potential than dyer's knotweed, evaluated as either amount of indigo either per leaf weight or per plant. However, in water stress conditions, woad appeared to be drought tolerant as opposed to dyer's knotweed revealed very sensitive. In fact, in dyer's knotweed leaf yield was over 50% reduced in water stress field conditions, characterizing central and southern Italy during July and August, as compared to some 30% in woad. Dyer's knotweed appears to be more productive, providing water is supplied appropriately, thus making proper irrigation plans necessary to achieve sustainable high yields.
Environmental and Experimental Botany 12/2006; · 3.00 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Fruits from the same variety of Olea europaea L., grown under different environmental conditions in the north of Tunisia, were harvested at the same ripening degree and immediately processed. The volatile profile of virgin olive oils was established using solid phase, micro-extraction (SPME) and gas chromatography-mass spectrometry (GC-MS). Compounds belonging mainly to the following chemical classes characterised the volatile profiles: esters, aldehydes, ketons, aliphatic alcohols and hydrocarbons. Significant differences in the proportions of volatile constituents from oils of different geographical origins were detected and the major volatile in approximately 50% of the oil samples was the aldehyde (E)-2-hexenal. The results suggest that, beside the genetic factor, environmental conditions influence the volatile formation.
[Show abstract][Hide abstract] ABSTRACT: The methanolic extract of leaves of Michelia figo Spreng. (Magnoliaceae), as well as several purified fractions, showed a concentration-dependent vasorelaxing effect on aortic rings endothelium-deprived and pre-contracted by norepinephrine (NE). For further pharmacological investigation on the mechanism of action, the fraction S4 was selected, since it showed the best vasodilator properties. The pharmacological effect was not produced through the stimulation of cyclooxygenase, adenyl cyclase, or guanylyl cyclase, since selective inhibitors did not prevent the fraction S4-induced effects. Moreover, the vasorelaxing effect of the fraction was resistant to the block of nifedipine-sensitive Ca(2+) channels. The fraction S4 (10(-4) g/ml) produced a shift towards the right of the concentration-contractile response curve to NE, in normal conditions, and the shift was more evident in Ca(2+)-free Tyrode solution, suggesting an action on intracellular Ca(2+)-channels. The vasodilator action of fraction S4 on NE pre-contracted rings was not prevented by cyclopiazonic acid (blocker of Ca(2+)/ATPase), which excludes a role for mechanisms involving the storage of Ca(2+) in the sarcoplasmic reticulum. The reduction of the contraction elicited by caffeine, an opener of ryanodine-sensitive receptors, suggests that the fraction S4 of Michelia figo leaves could produce the vasorelaxing response by the blockade of ryanodine-sensitive Ca(2+) channels of the sarcoplasmic reticulum.
Journal of Ethnopharmacology 05/2004; 91(2-3):263-6. · 2.94 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The seasonal variations of the composition of the essential oil of Artemisia verlotiorum leaves have been analyzed by ion-trap GC-EIMS and GC-CIMS. Twelve samples have been collected, one for each month of the year. The main components identified were: 1,8-cineole, germacrene D, β-thujone, β-caryophyllene, borneol, camphor, and myrcene. Qualitative and quantitative have been observed for some compounds. With the exception of November, 1,8-cineole was the main component of the essential oil.
Biochemical Systematics and Ecology 04/2004; 32(4):423-429. · 1.17 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A method to quantify the indigo precursor indican (indoxyl-beta-D-glucoside) in Polygonum tinctorium L. has been developed. Plant material was extracted in deionized water, and indican was identified and quantified using high performance liquid chromatography (HPLC) coupled to an evaporative light scattering detector (ELSD). Results confirmed that with this method it is possible to measure indican content in a short time, obtaining reliable and reproducible data. Using this method, leaf indican content was quantified every 15 days during the growing season (from May to October) in P. tinctorium crops grown in a field experiment in Central Italy. Results showed that indican increased along the growing season until flowering and was positively affected by photosynthetic active radiation (PAR). Indican is naturally hydrolyzed by native beta-glucosidase to indoxyl and glucose, the indoxyl yielding indigo. The activity of two enzymes, sweet almond beta-glucosidase and Novarom G preparation, were compared with P. tinctorium native beta-glucosidase to evaluate indigo production. Results showed that the ability to promote indigo formation increased as follows: almond beta-glucosidase <or= Novarom G.
[Show abstract][Hide abstract] ABSTRACT: The chemical composition of the volatile fractions from leaves of three Olea europaea L. cultivars (Leccino, Frantoio, and Cipressino) harvested at two different times of the year were examined by GC and GC-MS. The results showed a high content of aliphatic aldehydes in the three cultivars during both harvesting periods and an increase of (E)-2-hexenal (an aldehyde with high antimicrobial properties) percentage from July to November.
Journal of Agricultural and Food Chemistry 04/2003; 51(7):1994-9. · 3.11 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The chemical compositions of the volatile fractions from three Olea europaea L. cultivars (Leccino, Frantoio, and Cipressino) were examined by GC and GC-MS. The results showed that the cultivars can be distinguished on the basis of the volatile fraction compositions.
Journal of Agricultural and Food Chemistry 12/2001; 49(11):5409-11. · 3.11 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The antimicrobial activity of extracts of Geum rivale (Rosaceae) and that of some isolated constituents, on bacteria and fungi, was evaluated. The activity was concentrated in the triterpenes fraction and, for gram+ and gram- bacteria, also in the flavonoids fraction.
Phytotherapy Research 12/2000; 14(7):561-3. · 2.40 Impact Factor