16 book of abs nmmc_10 poster_antibacterial_2

8/7/2019 16 book of ABS NMMC_10 Poster_ANTIBACTERIAL_2

1/23

POSTERS (P)

Antibacterial andAntiviral Agents

163


2/23

INVESTIGATION ON ANTIMICROBIAL EFFECT OF EXTRACTS

FROM RHUS CORIARIA L. (SUMAC)

Santagati, N.A (1), Auditore, R. (1), Nicolosi, D. (2), Maffei Facino R (3)

(1) Department of Pharmaceutical Sciences, University of Catania, V.le A.Doria 6, 95125 Catania, Italy.(2) Department of Microbiology and Gynecological Sciences, University of Catania, Via Androne 81, 95100

Catania, Italy(3) Piero Pratesi Department of Pharmaceutical Sciences, University of Milan, Via Mangiagalli, 25, 20133

Milan, [email protected]

Sumac is the common name for a genus (Rhus) that contains over 250 individual species of

flowering plants in the family Anacardiaceae. These plants are found in temperate and tropical

regions worldwide, often grow in areas of marginal agricultural capacity, and have a long historyof use by indigenous people for medicinal and other uses. The research efforts on sumac

extracts to date indicate a promising potential for this plant family to provide bioproducts with thefollowing reported desirable bioactivities: antifibrogenic, antifungal, antiinflammatory,

antimalarial, antimicrobial, antimutagenic, antioxidant, antithrombin, antitumorigenic, antiviral,

cytotoxic, hypoglycaemic, and leukopenic [1]. Extracts of Rhus coriariafruits obtained by ethanoland water exhibited a broad range of antimicrobial activity by inhibiting the growth of several

Gram positiveand Gram negativespecies [1].

Nevertheless, we presume that sumacs antimicrobial profile is still incomplete because the

majority of studies on Rhus coriariaspecies have focused only on its fruits and seed, little is

know about the biological activity of the constituents of its leaves.

Phytochemical studies on this plant showed that its leaves contained phenolic acids,

anthocyanins, hydrolysable tannins and gallic acid derivates, condensed tannins, several

flavonoids as quercetin and kaempferol glycosides. These substances have gained interest

because may reduce the risk of chronic diseases reinforcing the defences against free radical

species.

In our previous studies, we reported new information about cardioprotective activity of

hydrolysable gallotannins from Sicilian sumac (Rhus Coriaria L). leaves extracts [2] and theapplication in the treatment of chronic disease as osteoarthritis [3].

The aim of this work is to investigate antimicrobial activity of Rhus coriarialeaves contents.

Leaves of sumac were obtained from a commercial plantation in Catania (Italy), and were

extracted with various solvents to carry out a preliminary screening. The antimicrobial effect ofour extracts (methanolic, water, methanolic/water, acetone/water) was studied on the growth of

some bacterial strains. It was found to be effective against several of the test organisms with

Gram positivestrains being more sensitive than Gram negativestrains taken into account in our

study. Preliminary results shows a good activity primarily for the methanolic extract. The

complete investigation will be next reported.

References

1. SIERRA RAYNE e G. MAZZA, 2007. Biological Activities of Extracts from Sumac (Rhus spp.): A Review.Plant Foods Human Nutrition, 62, 165-175.

2. SANTAGATI N.A, et al., 2009. Antioxidant and protective effects of Sumac leaves on chondrocytes.Journal of Medicinal Plants Research, 3(11), 855-861.

3. SANTAGATI N.A, et al., 2009. Anti-Ischemic Activity and Endothelium-Dependent Vasorelaxant Effectof Hydrolisable Tannins from the Leaves of Rhus coriaria (Sumac) in Isolated Rabbit Heart and ThoracicAorta. Planta Med, 75, 1-7.

164
mailto:[email protected]:[email protected]


3/23

HOW CLOSE CAN THEORETICAL MODELS COME TO REALITY?

HINTS FROM THE HIV-1 INTEGRASE PROJECT

Barreca, M. L. (1), Iraci, N.(1), De Luca L.(2), Chimirri, A.(2)

(1) Dipartimento di Chimica e Tecnologia del Farmaco, Universit di Perugia, via del Liceo 1, 06123, Perugia,Italy

(2) Dipartimento Farmaco-Chimico, Universit di Messina, Viale Annunziata, 98168, Messina, Italy

[email protected]

The recent approval of the integrase strand transfer inhibitor (INSTI) raltegravir for first-line HIV-

1 therapy represents a major success in the history of antiretroviral research and is the result of

a drug development process which encountered exceptional difficulties.1

In fact, despite the unique role of IN in the viral replication process, structure-based design has

been prohibitively hindered for years by the lack of detailed structural information about thethree-domain protein structure and its interaction with DNA substrates, metal co-factors and

inhibitors.

