Search

The multitarget therapeutic strategy, as opposed to the more traditional 'one disease-one target-one drug', may hold promise in treating multifactorial neurodegenerative syndromes, such as Alzheimer's disease (AD) and related dementias. Recently, combining a photopharmacology approach with the multitarget-directed ligand (MTDL) design strategy, we disclosed a novel donepezil-like compound, namely 2-(4-((diethylamino)methyl)benzylidene)-5-methoxy-2,3-dihydro-1H-inden-1-one (1a), which in the E isomeric form (and about tenfold less in the UV-B photo-induced isomer Z) showed the best activity as dual inhibitor of the AD-related targets acetylcholinesterase (AChE) and monoamine oxidase B (MAO-B). Herein, we investigated further photoisomerizable 2-benzylideneindan-1-one analogs 1b–h with the unconjugated tertiary amino moiety bearing alkyls of different bulkiness and lipophilicity. For each compound, the thermal stable E geometric isomer, along with the E/Z mixture as produced by UV-B light irradiation in the photostationary state (PSS, 75% Z), was investigated for the inhibition of human ChEs and MAOs. The pure E-isomer of the N-benzyl(ethyl)amino analog 1h achieved low nanomolar AChE and high nanomolar MAO-B inhibition potencies (IC50s 39 and 355 nM, respectively), whereas photoisomerization to the Z isomer (75% Z in the PSS mixture) resulted in a decrease (about 30%) of AChE inhibitory potency, and not in the MAO-B one. Molecular docking studies were performed to rationalize the different E/Z selectivity of 1h toward the two target enzymes. [ABSTRACT FROM AUTHOR]

HBDI‐like chromophores represent a novel set of biomimetic switches mimicking the fluorophore of the green fluorescent protein that are currently studied with the hope to expand the molecular switch/motor toolbox. However, until now members capable of absorbing visible light in their neutral (i. e. non‐anionic) form have not been reported. In this contribution we report the preparation of an HBDI‐like chromophore based on a 3‐phenylbenzofulvene scaffold capable of absorbing blue light and photoisomerizing on the picosecond timescale. More specifically, we show that double‐bond photoisomerization occurs in both the E‐to‐Z and Z‐to‐E directions and that these can be controlled by irradiating with blue and UV light, respectively. Finally, as a preliminary applicative result, we report the incorporation of the chromophore in an amphiphilic molecule and demonstrate the formation of a visible‐light‐sensitive nanoaggregated state in water. [ABSTRACT FROM AUTHOR]

An easy and viable crosslinking procedure by click-chemistry (click-crosslinking) of hyaluronic acid (HA) was developed. In particular, the clickable propargyl groups of hyaluronane-based HA-FA-Pg graft copolymers showing low and medium molecular weight values were exploited in crosslinking by click-chemistry by using a hexa(ethylene glycol) spacer. The resulting HA-FA-HEG-CL materials showed an apparent lack of in vitro cytotoxic effects, tuneable water affinity, and rheological properties according to the crosslinking degree that suggests their applicability in different biomedical fields. [ABSTRACT FROM AUTHOR]

A new Morita-Baylis-Hillman Adduct (MBHA) derivative 7 was designed and synthesized to obtain a reactive molecule potentially capable of labelling basic amino acid residues. Compound 7 was easily prepared and characterized from the point of view of its photophysical and photochemical features before then to be used in labelling experiments with amino acid. [Display omitted] • A new Morita-Baylis-Hillman derivative was designed to obtain a reactive molecule capable of labelling basic amino acids. • This compound was promptly synthesized in three steps from commercially available intermediates. • This compound showed an intriguing photochemical activity, which was characterized by photophysical and NMR studies. • These results pave the way for the use of the derivative in the fluorogenic labeling of proteins. [ABSTRACT FROM AUTHOR]

A water-soluble Morita–Baylis–Hillman adduct (MBHA) derivative (3) was previously shown to self-assemble in a water environment into functional nanoreactors capable of performing multiple attacks and functionalization of N-acetylhexahistidine. In order to challenge this intriguing reactivity in a model protein more complex than N-acetylhexahistidine, the single-chain Fv antibody CRB0137 was characterized from the point of view of its structure and made to react with 3 in kinetics experiments. The results of these studies suggested that MBHA derivative 3 reacted typically with the amino acid residues of the CRB0137 hexahistidine tag leading to the formation of multi-PEGylated species. Overall, they demonstrate the viability of a new methodology for the site-specific PEGylation of engineered proteins bearing poly-histidine tags. [ABSTRACT FROM AUTHOR]

Water-soluble MBHA derivatives were found to self-assemble in a water environment to generate aggregates showing core–shell architectures. The aggregates appeared to be capable of working as nanoreactors performing a multi-functionalization of poly-histidine fragments, which after an initial interaction with the solvated oligo(ethylene glycol) shell reach the reactive core. [ABSTRACT FROM AUTHOR]

