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Ursolic acid (UA), a pentacyclic triterpenoid acid found in many medicinal plants and aromas, is known for its antibacterial effects against multi-drug-resistant (MDR) Gram-positive bacteria, which seriously threaten human health. Unfortunately, UA water-insolubility, low bioavailability, and systemic toxicity limit the possibilities of its application in vivo. Consequently, the beneficial activities of UA observed in vitro lose their potential clinical relevance unless water-soluble, not cytotoxic UA formulations are developed. With a nano-technologic approach, we have recently prepared water-soluble UA-loaded dendrimer nanoparticles (UA-G4K NPs) non-cytotoxic on HeLa cells, with promising physicochemical properties for their clinical applications. In this work, with the aim of developing a new antibacterial agent based on UA, UA-G4K has been tested on different strains of the Enterococcus genus, including marine isolates, toward which UA-G4K has shown minimum inhibitory concentrations (MICs) very low (0.5–4.3 µM), regardless of their resistance to antibiotics. Time-kill experiments, in addition to confirming the previously reported bactericidal activity of UA against E. faecium, also established it for UA-G4K. Furthermore, cytotoxicity experiments on human keratinocytes revealed that nanomanipulation of UA significantly reduced the cytotoxicity of UA, providing UA-G4K NPs with very high LD50 (96.4 µM) and selectivity indices, which were in the range 22.4–192.8, depending on the enterococcal strain tested. Due to its physicochemical and biological properties, UA-G4K could be seriously evaluated as a novel oral-administrable therapeutic option for tackling difficult-to-treat enterococcal infections.

Difficult-to-treat bacterial infections caused by resistant human and plant pathogens severely afflict hospitals, and concern the agri-food sectors. Bacteria from the Pseudomonadaceae family, such as P. aeruginosa, P. putida, P. fluorescens, and P. straminea, can be responsible for severe nosocomial infections in humans. P. fragi is the major cause of dairy and meat spoilage, while P. syringae can infect a wide range of economically important plant species, including tobacco, kiwi, and tomato. Therefore, a cationic water-soluble lysine dendrimer (G5-PDK) was tested on several species of Pseudomonas genus. Interestingly, G5-PDK demonstrated variable minimum inhibitory concentrations (MICs), depending on their pigment production, on Pseudomonas aeruginosa (1.6-&gt, 6.4 µM), MICs = 3.2–6.4 µM on P. putida clinical isolates producing pyoverdine, and very low MICs (0.2–1.6 µM) on strains that produced non-pigmented colonies. Time-kill experiments established the rapid bactericidal activity of G5-PDK. In the cytotoxicity experiments on human keratinocytes, after 4 h of treatment with G5-PDK at concentrations 16–500 × MIC, more than 80% of viable cells were observed, and after 24 h, the selectivity indices were maintained above the maximum value reported as acceptable. Due to its proven bactericidal potency and low cytotoxicity, G5-PDK should be seriously considered to counteract clinically and environmentally relevant Pseudomonas isolates.

To exploit the full potential of pomegranate marcs, this study explores different conditions of ‘green’ extraction of ellagitannins and other bio-active phenolic compounds from the ‘external by-product’ of pomegranate industrial processing. Significant recoveries of ellagitannins, free ellagic acid and radical scavenging compounds were obtained by coupling both the traditional (MH) or the hydro-diffusion gravity (MHG) microwave assisted drying to a direct ultrasound assisted extraction (UAE) using a food-grade solvent (EtOH/H2O). The amounts of the ellagitannins after microwave drying were always significantly higher than with the traditional oven drying. Moreover, microwaves reduced the drying times from several hours to few minutes reaching comparable residual moisture content. The microwave hydro-diffusion gravity system allowed the recovery of bio-active compounds in the condensed water too. The comparison of UAE with traditional maceration and decoction highlighted the higher efficiency of UAE in the quicker extraction of bio-active compounds, except for the total ellagitannins which were better recovered after the longer maceration.

