Guido Angelini | Università degli Studi "G. d'Annunzio" Chieti Pescara (original) (raw)

Papers by Guido Angelini

Journal of Organic Chemistry, Jul 9, 2015

The effects of a para substituent, as the electron-donating −OCH 3 and −OtBu groups and the elect... more The effects of a para substituent, as the electron-donating −OCH 3 and −OtBu groups and the electron-withdrawing −Br and −F atoms, on azobenzene isomerization have been investigated in a series of imidazolium ionic liquids (BMIM PF 6 , BMIM BF 4 , BMIM Tf 2 N, EMIM Tf 2 N, BM 2 IM Tf 2 N, and HMIM Tf 2 N). The thermal cis−trans conversion tends to be improved in the presence of the substituent, as pointed out by the first-order rate constants measured at 25°C. Both the rotation and the inversion mechanisms occur in BMIM Tf 2 N, EMIM Tf 2 N, and HMIM Tf 2 N, as highlighted by typical V-shape Hammett plots, but only rotation takes place in BMIM PF 6 , BMIM BF 4 , and BM 2 IM Tf 2 N. The possible interactions between the cation and the anion of the solvent and both the isomers of the azobenzene derivatives have been studied by small-wideangle X-ray scattering (SWAXS). The calculated cis population in the photostationary state and the hardness parameter η of the trans isomer show that azobenzene and F-azobenzene are the less reactive molecules for the trans−cis conversion in all the investigated ionic liquids.

RSC Advances, 2020

A series of 2-anilinopyrimidines including novel derivatives has been obtained from 2-chloro-4,6d... more A series of 2-anilinopyrimidines including novel derivatives has been obtained from 2-chloro-4,6dimethylpyrimidine by aromatic nucleophilic substitution with differently substituted anilines under microwave conditions. The substituents had a significant impact on the course and efficiency of the reaction. The results reported herein demonstrate the efficacy of microwaves in the synthesis of the title heterocyclic compounds as compared to the results obtained with conventional heating. The 2anilinopyrimidines described are of potential bioactivity.

Molecules, Aug 25, 2021

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

ChemistrySelect, Aug 28, 2019

The inductively coupled plasma optical emission spectrometry (ICP-OES) is a high resolution spect... more The inductively coupled plasma optical emission spectrometry (ICP-OES) is a high resolution spectroscopic technique based on the emission intensity at specific wavelengths of a given element within the sample to obtain both qualitative and quantitative information about ions concentration in aqueous solution. The concentration of Ag + in aqueous solution from negatively charged silver nanoparticles (AgNPs) has been determined by ion selective electrode (ISE) analysis at room temperature. The tested AgNPs solutions have been electro-chemically prepared without using any coating agent. The obtained data have been compared to those obtained from the same samples by using ICP-OES. The good correlation between the two techniques highlights that ISE could be successfully applied as valid alternative to ICP-OES to determine the silver ion concentration in the investigated conditions. High level of reproducibility, accurate measurements and affordability represent the main advantages of the method described herein.

Materials research express, Oct 3, 2017

A new electronic device has been assembled and employed to obtain a stable solution of spherical ... more A new electronic device has been assembled and employed to obtain a stable solution of spherical uncoated silver nanoparticles (SNPs) in only 10 min. Time of current inversion phase, number of electrodes and purification procedure have been optimized; different techniques as UV–vis spectroscopy, transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), dynamic laser light scattering (DLS) have been carried out to characterize the SNPs in size, shape and morphology. The stability of the SNPs solution has been tested by Zeta-Potential measurements. The results presented herein show that the obtained nanoparticles kept in the dark at 5 °C under inert atmosphere remain stable for at least 1 month.