A new family of light driven molecular rotary motors, which can be synthesized from easily available precursor compounds and which are capable of completing a full 360° revolution by two photoisomerization steps only, is proposed. The non-adiabatic molecular dynamic simulations show that the photoisomerization steps of the motor's working cycle occur on an ultrafast time scale (ca. 200–300 fs), have a very high quantum yield of isomerization (0.91–0.97), and display high selectivity of torsion in the same direction. It is expected that the new motor should remain operational at lower temperatures than the currently existing motors. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two benzofulvene derivatives bearing a 4-pyridylacetylene substituent in different positions (i. e. 2 and 6) of the benzofulvene scaffold are designed and synthesized. • Both benzofulvene derivatives 2-PA- BF3a and 6-PA- BF3k showed the tendency to polymerize spontaneously in the consequence of solvent removal. • NMR and MALDI-TOF studies suggested for poly-6-PA- BF3k a higher structural homogeneity with respect to poly-2-PA- BF3a. • Poly-6-PA- BF3k show an interesting hole mobility value, which was found to be around two orders of magnitude higher than that of poly(vinylcarbazole). Two benzofulvene derivatives bearing a 4-pyridylacetylene substituent in different positions (i. e. 2 and 6) of the benzofulvene scaffold are designed and synthesized to evaluate the effects on the spontaneous solid-state polymerization of the presence of the same substituent in two different key positions of the 3-phenylbenzofulvene moiety. Both the benzofulvene derivatives showed the tendency to polymerize spontaneously in the consequence of solvent removal under reduced pressure without the addition of catalysts or initiators. The macromolecular structure of the stemming polymeric materials was investigated by NMR spectroscopy and MALDI-TOF mass spectrometry. Both NMR and MALDI-TOF studies confirmed the polymeric nature of the materials and suggested for the polybenzofulvene derivative bearing the 4-pyridylacetylene substituent in positions 6 a higher structural homogeneity with respect to the one bearing the same substituent in position 2. The photophysical characterization of the most homogeneous polybenzofulvene derivative led to the discovery of its outstanding hole mobility value, which was found to be around one order of magnitude higher than that previously measured for two oligothiophene-based polybenzofulvene derivatives and almost two orders of magnitude higher than that of poly(vinylcarbazole), commonly used as hole-transporter matrix. This result places the new polybenzofulvene derivative in an outstanding position as a promising material for field-effect transistor (FET) device applications. [ABSTRACT FROM AUTHOR]

While rotary molecular switches based on neutral and cationic organic -systems have been reported, structurally homologous anionic switches providing complementary properties have not been prepared so far. Flere we report the design and preparation of a molecular switch mimicking the anionic p-HBDI chromophore of the green fluorescent protein. The investigation of the mechanism and dynamics of the E/Z switching function is carried out both computationally and experimentally. The data consistently support axial rotary motion occurring on a sub-picosecond time scale. Transient spectroscopy and trajectory simulations show that the nonadiabatic decay process occurs in the vicinity of a conical intersection (CInt) between a charge transfer state and a covalent/diradical state. Comparison of our anionic p-HBDI-like switch with the previously reported cationic N-alkyl indanylidene pyrrolinium switch mimicking visual pigments reveals that these similar systems translocate, upon vertical excitation, a similar net charge in the same axial direction. [ABSTRACT FROM AUTHOR]

Specificnoncovalent interactions are commonly used by nature tomodulate numerous processes including cell recognition, viral adhesion,and transmembrane communications. Here we report on the design, synthesis,and preliminary characterization of new supramolecular glycodendrimer-basedhybrid drugs based on adamantyl-modified glycodendrimers of third,fourth, or fifth generation (mPPI-G3-AdaB, mPPI-G4-AdaB, and mPPI-G5-AdaB) and a new heterobifunctional ligand.This component was tailored to bind through noncovalent interactionsboth the multimeric natural 5-HT3receptor (through anoptimized arylpiperazine pharmacophore) and the adamantyl groups locatedon the glycodendrimer surfaces (through a β-cyclodextrin residue)giving rise to biorelevant supramolecular constructs. [ABSTRACT FROM AUTHOR]

Multivalency is widely used in nature in specific recognition processes. This paper describes an approach to multivalency in the pentameric 5-HT3 receptor, a ligand-gated ion channel, which constitutes an example of intrinsically multivalent biological receptors. Owing to the picomolar Ki value, TETRA-L represents an outstanding multivalent ligand for the neurotransmitter receptor. [ABSTRACT FROM AUTHOR]

[Display omitted] • Benzofulvene derivatives 6-Pyr- BF3k and 6-PTPC- BF3k bearing uncomplexed and complexed pyridine rings are synthesized. • The solvent removal from a 6-Pyr- BF3k solution leads to the spontaneous formation of the homopolymer poly-6-Pyr- BF3k. • The same procedure applied to the 6-PTPC- BF3k monomer highlights the competition between polymerization and crystallization. • Uncomplexd poly-6-Pyr- BF3k show interesting emission properties, while poly-6-PTPC- BF3k shows low emission quantum yield. Benzofulvene derivatives bearing complexed and un-complexed pyridine rings are designed and synthesized to assess the effects on the spontaneous solid-state polymerization of the presence in position 6 of the 3-phenylbenzofulvene moiety of bulky substituents capable of establishing metallophilic interactions. Both the benzofulvene monomers are found to polymerize spontaneously upon solvent removal under reduced pressure in the apparent absence of catalysts or initiators. The resulting polybenzofulvene derivatives are characterized by NMR spectroscopy, MALDI-TOF mass spectrometry, and in photophysical studies. [ABSTRACT FROM AUTHOR]