Ursolic acid (UA) is a pentacyclic triterpenoid found in many medicinal plants and aromas endowed with numerous in vitro pharmacological activities, including antibacterial effects. Unfortunately, UA is poorly administered in vivo, due to its water insolubility, low bioavailability, and residual systemic toxicity, thus making urgent the development of water-soluble UA formulations. Dendrimers are nonpareil macromolecules possessing highly controlled size, shape, and architecture. In dendrimers with cationic surface, the contemporary presence of inner cavities and of hydrophilic peripheral functions, allows to encapsulate hydrophobic non-water-soluble drugs as UA, to enhance their water-solubility and stability, and to promote their protracted release, thus decreasing their systemic toxicity. In this paper, aiming at developing a new UA-based antibacterial agent administrable in vivo, we reported the physical entrapment of UA in a biodegradable not cytotoxic cationic dendrimer (G4K). UA-loaded dendrimer nanoparticles (UA-G4K) were obtained, which showed a drug loading (DL%) much higher than those previously reported, a protracted release profile governed by diffusion mechanisms, and no cytotoxicity. Also, UA-G4K was characterized by principal components analysis (PCA)-processed FTIR spectroscopy, by NMR and elemental analyses, and by dynamic light scattering experiments (DLS). The water solubility of UA-G4K was found to be 1868-fold times higher than that of pristine UA, thus making its clinical application feasible.

Children affected by chronic liver disease exhibit impaired neurocognitive development and growth due to the low absorption and digestion of nutrients. Furthermore, malnutrition is an adverse prognostic factor in liver transplantation as it is associated with an increase in morbidity and mortality. D-α-tocopheryl-polyethylene-glycol-succinate (TPGS) is currently administered per os as a vitamin E source to improve children’s survival and well-being, however, TPGS alone does not reverse spinocerebellar degeneration and lipid peroxidation. To potentiate the effects of TPGS, we loaded micelles with resveratrol (RES), a natural polyphenol, with antioxidant and antiinflammatory activities, which has demonstrated protective action in the liver. Firstly, we investigated the suitability of TPGS to encapsulate RES in micelles by means of a phase-solubility study, then RES-TPGS formulations were prepared via solvent casting and solvent diffusion evaporation methods. RES-TPGS colloidal dispersions showed small mean diameters (12 nm), low polydispersity, and quite neutral Zeta potentials. The formulations showed a sustained drug release and a good drug loading capacity, further confirmed by infrared spectroscopy and differential scanning calorimetry. RES-TPGSs exhibited unaltered antioxidant activity compared to pristine RES via the DPPH assay and a significant reduction in toxicity compared to empty TPGS on HaCaT cells. Thus, RES-TPGS micelles may overcome the challenges of current liver disease therapy by providing more protective effects thanks to the antioxidant activity of RES and by reducing the surfactant toxicity on normal cells.

Atherosclerosis is a chronic progressive disease involving inflammatory events, such as the overexpression of adhesion molecules including the endothelial Vascular Cell Adhesion Molecule-1 (VCAM-1). VCAM-1 is rapidly overexpressed in the first stages of atherosclerosis, thus representing a promising target for early atheroma detection. Two novel Positron Emission Tomography (PET) radiopharmaceuticals (MacroP and NAMP), based on the VCAM-1-binding peptide having sequence VHPKQHRGGSKGC, were synthesized and characterized. MacroP is derived from the direct conjugation of a DOTA derivative with the peptide, while NAMP is a biotin derivative conceived to be employed in a three-step pretargeting system, involving the use of a double-chelating derivative of DOTA. The identity of the newly synthesized radiopharmaceuticals was confirmed by mass spectrometry and, after radiolabeling with 68Ga, both showed high radiochemical purity, in vitro tests on human umbilical vein endothelial cells evidenced their VCAM-1 binding ability, with higher radioactive uptake in the case of NAMP. Moreover, NAMP might also be employed in a theranostic approach in association with functionalized biotinylated nanoparticles.

Low-molecular-weight organic ammonium salts exert excellent antimicrobial effects by interacting lethally with bacterial membranes. Unfortunately, short-term functionality and high toxicity limit their clinical application. On the contrary, the equivalent macromolecular ammonium salts, derived from the polymerization of monomeric ammonium salts, have demonstrated improved antibacterial potency, a lower tendency to develop resistance, higher stability, long-term activity, and reduced toxicity. A water-soluble non-quaternary copolymeric ammonium salt (P7) was herein synthetized by copolymerizing 2-methoxy-6-(4-vinylbenzyloxy)-benzylammonium hydrochloride monomer with N, N-di-methyl-acrylamide. The antibacterial activity of P7 was assessed against several multidrug-resistant (MDR) clinical isolates of both Gram-positive and Gram-negative species. Except for colistin-resistant Pseudomonas aeruginosa, most isolates were susceptible to P7, also including some Gram-negative bacteria with a modified charge in the external membrane. P7 showed remarkable antibacterial activity against isolates of Enterococcus, Staphylococcus, Acinetobacter, and Pseudomonas, and on different strains of Escherichia coli and Stenotrophomonas maltophylia, regardless of their antibiotic resistance. The lowest minimal inhibitory concentrations (MICs) observed were 0.6–1.2 µM and the minimal bactericidal concentrations (MBC) were frequently overlapping with the MICs. In 24-h time–kill and turbidimetric studies, P7 displayed a rapid non-lytic bactericidal activity. P7 could therefore represent a novel and potent tool capable of counteracting infections sustained by several bacteria that are resistant to the presently available antibiotics.

