Search results for "compounds"
showing 10 items of 3372 documents
Synthesis, characterization and the first crystal structure of the Zn(II) complex of 4,6-O-ethylidine-N-(2-hydroxybenzylidene)-β-D-glucopyranosylamine
2001
4,6-O-Ethylidine-N-(2-hydroxybenzylidene)-β-D-glucopyranosylamine (H3L1) and N-(5-bromo-2-hydroxybenzylidene-4,6-O-ethylidine-β-D-glucopyranosylamine (H3L2) molecules possessing a–C-1–N=C(H)–moiety for metal-ion binding were synthesized by condensing the 4,6–O–ethylidene–β–D–glucopyranosylamine with salicylaldehyde or 5–bromosalicylaldehyde. Complexes of these ligands with Zn(II) were isolated and characterized using elemental analysis, FTIR, UV–Vis absorption, NMR spectroscopic and FAB mass spectrometric techniques. The structure of the Zn(II) complex derived from H3L1 was established for the first time by a single-crystal X-ray diffraction study. The anomeric nature of the saccharide moie…
Biomimetic diels–alder cyclizations for the construction of the brevianamide, paraherquamide, sclerotamide, asperparaline and VM55599 ring systems
1998
Abstract A potentially bio-mimetic Diels–Alder cyclization to construct the bicyclo[2.2.2] ring system common to the paraherquamides, marcfortines, sclerotamides, brevianamides, VM55599, and asperparaline is reported. Epi-deoxybrevianamide E (22) is converted into the corresponding lactim ether (23) and then oxidized with DDQ to provide an azadiene (24) which is tautomerized in the presence of base to azadiene 25 which, spontaneously cyclizes to give a 2:1 mixture of cycloadducts 26 and 27. These cycloadducts are each in turn, converted into d , l -C-19-epi-brevianamide A (20) and d , l -brevianamide B (6). The stereochemical implications of the [4+2] cycloaddition is discussed in the conte…
Mapping quantitative trait loci affecting biochemical and morphological fruit properties in eggplant (Solanum melongena L.)
2016
Eggplant berries are a source of health-promoting metabolites including antioxidant and nutraceutical compounds, mainly anthocyanins and chlorogenic acid; however, they also contain some anti-nutritional compounds such as steroidal glycoalkaloids (SGA) and saponins, which are responsible for the bitter taste of the flesh and with potential toxic effects on humans. Up to now, Quantitative Trait Loci (QTL) for the metabolic content are far from being characterized in eggplant, thus hampering the application of breeding programs aimed at improving its fruit quality. Here we report on the identification of some QTL for the fruit metabolic content in an F2 intraspecific mapping population of 156…
Investigation on the influence of spray-drying technology on the quality of Sicilian Nero d’Avola wines
2018
The purpose of the present work was to find a correlation between microencapsulation technology applied to wines and the resulting quality of the wine itself in terms of volatile composition and phenolic profile. To this aim, samples of Nero d'Avola wines produced in Sicily (Italy) were investigated in order to: i) elucidate the aromatic composition by means of HSâSPME coupled with GCâMS; ii) assess the polyphenolic content by UHPLC mass spectrometry; iii) compare the results obtained from both the screenings with those relative to the same wines that had previously been subjected to spray-drying. The results showed a marked reductionThe results here obtained evidenced a marked reductio…
Sequestering aromatic molecules with a spin-crossover Fe(II) microporous coordination polymer.
2012
All in a spin: A series of three-dimensional porous coordination polymer {Fe(dpe)[Pt(CN)(4)]}⋅G (dpe = 1,2-di(4-pyridyl)ethylene; G = phenazine, anthracene, or naphthalene) exhibiting spin crossover and host-guest functions is reported. The magnetic properties of the framework are very sensitive to the chemical nature (aromatic or hydroxilic solvents) and the size of the included guest molecules.
Radioactively labelled epoxides. part V. Tritium labelled K-region oxides and trans-dihydrodiols of pyrene, benzo[a]pyrene and dibenz[a, h]anthracene
1987
Tritium labelled K-region oxides of pyrene, benzo[a]pyrene and dibenz[a,h]anthracene have been prepared by cyclization of the corresponding trans-dihydrodiols which were obtained by reduction of K-region quinones with sodium borotritide in the presence of oxygen. This synthetic pathway not only yields two metabolically important radioactively labelled derivatives of polycyclic aromatic hydrocarbons in a simple and efficient manner, but also requires a rather inexpensive source of tritium.
Electronic Interactions in a New π-Extended Tetrathiafulvalene Dimer
2006
The first pi-extended tetrathiafulvalene (exTTF) dimer in which the two exTTF units are covalently connected by 1,3-dithiole rings has been obtained in a multistep synthetic procedure involving the Ullmann cross-coupling reaction by using copper(I) thiophene-2-carboxylate (CuTC). The electronic spectrum reveals a significant electronic interaction between the exTTF units. The electrochemical study carried out by cyclic voltammetry in solution and in thin-layer conditions, and the electrochemical simulation and spectroelectrochemical (SEC) measurements confirm the electronic communication and show that the oxidation of dimer 14 occurs as two consecutive 2 e(-) processes D(0)-D(0)-->D(2+)-D(0…
Anti-cancer activity of di- and tri-organotin(IV) compounds with D-(+)-Galacturonic acid on human tumor cells
2018
Abstract We have compared the anti-proliferative activity in vitro, of R2SnGala (1-3) [R = Me, n-Bu, Ph] and novel R3SnGala (4, 5) [R = Me, n-Bu] with D-(+)-Galacturonic acid [HGala; Galaq-, q = (2) and (1) for R2SnGala and R3SnGala, respectively] compounds, towards human tumor cell lines of intestinal carcinoma (HCT-116) and breast adenocarcinoma (MCF-7). The new synthesized 4 and 5 compounds were characterized, in solution, by 1H, 13C and 119Sn NMR, that showed that HGala acts as monoanionic moiety and evidenced the dynamic behavior of the compounds, due to inter-conversions involving the anomeric carbon atom of the ligand. Cell viability, apoptosis induction and cell cycle distribution w…
Anti-/pro-oxidant concentration-dependent activity of natural phenolic compounds in bio-polyesters
2017
Polylactic acid (PLA) is a biodegradable bio-based polyester of increasing industrial interest because of its unique properties, such as low toxicity, bio- and eco-compatibility. Indeed, PLA is a suitable material for several “green” applications in different fields, among other food packaging, textile fibres and biomedical devices [1]. PLA performances, in terms of durability, are limited by several chemical aging mechanisms, such as thermal decomposition, hydrolysis, photo-oxidation, natural weathering and thermo-oxidation at high temperature [2]. Therefore, to avoid the decay of its physical and mechanical properties, the addition of anti-oxidants and/or light stabilizers is imperative. …
Antimicrobial activity of biogenically produced spherical Se-nanomaterials embedded in organic material against Pseudomonas aeruginosa and Staphyloco…
2017
In an effort to prevent the formation of pathogenic biofilms on hydroxyapatite (HA)-based clinical devices and surfaces, we present a study evaluating the antimicrobial efficacy of Spherical biogenic Se-Nanostructures Embedded in Organic material (Bio Se-NEMO-S) produced by Bacillus mycoides SelTE01 in comparison with two different chemical selenium nanoparticle (SeNP) classes. These nanomaterials have been studied as potential antimicrobials for eradication of established HA-grown biofilms, for preventing biofilm formation on HA-coated surfaces and for inhibition of planktonic cell growth of Pseudomonas aeruginosa NCTC 12934 and Staphylococcus aureus ATCC 25923. Bio Se-NEMO resulted more e…