Given the increasing importance of selective INSTIs for AIDS medicine and their novel

mechanism acting upon a protein/DNA complex, a model of HIV-1 integrase-Mg-DNA complex

was built and later used as a target for induced-fit docking (IFD) studies of six different INSTIs.2,3

The in silicofindings provided new insight into the possible mechanism of inhibition and binding

conformations of INSTIs, and were consistent with the available drug resistance mutation data.In February 2010, Hare et al. reported the X-ray structure of full-length foamy virus IN in complex

with its cognate 3-processed DNA substrate and two INSTIs (raltegravir and elvitegravir).4Besides the great value for HIV research, this novel structural information has allowed us to

understand strengths and weaknesses of the theoretical models, and of the molecular modeling

techniques used in our project.

In particular, the crystallographic data suggest

an induced-fit mechanism of inhibition, where

the halobenzyl groups of INSTIs fit into a pocket

created by displacement of the terminal 3

adenosine. Of note, in agreement with these

recent experimental observations, we reportedthat during the IFD run, the 3-terminal adenine

nucleotide underwent a dramatic conformational

movement in order to allow insertion of the

substituted benzyl moiety between the two viral

DNA strands.2

References

1. MARCHAND, C. et al., 2010. HIV-1 IN inhibitors: 2010 update and perspectives. Curr Top Med Chem.,9(11), 1016-37.

2. BARRECA, M.L. et al., 2009. Induced-fit docking approach provides insight into the binding mode andmechanism of action of HIV-1 integrase inhibitors. ChemMedChem, 4 (9), 1446-56.

3. This work was supported by THINC - EU FP7 project (HEALTH-F3-2008-201032)4. HARE, S. et al., 2010. Retroviral intasome assembly and inhibition of DNA strand transfer. Nature, 464

(7286), 232-36.

165

Figure 1. Raltegravir binding modes: crystallographicposition (green) and IFD solution (white)


4/23

DESIGN, SYNTHESES AND PRELIMINARY IN VITROAND INSILICOANTI-FLAVIVIRIDAEACTIVITY OF IMIDAZOQUINOLINEDERIVATIVES.

Carta, A., Briguglio, I., Piras, S., Vitale, G., Paglietti, G.

Dipartimento Farmaco Chimico Tossicologico, Universit degli Studi di Sassari, Via Muroni 23/a, 07100Sassari, Italy.

The Flaviviridae family, containing viruses with single-stranded positive-sense RNA genomes

(ssRNA+), comprises three genera and several viruses that are currently unassigned to specific

genera. The Hepacivirus genus includes the hepatitis C virus (HCV). Viruses within the

Flaviviridae family cause significant diseases in human and animal populations.

HCV is a major cause of human hepatitis, globally. The World Health Organization (WHO)

estimates that over 170 million people worldwide are presently infected with this virus. Most

infections become persistent and about 60% of cases progress towards chronic liver disease.Chronic HCV infection can lead to development of cirrhosis, hepatocellular carcinoma and liver

failure.1 Pegylated interferon in combination with ribavirin is used in the clinic for hepatitis due to

HCV. Unfortunately, this therapy has limited efficacy and is often associated with severe and

adverse events.

Recently, we reported the synthesis of the [4,7]phenantroline nucleus, and of several related

derivatives, which emerged as a new class of antiviral agents endowed with both in vitroand in

silico activity against ssRNA+ viruses.2

Molecular modeling of the interactions between [4,7]phenantrolines and the RNA-dependent

RNA polymerase (RdRp), termed NS5B in the case of the Hepaciviruses and Pestiviruses,confirmed the supposed activity against HCV NS5B of this angular N-tricyclic system. On thisground, recently we have reported the synthesis of three series of linear N-tricyclic systems,

derived from the quinoline ring. In particular, we have studied triazolo[4,5-g]q uinolines,

imidazo[4,5-g]quinolines and pyrido[2,3-g]quinoxalines.3

Between them, 4-(4-chloro-3H-imidazo[4,5-g]quinolin-2-yl)benzonitrile (1) and 4-chloro-2-(4-

nitrophenyl)-3H-imidazo[4,5-g]quinoline (4) stood out for their anti-Flaviviridaeactivities.