Journal of Molecular Liquids, Jun 1, 2019

The thermal cis-trans isomerization of azobenzene and 4-methoxyazobenzene has been investigated i... more The thermal cis-trans isomerization of azobenzene and 4-methoxyazobenzene has been investigated in aqueous solution in the presence of electrochemically synthesized silver nanoparticles (AgNPs) in the concentration range 0.32-32 ppm. The samples in which the investigated molecules in trans state have been converted into the cis isomer by irradiation immediately after their addition to the AgNPs solution show different kinetic behavior: in the case of azobenzene the cis-trans isomerization does not occur; in the case of 4-methoxyazobenzene the reaction follows a first order decay. The samples in which the molecules have been added in trans state and left in solution for 120 h before their conversion into the cis isomers by irradiation show a similar behavior by which the cis-trans isomerization occurs according to the Kohlrausch-Williams-Watts stretched exponential kinetics. The UV-vis spectra and kinetics measurements performed at 25 ± 0.1° C supported by zeta potential analysis reflect the existence of different microenvironments for the cis and trans isomers of azobenzene and 4-methoxyazobenzene in solution in the presence of AgNPs in the investigated silver concentration range.

Chemical Research in Toxicology, Aug 12, 2016

RSC Advances, 2014

The pKa values of three fluorinated phenols, 2,4,6-trifluorophenol (3FP), 2,3,5,6-tetrafluorophen... more The pKa values of three fluorinated phenols, 2,4,6-trifluorophenol (3FP), 2,3,5,6-tetrafluorophenol (4FP) and 2,3,4,5,6-pentafluorophenol (5FP) have been measured by using UV-vis and 19F-NMR spectroscopy at 25 °C in water and in the presence of pure POPC, pure DDAB and mixed POPC–DDAB liposomes.

Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2022

Journal of Enzyme Inhibition and Medicinal Chemistry, 2017

View related articles View Crossmark data Citing articles: 3 View citing articles RESEARCH PAPER ... more View related articles View Crossmark data Citing articles: 3 View citing articles RESEARCH PAPER Dual targeting of cancer-related human matrix metalloproteinases and carbonic anhydrases by chiral N-(biarylsulfonyl)-phosphonic acids

Journal of Drug Delivery Science and Technology, Oct 1, 2016

Abstract Polymeric micelles based on HPMA [ N -(2-hydroxypropyl) methacrylamide] polymers were re... more Abstract Polymeric micelles based on HPMA [ N -(2-hydroxypropyl) methacrylamide] polymers were recently evaluated as drug delivery systems of several anticancer drugs. The development of polymeric micelles to solubilize R-(+)-MRJF4, a potential anticancer prodrug, is reported in this paper. Two different amphiphilic block copolymers based on PEG-HPMA [( ω -methoxypoly (ethylene glycol)- b -( N -(2-benzoyloxy-propyl) methacrylamide)- co -( N -(2-lactoyloxypropyl) methacrylamide) (PEG-HPMA-Bz-L) and ( ω -methoxy poly (ethylene glycol)- b -( N -(2-benzoyloxypropyl) methacrylamide (PEG-HPMA-Bz)] were synthesized and investigated for this purpose. Results showed that both polymers were able to efficiently solubilize the drug at concentrations of 2 and 4 mg/mL and polymer concentration of 9 mg/mL yielding polymeric micelles with a size of 53–83 nm. Release studies showed that the formulation obtained using PEG-HPMA-Bz-L slowly released R-(+)-MRJF4 for 7–8 days. Moreover, cytotoxicity studies performed on C6 glioma cells revealed that, after 48 h, R-(+)-MRJF4-loaded PEG-HPMA-Bz and PEG-HPMA-Bz-L micelles possessed a higher antiproliferative activity when compared to free R-(+)-MRJF4, implying that the formulations could be internalized by the cells. Taken together, our results suggest that PEG-HPMA-Bz-L polymeric micelles are interesting to optimize the therapeutic efficacy of R-(+)-MRJF4.

Journal of Computer-aided Molecular Design, Apr 1, 2005

We have computationally studied the interaction modes, localization and orientation of a benzene ... more We have computationally studied the interaction modes, localization and orientation of a benzene (Bz) molecule on the surface of micelles formed by cetyltrimethylammonium salts CTAX. Experimental 1 H-NMR data on complexation shifts induced by Bz on the polar head hydrogens and on the adjacent methylene hydrogens of CTAX have been interpreted using a computational approach that combines an automatic molecular docking procedure with a calculation module that accounts for NMR complexation shifts due to ring current diamagnetic anisotropy. Three different models were used to reduce the complexity of the micellar system. Computational results, in good agreement with available experimental data, point to a preferential localization of the Bz molecule along the CTAX alkyl tail, about 3.9 Å away from the charged nitrogen. The Bz molecular plane is predicted perpendicular to the CAH bonds of the alkyl tail. The good results obtained with the simplest model suggest that it could be used to study more complex systems involving surfactants endowed with molecular recognition or catalytic abilities.

