196,286 research outputs found
Controllo delle batteriosi in germogli di calla
No full textL’attività antimicrobica di estratti di Melia azedarach e dell’acido carnocico (AC) è stata valutata su isolati batterici e su germogli di calla (Zantedeschia aethiopica) contaminati. Gli estratti etanolici di frutto (polpa e buccia, PE) e di semi (SE) di M. azedarach hanno mostrato attività battericida su diversi isolati batterici, tuttavia PE (20 mL/100 mL di mezzo) è risultato fitotossico. PEE (10 mL/100 mL, ottenuto per evaporazione dell’etanolo da PE) ha ridotto drasticamente lo sviluppo dei batteri nei germogli, mostrando ridotta tossicità. AC (200-400 mg/L) ha inibito efficacemente la crescita di sospensioni batteriche e, a concentrazioni elevate (400 mg/L), ha indotto parziale senescenza e inibizione radici dello sviluppo radicale
Effetto di derivati dell'urea sulla radicazione avventizia in vitro di microtalee micropropagate di corbezzolo
No full textRiassunto
La radicazione avventizia è un passaggio chiave della propagazione vegetativa di specie di interesse forestale, agricolo, orticolo e ornamentale. Questo processo può essere stimolato mediante l’applicazione esogena di auxina ma il solo trattamento con auxine non è sempre in grado di stimolare la formazione di un apparato radicale funzionale. In questo lavoro è stato indagato l’effetto di due derivati ureidici di sintesi, coadiuvanti la radicazione avventizia, N,N’-bis-(2,3-metilenediossifenil)urea e 1,3-di(benzo[d]ossazol-5-il)urea, in microtalee recalcitranti di Arbutus unedo L.
Abstract
Adventitious roots are post-embryonic roots which arise from non-pericycle tissue in stem and leaves. Adventitious rooting is a key step in vegetative propagation of plants, as it is a prerequisite for the successful production of viable clones.
Many environmental and endogenous factors, such as temperature, light conditions, hormones and tissue maturity, may affect adventitious root formation.
Auxin has been shown to be intimately involved in the process of adventitious rooting. In fact, exogenous auxin application may stimulate this process in those cuttings in which it doesn’t occur naturally. But, sometimes, auxin alone isn’t able to reduce the woody plant recalcitrance and to achieve a high quality root system. Many efforts have been made to enhance rooting, investigating the effect of other natural or synthetic molecules. Two urea derivatives, the N,N’-bis-(2,3-methylenedioxyphenyl)urea and the 1,3-di(benzo[d]oxazol-5-yl)urea, that do not show any biological activity per se, can act as adventitious rooting adjuvants in several rooting systems. Here we report the effect of these compounds in recalcitrant strawberry tree (Arbutus unedo L.) microcuttings. Our results confirm the activity of these two compounds as enhancers of in vitro adventitious rooting process, in the simultaneously presence of exogenous auxin
Disegno, sintesi e valutazione farmacologica di nuovi inibitori della proteina Rac1
No full textUna nuova classe di composti efficaci come inibitori dell’interazione RAC1- TIAM è stata progettata e sintetizzata a partire da reagenti semplici ed economici come nitroacetati, tioli, ortoformiato e ciclopentadiene.[1] I composti sintetizzati differiscono per la stereochimica dei sostituenti installati su uno scaffold norbornanico comune. La preparazione dei composti AR129, 148, 177, 180, 194, 201 si basa su un comune schema sintetico che prevede tre step fondamentali: i) costruzione dello scaffold norbornenico mediante reazione di cicloaddizione di Diels-Alder tra l’opportuno acrilato e ciclopentadiene;[2] ii)funzionalizzazione del doppio legame norbornenico mediante idroarilazione di Heck; iii) amminazione di Buchwald seguita da manipolazioni finali di tipo riduttivo e deprotettivo. La procedura è stata ottimizzata ed è stato operato uno scale-up dei composti AR129 e AR 148. Per quanto riguarda la reazione di idroarilazione di Heck è stata osservata una differente reattività dei nuclei norbornenici ottenuti dalla cicloaddizione che ci ha indotto ad approfondire i fattori che regolano regiochimica e reattività di tale reazione su substrate scope più ampio mettendo in evidenza effetti long-range di EWG in posizione endo con l'orbitale p del doppio legame.[3] Successivi sviluppi hanno dimostrato che la reazione procede con successo anche in assenza di leganti di tipo fosfinico. Inoltre la modellazione della reazione sul norbornene semplice ha messo in luce la possibilità di condurre tale reazione anche in solventi non coordinanti rendendo ipotizzabili meccanismi di reazione alternativi.