Abstract: A small series of serotonin 5-HT4 receptor ligands has been designed from flexible 2-methoxyquinoline compounds 7a,b by applying the conformational constraint approach. Ligands 7a,b and the corresponding conformationally constrained analogues 8a–g were synthesized and their interactions with the 5-HT4 receptor were examined by measuring both binding affinity and the ability to promote or inhibit receptor–G protein coupling. Ester derivative 7a and conformationally constrained compound 8b were demonstrated to be the most interesting compounds showing a nanomolar 5-HT4R affinity similar to that shown by reference ligands cisapride (1) and RS-23,597-190 (4). The result was rationalized by docking studies in term of high similarity in the binding modalities of flexible 7a and conformationally constrained 8b. The intrinsic efficacy of some selected ligands was determined by evaluating the receptor–G protein coupling and the results obtained demonstrated that the nature and the position of substituents play a critical role in the interaction of these ligands with their receptor. [Copyright &y& Elsevier]

[Display omitted] • Neutral platinum(II) complex 2-PTPC- BF3a was prepared from benzofulvene derivative 2-Pyr- BF3a. • Complex 2-PTPC- BF3a was found to aggregate into an ordered crystalline solid-state without significant spontaneous polymerization. • Crystalline powder of 2-PTPC- BF3a is insensible to UV-light irradiation, while its dispersions in chloroform produced the corresponding polymer poly-2-Pyr- BF3a. • Curiously, the UV-light irradiation of the crystalline films deposited from THF solutions on quartz substrates produce oligomers of poly-2-PTPC- BF3a which show significant emission. Neutral platinum(II) complex 2-PTPC- BF3a was easily prepared from benzofulvene derivative 2-Pyr- BF3a in order to evaluate the effects in the aggregation/polymerization behavior of a bulky substituent capable of establishing intermolecular metal–metal interactions in the close proximity of the putative polymerization center. Complex 2-PTPC- BF3a was found to aggregate into an ordered crystalline solid-state without significant spontaneous polymerization, but the UV-light irradiation of its dispersions in chloroform produced corresponding oligomers, which were characterized by NMR spectroscopy and MALDI-TOF mass spectrometry. On the other hand, the UV-irradiation of the platinum complex in the solid-state produced different results probably depending on the aggregate architecture. Notably, the crystalline films deposited from THF solutions on quartz substrates showed weak emissions, which progressively increased upon irradiation with the formation of oligomers devoid of the aggregation-induced quenching sites that seemed to affect the emission of poly-2-PTPC- BF3a. Finally, DFT calculations were performed on platinum complex 2-PTPC- BF3a in the aim of rationalizing the observed photophysical features. [ABSTRACT FROM AUTHOR]

• 2-Pyr- BF3a organizes into a crystalline solid-state without spontaneous polymerization. • Photopolymerization occurs in amorphous films, but not in solution or in crystals. • The polymer shows a more intense emission in solution than in the solid state. Benzofulvene derivative 2-Pyr- BF3a was designed and synthesized to evaluate the effects of a pyridine ring in position 2 of the 3-phenylbenzofulvene moiety on the spontaneous solid-state polymerization. The monomer was found to organize into an ordered crystalline solid-state without significant spontaneous polymerization, but the irradiation of amorphous film samples with UV-light produced photopolymerization. Resulting poly-2-Pyr- BF3a was characterized by NMR spectroscopy, MALDI-TOF mass spectrometry, and photophysical studies in comparison with the corresponding monomer. Interestingly, monomer 2-Pyr- BF3a was weakly emissive in diluted solutions, but increased its PLQY in the crystalline solid. Conversely, after photopolymerization the monomeric unit in the polymer enhanced its emission intensity in solution while in the solid state results weakly emissive. Even more interestingly, this benzofulvene monomer and its synthetic precursors 2 and 3 showed long-lived emission suggesting a phosphorescence nature of the emission process. Finally, DFT and TDDFT calculations were performed in order to rationalize the experimental data. [ABSTRACT FROM AUTHOR]