Journal of Molecular Liquids, May 1, 2018

The triblock copolymer L121 [poly(ethylene glycol) 5-block-poly(propylene glycol) 68-block-poly(e... more The triblock copolymer L121 [poly(ethylene glycol) 5-block-poly(propylene glycol) 68-block-poly(ethylene glycol) 5 ], the room temperature ionic liquid BMIM BF 4 (1-butyl-3-methylimidazolium tetrafluoroborate) and the polymer PEG-400 (polyethylene glycol-400) have been compared in their liquid state to test their sorption capability of CO 2 by exposure to high-pressure gas for 3 h in a controlled system. The presence of the gas in the studied systems has been determined at atmospheric pressure in the temperature range 288.15-313.15 K by using near-infrared (NIR) spectroscopy. The CO 2 sorption in BMIM BF 4 and PEG-400 was very small and detectable up to 293.15 K, only L121 showed the CO 2 typical bands in the NIR region of the spectra up to 313.15 K, thus a linear correlation can be obtained by plotting the CO 2 absorbance of those bands as a function of temperature. The effect induced by temperature on the swelling degree of L121 copolymer has also been investigated.

Tetrahedron, May 1, 2017

The UVevis spectra of a-nitrocyclohexanone were determined at 25 C in a series of solvents, inclu... more The UVevis spectra of a-nitrocyclohexanone were determined at 25 C in a series of solvents, including room-temperature ionic liquids, water and CH 3 CN/CHCl 3 binary mixtures. A multiple linear regression analysis was performed by applying the Catal an empirical multiparameter solvent approach. Polarizability plays the major role in the solute-solvent interactions, as demonstrated by the quantification of the single solvent contributions, while an excellent linear correlation was found between the experimental and calculated solvent-dependent maxima adsorption bands. The solvatochromic trend of anitrocyclohexanone in the investigated media was confirmed by applying the Spange empirical solvent parameters for the ionic liquids in the KamleteTaft scale.

Biochimica Et Biophysica Acta - Biomembranes, Nov 1, 2013

Three crown ether derivatives, 1,2-O-dioleoyl-3-O-{2-[(12-crown-4)methoxy]ethyl}-sn-glycerol (12C... more Three crown ether derivatives, 1,2-O-dioleoyl-3-O-{2-[(12-crown-4)methoxy]ethyl}-sn-glycerol (12C4L), 1,2-O-dioleoyl-3-O-{2-[(15-crown-5)methoxy]ethyl}-sn-glycerol (15C5L) and 2,3-naphtho-15-crown-5 (NAP5), have been incorporated into 1-palmitoyl-2-oleoyl-phosphatydilcholine (POPC) liposomes. The size of the crown ether and the lipophilic moiety of 12C4L, 15C5L and NAP5 influence the stability and the properties of the extruded POPC liposomes determined at 25°C in buffered aqueous solution at pH 7.4. The investigated liposomes are zwitterionic for POPC headgroups but can be turned into cationic aggregates in the presence of divalent cations. The capability of these systems to complex DNA has been demonstrated by SAXS experiments.

Current Drug Targets, Nov 19, 2015

The self-assembly of a series of triblock copolymers Pluronics (P85, P105 and L121) has been inve... more The self-assembly of a series of triblock copolymers Pluronics (P85, P105 and L121) has been investigated in some ionic liquids (BMIMBF4, BMIMPF6 and BMIMTf2N) by using Near-Infrared spectroscopy. The formation of supramolecular structures has been confirmed by optical microscopy. The solvation degree and the aggregation behaviour of P85, P105 and L121 depend on the interactions between the imidazolium ring of the ionic liquid and the hydrophilic moiety of the copolymer. Fluorescent vesicles can be observed after the incorporation of Nile Red into the polymeric bilayer of L121 or by linking fluorescein isothiocyanate to the copolymer structure.

