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Angelini G, Gasbarri C. Green synthesis and properties of silver nanoparticles in sulfobutylether-β-cyclodextrin aqueous solution. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2021.127924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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2
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Liposomal membrane permeability assessment by fluorescence techniques: Main permeabilizing agents, applications and challenges. Int J Pharm 2020; 580:119198. [PMID: 32169353 DOI: 10.1016/j.ijpharm.2020.119198] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 02/19/2020] [Accepted: 03/02/2020] [Indexed: 01/08/2023]
Abstract
Liposomes are lipid vesicles made of one or multiple lipid bilayers surrounding an internal aqueous core. They are broadly employed as models to study membrane structure and properties. Among these properties, liposome membrane permeability is crucial and widely assessed by fluorescence techniques. The first part of this review is devoted to describe the various techniques used for membrane permeability assessment. Attention is paid to fluorescence techniques based on vesicle leakage of self-quenching probes, dye/quencher pair or cation/ligand pair. Secondly, the membrane-active agents inducing membrane permeabilization is presented and details on their mechanisms of action are given. Emphasis is also laid on the intrinsic and extrinsic factors that can modulate the membrane permeability. Hence, a suitable liposomal membrane should be formulated according to the aim of the study and its application.
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Mura P. Advantages of the combined use of cyclodextrins and nanocarriers in drug delivery: A review. Int J Pharm 2020; 579:119181. [PMID: 32112928 DOI: 10.1016/j.ijpharm.2020.119181] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 02/24/2020] [Accepted: 02/25/2020] [Indexed: 01/09/2023]
Abstract
Complexation with cyclodextrins (CDs) has been widely and successfully used in pharmaceutical field, mainly for enhancing solubility, stability and bioavailability of a variety of drugs. However, some important drawbacks, including rapid removal from the bloodstream after in vivo administration, or possible replacement, in biological media, of the entrapped drug moieties by other molecules with higher affinity for the CD cavity, can limit the CDs effectiveness as drug carriers. This review is focused on combined strategies simultaneously exploiting CD complexation, and loading of the complexed drug into various colloidal carriers (liposomes, niosomes, polymeric nanoparticles, lipid nanoparticles, nanoemulsions, micelles) which have been investigated as a possible means for circumventing the problems associated with both such carriers, when used separately, and join their relative benefits in a unique delivery system. Several examples of applications have been reported, to illustrate the possible advantages achievable by such a dual strategy, depending on the CD-nanocarrier combination, and mainly resulting in enhanced performance of the delivery system and improved biopharmaceutical properties and therapeutic efficacy of drugs. The major problems and/or drawbacks found in the development of such systems, as well as the (rare) case of failures in achieving the expected improvements have also been highlighted.
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Affiliation(s)
- Paola Mura
- Department of Chemistry, Florence University, via Schiff 6, Sesto Fiorentino, Florence, Italy.
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Silver nanoparticles as interactive media for the azobenzenes isomerization in aqueous solution: From linear to stretched kinetics. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.04.048] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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Zappacosta R, Cornelio B, Pilato S, Siani G, Estour F, Aschi M, Fontana A. Effect of the Incorporation of Functionalized Cyclodextrins in the Liposomal Bilayer. Molecules 2019; 24:E1387. [PMID: 30970572 PMCID: PMC6479378 DOI: 10.3390/molecules24071387] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Revised: 04/05/2019] [Accepted: 04/06/2019] [Indexed: 11/16/2022] Open
Abstract
Liposomes loaded with drug–cyclodextrin complexes are widely used as drug delivery systems, especially for species with low aqueous solubility and stability. Investigation of the intimate interactions of macrocycles with liposomes are essential for formulation of efficient and stable drug-in-cyclodextrin-in-liposome carriers. In this work, we reported the preparation of unilamellar vesicles of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) embedded with native β-cyclodextrin and two synthetic derivatives: heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin (TMCD) and heptakis(2,3-di-O-acetyl)-β-cyclodextrin (DACD). We then studied the effect of these macrocycles on the liposomal size, membrane viscosity, and liposomal stability at different temperatures and concentrations. We observed that TMCD and DACD affected vesicle size and the change of size was related to CD concentration. Irrespective of its nature, the macrocycle established interactions with the phospholipidic head groups, preventing cyclodextrins to diffuse into the lipid bilayer, as confirmed by molecular dynamics simulations. Such supramolecular structuring improves liposome stability making these colloid systems promising carriers for biologically active compounds.