To counteract the growing bacterial resistance, we previously reported the remarkable antimicrobial activity of amino acid-conjugated cationic dendrimers (CDs) against several Gram-negative species, establishing that the cationic lysine was essential for their potency. In this paper, CDs conjugated with lysine and arginine and encapsulating ursolic and oleanolic acids (UOACDs) were assumed to be excellent candidates for developing new antibacterial agents, possibly active against Gram-positive species. Indeed, both the guanidine group of arginine and the two triterpenoid acids are items known for directing antibacterial effects, particularly against Gram-positive bacteria. The cationic dendrimers were obtained by peripheral conjugation with the selected amino acids and by entrapping a physical mixture of the commercial triterpenoid acids. The cationic compounds were characterized and successfully tested against 15 Gram-positive isolates. Interesting minimum inhibitory concentration (MIC) values were obtained for all the dendrimer-drug agents, establishing that the antibacterial activity observed for the UOACDs strongly depended on the density and on the type of the cationic groups of the cationic amino acid-conjugated dendrimers and not on the presence and the release of UOA. Particularly, lysine was critical for potency, while arginine was critical for redirecting activity against Gram-positive species. Especially, a high cationic character, associated with a balanced content of lysine/arginine, produced a remarkable antimicrobial effect (MIC = 0.5–8.7 µM).

Oxidative stress (OS), triggered by overproduction of reactive oxygen and nitrogen species, is the main mechanism responsible for several human diseases. The available one-target drugs often face such illnesses, by softening symptoms without eradicating the cause. Differently, natural polyphenols from fruits and vegetables possess multi-target abilities for counteracting OS, thus representing promising therapeutic alternatives and adjuvants. Although in several in vitro experiments, ellagitannins (ETs), ellagic acid (EA), and its metabolites urolithins (UROs) have shown similar great potential for the treatment of OS-mediated human diseases, only UROs have demonstrated in vivo the ability to reach tissues to a greater extent, thus appearing as the main molecules responsible for beneficial activities. Unfortunately, UROs production depends on individual metabotypes, and the consequent extreme variability limits their potentiality as novel therapeutics, as well as dietary assumption of EA, EA-enriched functional foods, and food supplements. This review focuses on the pathophysiology of OS; on EA and UROs chemical features and on the mechanisms of their antioxidant activity. A discussion on the clinical applicability of the debated UROs in place of EA and on the effectiveness of EA-enriched products is also included.

2-(4-Bromo-3,5-diphenyl-pyrazol-1-yl)-ethanol (BBB4) was synthetized and successfully evaluated concerning numerous biological activities, except for antimicrobial and cytotoxic effects. Due to the antimicrobial effects possessed by pyrazole nucleus, which have been widely reported, and the worldwide need for new antimicrobial agents, we thought it would be interesting to test BBB4 and to evaluate its possible antibacterial effects. Nevertheless, since it is water-insoluble, the future clinical application of BBB4 will remain utopic unless water-soluble BBB4 formulations are developed. To this end, before implementing biological evaluations, BBB4 was herein re-synthetized and characterized, and a new water-soluble BBB4-based nano-formulation was developed by its physical entrapment in a biodegradable non-cytotoxic cationic dendrimer (G4K), without recovering harmful solvents as DMSO or surfactants. The obtained BBB4 nanoparticles (BBB4-G4K NPs) showed good drug loading (DL%), satisfying encapsulation efficiency (EE%), and a biphasic quantitative release profile governed by first-order kinetics after 24 h. Additionally, BBB4-G4K was characterized by ATR-FTIR spectroscopy, NMR, SEM, dynamic light scattering analysis (DLS), and potentiometric titration experiments. While, before the nanotechnological manipulation, BBB4 was completely water-insoluble, in the form of BBB4-G4K NPs, its water-solubility resulted in being 105-fold higher than that of the pristine form, thus establishing the feasibility of its clinical application.