In order to evaluate the potential of a technology platform based on hyaluronan copolymers grafted with propargylated ferulate fluorophores (HA-FA-Pg) in the development of drug delivery systems, the propargyl groups of HA-FA-Pg derivatives were employed with oleic acid (OA) or stearic acid (SA) residues across a biocompatible hexa(ethylene glycol) (HEG) spacer. The designed materials (i.e., HA-FA-HEG-OA or HA-FA-HEG-SA) showed clear-cut aggregation features in an aqueous environment, as confirmed by dynamic light scattering (DLS) and transmission electron microscopy (TEM), generating nanoaggregate systems. In fact, HA-FA-HEG-OA and HA-FA-HEG-SA derivatives showed the property to create self-assembled cytocompatible nanostructured aggregates in water, thanks to the simultaneous presence of hydrophilic portions in the polymeric backbone, such as hyaluronic acid, and hydrophobic portions in the side chains. Furthermore, the designed materials interact with living cells showing a high degree of cytocompatibility. The potential ability of nanosystems to load pharmacologically active molecules was assessed by the physical entrapment of olanzapine into both polymeric systems. The drug loading evaluation demonstrated that the nanoparticles are able to incorporate a good quantity of olanzapine, as well as improve drug solubility, release profile, and cytocompatibility. [ABSTRACT FROM AUTHOR]

A new polymer brush was synthesized by spontaneous polymerization of benzofulvene macromonomer 6-MOEG-9-T-BF3k bearing a nona(ethylene glycol) side chain linked to the 3-phenylindene scaffold by means of a triazole heterocycle. The polymer structure was studied by SEC-MALS, NMR spectroscopy, and MALDI-TOF MS techniques, and the results supported the role of oligomeric initiatory species in the spontaneous polymerization of polybenzofulvene derivatives. The aggregation features of high molecular weight poly-6-MOEG-9-T-BF3k-FE were investigated by pyrene fluorescence analysis, dynamic light scattering studies, and transmission electron microscopy, which suggested a tendency towards the formation of spherical objects showing dimensions in the range of 20–200 nm. Moreover, poly-6-MOEG-9-T-BF3k-FE showed an interesting cytocompatibility in the whole concentration range tested that, besides its aggregation features, makes this polybenzofulvene brush a good polymer candidate for nanoencapsulation and delivery of drug molecules. Finally, the photo-physical features of poly-6-MOEG-9-T-BF3k-FE could allow the biodistribution of the resulting drug delivery systems to be monitored by fluorescence microscopy techniques. [ABSTRACT FROM AUTHOR]

RNA‐based tools for biological and pharmacological research are raising an increasing interest. Among these, RNA aptamers whose biological activity can be controlled via illumination with specific wavelengths represent an important target. Here, we report on a proof‐of‐principle study supporting the viability of a systematic use of Morita‐Baylis‐Hillman adducts (MBHAs) for the synthesis of light‐responsive RNA building blocks. Accordingly, a specific acetylated MBHA derivative was employed in the functionalization of the four natural RNA bases as well as two unnatural bases (5‐aminomethyl uracil and 5‐methylaminomethyl uracil). The results reveal a highly selective functionalization for both unnatural bases. The conjugation products were then investigated spectroscopically, photochemically and computationally. It is shown that when a single light‐responsive unit is present (i. e. when using 5‐methylaminomethyl uracil), the generated unnatural uracil behaves like a cinnamic‐framework‐based photochemical switch that isomerizes upon illumination through a biomimetic light‐induced intramolecular charge transfer mechanism driving a barrierless and, therefore, ultrafast reaction path. [ABSTRACT FROM AUTHOR]

The synthesis of new bis‐deoxy‐coelenterazine (1) derivatives bearing ester protective groups (acetate, propionate and butyrate esters) was accomplished. Moreover, their hydrolytic stability at room temperature was evaluated in dimethylsulfoxide (DMSO) as solvent, using the nuclear magnetic resonance (NMR) spectra of the key products at different time intervals. The results showed an increasing hydrolysis rate according to longest aliphatic chain, with a half‐life of 24 days of the more stable acetate derivative (4a). Furthermore, the analysis of the experimental data revealed the greater stability of the enol tautomer in this aprotic polar solvent. This result was confirmed by theoretical calculations using the density functional theory (DFT) approach, which gave us the opportunity to propose a detailed decomposition mechanism. Additionally, the derivatives obtained were tested by bioluminescence luciferase assays to evaluate their potential use as extracellular pH‐sensitive reporter substrates of luciferase. The biological data support the idea that further structural modifications of these molecules may open promising perspectives in this field of research. [ABSTRACT FROM AUTHOR]

Spontaneous polymerization is an intriguing phenomenon in which pure monomers begin their polymerization without initiators or catalysts. Previously, 3-phenylbenzofulvene monomers were found to polymerize spontaneously after solvent removal. Here, eight new 3-substituted benzofulvene monomers 1a–h were synthesized in order to investigate the effects of differently substituted aromatic rings in position 3 of the benzofulvene scaffold on spontaneous polymerization. The newly synthesized monomers maintained the tendency toward spontaneous polymerization. However, monomer 1a, bearing an ortho-methoxy substituted phenyl, polymerized hardly, thus producing low polymerization yields, inhomogeneous structure, and low molecular weight of the obtained polymeric material. This result suggested the importance of the presence of hydrogen atoms in the 2′-position to achieve productive interactions among the monomers in the recognition step preluding the spontaneous polymerization and among the monomeric units in the polybenzofulvene backbones. Moreover, this study paves the way to modify the pendant rings in position 3 of the indene scaffold to synthesize new polybenzofulvene derivatives variously decorated. [ABSTRACT FROM AUTHOR]