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Affiliation(s)
- Romina Zappacosta
- Dipartimento di Farmacia, Università "G. d'Annunzio", Via dei Vestini snc, I-66100 Chieti, Italy.
| | - Benedetta Cornelio
- Normandie Univ, INSA Rouen, UNIROUEN, CNRS, COBRA (UMR 6014 & FR3038), 76000 Rouen, France.
| | - Serena Pilato
- Dipartimento di Farmacia, Università "G. d'Annunzio", Via dei Vestini snc, I-66100 Chieti, Italy.
| | - Gabriella Siani
- Dipartimento di Farmacia, Università "G. d'Annunzio", Via dei Vestini snc, I-66100 Chieti, Italy.
| | - François Estour
- Normandie Univ, INSA Rouen, UNIROUEN, CNRS, COBRA (UMR 6014 & FR3038), 76000 Rouen, France.
| | - Massimiliano Aschi
- Dipartimento di Scienze Fisiche e Chimiche, Università di L'Aquila, Via Vetoio snc, I-67100 L'Aquila, Italy.
| | - Antonella Fontana
- Dipartimento di Farmacia, Università "G. d'Annunzio", Via dei Vestini snc, I-66100 Chieti, Italy.
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Alavi M, Hamidi M. Passive and active targeting in cancer therapy by liposomes and lipid nanoparticles. Drug Metab Pers Ther 2019; 34:dmpt-2018-0032. [PMID: 30707682 DOI: 10.1515/dmpt-2018-0032] [Citation(s) in RCA: 122] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 11/20/2018] [Indexed: 05/23/2023]
Abstract
Considerable development in the application of injectable drug delivery systems for cancer therapy has occurred in the last few decades. These improvements include liposomes, lipid nanoparticles (LNPs), and other nanoparticles with or without macromolecular conjugates. For example, liposomal doxorubicin modified by poly(ethylene glycol) (Doxil) was the first liposome with anti-cancer effects which was approved by the US Food and Drug Administration, whereas Abraxane (modified albumin nanoparticles loaded by paclitaxel) was recently confirmed for the treatment of breast cancer. Recently, drug delivery systems by LNPs are an emerging technology with numerous advantages over conventional liposomes and chemotherapy using free drug treatment of cancer. These properties are biocompatibility, controlled and sustained release of anti-tumor drugs, and lower toxicity. Valuable experiments on these drug delivery systems offer better treatment of multidrug-resistant cancers and lower cardiotoxicity. LNPs have been presented with high functionality in chemotherapeutic targeting of breast and prostate cancer. The basis for this targeting behavior has been shown to be both passive and active targeting. The main objective of this review was an overview of the current position of the liposome-based drug delivery systems in targeted anticancer chemotherapy.
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Affiliation(s)
- Mehran Alavi
- Department of Nanobiotechnology, Faculty of Science, Razi University, Kermanshah, Iran
| | - Mehrdad Hamidi
- Zanjan Pharmaceutical Nanotechnology Research Center (ZPNRC), Zanjan, Iran
- Department of Pharmaceutical Nanotechnology, School of Pharmacy, Zanjan University of Medical Sciences, Zanjan, Iran
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Angelini G, Gasbarri C. Learning organic chemistry day by day: The best choice of the best pharmacy students. CURRENTS IN PHARMACY TEACHING & LEARNING 2018; 10:795-802. [PMID: 30025782 DOI: 10.1016/j.cptl.2018.03.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 10/31/2017] [Accepted: 03/02/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND AND PURPOSE During over ten years of experience in teaching organic chemistry at the Department of Pharmacy we have tried to answer the following question: why do most students tend to take the exam one, two, or more years after the end of the course they have attended? Several reasons could justify this delay, but three seem to be the most common drawbacks for our students: a) time needed for the comprehension of the arguments; b) the number of mandatory exams to pass before organic chemistry; c) lack of a self-evaluation method. EDUCATIONAL ACTIVITY AND SETTING To increase the number of students in the exam sessions of the semester just after the course we have proposed two strategies: 1) a systematic, but stressless, approach by which homework and everyday life examples concerning organic chemistry are used to increase the sense of responsibility in studying; 2) the modification of the number of mandatory exams required for organic chemistry. FINDINGS The rate of successful students in the exam sessions at the end of the course increased from 38.3 up to 61.3%. Interestingly, the highest scores tend to be obtained by students in the first session available just after the conclusion of the course. DISCUSSION AND SUMMARY The combined effect of Strategy 1 and Strategy 2 seems to be effective in promoting the learning of organic chemistry and points out that the best performances tend to be associated with students which follow organized studying.