166


5/23

Now we report the synthesis, in vitro antiviral screening, cytotoxicity studies and molecular

modeling of the two above imidazoquinolines and their derivatives of molecular simplification,against representative Flaviviridae viruses.

Through this preliminary study the new class of RNA-dependent RNA polymerase (RdRp) of

Flaviviridae inhibitor, the linear N-tricyclic system derived by expansion of the quinoline nucleus

with imidazole, has been discovered.

References

1. Bosch, F. X., Ribes, J., Cleries, R., Diaz, M. , 2005. Epidemiology of hepatocellular carcinoma. Clin.Liver Dis., 9, 191-211.

2. Carta, A., Loriga, M., Paglietti, G., Ferrone, M., Fermeglia, M., Pricl, S., Sanna, T., Ibba, C., La Colla,P., Loddo, R., 2007. Design, synthesis and preliminary in vitro antiviral activity of 4,7-phenantrolines and4,7-phenantrolin-1-ones against a single-stranded positive sense RNA genome viruses, Bioorg. Med.Chem., 15, 1914-1927.

3. Carta, A. , Vitale, G. , Piras, S. , Sias, A. , Corona, P. , Paglietti, G. , 2008. Quinoline Tricyclic Derivatives.Design, Synthesis and Preliminary In vitro and In silico Antiviral Activity Against Flaviviridae Family ofThree New Classes of Virus-Encoded RNA-Dependent RNA Polymerase (RdRp) Inhibitors, XIXNational Meeting on Medicinal Chemistry della SCI, Verona, 14-18 Settembre, Atti, P-091, p. 179.

167


6/23

QUINOLINE DERIVATIVES. DESIGN, SYNTHESES ANDPRELIMINARY IN VITRO AND IN SILICO ANTIVIRAL ACTIVITY.

Carta, A., Briguglio, I., Corona, P., Vitale, G., Paglietti, G.

Dipartimento Farmaco Chimico Tossicologico, Universit degli Studi di Sassari, Via Muroni 23/a, 07100Sassari, Italy.

This research is inserted in a large program of design, synthesis and both in silico and in vitroscreening of new classes of non-nucleoside antiviral agents, active against viruses containingsingle-stranded, positive-sense RNA genomes (ssRNA+).Viruses are obligate intracellular parasites and borrow cellular metabolic pathways. They encodeproteins resembling cellular proteins and force their host cell to produce progeny virions. Thus, thedifference between inhibiting a viral protein or its cellular equivalent may be very small, so that

most compounds inhibiting viral replication are also toxic to the host. This is the main reason whyantiviral drugs have not been developed as rapidly as antibacterial, antifungal or antiprotozoalagents. To produce progeny, viruses require seven general steps: (a) adsorption and entry, (b)uncoating and processing, (c) transcription of early proteins, (d) viral genome replication, (e)synthesis of late proteins, (f) processing and assembly and finally (g) egress of virions from cells.This contributions have been focused on studying the antiviral activities through the inhibition ofthe polymerase enzyme (step d).Important ssRNA+ viruses are those belonging to the Picornaviridae family. These viruses causea variety of illnesses, including meningitis, cold, heart infection, conjunctivitis, and hepatitis 1. Thisfamily includes nine genera, some of which comprise major human pathogens, namely,Enterovirus (including Poliovirus, Coxsackievirus, Echovirus), Rhinovirus (approximately 105

serotypes), and Hepatovirus (Hepatitis A virus [HAV]). At present, no specific antiviral therapy isavailable for the treatment of Picornaviridae infections.Furthermore, viruses belonging to the Flaviviridae family cause clinically significant diseases inhumans and animals. This virus family includes three genera: Pestiviruses, Flaviviruses andHepaciviruses. Hepatitis C Virus (HCV) is a major cause of human hepatitis, globally.2 Mostinfections become persistent, and about 60% of cases progress toward chronic liver disease,which in turn, can lead to development of cirrhosis, hepatocellular carcinoma, and liver failure. 3,4

Further, we tested our compounds for activity against viruses representative of an additional genusof ssRNA+ genomes [Human immunodeficiency virus (HIV-1)], of double stranded RNA genomes(dsRNA) [Reovirus (Reo-1)], and of single-stranded, negative-sense RNA genomes (ssRNA-)[respiratory syncytial virus (RSV) and vesicular stomatitis virus (VSV)].