A molecular motor potentially performing a continuous unidirectional rotation is studied by a multidisciplinary approach including organic synthesis, transient spectroscopy and excited state trajectory calculations. A stereogenic center was introduced in the N-alkylated indanylidene–pyrroline Schiff base framework of a previously investigated light-driven molecular switch in order to achieve the unidirectional C＝C rotary motion typical of Feringa's motor. Here we report that the specific substitution pattern of the designed chiral molecule must critically determine the unidirectional efficiency of the light-induced rotary motion. More specifically, we find that a stereogenic center containing a methyl group and a hydrogen atom as substituents does not create a differential steric effect large enough to fully direct the motion in either the clockwise or counterclockwise direction especially along the E → Z coordinate. However, due to the documented ultrafast character and electronic circular dichroism activity of the investigated system, we find that it provides the basis for development of a novel generation of rotary motors with a biomimetic framework and operating on a picosecond time scale. [ABSTRACT FROM AUTHOR]

Selective ligands of the CB2 receptor are receiving considerable attention due to their potential as therapeutic agents for a variety of diseases. Recently, 7-hydroxy-5-oxopyrazolo[4,3-b]pyridine-6-carboxamide derivatives were shown to act at the CB2 receptor either as agonists or as inverse agonists/antagonists in vitro and to have anti-osteoarthritic activity in vivo. In this article, we report the synthesis, pharmacological profile, and molecular modeling of a series of twenty-three new 7-hydroxy-5-oxopyrazolo[4,3-b]pyridine-6-carboxamides with the aim of further developing this new class of selective CB2 ligands. In addition to these compounds, seven other analogs that had been previously synthesized were included in this study to better define the structure–activity relationship (SAR). Ten of the new compounds studied were found to be potent and selective ligands of the CB2 receptor, with Ki values ranging from 48.46 to 0.45 nM and CB1/CB2 selectivity indices (SI) ranging from >206 to >4739. In particular, compounds 54 and 55 were found to be high-affinity CB2 inverse agonists that were not active at all at the CB1 receptor, whereas 57 acted as an agonist. The functional activity profile of the compounds within this structural class depends mainly on the substitution pattern of the pyrazole ring. [ABSTRACT FROM AUTHOR]

Starting from 5-(pyrrol-1-yl)pyrazole derivatives, the synthesis of triazole-based compounds by isosteric replacement of pyrrole and pyrazole was studied. The amido derivatives were obtained by organocatalyzed cycloaddition reactions between aryl azides and β-ketoamides or β-ketoesters. The synthesis of the second series of compounds, namely 5-(triazol-1-yl)pyrazole derivatives, involved the preparation of 5-azido-1H-pyrazole derivatives to be subjected to cycloaddition with alkynes. [ABSTRACT FROM AUTHOR]

α-Lipoic acid is a sulfur-containing nutrient endowed with pleiotropic actions and a safe biological profile selected to replace the unsaturated alkyl acid of capsaicin with the aim of obtaining lipoic amides potentially active as a TRPV1 ligand and with significant antioxidant properties. Thus, nine compounds were obtained in good yields following a simple synthetic procedure and tested for their functional TRPV1 activity and radical-scavenger activity. The safe biological profile together with the protective effect against hypoxia damage as well as the in vitro antioxidant properties were also evaluated. Although less potent than capsaicin, almost all lipoic amides were found to be TRPV1 agonists and, specifically, compound 4, the lipoic analogue of capsaicin, proved to be the best ligand in terms of efficacy and potency. EPR experiments and in vitro biological assays suggested the potential protective role against oxidative stress of the tested compounds and their safe biological profile. Compounds 4, 5 and 9 significantly ameliorated the mitochondrial membrane potential caused by hypoxia condition and decreased F2-isoprostanes, known markers of oxidative stress. Thus, the experimental results encourage further investigation of the therapeutic potential of these lipoic amides. [ABSTRACT FROM AUTHOR]

Reaction of 3-amino-1H-pyrazole-4-carbonitrile with 2,4-pentanedione yielded 5,7-dimethylpyrazolo[1,5-a]pyrimidine-3-carbonitrile, which was easily and efficiently transformed into a small library of amido derivatives. This procedure opens the way to new compounds potentially endowed with interesting biological activities. [ABSTRACT FROM AUTHOR]

Two novel benzofulvene monomers bearing propargyl or allyl groups have been synthesized by means of readily accessible reactions, and were found to polymerize spontaneously by solvent removal, in the apparent absence of catalysts or initiators, to give the corresponding polybenzofulvene derivatives bearing clickable propargyl or allyl moieties. The clickable propargyl and allyl groups were exploited in appropriate click reactions to develop a powerful and versatile 'grafting onto' synthetic methodology for obtaining tailored polymer brushes. [ABSTRACT FROM AUTHOR]