Macromolecular systems with well-defined sizes, shapes and high controlled architecture like dendrimers are of eminent interest in nanomedical applications such as drug delivery, gene transfection, and imaging. In this paper versatile protocols for the synthesis of polyester-based, hydrolysable, polycationic dendrimers have been setup. Fourth and fifth generation dendrimers equipped with several peripheral hydroxyl groups were prepared from 2, 2-bis(hydroxymethyl)propanoic acid. They were successfully esterified with arginine alone or mixed with lysine or O-methyltyrosine and with dipeptide arginine-glycine and seven polycationic dendrimers were finally obtained as hydrochlorides. Their structures and composition were confirmed by NMR analysis and by experimental molecular weight computed by volumetric titration and their buffer capacity was higher than fourth generation polyamidoamine (G4- PAMAM) derivatives taken as reference. The synthesized dendrimers harmonize a polycationic character and a buffer capacity which presuppose a good transfection efficiency with a degradable scaffold thus appearing as a promising team of new non-toxic vectors for biomedical applications.

Dendrimers, the emerging man made, highly branched, star-shaped macromolecules with nanometer-scale dimensions are well known for their well defined and high controlled architecture, their versatility and high functionality and are of eminent interest in nanomedical applications such as drug delivery, gene transfection, and imaging. In this paper, versatile protocols for the synthesis of polyester-based, hydrolysable, polycationic dendrimers have been setup. A fourth generation dendrimer equipped with 48 peripheral hydroxyl groups was prepared from 2,2-bis(hydroxymethyl)propanoic acid and was used for grafting BOC-amino acids or as “hypercores” on which dendrons functionalized with BOC-amino acids were attached. A library of 15 polycationic homo- and hetero-dendrimers in the form of hydrochloride was obtained. Their structures and composition were confirmed by NMR analysis and by experimental molecular weight computed by volumetric titration. Their buffer capacity and results obtained from cytotoxicity assays and tests of binding with both pDNA and siRNA were very satisfactory.

Even though immunotherapy has radically changed the search for anticancer therapies, there are still many different pathways that are open to intervention with traditional small molecules. To expand our investigation in the anticancer field, we report here a new series of compounds in which our previous pyrazole and imidazopyrazole scaffolds are linked to a differently decorated phenyl ring through an acylhydrazone linker. Preliminary tests on the library were performed at the National Cancer Institute (USA) against the full NCI 60 cell panel. The best compounds among the imidazopyrazole series were then tested by immunofluorescence staining for their inhibition of cell proliferation, apoptosis induction, and their effect on the cell cycle and on microtubules. Two compounds, in particular 4-benzyloxy-3-methoxybenzyliden imidazopyrazole-7-carbohydrazide showed good growth inhibition, with IC50 values in the low-micromolar range, and induced apoptosis. Both compounds altered the cell-cycle phases with the appearance of polyploid cells. Immunofluorescence analysis evidenced microtubules alterations; tubulin polymerization assays and docking studies suggested the tubulin system to be the possible, although not exclusive, target of the new acylhydrazone series reported here.

Natural polyphenols such as Gallic Acid (GA) form an important class of bioactive chemical entities that, having innumerable biological properties, could represent a safer alternative to common drugs against several disorders, including platelet aggregation, radical oxygen species (ROS) hyperproduction, oxidative stress (OS) and bacterial infections. Unfortunately, their clinical uses are limited by pharmacokinetics drawbacks and high sensitivity to environmental factors. In order to overcome these problems and to exploit the GA curative potentials, it has been linked to a biodegradable nanospherical dendrimer matrix, capable of protecting it, thus obtaining a GA-enriched nanosized dendrimer (GAD) endowed with a strong antioxidant capacity. GAD activity as an inhibitor of platelet aggregation and ROS accumulation and its antibacterial efficiency are evaluated here and compared to those of free GA, obtaining outcomes never achieved. Regarding platelet aggregation induced by thrombin and collagen, the GAD proved to be stronger by 7.1 and 7.3 times, respectively. Furthermore, the GAD showed a ROS inhibitory activity higher than that of GA by 8.1 (thrombin) and 6.9 (collagen) times. Concerning the antibacterial activities, evaluated on eleven multi-resistant Gram-positive strains of clinical relevance, the GAD is far more potent than GA, by exerting a growth inhibitory activity at MIC (μM) concentrations lower by factors in the range 12–50.