Here, we report our new pathway to the synthesis of 8-chloroquinoline-6,7-diamines and severalrelated derivatives, as well as the results of both cell-based antiviral assays and moleculardynamics simulations.

References

1. Enterovirus surveillance: MMWR Morb. Mortal Wkly Rep. 2006, 55, 153.2. Hayashi, P. H., Di Bisceglie, A. M. 2005. Med. Clin. North Am. 89, 371.3. Echevarria-Mayo, J. M., 2006. Enferm. Infecc. Microbiol. Clin. 24, 45.4. Bosch, F. X., Ribes, J., Cleries, R., Diaz, M., 2005. Clin. Liver Dis. 9, 191.

168


7/23

IDENTIFICATION OF NEW SCAFFOLDS FOR THE INHIBITION OFHIV-1 REVERSE TRANSCRIPTASE ASSOCIATED RIBONUCLEASEH FUNCTION BY MEANS OF SHAPE BASED SIMILARITY

SCREENING.

Distinto, S.(1), Esposito, F.(2), Maccioni, E.(3), Cardia, M.C.(3), Markt, P.(4), Tramontano,E.(2), Sanna, M.L.(3),

Meleddu, R.(3).

(1) Dipartimento di Scienze Farmacobiologiche, Complesso Nin Barbieri, Universit degli Studi diCatanzaro Magna Graecia, 88021, Roccelletta di Borgia (CZ), Italy.

(2) Dipartimento di Scienze Applicate ai Biosistemi, Sezione di Biochimica e Biologia Molecolare, CittadellaUniversitaria, 09042, Monserrato (CA), Italy

(3) Dipartimento Farmaco Chimico Tecnologico, Universit degli Studi di Cagliari, Via Ospedale 72, 09124,Cagliari, Italy.

(4)

Department of Pharmaceutical Chemistry, Leopold-Franzens-University of Innsbruck, Innrain 52, 6020,Innsbruck, [email protected]

The human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) is one of the most

attractive targets for the design of new antiviral drugs. It is a key role enzyme for viral replication

which has two associated catalytic functions: a DNA polymerase activity, that recognizes both

RNA and DNA as template, and a ribonuclease H (RNase H) activity, that selectively degrades

the RNA of the hybrid RNA:DNA replicative intermediate [Telesnitsky, A., et al., 1997, Hughes,S.H.; et al.,1998, Nikolenko, G. N.; et al., 2005]. Recently, a few hydrazone derivatives has been

reported to selectively inhibit the HIV-1 RNase H function [Himmel, D.M.et al., 2006].

A shape-based method, Rapid Overlay of Chemical Structures (ROCS) [ROCS OpeneyeScientific Software], was applied to perform in silico similarity screening of National Cancer

Institute database. HIV-1 RT activities were measured in biochemical assays.

The highly optimized screening platform ROCS for shape-based virtual screening led us to

identify a set of molecules which have been tested on the HIV-1 RT functions. Compounds with

different scaffolds have shown to inhibit one or both RT-associated activities. The lead structures

identified will be object of further optimization.

References

1. TELESNITSKY, A., et al., 1997. Reverse Transcriptase and the generation of retroviral DNA. In

Retroviruses, Coffin, J-M. et al. Eds., CSHL Press: Cold Spring Harbor, NY, 121-160.2. HUGHES, S.H.; et al.,1998. RNase H of retroviral reverse transcriptases. In Ribonucleases H, Crouch,

R.J; Toulm, J.J. Eds. Les Editions Inserm: Paris,195-224.3. NIKOLENKO, G. N.; et al., 2005. Mechanism for nucleoside analog-mediated abrogation of HIV-1

replication: Balance between RNase H activity and nucleotide excision. Proc. Natl. Acad. Sci. USA, 102,2093-2098.

4. HIMMEL, D.M.et al., 2006. HIV-1 Reverse Transcriptase Structure with RNase H Inhibitor DihydroxyBenzoyl Naphthyl Hydrazone Bound at a Novel Site. ACS Chem. Biol., 1, 702-710.

