Search results for "Molecular chemistry"
showing 10 items of 1103 documents
Thermodynamics and kinetics of ion permeation in wild-type and mutated open active conformation of the human α7 nicotinic receptor
2020
Molecular studies of human pentameric ligand-gated ion channels (LGICs) expressed in neurons and at neuromuscular junctions are of utmost importance in the development of therapeutic strategies for neurological disorders. We focus here on the nicotinic acetylcholine receptor nAChR-α7, a homopentameric channel widely expressed in the human brain, with a proven role in a wide spectrum of disorders including schizophrenia and Alzheimer's disease. By exploiting an all-atom structural model of the full (transmembrane and extracellular) protein in the open, agonist-bound conformation we recently developed, we evaluate the free energy and the mean first passage time of single-ion permeation using …
Effects of the net charge on abundance and stability of supramolecular surfactant aggregates in gas phase
2011
Self-assembling of amphiphilic molecules under electrospray ionization (ESI) conditions is characterized by quite unexpected phenomenology. The noticeable differences with respect to the condensed phase are attributable to the absence of the surfactant-solvent interactions, the presence of net charge in the aggregates, and the strong deviation from equilibrium conditions. Aiming to investigate the effects of the net charge on abundance and stability of supramolecular surfactant aggregates, positively and negatively charged aggregates of sodium bis(2-ethylhexyl)sulfosuccinate (AOT) and sodium methane sulfonate (MetS), butane sulfonate (ButS) and octane sulfonate (OctS) have been studied by E…
Oligoamide Foldamers as Helical Chloride Receptors-the Influence of Electron-Withdrawing Substituents on Anion-Binding Interactions.
2019
The anion-binding properties of three closely related oligoamide foldamers were studied using NMR spectroscopy, isothermal titration calorimetry and mass spectrometry, as well as DFT calculations. The 1 H NMR spectra of the foldamers in [D6 ]acetone solution revealed partial preorganization by intramolecular hydrogen bonding, which creates a suitable cavity for anion binding. The limited size of the cavity, however, enabled efficient binding by the inner amide protons only for the chloride anion resulting in the formation of a thermodynamically stable 1:1 complex. All 1:1 chloride complexes displayed a significant favourable contribution of the entropy term. Most likely, this is due to the …
New 1,2,4-oxadiazole nortopsentin derivatives with cytotoxic activity
2019
New analogs of nortopsentin, a natural 2,4-bis(3&prime
Species-Specific Antioxidant Power and Bioactive Properties of the Extracts Obtained from Wild Mediterranean Calendula Spp. (Asteraceae)
2019
In this study we focused on four taxa of the genus Calendula (C. maritima, C. suffruticosa subsp. fulgida, C. arvensis, and the hybrid between the first two ones), collected in Mediterranean area (Sicily). Six extracts for each species were obtained using solvents with increasing polarity (hexane, ethanol 80%, acetone 70%, and water) and through extraction by supercritical fluids (SFE). It has been observed that the solvent with the highest extraction efficiency was ethanol 80% for all species. However, SFE extracts showed high antioxidant activity comparable to the ethanol 80% extract (polyphenol, DPPH, and reducing power method). These findings were confirmed by in vitro analysis (MTT ass…
Daphne striata Tratt. and D. mezereum L.: a study of anti-proliferative activity towards human cancer cells and antioxidant properties
2018
In this study, we investigated for the first time the anti-proliferative and antioxidant properties of D. mezereum and D. striata. The aerial parts were extracted by maceration with n-hexane, dichloromethane, and methanol. MPLC, GC, and GC-MS were used for the phytochemical study. The anti-proliferative activity was tested against MCF-7, A549, LNCaP, ACHN, and C32 cancer human cells. The antioxidant activity was measured by employing β-carotene bleaching, ABTS, DPPH, and FRAP tests. The Relative Antioxidant Capacity Index (RACI) was applied from the perspective of statistics. D. mezereum dichloromethane extract showed a remarkable anti-proliferative with an IC50 of 6.08 μg/mL against LNCaP …
Phytochemical profile of three Ballota species essential oils and evaluation of the effects on human cancer cells
2017
Three Ballota species, Ballota undulata, Ballota saxatilis and Ballota nigra ssp. foetida, were investigated for their cytotoxicity against two human cancer cells, hepatoma HepG2 cell line and breast cancer MCF-7 cell line, and for their antioxidant activity. The chemical composition of essential oils was studied by GC and GC–MS. Sesquiterpenes were the main constituents. The most antiproliferative essential oil against HepG2 cells was B. undulata with a percentage of inhibition of 81.36 ± 3.54 at a concentration of 100 μg/mL, while against MCF-7 cells essential oil from B. saxatilis was the most active with a percentage of inhibition of 24.18 ± 1.13 at a concentration of 100 μg/mL. The ant…
Green biotechnology for valorisation of residual biomasses in nutraceutic sector: Characterization and extraction of bioactive compounds from grape p…
2019
The grape pomace (GP) is an important by-product of winemaking, accounting for about 13-25% of the grapes processed. The aim of this work was to investigate the nutritional and antioxidant composition of GP obtained from Nero d’Avola (NA) grape, one of the most important indigenous varieties in Italy, in order to verify application in nutraceutics. Seeds and skin of the GP were studied for their nutritional and antioxidants composition, fatty acid and polyphenols profile, bioactives properties in vitro, by gravimetric, spectrophotometric and chromatographic techniques. The results showed that NAGP seeds are rich in the beneficial polyunsaturated fatty acids and that the polyphenols extracte…
CCDC 1524052: Experimental Crystal Structure Determination
2017
UDAKOC : diaqua-(μ-1,13-dioxa-4,7,10,16,19,22-hexaazacyclotetracosane)-bis(perchlorato)-di-copper(ii) diperchlorate tetrahydrate Space Group: P21/c, Cell: a 11.8763(3)Å b 13.9146(4)Å c 13.4024(4)Å, α 90.00° β 123.439(2)° γ 90.00° Work published 2017 via Cambridge Crystallographic Data Centre.
Composition and biological activities of the essential oil from a Sicilian accession of Prangos ferulacea (L.) Lindl
2019
Prangos ferulacea (L.) Lindl. (Fam. Apiaceae), is an orophilous species of eastern Mediterranean and western Asia which possesses several biological properties, which are worthy of exploitation in different fields. With the aim to provide new insights into the phytochemistry and pharmacology of this species, a local accession growing in Sicily (South Italy) was investigated as well. Notably, the P. ferulacea essential oil chemical composition and the antioxidant, anti-acetylcholinesterase (AChE) and cytotoxic activities have been studied. This analysis allowed to identify a new chemotype and to report good biological results for this oil. © 2019 Informa UK Limited, trading as Taylor & F…