Letteratura scientifica selezionata sul tema "Ilex aquifolium L"

Porast gradskog stanovništva uz istovremeno smanjenje zelenih površina ima za posljedicu da se od urbanog zelenila traži da ispuni što veći broj funkcija. Osim ukrasne funkcije, od biljnih vrsta se traži da što više doprinose uslugama koje pruža urbani ekosustav, pokazuju otpornost na biotički i abiotički stres te imaju minimalni negativni utjecaj na čovjeka i okoliš. Zbog dugog životnog vijeka, podnošenja raznolikih okolišnih uvjeta, pridonošenja kvaliteti zraka i tla u gradu te visoke dekorativnosti, božikovina se može ubrojiti u multifunkcionalne biljne vrste pogodne za oblikovanje zelenih urbanih površina. Osim adaptiranosti na lokalne uvjete, kao hrvatska autohtona vrsta s dugom tradicijom primjene u uređenju interijera, privatnih i javnih zelenih površina, božikovina ujedno odražava karakter i običaje okruženja u kojem se koristi. Potencijalno štetni utjecaj vrste ogleda se u emisiji biogenih hlapivih organskih spojeva, otrovnosti te umjerenoj alergenosti muških primjeraka.

Membrane thermostability of `Needlepoint' Chinese holly (Ilex cornuta Lindl. & Paxt.), `Albo-marginata' English holly (Ilex aquifolium L.), and `Nellie R. Stevens', an Ilex aquifolium × Ilex cornuta hybrid, was determined by measuring electrolyte leakage in excised leaves and roots. The critical midpoint heat-killing temperature (T,) after a 30-min exposure was 54.4 ± 0.4C for `Nellie R. Stevens' leaves and was ≈ lC higher than that for Chinese (52.9 ± 0.3C) or English holly (52.9 ± 0.4C). The Tm for English holly roots (53.9 ±_ 1.5C) was higher than that for either `Nellie R. Stevens' (51.7 ± 0.3C) or Chinese holly (50.1 ± 0.3C). The results of this study suggest that English holly and `Nellie R. Stevens' leaves and roots can withstand direct heat injury equal to or greater than that of Chinese holly.

U prirodi su uočeni značajni mutageni oblici autohtonih vaskularnih biljnih vrsta, čime se izražava proces intraspecifične raznolikosti. Ovaj rad se bavi sa: Ilex aquifolium L. f. bacciflava Rehd., Sambucus nigra L. f. laciniata (Mill.) DC., dajući neke opšte karakteristike koje su već poznate u literaturi, i sa Salvia glutinosa L. f. sagittifolia Šilić, f. nov. opisan kao novi oblik.

Plants from the Ilex genus are known for properties such as antimicrobial and anti-inflammatory activity, can act as antiobesity agents and thus can be helpful in medicine. Some holly species, such as Ilex paraguariensis (widely known in the form of popular beverage: yerba mate), have been investigated, while others have been partially researched or remain unknown. Therefore, we performed qualitative and quantitative phytochemical analyses and screened antimicrobial properties of lesser-studied species (I. aquifolium L., I. aquifolium ‘Argentea Marginata’ and I. × meserveae ‘Blue Angel’). I. paraguariensis was used as a standard species for comparison purposes. Investigations were performed on water extracts due to their expected activity and composition. Antimicrobial research included evaluating minimal inhibitory, bactericidal (Staphylococcus aureus and Escherichia coli) and fungicidal concentration (Candida albicans, Alternaria alternata, Fusarium oxysporum, and Aspergillus niger) of extracts. The influence of the extracts on the production, eradication, and viability of bacterial biofilms was also analysed. It was established that Ilex paraguariensis possesses the richest profile of hydroxycinnamic acids derivatives in terms of component concentration and diversity. Ilex spp., especially I. × meserveae, contain a slightly higher amount of flavonoids and more different flavonoid derivatives than I. paraguariensis. However, the strongest antibacterial activity was shown by I. aquifolium L. and its cultivar ‘Argentea Marginata’ in terms of minimal inhibitory, bactericidal and fungicidal concentration, and biofilm assays. Extracts from both species significantly reduced the biofilm viability of S. aureus as well, which may be of use in the production of multicomponent lavaseptics, antiseptics, diuretics (supporting urinary tract infection therapy) and, due to their action on fungi, additives to growth media for specific fungi. The significant content of saponins enables Ilex extracts to be used as natural emulsifiers, for example, in cosmetics. Moreover, relatively high chlorogenic acid and rutin content may suggest use of Ilex spp. to treat obesity, digestive problems, in chemoprevention, and as preservatives in the food industry.

The germination dynamics ofIlex aquifoliumL. were studied in central Spain using a 3-year field sowing experiment. Ten triads of bags (n= 30 seeds per bag) were buried randomly in four different microhabitats: inside the holly woodland, along the forest edge, in open grassland and under isolated shrubs. Bags were harvested annually, and seeds were analysed for seed viability, embryo development changes and germination. Holly seeds did not germinate until the second year. Embryo development and seed germination were faster at the forest edge, with a total germination proportion of 63% of sown seeds. Germination in the holly woodland (48%), under the shrubs (46%) and in grassland (46%) were very similar. Thus, recruitment ofIlexpopulations in this region is not limited by requirements for germination. After the third year, the seed bank was reduced by 80–90% of the initial seeds, so it can be considered as a short-persistent seed bank. Holly seed behaviour can enhance recruitment in semi-open areas, such as forest edges. Linked to the short persistence of its seed bank, this species can be considered an intermediate strategist between mature forest specialists and early successional species. This work contributes to a deeper knowledge of the germination ecology ofI. aquifolium, in an effort to determine the relative importance of germination/ dormancy processes within holly population dynamics.