Molecules, Oct 27, 2017

Monovarietal virgin olive oils (VOOs) are very effective to study relationships among sensory att... more Monovarietal virgin olive oils (VOOs) are very effective to study relationships among sensory attributes, the compounds responsible for flavour, and factors affecting them. The stimulation of the human sensory receptors by volatile and non-volatile compounds present in monovarietal virgin olive oils gives rise to the sensory attributes that describe their peculiar delicate and fragrant flavours. The formation of these compounds is briefly illustrated and the influence of the agronomic and technological factors that affect their concentrations in the oil is examined. The relationships between compounds responsible for the olive oil flavour and sensory attributes are discussed. Several approaches for the varietal differentiation of monovarietal virgin olive oils are also overviewed.

Arkivoc, Jul 2, 2022

The association between cyclodextrins (CDs) and silver nanoparticles (AgNPs) has been successfull... more The association between cyclodextrins (CDs) and silver nanoparticles (AgNPs) has been successfully exploited in a large number of applications. Generally, CDs act as stabilizers, however, their reactivity as reducing agents can be directly involved in the synthesis of AgNPs. Herein, the most recent results regarding AgNPs prepared by chemical reduction from native α-, β-and γ-cyclodextrins are reported. The behavior of CDs in host-guest inclusion complexes onto the metal surface, and the effects on the AgNPs properties have also been examined. Unlike β-CD/AgNPs and γ-CD/AgNPs, additional reducing agents were required for the investigated α-CD/AgNPs.

Acta Chimica and Pharmaceutica Indica, 2020

Poly(ethylene oxide)-poly(propylene oxide)-poly (ethylene oxide) triblock copolymers are high mol... more Poly(ethylene oxide)-poly(propylene oxide)-poly (ethylene oxide) triblock copolymers are high molecular weight non ionic surfactants, commercially available as Pluronic. Generally, polymeric micelles and vesicles represent highly biodegradable and biocompatible systems, involved in a large range of applications from drug delivery to nanostructured materials due to their thickness, mechanical stability, and chemical functionality. One of the most investigated Pluronic is L121 considered as an ideal copolymer for drug target because of the capability to aggregate into vesicles having strong solute retention. Recently, the critical aggregation concentration of L121 in some ionic liquids and in D2O has been spectroscopically determined (Angelini, G.; Gasbarri, C., Curr. Drug Targets 2015, 16, 1606-1611), while a dense three-dimensional network showing a viscoelastic gel-like behavior has been observed in the presence of single-walled carbon nanotubes above a critical percolation concentration (Gasbarri et al., Chem. Eur. J. 2016, 22, 546-549). The aim of this work was to determine the efficacy of L121 as solvent for carbon dioxide sorption. Successful method to capture CO2 are based on polyethylene and polypropylene glycols under high pressure as demonstrated by the spectral changes of the polymer in the liquid state before and after the gas exposure. L121 shows the CO2 typical bands in the NIR region of the spectra from 15 to 40 °C according to a linear correlation. The effect induced by temperature on the swelling degree of L121 was also investigated and compared to the data obtained by using other viscous media, as Triton X-100 and BMIM BF4 (Angelini et al. J. Mol. Liquids 2018, 258, 85-88).

Molecules, Jul 29, 2017

BMIM PF 6 (1-butyl-3-methylimidazolium hexafluorophosphate) and BMIM Tf 2 N (1-butyl-3-methylimid... more BMIM PF 6 (1-butyl-3-methylimidazolium hexafluorophosphate) and BMIM Tf 2 N (1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide) are two conventional room-temperature ionic liquids widely employed and investigated as reaction media. Despite the presence of the same imidazolium ring in their structure they are different in many chemical and physical properties due to the nature of the anions. The thermal cis-trans isomerization of an electronically activated azobenzene have been used as reaction model to compare the behavior of PF 6 − and Tf 2 N −. Rotation is the mechanism by which the investigated azobenzene is converted into the trans isomer spontaneously in the dark both in BMIM PF 6 and in BMIM Tf 2 N. The kinetic rate constants of the process have been determined at different temperatures and the activation energies of the reaction have been calculated according to the Arrhenius and Eyring equations. The results presented herein highlight different solute-solvent interactions involving the PF 6 − and Tf 2 N − anions during the cis-trans isomerization.