Riferimenti:
1. N. Ferri, A. Corsini, P. Bottini, F. Clerici, A. Contini, J Med. Chem., 2009, 52(14), 4087 – 90.
2. A. Ruffoni, A. Contini, S. Pellegrino, M. L. Gelmi, R. Soave, F. Clerici, Tetrahedron., 2012, 68, 1951 – 62.
3. A. Ruffoni, A. Casoni, S. Pellegrino, M. L. Gelmi, F. Clerici, Current Organic Chem. 2012, 16, 2
Utilizzo di due ceppi di Agrobacterium rhizogenes per la trasformazione di Ocimum basilicum L.: risultati preliminari
No full textOcimum basilicum L. is one of the most famous plant used in the Mediterranean foods. It is rich in terpenoidic compounds like estragol, linalool, camphor, eugenol and in the well studied antioxidant molecule Rosmarinic Acid. Protocols for tissue culture and genetic transformation were set up with the aim to obtain in vitro biomass cell culture and/or hairy roots (HR), for secondary metabolite extraction in controlled conditions. In vitro transformation of O. basilicum was performed by leaf co-cultivation (for 15 or 30 minutes) with A. rhizogenes strains LBA 9402 and ATCC 15834. Then the explants were transferred onto basal medium MS for 48 hours in light. Afterword they were transplanted onto Petri dishes with MS medium added with cefotaxime 100 mg/L. After 20 days 100% of leaves treated with LBA 9402 strain developed new roots; these roots showed the characteristic hairy root behaviour and grew fast. Only 10% of leaves treated with 15834 strain developed putative HR roots. More than 15 HR clonal lines showed the characteristic transgenic morphology and had a high and fast growth rate. The presence of a fragment of rolC gene, was confirmed in a HR putative transformed line
Gli uomini
No full textVengono presentate le diverse figure che caratterizzavano e caratterizzano la vita dell'alpeggio e la produzione (di cui la stagionatura è fase fondamentale) del formaggio Bitt
Epidemiology of Avian Metapneumovirus Infection in Italy
No full textAt the beginning of 2000 little information was available on circulation and molecular epidemiology of AMPV Italian poultry except for the data regarding the first Italian isolates made in the late 80s, which were shown to be B subtypes (Juhasz and Easton, 1994; Sperati Ruffoni L., personal communication). Moreover even though the vaccination was widely applied, disease still occurs occasionally in young as well older turkeys. This paper reports some studies performed in Italy since 2001 in order to understand better the epidemiology of AMPV and prophylactic problems encountered in the field
Direct Measures of Path Delays on Commercial FPGA Chips
No full textWe present a general technique for measuring the propagation delay on the internal wires of FPGA chips. The measure is based on the comparison between the operating frequencies of two ring oscillators that differ only for the structure under test, that is included (or not) in the loop. Experimental results are presented for a device of the Xilinx XC4000 family
In Vitro morphogenesis and micropropagation of Anemone coronaria L. hybrids.
No full textAmong the species of the genus Anemone, A. coronaria L. is one of the most widely grown for cut flower production. As the homogeneity of F, seed population is still a problem, a study on the possibility of establishing a reliable system of in vitro multiplication of parental plants has been carried out. Seeds and immature flowers were used as explants. Multiplication phase was established using the cytokinin 2iP (9.84 mu M) which increased both the multiplication rate and the fresh weight of the clusters. The rooting phase was studied by evaluating root development and the tuber enlargement. The rooting medium, containing 2.85 mu M IAA and 2.43 mu M IBA, allowed root emission and the increase of the tuber size during the four months of culture. After the acclimatization trials it was possible to identify a tuber weight threshold (500 mg) above which the acclimatization was good. The plants coming from in vitro culture grew normally. No phenotypic variants were noted and the quality of the flowers was comparable to the commercial standard
Spherical shape supramolecular structure of serum stable self- assembled pentapeptides containing the constrained norbornene amino acid
No full textSelf-assembly is a spontaneous process by which unordered systems of monomers organize into ordered structures as the result of non-covalent interactions and lies behind a number of biological nanostructures. The concept of self-assembly has also been used in many disciplines for constructing useful materials. Supramolecular spontaneous assembly of high molecular weight peptides or peptides conjugated with non-peptidic molecules has been reported. Less is known on the self-assembly of short peptides alone which self-organize predominantly into nanotubes and nanofibers. Spherical (micellar and vesicle-like) architectures are rarely described although they appear very attractive, due to promising applications in biomedicine and nanotechnology.1 Besides the numerous advantages of using peptides containing natural amino acids for nanostructures, they present some limitations such as low bio-stability and unstable conformation especially when they are short or medium-sized. The insertion of unnatural amino acids in the peptide sequences is a well-known tool to overcome these problems.2 Here we report on the preparation and self-assembly of short hydrophobic peptides able to stabilize the formation of supramolecular spherical shape assemblies in water. Two diastereoisomeric pentapeptides AcAla-NRB-Ala-Aib-AlaNH2 1 and 2, containing the unnatural constrained norbornene amino acid (NRB) 3, were prepared. Interestingly, peptides 1 and 2 are insoluble in organic solvent but completely soluble in water despite the presence of hydrophobic non polar norbornene scaffold.
The formation of a supramolecular assembly in water was assessed by DLS analyses for both 1 and 2 either as pure compounds or as a mixture. In all cases, the obtained assemblies showed almost monomodal distributions in the size range of 320-370 nm with low polidispersity. To assess their stability in conditions mimicking the in vivo environment, they were suspended in fetal bovine serum. Interestingly, peptide assemblies were found to keep their size and shape. An interesting feature of these peptides is also the presence of the C-C double bond in the norbornene scaffold, which could allow the easy labeling of the system introducing a variety of useful biotag.
1. Panda, J. J.; Chauhan, V. S. Polym. Chem. 2014, 5, 4418
2. Ruffoni, A. et al. RSC Adv., 2015, 5, 32643-3265
Editorial: Design and Fabrication Tools for Advanced Materials: Applications in Biomechanics and Mechanobiology
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