The immune system and the central nervous system message each other to preserving central homeostasis. Both systems undergo changes during aging that determine central age-related defects. Ellagic acid (EA) is a natural product which is beneficial in both peripheral and central diseases, including aging. We analyzed the impact of the oral administration of a new oral ellagic acid micro-dispersion (EAm), that largely increased the EA solubility, in young and old mice. Oral EAm did not modify animal weight and behavioral skills in young and old mice, but significantly recovered changes in &ldquo, ex-vivo, in vitro&rdquo, parameters in old animals. Cortical noradrenaline exocytosis decreased in aged mice. EAm administration did not modify noradrenaline overflow in young animals, but recovered it in old mice. Furthermore, GFAP staining was increased in the cortex of aged mice, while IBA-1 and CD45 immunopositivities were unchanged when compared to young ones. EAm treatment significantly reduced CD45 signal in both young and old cortical lysates, it diminished GFAP immunopositivity in young mice, but failed to affect IBA-1 expression in both young and old animals. Finally, EAm treatment significantly reduced IL1beta expression in old mice. These results suggest that EAm is beneficial to aging and represents a nutraceutical ingredient for elders.

Ellagic acid, a polyphenolic compound present in fruit and berries, has recently been the object of extensive research for its antioxidant activity, which might be useful for the prevention and treatment of cancer, cardiovascular pathologies, and neurodegenerative disorders. Its protective role justifies numerous attempts to include it in functional food preparations and in dietary supplements, and not only to limit the unpleasant collateral effects of chemotherapy. However, ellagic acid use as a chemopreventive agent has been debated because of its poor bioavailability associated with low solubility, limited permeability, first pass effect, and interindividual variability in gut microbial transformations. To overcome these drawbacks, various strategies for oral administration including solid dispersions, micro and nanoparticles, inclusion complexes, self-emulsifying systems, and polymorphs were proposed. Here, we listed an updated description of pursued micro and nanotechnological approaches focusing on the fabrication processes and the features of the obtained products, as well as on the positive results yielded by in vitro and in vivo studies in comparison to the raw material. The micro and nanosized formulations here described might be exploited for pharmaceutical delivery of this active, as well as for the production of nutritional supplements or for the enrichment of novel foods.

Ellagic acid (EA) is a bioactive natural polyphenol with antioxidant and several other beneficial properties, but unfortunately it cannot be exploited for in vivo therapeutic applications because of its poor water solubility and accordingly low bioavailability. Aiming to increase EA solubility, an EA solid microdispersion was realized by employing only water and low methoxylated pectin as a food compatible excipient by applying spray drying technology. It showed a 22% (w/w) Drug Loading (DL), a 30 times improved water solubility and remarkable radical scavenging activity. Subsequently, adopting non-PAMAM hydrophilic and amphiphilic dendrimers as nanocontainers, two EA nanodispersions were achieved (60–70 nm) with 46 and 53% (w/w) DL, water solubility 300 to 1000 times higher than that of free EA and good antioxidant capability. In both cases, toxic agents such as castor oil, Tween 80 or the extensively used but not so safe PEG400 were avoided and no previously used carriers, including β-cyclodextrins, were adopted. The prepared micro- and nanodispersions showed water solubility never obtained before and represent non-toxic EA reservoirs suitable for food and biomedical applications.

It is well-known that the health properties attributed to several fruits, herbs, seeds and their processed foods/beverages are due to an important group of natural polyphenols classified as hydrolysable tannins (HT) named ellagitannins (ETs), that encompass both one or more gallic acid (GA) units and one or more hexahydroxydiphenoic acid (HHDP) units, ester-connected with a sugar residue. In vivo, ETs are rather not absorbed and in gastrointestinal tract (GIT), they are hydrolysed providing mainly ellagic acid (EA). Due to its trivial water-solubility, first pass effect, metabolism in GIT, or irreversible binding to cellular DNA and proteins, EA has a very low bioavailability. Some authors are studying methods to increase EA water-solubility and thus to improve its bioavailability. At the same, EA metabolism to urolithins (UROs), whose concentration and activity is inter-individual and intra-individual dependent, is still under study and not completely elucidate. Numerous in vitro and in vivo studies have been carried out to define the molecular and cellular events underlying the beneficial effects that this compound and its metabolites exert in pathological conditions. The anti-inflammatory and the antioxidant properties of EA attracted the interest of researchers for its potential health benefits in humans, including anti-cancer, anti-diabetes activities and cardio-protection. Nevertheless, lately the attention paid to EA is focusing on its potential protective action towards several neurodegenerative disorders. Thus, EA is investigated as a potential “lead compound” endowed with multi-target pharmacological properties on CNS. Since the identification of the pharmacophore(s) responsible for both health benefits and collateral effects of this compound is crucial in drug discovery, this review aims to provide an all-round updated analysis of the literature concerning EA involvement in several CNS disorders, hoping that such information will be useful to researchers involved in multi-target drug design for CNS.