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Affiliation(s)
- Guido Angelini
- Department of Pharmacy, University "G. d'Annunzio" of Chieti-Pescara, Chieti 66100, Italy.
| | - Carla Gasbarri
- Department of Pharmacy, University "G. d'Annunzio" of Chieti-Pescara, Chieti 66100, Italy.
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Liposomes entrapping β-cyclodextrin/ibuprofen inclusion complex: Role of the host and the guest on the bilayer integrity and microviscosity. Chem Phys Lipids 2017; 209:61-65. [DOI: 10.1016/j.chemphyslip.2017.09.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 09/14/2017] [Accepted: 09/29/2017] [Indexed: 11/22/2022]
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Angelini G, Campestre C, Scotti L, Gasbarri C. Kinetics and Energetics of Thermal Cis-Trans Isomerization of a Resonance-Activated Azobenzene in BMIM-Based Ionic Liquids for PF₆ -/Tf₂N - Comparison. Molecules 2017; 22:E1273. [PMID: 28758922 PMCID: PMC6152290 DOI: 10.3390/molecules22081273] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 07/27/2017] [Accepted: 07/27/2017] [Indexed: 02/05/2023] Open
Abstract
BMIM PF₆ (1-butyl-3-methylimidazolium hexafluorophosphate) and BMIM Tf₂N (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 PF₆- and Tf₂N-. Rotation is the mechanism by which the investigated azobenzene is converted into the trans isomer spontaneously in the dark both in BMIM PF₆ and in BMIM Tf₂N. 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 PF₆- and Tf₂N- anions during the cis-trans isomerization.
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Affiliation(s)
- Guido Angelini
- Department of Pharmacy, University "G. d'Annunzio" of Chieti-Pescara, via dei Vestini, 66100 Chieti, Italy.
| | - Cristina Campestre
- Department of Pharmacy, University "G. d'Annunzio" of Chieti-Pescara, via dei Vestini, 66100 Chieti, Italy.
| | - Luca Scotti
- Department of Oral Science, Nano and Biotechnology, University "G. d'Annunzio" of Chieti-Pescara, via dei Vestini, 66100 Chieti, Italy.
| | - Carla Gasbarri
- Department of Pharmacy, University "G. d'Annunzio" of Chieti-Pescara, via dei Vestini, 66100 Chieti, Italy.
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Zappacosta R, Fontana A, Credi A, Arduini A, Secchi A. Incorporation of Calix[6]Arene Macrocycles and (Pseudo)Rotaxanes in Bilayer Membranes: Towards Controllable Artificial Liposomal Channels. ASIAN J ORG CHEM 2015. [DOI: 10.1002/ajoc.201402244] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Chen J, Lu WL, Gu W, Lu SS, Chen ZP, Cai BC, Yang XX. Drug-in-cyclodextrin-in-liposomes: a promising delivery system for hydrophobic drugs. Expert Opin Drug Deliv 2014; 11:565-77. [PMID: 24490763 DOI: 10.1517/17425247.2014.884557] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Recently, the entrapment of hydrophobic drugs in the form of water-soluble drug-cyclodextrin (CD) complex in liposomes has been investigated as a new strategy to combine the relative advantages of CDs and liposomes into one system, namely drug-in-CD-in-liposome (DCL) systems. AREAS COVERED For DCLs preparation, an overall understanding of the interaction between CDs and lipid components of liposomes is necessary and valuable. The present article reviews the preparation, characterization and application of DCLs, especially as antitumor or transdermal carriers. Double-loading technique, an interesting strategy to control release and increase drug-loading capacity, is also discussed. EXPERT OPINION DCL approach can be useful in increasing drug solubility and vesicles stability, in controlling the in vivo fate of hydrophobic drugs and in avoiding burst release of drug from the vesicles. To obtain stable DCL, the CDs should have a higher affinity to drug molecules compared with liposomal membrane lipids. DCLs prepared by double-loading technique seem to be a suitable targeted drug delivery system because they have a fast onset action with prolonged drug release process and the significantly enhanced drug-loading capacity. In particular, DCLs are suitable for the delivery of hydrophobic drugs which also possess volatility.