A series of 4-phenyl-6 H -imidazo[1,5- a thieno[3,2- f [1,4]diazepine-7-carboxylate esters were synthesized and tested as central benzodiazepine receptor (CBR) ligands by the ability to displace 3H]flumazenil from rat cortical membranes. All the compounds showed high affinity with IC 50 values ranging from 5.19 to 16.22 nM. In particular, compounds 12b (IC 50 = 8.66 nM) and 12d (IC 50 = 5.19 nM) appeared as the most effective ligands being their affinity values significantly lower than that of diazepam (IC 50 = 18.52 nM). Compounds 12a-f were examined in vivo for their pharmacological effects in mice and five potential benzodiazepine (BDZ) actions were thus taken into consideration: anxiolytic, anticonvulsant, anti-amnesic, hypnotic, and locomotor activities. All the new synthesized compounds were able to induce a significant antianxiety effect and, among them, compound 12f protected pentylenetetrazole (PTZ)-induced convulsions in a dose-dependent manner reaching a 40% effect at 30 mg/kg. In addition, all the compounds were able to significantly prevent the memory impairment evoked by scopolamine, while none of them was able to interfere with pentobarbital-evoked sleep and influence motor coordination. Moreover, title compounds did not affect locomotor and exploratory activity at the same time and doses at which the anti-anxiety effect was observed. Finally, molecular docking simulations were carried out in order to assess the binding mode for compounds 12a-f. The obtained results demonstrated that these compounds bind the BDZ binding site in a similar fashion to flumazenil. Image 1 • Design, synthesis and biological evaluation of novel central benzodiazepine receptor ligands. • Compounds 12a-f are efficacious as anxiolitic agents in vivo. • In silico studies highlight a binding mode into the BDZ binding site similar to flumazenil. [ABSTRACT FROM AUTHOR]

The derivatives of the 7-hydroxy-5-oxopyrazolo[4,3-b]pyridine-6-carboxamide scaffold have been reported recently as potent and selective agonists/inverse agonists of the cannabinoid type-2 receptor (CB2R), but the synthetic way adopted has not yet allowed the structure–activity relationship to be fully explored. Herein, we describe a novel synthetic approach based on the use of a 2-tetrahydropyranyl (THP)-protected precursor that opens the way to obtain either N1- or N2-substituted analogs endowed with agonist or inverse agonist activity, respectively, at the CB2 receptor. [ABSTRACT FROM AUTHOR]

LDN-212320 (3) was found to be a potent EAAT2 activator at a translational level, restoring the normal clearance of glutamate and providing neuronal protection. Since the pharmacologic activation of EAAT2 represents a valuable strategy to relieve neuropathic pain, we synthesized novel activators (4a–f) of EAAT2. Among them 4f, analyzed in comparison with 3 by different paradigms in a rat model of oxaliplatin-induced neuropathic pain, showed the better antihypersensitive profile being able to fully counteract the oxaliplatin-induced neuropathy. [ABSTRACT FROM AUTHOR]

A tri-component polymer brush (TCPB ), composed of a polybenzofulvene copolymer bearing low molecular weight hyaluronic acid (HA) on the surface of its cylindrical brush-like backbone and oligo-PEG fractions, was employed in the preparation of 350 nm nanostructured drug delivery systems capable of delivering the anticancer drug doxorubicin. The obtained drug delivery systems were characterized on the basis of drug loading and release, dimensions and zeta potential, morphology and in vitro cell activity, and uptake on three different human cell lines, namely the bronchial epithelial 16HBE, the breast adenocarcinoma MCF-7, and the colon cancer HCT116 cells. Finally, the ability of doxorubicin-loaded TCPB nanoparticles (DOXO-TCPB) to be internalized into cancer cells by CD44 receptor mediated uptake was assessed by means of uptake studies in HCT cells. These data were supported by anti-CD44-FITC staining assay. The proposed TCPB nanostructured drug delivery systems have many potential applications in nanomedicine, including cancer targeted drug delivery. [ABSTRACT FROM AUTHOR]

Neurodegenerative diseases are disorders related to the degeneration of central neurons that gradually lead to various, severe alterations of cognitive and/or motor functions. Currently, for no such diseases does any pharmacological treatment exist able to arrest its progression. Riluzole ( 1 ) is a small molecule able to interfere with multiple cellular and molecular mechanisms of neurodegeneration, and is the only approved treatment of amyotrophic lateral sclerosis (ALS), the progression of which proved to significantly slow, thus increasing somewhat average survival. Here we report the synthesis of differently functionalized 4 H -3,1-benzothiazine ( 5 – 6 ) and 2 H -1,4-benzothiazine ( 7 ) series as superior homologues of 1 . Biological evaluation demonstrated that amidine 4 H -3,1-benzothiazine derivatives 5b - d can reduce glutamate and LDH release in the oxygen/glucose deprivation and reperfusion model (OGD/R) applied to brain slices with a higher potency than 1 . Moreover the mentioned compounds significantly reduce glutamate- and 6-hydroxydopamine (6-OHDA)-induced cytotoxicity in neuroblastoma cells. In addition, the same compounds limit ROS formation in both neuronal preparations. Finally, 5c proved effective in inhibiting neuronal voltage-dependent Na + and Ca 2+ -channels, showing a profile comparable with that of 1 . [ABSTRACT FROM AUTHOR]