5. ROCS Openeye Scientific Software, Inc.

169


8/23

D-AMINO ACIDS CONTAINING TEMPORIN L ANALOGUES

Carotenuto, A. (1), Mangoni, M.L.(3), Gaddi, L.M.(1), Saviello, M.R.(1), Di Maro, S.(1), Campiglia, P.(2), Gomez-

Monterrey, I.(1)

, Auriemma, L.(1)

, Novellino, E.(1)

, Grieco, P.(1)

(1) Department of Pharmaceutical Chemistry and Toxicology, University of Napoli, Via Domenico Montesano49, I-80131 Napoli, Italy;

(2) Department of Pharmaceutical Science, University of Salerno, I-84084 Fisciano, Salerno, Italy;(3) Facolt di Medicina e Chirurgia, University of Rome La [email protected]

Temporins are antimicrobial peptides (AMPs) isolated from the skin of Red European frog Rana

temporaria. They are active particularly against Gram-positive bacteria, Candida species, fungi.

They have the ability to bind and permeate both artificial and biological membranes.We have recently investigated two members of this AMP family Temporin L and Temporin A [1,2].

At the same time, we developed new analogues of these peptides, among which Pro3TL

(FVPWFSKFLGRILNH2) exhibiting a higher antimicrobial activity and a lower hemolytic activity

than the native peptide TL. New analogues of Pro3TL, where C-terminal residues were replaced

one-by-one by D-amino acid, are now tested and analysed by NMR techniques.

References

1. CAROTENUTO, A.; et.al., 2008. A different molecular mechanism underlying antimicrobial andhemolytic actions of temporins A and L. J. Med. Chem., 51, 2354-2362.

2. SAVIELLO, M.R.; et.al., 2010. New insight into the mechanism of action of the temporin antimicrobialpeptides. Biochemistry, 49, 1477-1485.

170


9/23


10/23

SYNTHESIS AND CHARACTERIZATION OF NEW PENTAPHYRINS

AS POTENTIAL PDT DRUGS.

Fedele, R.(1)

, Rossi, G.(1)

, Goi, D.(1)

, Comuzzi, C.(1)

(1) Department of Chemical and Technological Sciences, v. del Cotonificio 108, I-33100, Udine, [email protected]

Here we present the synthesis and characterization of new porphyrogenic macrocycles intendedas photosensitizer agentsfor the Photodynamic Therapy (PDT) and disinfection applications.

PDT is a promising cancer treatment which involves the topical or systemic administration to the

tumor tissue of a photosensitizer agent, which is subsequently activated by light. The activated

photosensitizer transfers energy to molecular oxygen to generate reactive oxygen species(ROS), in particular singlet oxygen, with cell death as a result.1

As reactions involving singlet oxygen occur in the immediate environment of the photosensitizer,

the photodamage is confined to the tissue area that has been treated with light. 2 PDT is

recognized as a very effective approach for cancer treatment but it can be also applied for

disinfection purposes.3, 4

In general extensive elimination of pathogens can be achieved under very mild irradiation

conditions, such as short incubation times and low fluence rates which guarantees a high degree

of selectivity in comparison with the main constituents of host tissues. The photosensitizingagentscan also be applied for disinfection, being effective toward both wild strains and antibiotic

resistant gram-positive and gram-negative bacteria, yeasts, viruses, fungi and parasites.

As PDT has all these potentialities, efforts are directed to produce a new generation of

photosensitizers with enhanced biological properties with respect to the molecules commonly

used. In this context, we report here the synthesis and the characterization of new expanded

porphyrins, belonging to the class of pentaphyrins which posses promising photosensitizing

features.5

References

1. PERVAIZ, S., 2001. Reactive oxygen-dependent production of novel photochemotherapeutic agents.FASEB Journal, 15, 612-617.

2. MOAN, J.; BERG, K., 1991. The photodegradation of porphyrins in cells can be used to estimate thelifetime of singlet oxygen. Photochemistry and Photobiology, 53, 549-53.

3. BABILAS, P; SCHREML, S; LANDTHALER, M, et al., 2010. Photodynamic therapy in dermatology:state-of-the-art. Photodermatology Photoimmunology & Photomedicine, 26, (3), 118-132;.

4. CASTEEL, M.J., et al., 2004. Photoinactivation of Hepatitis A virus by synthetic porphyrins.Photochemistry and Photobiology, 80, 294-300.

5. COMUZZI, C. et al, 2006. Synthesis and Biological Evaluation of New Pentaphyrin Macrocycles forPhotodynamic Therapy. Journal of Medicinal Chemistry, 49, 196-204.