L’objectif de ce travail de thèse était de déterminer la composition chimique d’extraits de plantes de Corse encore peu ou pas étudiées et susceptibles d’avoir des activités biologiques valorisables. Cette étude a été menée en mettant en œuvre la méthodologie d’analyse des mélanges complexes par RMN 13C, développée depuis une trentaine d’années par l’équipe « Chimie et Biomasse » de l’UMR CNRS 6134 Sciences pour l’Environnement de l’université de Corse. Dans une première partie, nous avons étudié la composition chimique d’extraits de houx commun (Ilex aquifolium L.). Deux extraits de feuilles (obtenus à l’hexane et au dichlorométhane) ont chacun subi deux fractionnements successifs par chromatographie sur colonne ouverte de silice. L’analyse par RMN 13C (CPG(Ir) et CPG-SM également dans certains cas) des extraits bruts et des fractions de chromatographie a permis l’identification de onze triterpènes dont l’α-amyrine et la β-amyrine et certains de leurs esters. Parallèlement, deux acides triterpéniques d’intérêt (acide ursolique et acide oléanolique) ont été quantifiés par RMN 1H au sein de l’extrait brut au dichlorométhane via une méthode rapide mise au point et validée (justesse, linéarité, précision des mesures). Ces deux composés représentent respectivement 55,3% et 20,8% de l’extrait. Nous avons également réalisé, en collaboration avec l’équipe « Biochimie et Biologie Moléculaire du Végétal » de l’université de Corse, des tests antimicrobiens sur les extraits et certaines fractions de chromatographie. Les deux acides triterpéniques précédemment cités ont montré une activité antimicrobienne comparable à celle du chloramphénicol (antibiotique de référence) vis-à-vis de trois bactéries à Gram positif, Staphylococcus aureus, Staphylococcus epidermidis et Bacillus cereus (CMI = 4 et 8 mg.L-1 vs. 2 et 4 mg.L-1). Par ailleurs, nous avons préparé des extraits de baies de houx en utilisant différents solvants : hexane, dichlorométhane, dichlorométhane/acétate d’éthyle (50/50, v/v). Les deux derniers extraits (dichlorométhane et dichlorométhane/acétate d’éthyle) ont subi des fractionnements successifs et l’étude des spectres RMN 13C des extraits bruts et des fractions de chromatographie a permis d’identifier neuf triterpènes (précédemment identifiés), cinq dérivés phénoliques, six monosaccharides ainsi que quatre lactones (la ménisdaurilide, l’aquilégiolide, la 7-épi-griffonilide et la dasycarponilide) non encore répertoriées dans le houx commun. Dans une seconde partie, nous avons étudié la composition chimique d’extraits de fleurs et de racine de Calicotome villosa (Poir.) Link. Les extraits de fleurs obtenus au dichlorométhane et à l’acétate d’éthyle ont été soumis à des chromatographies successives. L’analyse par RMN 13C des extraits bruts et des fractions de chromatographie a permis l’identification de trois flavonoïdes, cinq dérivés glucosylés de flavonoïdes et quatre phénylpropanoïdes. Dans cette partie, nous nous sommes également intéressés à la composition chimique d’un extrait méthanolique de racine de C. villosa qui n’a fait l’objet d’aucune étude de ce type au préalable. Cet extrait a été soumis à plusieurs fractionnements successifs et dix-huit composés, notamment des stérols, des flavonoïdes, un polyphénol et des ptérocarpanes ont été identifiés par RMN 13C
The aim of this work was to determine chemical composition of wild growing corsican understudied plant species, with potential biological activities. This study was realized using the computerized NMR method developed over the past thirty years by the University of Corsica “Chimie et Biomasse” group, UMR CNRS “Sciences Pour l’environnement”. Identified secondary metabolites were then undertaken to evaluate their antimicrobial properties. As part of this study, we selected on the first place commun holly (Ilex aquifolium L.). After two successive column chromatography, hexane and dichloromethane leaves crude extracts and all chromatography fractions were analyzed by 13C NMR (GC(RI) and GC-MS sometimes) to allow the identification of eleven triterpens and α- and β-amyrin esters. Among identified compounds, ursolic acid and oleanolic acid were also quantified by 1H NMR in the dichloromethane crude extract using a reliable method developped and validated (accuracy, linearity precision of measurements). Ursolic acid accounted for 55.3% of the extract, followed by oleanolic acid, 20.8%. Evaluation of previous identified compounds antimicrobial activities has been performed in collaboration with « Biochimie et Biologie Moléculaire du Végétal » group (University of Corsica). Triterpen acids and chloramphenicol (reference antibiotic) displayed similar antibacterial activities against three Gram-positive bacteria, Staphylococcus aureus, Staphylococcus epidermidis and Bacillus cereus (MIC = 4 and 8 mg.L-1 vs. 2 and 4 mg.L-1). Moreover, dichloromethane and dichloromethane/ethyl acetate (50/50, v/v) berries extracts were submitted to successive column chromatography. Crude extracts and chromatography fractions 13C NMR spectra revealed presence of nine triterpens previously identidied, five phenolics derivatives, six monosaccharides and four lactones (menisdaurilide, aquilegiolide, dasycarponilide and 7-epi-griffonilide) were first time identified in berries holly extracts. On the second place, we determined chemical compositions of Calicotome villosa (Poir.) Link flowers and root extracts. 13C NMR analysis of dichloromethane and ethyl acetate flowers extracts and their chromatography fractions, allowed the identification of three flavonoids, five glycosyl flavonoids and four phenylpropanoids. We also studied chemical composition of a methanol root extract which has never been submitted to any chemical composition study. After successive column chromatography, eighteen compounds were identified by 13C NMR including sterols, flavonoids, a polyphenol and pterocarpans