Two new fluorophenylindenone derivatives were designed as potential p38α MAPK modulators by preserving the key interactions of the vicinal pyridine/fluorophenyl pharmacophore with the enzyme protein. Interestingly, these two fluorophenylindenone isomers showed divergent activities, with compound 6 behaving as an inhibitor and 5 as a putative activator. These results were rationalized by docking studies and molecular dynamics simulations in terms of stabilization of DFG loop, by compound 5 in a conformation more accessible to phosphorylation. [ABSTRACT FROM AUTHOR]

The design of compounds able to combine the selective inhibition of cyclooxygenase-2 (COX-2) with the release of nitric oxide (NO) is a promising strategy to achieve potent anti-inflammatory agents endowed with an overall safer profile and reduced toxicity upon gastrointestinal and cardiovascular systems. With the aim of generating novel and selective COX-2 inhibiting NO-donors (CINOD) and encouraged by the promising results obtained with our nitrooxy- and hydroxyethyl ethers 11 and 12 reported in previous works, we shifted our attention on the synthesis of isosteric thioanalogs nitrooxy- and hydroxy ethyl sulfides 13a-c and 14a-c, respectively, along with their oxidation products nitrooxy- and hydroxyethyl sulfoxides 15a-c and 16a-c, respectively, also referred to as thio-CINOD. Preliminary data and metabolic analysis highlighted how the isosteric substitution of the ethereal oxygen atom of 11a-c with sulfur in compounds 13a-c , independently from the presence and the number of fluorine atoms in N 1 -phenyl ring, leads to new selective and highly potent COX-2 inhibitors, capable to induce vasorelaxant responses in vivo. The same behavior is observed with their oxidized counterparts nitrooxyethyl sulfoxides 15a-c , in which the oxidation state of the sulfur atom and the presence of the additional oxygen atom play a substantial role in enhancing compounds activity and vasorelaxation. In addition, the screened compounds proved significantly efficacious in mouse models of inflammation and nociception at the dose of 20 mg/kg. [Display omitted] • Novel analgesic/anti-inflammatory agents 13 – 16 as dual selective COX-2 inhibitors containing a NO donor moiety were proposed. • SARs of target compounds 13 – 16 are carefully explored. • The isosteric O-to-S replacement led to selective and highly potent COX-2 inhibitors 13a-c and 15a-c. • Hydroxyethyl sulfides 14a-c also showed an efficacious and selective COX-2 inhibitory activity. • Compounds 13a-c and 15a-c , containing a NO donor moiety, showed intriguing vasorelaxant properties. [ABSTRACT FROM AUTHOR]

A series of imidazo[1,5-a]quinoline derivatives was designed and synthesized as central benzodiazepine receptor (CBR) ligands. Most of the compounds showed high CBR affinity with Ki values within the submicromolar and subnanomolar ranges with interesting modulations in their structure-affinity relationships. In particular, fluoroderivative 7w (Ki = 0.44 nM) resulted in the most potent ligand among the imidazo[1,5-a]quinoline derivatives described so far. Overall, these observations confirmed the assumption concerning the presence of a large though apparently saturable lipophilic pocket in the CBR binding site region interacting with positions 4 and 5 of the imidazo[1,5-a]quinoline nucleus. The in vivo biological characterization revealed that compounds 7a,c,d,l,m,q,r,w show anxiolytic and antiamnestic activities without the unpleasant myorelaxant side effects of the classical 1,4-BDZ. Furthermore, the effect of 7l,q,r, and 8i in lowering lactate dehydrogenase (LDH) release induced by ischemia-like conditions in rat brain slices suggested neuroprotective properties for these imidazo[1,5-a]quinoline derivatives. [ABSTRACT FROM AUTHOR]

Positron emission tomography (PET) can be used to monitor in vivo translocator protein (TSPO) expression by using specific radioligands. Recently, several [11C]PK11195 analogues have been synthesized to improve binding stability and brain availability. [18F]VC701 was synthesized and validated in CD healthy rats by biodistribution and inhibition analysis. Imaging studies were also conducted on animals injected unilaterally in the striatum with quinolinic acid (QA) to evaluate the TSPO ligand uptake in a neuroinflammation/ neurodegenerative model. [18F]VC701 was synthesized with a good chemical and radiochemical purity and specific activity higher than 37 GBq/µmol. Kinetic studies performed on healthy animals showed the highest tracer biodistribution in TSPO-rich organs, and preadministration of cold PK11195 caused an overall radioactivity reduction. Metabolism studies showed the absence of radiometabolites in the rat brain of QA lesioned rats, and biodistribution analysis revealed a progressive increase in radioactivity ratios (lesioned to nonlesioned striatum) during time, reaching an approximate value of 5 4 hours after tracer injection. These results encourage further evaluation of this TSPO radioligand in other models of central and peripheral diseases. [ABSTRACT FROM AUTHOR]