172


11/23

LINEZOLID HYBRID ANALOGS: SYNTHESIS AND ANTIMICROBIALSTUDIES OF OXAZOLIDINONE-MERCAPTOBENZOTHIAZOLE

COMPOUNDS.

Santoro G., Muraglia M., Carrieri A., Florio M. A., Di Mola A., Corbo F.

Universit degli Studi di Bari, Dip. Farmaco-Chimico, via E. Orabona 4, 70125 [email protected]

The current interest in the development of new antimicrobial agents can be partially ascribed

both to increasing emergence of bacterial resistance to antibiotic therapy and to newly emergingpathogens. Since the incidence of multidrug resistance among Gram positive bacterial

pathogens, in particular methicillin-resistant staphylococci, penicillin-resistant pneumococciand

vancomycin-resistant enterococciis increasing, the development of new and effective agents areurgent needs. Oxazolidinones are a totally new synthetic class of antimicrobial agentsdiscovered early as MAO inhibitors and later developed for their antibacterial activity. They

represent a quite interesting novel class of antibacterial agents and Linezolid is the only

compound to be approved by FDA for clinical use in the treatment of infections caused by above

resistant bacteria.1

With the aim to enhance potency, to expand antibacterial spectrum, to decrease the toxicity and

to improve the DMPK properties of this family of antibiotics, we planned to synthesize a seriesof new oxazolidinone derivatives in which we linked the oxazolidinone ring and the

mercaptobenzothiazole moiety, which as known, shows a good antibacterial activity against both

Gram-positive and Gram-negative strains.2,3Molecular modeling studies have been also carried out in order to define steric/electronic

properties of new molecules for a better antibacterial activity. In particular the effects of different

substituents on the benzothiazoles nucleus will give us a precise information on the role of thetwo pharmacophoric moieties on the antibacterial activity of these compounds.

X-ray structure studies carried out recently4 served as starting point for the rational design of the

plausible new lead compound and to develop a series of its derivatives.

The synthetic strategy followed, the molecular studies and biological results will be discussed.

References

1. Yu, D.; Huiyuan, G., 2002 Synthesis and antibacterial activity of linezolid analogues Bioorg. Med.Chem. Lett, 12, 857.

2. Oren, I.; Yalcin, I.; Sener, E.; Ucarturk, N., 2004 Synthesis and structureactivity relationships of newantimicrobial active multisubstituted benzazole derivatives Eur. J. Med. Chem., 39, 291

3. Franchini C., Muraglia M., Corbo F., Florio M. A., Di Mola A., Rosato A., Matucci R., Nesi M., VanBambeke F., Vitali C. 2009 Synthesis and Biological Evaluation of 2-Mercapto-1,3-benzothiazoleDerivatives with Potential Antimicrobial Activity Arch.Pharm.Chem., 342, 605-613.

4. Ippolito, J.A.; Kanyo, Z.F.; Wang, D.; Franceschi, F.J.; Moore, P.B.; Steitz, T.A.; Duffy, E.M., 2008Crystal Structure of the Oxazolidinone Antibiotic Linezolid Bound to the 50S Ribosomal Subunit J.Med. Chem., 51, 3353.

173


12/23

NEW 4-DIAZOPYRAZOLE DERIVATIVES AS POTENTIAL

ANTIBIOFILM AGENTS

Raimondi M.V.(1), Maggio, B.(1), Raffa, D.(1), Plescia, F.(1), Schillaci, D.(1), Plescia, S.(1), Daidone, G.(1)

(1) Dipartimento di Chimica e Tecnologie Farmaceutiche, Via Archirafi, 32, 90123-Palermo, [email protected]

Many infections such as otitis media, sinusitis, cholesteatoma, tonsillitis and adenoiditis are

caused by biofilm forming mucosal pathogens (P. aeruginosa, S. aureus, S. peneomoniae, H.

influenzae and M. catarrhalis). Moreover, the role of biofilms in the chronic otolaryngologic

infections has been recognized for otitis media, tonsillitis and rhinosinusitis [1]. Finally, bacterial

biofilms of S. aureus, S. epidermis and E. faecalisare the leading cause of medical device-

related infections [2]. Pathogens growing as biofilms are intrinsically resistant to conventional

antibiotics and therefore the discovery of new compounds able to act against biofilm aggregated

micro organisms is an urgent task.Previously, we reported the study on the antibiofilm activity of 4-diazopyrazole derivatives of type

1 against S. aureusATCC 29213, methycillin-resistant S. aureusATCC 43866 and methycillin-

resistant S. epidermis RP626 preformed biofilms [3]. The compounds were active at the

maximum tested concentration of 25 g/ml.