l-arginine is often covalently linked to vectors for gene or drug delivery as a means of increasing their transfection activity and reducing toxicity. This strategy relies on the protection of basic nitrogen atoms, for example, by employing the tert-butoxycarbonyl group. Our aim in the present work was to prepare the widely described α N, ω N, ω′ N-tris(tert-butyloxycarbonyl)-l-arginine as a single isomer in high yield and with high levels of purity for use in the esterification of dendrimers with several peripheral hydroxyl groups. Following three reported protocols which assured this goal, we observed the unexpected formation of four additional isomers. Using the first procedure, α N, ω N, ω′ N-tris(tert-butyloxycarbonyl)-l-arginine was never obtained. The second procedure delivered the desired compound as a mixture of geometric isomers (E/Z), while the third protocol led to a single isomer in high yield and purity, but with an unreported symmetrical structure. Since Boc protection is transient, this discovery would seem to be of little interest, but preliminary results from an ongoing investigation of the behavior of each of the isomers obtained in the esterification reactions of interest has shown that their reactivity depends on their structure. Although this research is ongoing, here we report a detailed description of these unexpected results, along with an NMR investigation focusing on the double-bond geometry and position which enabled confirmation of the structures.

The glycosylation of D-galactose glycopolymers to produce functionalized polymers expected to be bioactive as substrates or inhibitors of enzymes of the copper amine oxidase class (CAOs, EC 1.4.3.6), attained previously with an unpractical, but significant process requesting a large excess of glycosyl acceptor, has now been achieved with a method based on the use of peracetylated D-galactose moieties, in the presence of SnCl4 or BF3·Et2O as promoters, which employs glycosyl donors in nearly stoichiometric ratio with the desired glycosyl acceptor. After the synthesis of an appropriate model molecule acting as a guide, the new method was set up with extensive NMR investigations on the same model molecule and soluble polymeric reagents and products, performing a full rationalization of the chemical behavior of the various α and β pyranose and furanose forms of D-galactose residues. Glycosylated systems containing functionalities protected with trifluoroacetyl and acetyl groups were fully deprotected in one step through a reduction procedure with NaBH4.

Several anti-inflammatory agents based on pyrazole and imidazopyrazole scaffolds and a large library of substituted catechol PDE4D inhibitors were reported by us in the recent past. To obtain new molecules potentially able to act on different targets involved in inflammation onset we designed and synthesized a series of hybrid compounds by linking pyrazole and imidazo-pyrazole scaffolds to differently decorated catechol moieties through an acylhydrazone chain. Some compounds showed antioxidant activity, inhibiting reactive oxygen species (ROS) elevation in neutrophils, and a good inhibition of phosphodiesterases type 4D and, particularly, type 4B, the isoform most involved in inflammation. In addition, most compounds inhibited ROS production also in platelets, confirming their ability to exert an antiinflammatory response by two independent mechanism. Structure&ndash, activity relationship (SAR) analyses evidenced that both heterocyclic scaffolds (pyrazole and imidazopyrazole) and the substituted catechol moiety were determinant for the pharmacodynamic properties, even if hybrid molecules bearing to the pyrazole series were more active than the imidazopyrazole ones. In addition, the pivotal role of the catechol substituents has been analyzed. In conclusion the hybridization approach gave a new serie of multitarget antiinflammatory compounds, characterized by a strong antioxidant activity in different biological targets.

As a part of a work aimed at the synthesis of properly functionalized nanostructured glycopolymers suitable for interaction studies with copper amine oxidases, D-galactose was transformed through a six step sequence into the monomer N-(4-vinylbenzoyl)-6-amino-6-deoxy-D-galactose (1) which was converted into nanostructured crosslinked polymers (R1) by radical precipitation polymerization and into linear polymers (P1) by solution polymerization. The linear polymers were useful models for setting up glycosylation reactions to introduce N-trifluoroacetyl-4-(4-hydroxybutoxy)benzylamine residues in the presence of camphor sulfonic acid as the catalyst and to extend them to the nanostructured systems. The advancement of the glycosylation reaction was performed through the synthesis and glycosylation of N-benzoyl-6-amino-6-deoxy-D-galactose (9) as the model molecule for accurate NMR investigations. The removal of the trifluoroacetyl protecting group, unexpectedly stable, in glycosylated P1 and R1 was achieved with sodium borohydride.