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Affiliation(s)
- Jun Chen
- Nanjing University of Chinese Medicine, School of Pharmacy , Nanjing , PR China
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Gasbarri C, Angelini G. Spectroscopic investigation of fluorinated phenols as pH-sensitive probes in mixed liposomal systems. RSC Adv 2014. [DOI: 10.1039/c4ra01507j] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
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.
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Affiliation(s)
- Carla Gasbarri
- Dipartimento di Farmacia
- Università G. d'Annunzio di Chieti-Pescara
- 66100 Chieti, Italy
| | - Guido Angelini
- Dipartimento di Farmacia
- Università G. d'Annunzio di Chieti-Pescara
- 66100 Chieti, Italy
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Neutral liposomes containing crown ether-lipids as potential DNA vectors. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:2506-12. [DOI: 10.1016/j.bbamem.2013.06.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 05/27/2013] [Accepted: 06/06/2013] [Indexed: 11/18/2022]
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Carland JE, Mansfield RE, Ryan RM, Vandenberg RJ. Oleoyl-L-carnitine inhibits glycine transport by GlyT2. Br J Pharmacol 2013; 168:891-902. [PMID: 22978602 DOI: 10.1111/j.1476-5381.2012.02213.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Revised: 08/27/2012] [Accepted: 09/03/2012] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE Concentrations of extracellular glycine in the CNS are regulated by two Na(+)/Cl(-) -dependent glycine transporters, GlyT1 and GlyT2. Selective inhibitors of GlyT1 have been developed for the treatment of schizophrenia, whilst selective inhibitors of GlyT2 are analgesic in animal models of pain. We have assessed a series of endogenous lipids as inhibitors of GlyT1 and GlyT2. EXPERIMENTAL APPROACH Human GlyT1 and GlyT2 were expressed in Xenopus laevis oocytes, and the inhibitory actions of a series of acylcarnitines on glycine transport were measured using electrophysiological techniques. KEY RESULTS Oleoyl-L-carnitine inhibited glycine transport by GlyT2, with an IC(50) of 340 nM, which is 15-fold more potent than the previously identified lipid inhibitor N-arachidonyl-glycine. Oleoyl-L-carnitine had a slow onset of inhibition and a slow washout. Using a series of chimeric GlyT1/2 transporters and point mutant transporters, we have identified an isoleucine residue in extracellular loop 4 of GlyT2 that conferred differences in sensitivity to oleoyl-L-carnitine between GlyT2 and GlyT1. CONCLUSIONS AND IMPLICATIONS Oleoyl-L-carnitine is a potent non-competitive inhibitor of GlyT2. Previously identified GlyT2 inhibitors show potential as analgesics and the identification of oleoyl-L-carnitine as a novel GlyT2 inhibitor may lead to new ways of treating pain.