A new class of π-stacked polymers possessing interesting charge transport properties is represented by polydibenzofulvene derivatives. We study the electroluminescence properties of three π-stacked polybenzofulvene derivatives and compare them to those of the standard π-stacked poly(N-vinylcarbazole). Solution processable devices using one of these polymers as host with benzothiadiazole based dyes display performances overcoming those of the standard poly(N-vinylcarbazole) host. From a photophysical study, the superior performances of the polybenzofulvene containing a fluorene unit at the position 6 of the indene nucleus are explained to arise from its ability to self-assemble with the dyes in supramolecular organizations that reduce their microaggregation. [ABSTRACT FROM AUTHOR]

Abstract: In this study, a polybenzofulvene derivative named poly-6-MOEG-9-BF3k, was evaluated as polymeric material for the production of injectable thermoresponsive nano-aggregates able to load low molecular weight peptidic drug, like the anticancer leuprolide. Thermoresponsive behavior of poly-6-MOEG-9-BF3k was studied in aqueous media by evaluating scattering intensity variations by means of DLS in function of temperature. Zeta potential measurements and SEM observations were also carried out. Moreover, critical aggregation temperature of the poly-6-MOEG-9-BF3k polymer was evaluated by pyrene fluorescence analysis. Then, the ability of prepared thermoresponsive aggregates to protect this model oligopeptide drug and regulate its release rate in function of external temperature was evaluated in vitro. Finally, biocompatibility of poly-6-MOEG-9-BF3k aggregates was tested in vitro on a healthy cell line (human bronchial epithelial cell; 16-HBE) and in vivo on rat animal model upon subcutaneous administration. [Copyright &y& Elsevier]

In this paper we report about the preparation, physicochemical and biological characterization of a magneto responsive nanostructured material based on magnetite nanoparticles (NP) coated with hyaluronic acid (HA). A synthetic approach, based on a Cu(I)-catalyzed azide-alkyne 1,3-dipolar cycloaddition "click" reaction between azido-functionalized magnetite NP and a derivative of hyaluronic acid bearing propargylated ferulic acid groups (HA-FA-Pg), was developed to link covalently the polymer layer to the magnetite NP. The functionalization steps of the magnetite NP and their coating with the HA-FA-Pg layer were monitored by Fourier Transform Infrared (FTIR) spectroscopy and Thermal Gravimetric Analysis (TGA) while Dynamic Light Scattering (DLS) and ζ-potential measurements were performed to characterize the aqueous dispersions of the HA-coated magnetite NP. Aggregation and sedimentation processes were investigated also by UV-visible spectroscopy and the dispersions of HA-coated magnetite NP were found significantly more stable than those of bare NP. Magnetization and zero field cooled/field cooled curves revealed that both bare and HA-coated magnetite NP are superparamagnetic at room temperature. Moreover, cytotoxicity studies showed that the coating with HA-FA-Pg significantly reduces the cytotoxicity of the magnetite NP providing the rational basis for the application of the HA-coated magnetite NP as healthcare material. Image 1 • Covalent synthesis of a Hyaluronic-coated magnetic nanoparticles are reported. • Hyaluronic Acid coating improves the physicochemical and biological properties. • Hyaluronic Acid coating does not prevents the superparamagnetic behaviour at room temperature. [ABSTRACT FROM AUTHOR]

• Design, synthesis and biological evaluation of novel COX-2 selective inhibitors. • COX-2 inhibitors are efficacious as analgesic agents in vivo. • In silico studies highlight the binding mode of the compounds into COX-2 enzyme. A novel series of 1,5-diarylpyrrol-3-sulfur derivatives (10 – 12) was synthesized and characterized by NMR and mass spectroscopy and x-ray diffraction. The biological activity of these compounds was evaluated in in vitro and in vivo tests to assess their COX-2 inhibitory activity along with anti-inflammatory and antinociceptive effect. Results showed that the bioisosteric transformation of previously reported alkoxyethyl ethers (9a-c) into the corresponding alkyl thioethers (10a-c) still leads to selective and active compounds being the COX-2 inhibitory activity for most of them in the low nanomolar range. The oxidation products of 10a,b were also investigated and both couple of sulfoxides (11a , b) and sulfones (12a , b) showed an appreciable COX-2 inhibitory activity. Molecular modeling studies were performed to investigate the binding mode of the representative compounds 10b , 11b , and 12b into COX-2 enzyme and to explore the potential site of metabolism of 10a and 10b due to the different in vivo efficacy. Among the developed compounds, compound 10b showed a significant in vivo anti-inflammatory and antinociceptive activity paving the way to develop novel anti-inflammatory drugs. [ABSTRACT FROM AUTHOR]