Saccharidic monomers and a macromonomer were synthesized and copolymerized in the presence of divinylbenzene (DVB) as crosslinker in conditions of separation of phases to give hydrophilic nanostructured sugar-based vinyl copolymers. Appropriate model molecules such as N -benzyl- d -gluconamide for the saccharidic copolymers and 4-(4-chlorobutoxy)benzaldehyde and ( E )-4-(4-chloro-2-butenyloxy)benzaldehyde for electrophilic reagents prefiguring possible copper amine oxidase inhibitors allowed identification of conditions for useful monofunctionalizations mainly at the position 2 of the saccharidic units. The examined samples of the nanostructured copolymers from one of the monomers proved to be stable enough to tolerate the functionalization reactions without loss of morphology.

Through the synthesis and study of model systems as proper dithiane derivatives, vinyl monomers and soluble copolymeric reagents containing 2-unsubstituted 1,3-dithiane rings, we attained the key synthon 1,3-dithiane-5-methanol. Through its reaction with commercial resins, new polymeric reagents useful for supported organic synthesis and combinatorial chemistry were developed. Exploiting the reactivity of position 2 in 1,3-dithiane rings, such polymeric reagents were employed in the production of aldehydes from alkyl halides through a process entirely free from unpleasant odors.

A new series of indole-based analogues were recently identified as potential anticancer agents. The Knoevenagel-type indoles herein presented were prepared via a one-pot condensation of iminium salts with active methylene reagents and were isolated as single geometric isomers. Biological evaluation in different cell-based assays revealed an antiproliferative activity for some analogues already in the nanomolar range against leukaemia, breast and renal cancer cell lines. To explain these effects, the most promising analogues of the series were engaged in further cell-based studies. Compounds 5e, l, p and 6a, b highlighted a pro-apoptotic potential being able to induce apoptosis in HL60, K562 and MCF-7 cell lines in a dose and time-dependent manner. The ability of these compounds to arrest cell cycle at the G2/M phase inspired the immunofluorescence studies which allowed us to identify tubulin as a potential target for compounds 5l and 6b.

A new group of 5-(alkylamino)-9-isopropyl[1,2,4]triazolo[4,3- a ][1,8]naphthyridine derivatives bearing a CONHR group at the 6-position ( 1c – g ), designed to obtain new effective analgesic and/or anti-inflammatory agents, were synthesized and tested along with three new 9-alkyl-5-(4-alkyl-1-piperazinyl)- N,N -diethyl [1,2,4]triazolo[4,3- a ][1,8]naphthyridine-6-carboxamides ( 2b – d ). Besides, a new class of analogues of compounds 1 and 2 , bearing a Mannich base moiety at the 9-position ( 12a – d ), as well as the novel N,N -diethyl-5-(isobutylamino)-8-methyl-10-oxo-10 H -pyrimido[1,2- a ][1,8]naphthyridine-6-carboxamide ( 15 ) were prepared and tested. Compounds 1c – g exhibited very interesting anti-inflammatory properties in rats, whereas compounds 2b – d and 15 proved to be endowed with prevalent analgesic activity frequently associated with sedative effects in mice. On the contrary, the Mannich bases 12a – d resulted inactive. The most effective (80% inhibition of oedema) and potent (threshold dose 1.6 mg kg −1 with 31% inhibition of oedema) anti-inflammatory compound 1d did not show gastrolesive effects following 100 mg kg −1 oral administration in rats.

Et3N-mediated condensation of preformed or in situ generated indole iminium salts with active methylene reagents provides stereoselectively Knoevenagel-type indoles in moderate to good yields.

In order to obtain substrate-like inhibitors of copper amine oxidases (CAOs), a class of enzymes involved in important cellular processes as well as in crosslinking of elastin and collagen and removal of biogenic primary amines, we synthesized a set of benzylamine derivatives properly substituted at positions 2 and 6 and studied their biological activity towards some members of CAOs. With benzylamines 6, 7, 8 containing linear alkoxy groups we obtained reversible inhibitors of benzylamine oxidase (BAO), very active and selective toward diamine oxidase (DAO), lysyl oxidase (LO) and monoamine oxidase B (MAO B) characterized by a certain toxicity consequent to the crossing of the brain barrier. Poorly toxic, up to very active, reversible inhibitors of BAO, very selective toward DAO, LO and MAO B, were obtained with benzylamines 10, 11, 12 containing hydrophilic ω-hydroxyalkoxy groups. With benzylamines 13, 14, 15, containing linear alkyl groups endowed with steric, but not conjugative effects for the absence of properly positioned oxygen atoms, we synthesized moderately active inhibitors of BAO reversible and selective toward DAO, LO and MAO B. The cross examination of the entire biological data brought us to the conclusion that the bioactive synthesized compounds most likely exert their physiological role of reversible inhibitors in consequence of the formation of a plurality of hydrogen bonds or hydrophobic non-covalent interactions with proper sites in the protein. Accordingly, the reported inhibitors may be considered as a set of research tools for general biological studies and the formation of enzyme complexes useful for X-ray structure determinations aimed at the design of more sophisticated inhibitors to always better modulate the protein activity without important side effects.

