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11.
Domenico Armenise Nicolino De Laurentis Antonia Reho Antonio Rosato Flaviano Morlacchi 《Journal of heterocyclic chemistry》2004,41(5):771-775
A series of 6‐fluoro‐4‐(5 or 7)‐chloro‐2‐(difluorobenzoyl)aminobenzothiazoles 3a‐r were prepared to investigate their potential biological activity. In this work, the results of their in vitro antifungal activity against some strains of Candida albicans are reported. It was found that some derivatives displayed antifungal activity higher than that for 3k [1a] compound already described in literature. 相似文献
12.
Caffeic acid phenethyl ester (CAPE), an active component of propolis from honeybee hives, is known to have antimitogenic, anticarcinogenic, antinflammatory, and immunomodulatory properties. The paper describes a rapid and simple liquid chromatography-electrospray ionisation mass spectrometry method for qualitative and quantitative determination of CAPE. The chromatographic separation was performed with a Luna RP-C18 column using a water-acetonitrile linear gradient. The method was linear over a 0.125-80 ng/mL range (LOD = 62.5 pg/mL). The method was applied for the quantitation of caffeic acid phenethyl ester in crude propolis samples, which were analysed directly after extraction with ethyl acetate solution. 相似文献
13.
Angelo Mugnoli Domenico Spinelli Giovanni Consiglio Renato Noto 《Journal of heterocyclic chemistry》1988,25(1):177-183
The geometry obtained by a crystal structure determination of the title compounds, as compared with that of the analogous benzene derivatives, along with results of ab initio calculations, is used to interpret the different SNAr reactivities in some thiophene and benzene compounds. The smaller rotation of the nitro groups with respect to the aromatic rings observed in thiophene derivatives should be considered a relevant factor in the higher reactivity in the thiophene series. 相似文献
14.
A new method was developed for the determination of 2-furfural (2-F) and 5-methylfurfural (5-MF), two products of Maillard reaction in vinegar, with head-space solid-phase microextraction (HS-SPME) coupled to gas chromatography-mass spectrometry (GC-MS). A divinylbenzene (DVB)/carboxen (CAR)/polydimethylsiloxane (PDMS) fibre was used and SPME conditions were optimised, studying ionic strength effect, temperature effect and adsorption time. Both analytes were determined by calibration established on 2-furfural-d4 (2-F-d4). The method showed good linearity in the range studied (from 16 to 0.12 mg/l), with a regression coefficient r2 of 0.9999. Inter-batch precision and accuracy were found between 14.9 and 6.0% and between -11.7 and 0.2%, respectively. Detection limit was 15 microg/l. The method is simple and accurate and it has been applied to a series of balsamic and non-balsamic vinegars. 相似文献
15.
L. Turrio-Baldassarri A. Carere A. di Domenico S. Fuselli N. Iacovella F. Rodriguez 《Fresenius' Journal of Analytical Chemistry》1994,348(1-2):144-147
Summary The isomer specific determination of PCDD, PCDF and PCB was carried out on samples of air and inhalable particulate from Rome. Samples were taken daily for six months and pooled to yield two samples per month. Normal PCDD+PCDF concentrations expressed in TEQ ranged from 48 to 87 fg/m3, while total PCB ranged from 0.1 to 1.4 ng/m3. The 2, 3, 7, 8-substituted PCDD and PCDF congener pattern is shown together with the PCB congener pattern. 相似文献
16.
We discuss structural and thermodynamical properties of Baxter's adhesive hard sphere model within a class of closures which includes the Percus-Yevick (PY) one. The common feature of all these closures is to have a direct correlation function vanishing beyond a certain range, each closure being identified by a different approximation within the original square-well region. This allows a common analytical solution of the Ornstein-Zernike integral equation, with the cavity function playing a privileged role. A careful analytical treatment of the equation of state is reported. Numerical comparison with Monte Carlo simulations shows that the PY approximation lies between simpler closures, which may yield less accurate predictions but are easily extensible to multicomponent fluids, and more sophisticate closures which give more precise predictions but can hardly be extended to mixtures. In regimes typical for colloidal and protein solutions, however, it is found that the perturbative closures, even when limited to first order, produce satisfactory results. 相似文献
17.
Domenico Osella Mauro Ravera Carlo Floriani Euro Solari 《Journal of organometallic chemistry》1996,510(1-2):45-50
We describe the redox behaviour in non-aqueous solvents of some cyclopentadienyl(oxo)titanium derivatives. The derivative [Ti4{η5-C5H4(SiMe3)}4(μ-O)6] shows an electrochemically and chemically reversible le reduction process, followed by a multi-electron, chemically complicated reduction at a fairly cathodic potential. On the basis of the overall electrochemical features and the comparison with the redox behaviour of the quasi-planar compound [[Ti{η5-C5H4(SiMe3)}Cl(μ-O)]4] we propose an EECCEE mechanism for the first derivative, where the second electron-transfer induces a cascade of chemical reactions giving rise to irreversible cluster breakdown. The electrochemically induced fragmentation can be viewed as a retrosynthetic pathway. The heterometallic derivative [{Ti(η5-C5H4Me)2(μ2-MoO4)2}2] shows two consecutive reduction processes; the first is chemically reversible, and the second quasi-reversible. The molybdate bridges apparently increase the stability of the electrogenerated anions. However none of these poly-oxo clusters can be considered as good models of electron ‘sinks’. 相似文献
18.
The oxidation of some 3-(methoxy- and ethoxycarbonyl)tetrahydro-β-carboline derivatives with sodium periodate led to the formation of 1, 4-benzodiazonine derivatives or fully aromatic β-carbolines depending on both nature and number of substituents at 1-position. 相似文献
19.
20.
Grasso D Grasso G Guantieri V Impellizzeri G La Rosa C Milardi D Micera G Osz K Pappalardo G Rizzarelli E Sanna D Sóvágó I 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,12(2):537-547
An abnormal interaction between copper and the prion protein is believed to play a pivotal role in the pathogenesis of prion diseases. Copper binding has been mainly attributed to the N-terminal domain of the prion protein, but this hypothesis has recently been challenged in some papers which suggest that the C-terminal domain might also compete for metal anchoring. In particular, the segment corresponding to the helix II region of the prion protein, namely PrP180-193, has been shown both to bind copper and to exhibit a copper-enhanced cytotoxicity, as well as to interact with artificial membranes. The present work is aimed at extending these results by choosing the most representative model of this domain and by determining its copper affinity. With this aim, the different role played by the electrostatic properties of the C- and N-termini of PrP180-193 (VNITIKQHTVTTTT) in determining its conformational behaviour, copper coordination and ability to perturb model membranes was investigated. Owing to the low solubility of PrP180-193, its copper affinity was evaluated by using the shorter PrPAc184-188NH2 (IKQHT) analogue as a model. ESI-MS, ESR, UV/Vis, and CD measurements were carried out on the copper(II)/PrPAc184-188NH2 and copper(II)/PrP180-193NH2 systems, and showed that PrPAc184-188NH2 is a reliable model for the metal interaction with the helix II domain. The affinity of copper(II) for the helix II fragment is higher than that for the octarepeat and PrP106-126 peptides. Finally, the different ability of PrP180-193 analogues to perturb the DPPC model membrane was assessed by DSC measurements. The possible biological consequences of these findings are also discussed briefly. 相似文献