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Affiliation(s)
- J E Carland
- Discipline of Pharmacology, School of Medical Sciences, Bosch Institute, Sydney Medical School, University of Sydney, Sydney, NSW, Australia
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Gasbarri C, Angelini G, Fontana A, De Maria P, Siani G, Giannicchi I, Cort AD. Kinetics of demetallation of a zinc–salophen complex into liposomes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1818:747-52. [DOI: 10.1016/j.bbamem.2011.10.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Revised: 09/07/2011] [Accepted: 10/18/2011] [Indexed: 01/10/2023]
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Bortolus M, Parisio G, Maniero AL, Ferrarini A. Monomeric fullerenes in lipid membranes: effects of molecular shape and polarity. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:12560-12568. [PMID: 21888357 DOI: 10.1021/la202524r] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We report a combined theoretical and experimental study on the single-molecule interaction of fullerenes with phospholipid membranes. We studied pristine C(60) (1) and two N-substituted fulleropyrrolidines (2 and 3), one of which (3) bore a paramagnetic nitroxide group. Theoretical predictions of fullerene distribution and permeability across lipid bilayers were combined with electron paramagnetic resonance (EPR) experiments in aligned DMPC/DHPC bicelles containing the paramagnetic fulleropyrrolidine 3 or either one of the diamagnetic fullerenes together with spin-labeled lipids. We found that, at low concentrations, fullerenes are present in the bilayer as single molecules. Their preferred location in the membrane is only slightly influenced by the derivatization: all derivatives were confined just below the hydrophilic/hydrophobic interface, because of the key role played by dispersion interactions between the highly polarizable fullerene cage and the hydrocarbon chains, which are especially tight within this region. However, the deviation from spherical shape is sufficient to induce a preferential orientation of 2 and 3 in the membrane. We predict that monomeric fullerenes spontaneously penetrate the bilayer, in agreement with the results of molecular dynamics simulations, but we point out the limits of the currently used permeability model when applied to hydrophobic solutes.
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Affiliation(s)
- Marco Bortolus
- Dipartimento di Scienze Chimiche, Università di Padova via Marzolo 1, I-35131 Padova, Italy
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Maroto E, Filippone S, Martín-Domenech A, Suárez M, Martín N, Martínez-Alvarez R. Effect of substituents and protonation on the mechanism of 1,3-dipolar retro-cycloaddition reaction of pyrrolidino[60]- and [70]fullerenes. JOURNAL OF MASS SPECTROMETRY : JMS 2011; 46:1016-1029. [PMID: 22012668 DOI: 10.1002/jms.1983] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The mass spectra of new substituted pyrrolidino[60]- and [70]fullerenes have been obtained using electrospray ionization conditions in the positive and negative mode of detection with two different mass spectrometers, a quadrupole ion trap and a Fourier transform ion cyclotron resonance. Radical anions M(●-) and deprotonated molecules [M-H](-) are formed under negative electrospray ionization mass spectrometry conditions, and the collision-induced dissociations of both ionic species have been studied. Either negative odd-electron ions or negative even-electron ions undergo a retro-cycloaddition process forming the corresponding fullerene product ions C(60)(●-) and C(70)(●-). The generation of fullerene radical anions from deprotonated molecules is a new exception of the "even-electron rule." In contrast, the protonated molecules [M + H](+) obtained from the positive mode of detection do not undergo this cycloreversion reaction, and the MS(n) experiment reveals a variety of eliminations of neutral molecules involving different hydrogen shifts and multiple bond cleavages that lead eventually to substituted methanofullerene fragment ions. The observed fragmentations can be correlated with the electronic character of the substituents attached to the heterocyclic moiety. The results obtained from the thermal reactions of these compounds, carried out under different pH conditions, correlate well with those obtained in gas phase. The different behaviors between protonated and unprotonated molecules and ions can be explained assuming that the retro-cycloaddition reaction takes place only when the nitrogen atom of the pyrrolidine ring (the basic center of the molecule) is unprotonated both in gas and condensed phase. The protonation of the NH group inhibits the cycloreversion process, and therefore different fragmentations take place. The detailed mechanisms of the formation and evolution of the intermediate fragments are described.
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Affiliation(s)
- Enrique Maroto
- Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Complutense, Madrid, Spain
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Fontana A, Viale M, Guernelli S, Gasbarri C, Rizzato E, Maccagno M, Petrillo G, Aiello C, Ferrini S, Spinelli D. Strategies for improving the water solubility of new antitumour nitronaphthylbutadiene derivatives. Org Biomol Chem 2010; 8:5674-81. [DOI: 10.1039/c0ob00493f] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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