The aim of this work was to make new tools available for investigating the interactions between enzymes and substrate-like inhibitors in copper amine oxidases (CAOs), a class of enzymes that controls important cellular processes, such as the crosslinking of elastin and collagen, cell proliferation and the regulation of intracellular polyamines. Starting from previous work, we synthesized the poly(N,N-dimethylacrylamide)-based resin R2 and the new TentaGel resins T3 and T4 obtained by ether bonding CAO substrate-like inhibitor moieties onto commercial TentaGel S-Br, which contains bromomethyl groups susceptible to nucleophilic substitution reactions. We used polyacrylamide gel electrophoresis (PAGE) experiments to determine the capability of the prepared resins to capture plasma amine oxidase (PAO) and diamine oxidase (DAO), members of the CAO family. The poly(N,N-dimethylacrylamide)-based resin R2 was able to block PAO and DAO, being the first insoluble polymeric material capable of capturing enzymes of the CAO family. We synthesized the poly(N,N-dimethylacrylamide)-based resin R2 and the new TentaGel resins T3 and T4 obtained via immobilization of substrate-like inhibitors of copper amine oxidases (CAOs) onto commercial TentaGel S-Br. We used polyacrylamide gel electrophoresis experiments to determine the capability of the prepared resins to capture plasma amine oxidase (PAO) and diamine oxidase (DAO), members of the CAO family. The poly(N,N-dimethylacrylamide)-based resin R2 proved to be the first insoluble polymeric material capable of capturing enzymes of the CAO family such as PAO and DAO.

A simple one-pot procedure for the stereoselective synthesis of Knoevenagel-type indoles is described. The method is based on the in situ reaction of indole iminium salts (four of them are fully characterized) with acyclic symmetrical and unsymmetrical active methylene reagents in the presence of triethylamine. In general, the overall yields are moderate to good. Some of relevant reaction parameters and steric effects affecting stereoselectivity are discussed.

Completely odourless reductions of ketones to alkanes through condensation with 1,3-propanedithiol copolymers and cleavage of the formed 1,3-dithiane units with sodium and ammonia or tributyltin hydride and AIBN, useful as a new synthetic methodology for combinatorial chemistry, is reported. Selective reductions of ketones in presence of an ester or a second ketone group are exemplified.

Sugar-based co-polymers with saccharidic units in stable cyclic form and nanometric morphologies stabilized through crosslinking, adaptable through specific functionalizations to biochemical interaction studies with copper-containing amine oxidases, were synthesized from appropriate monomers and macromonomers. The most promising nanospherical co-polymer obtained, containing β- d -glucopyranosidic units, was employed in functionalization reactions with the help of model molecules, achieving useful transformations mainly at the 6-position and to a minor extent at the 2-position of the saccharidic system.

Saccharidic monomers and a macromonomer were synthesized and copolymerized in the presence of divinylbenzene (DVB) as crosslinker in conditions of separation of phases to give hydrophilic nanostructured sugar-based vinyl copolymers. Appropriate model molecules such as N -benzyl- d -gluconamide for the saccharidic copolymers and 4-(4-chlorobutoxy)benzaldehyde and ( E )-4-(4-chloro-2-butenyloxy)benzaldehyde for electrophilic reagents prefiguring possible copper amine oxidase inhibitors allowed identification of conditions for useful monofunctionalizations mainly at the position 2 of the saccharidic units. The examined samples of the nanostructured copolymers from one of the monomers proved to be stable enough to tolerate the functionalization reactions without loss of morphology.

The synthesis of polymer-supported 2-monosubstituted 1,3-dithianes from soluble copolymers bearing 1,3-propanedithiol groups, their lithiation, reactions with electrophiles such as aldehydes, ketones, α,β-unsaturated ketones and oxiranes, and cleavage of the produced dithioketal-protected α- or β-hydroxyketones with various reagents have been studied.

A completely odourless reliable synthesis of styrenic resins containing 1,3-propanedithiol functions able to form 1,3-dithiane derivatives with carbonyl compounds and back up the chemistry of thioacetals and thioketals isreported. The degree of functionalisation of the resin can be easily determined through the composition of the copolymerising mixture and confirmed by titration. The resins show good accessibility to various reagents and are effective for solid-phase synthesis being exploitable in the field of combinatorial chemistry.