Fig. 1: Chemical structures of 4-diazopyrazole derivatives. Compounds 1a-c, R: 1a = 4-Cl; 1b = 2,4-Cl2; 1c = 4-NO

2; 2a-i,

R: 2a = 4-NO2; 2b = 4-Cl; 2c = 3,4-Cl

2; 2d = 4-OBut; 2e = OBenz; 2f = 2,4-Cl

2; 2g = H; 2h = 4-OCH

3; 2i = 4-OPh.

On the basis of these results, we have prepared a new series of 4-diazopyrazole derivatives 2a-i and 3 which take the phenylureido or phenylacetamido moiety at 5-position of the pyrazole

nucleus. The compounds has been tested preliminarly against planktonic (single cells) strains ofS. aureus (ATCC 25923), S. aureus (ATCC 29213), E. coli (ATCC 25922) and P. aeruginosa(ATCC 9027), showing MICs values in the range 50-0.097 g/ml. Experimental work aimed to

verify the effect of the above compounds on the corresponding microbial biofilms are in progress.

References

1. POST, J.C., HILLER, N.L., NISTICO, L., STOODLEY, P., EHRLICH, G.D., 2007. Curr Opin OtolaryngolHead Neck Surgery, 15, 347-351.

2. DONELLI, G., FRANCOLINI, I., ROMOLI, D., GUAGLIANONE, E., PIOZZI, A., RAGUNATH, C.,

KAPLAN, J.B., 2007. Antimicrobial Agents Chemotherapy, 51, 2733-2740.3. SCHILLACI, D., MAGGIO, B., RAFFA, D., DAIDONE, G., CASCIOFERRO, S., CUSIMANO M.G.,

RAIMONDI, M.V., 2008. Chemotherapy, 54, 456-462.

174


13/23

BIOACTIVE FUROCOUMARIN DERIVATIVES INHIBITING IL-8EXPRESSION IN CYSTIC FIBROSIS CELLS AND IDENTIFIED BY AVIRTUAL SCREENING AGAINST NUCLEAR FACTOR KB (NF- B)

OF A FOCUS COMPOUND LIBRARY

Laura Piccaglia, Monica Borgattia, Elena Nicolisb, Nicoletta Bianchia, Irene Mancinia, Daniela Vedaldic,Francesco DallAcquac, Giulio Cabrinia and Roberto Gambaria

a BioPharmaNet, Department of Biochemistry and Molecular Biology Interdisciplinary Center for theStudy of Inflammation,

b Laboratory of Molecular Pathology, Laboratory of Clinical Chemistry and Haematology, University-Hospital, Verona

c Department of Pharmaceutical Science, University of Padova, Italy.

A structured-based Virtual Screening (VS) of differently substituted furocoumarins andanalogues has been carried out against NF- B in order to select molecules for their ability to

inhibit the binding of this transcription factor with the DNA and, possibly, to exhibit anti

inflammatory effects on cystic fibrosis (CF) cells. The focus library was developed starting from

known chemical structures from literature as well as retrieving compounds from suitable

commercial databases on the network. The first step of the present study was the construction

of a customized small molecules database. The prepared library of 1710 compounds contained

54 structures of angelicin derivatives (molecular weight range: 186-478), 1384 of psolaren

derivatives (molecular weight range: 186-619), 51 of Furo(3,2-c) chromen-4one structures(molecular weight range: 268-439) and 166 of benzoquinolizin-5-one analogues (molecular

weight range: 258-499). Molecular docking approach was followed against NF- B in both p50aggregation states using Glide software. The docking studies were carried out by using the extra

precision (XP) method on a subset of 1000 molecules selected by preceding Standard Precision(SP) procedure as implemented in Glide software. The selection of interesting docked

compounds was based on the docking GlideScore (G-Score) values in each target. All the best

ranked ligand poses were localized in the DNA binding surface of the N-terminal domains.

Among the ten highest-scored ligands selected from docking studies, five different molecules

were commercially available and investigated in further experimental analysis. Four

furocoumarin derivatives showed IC50

values in the range of 40-100 M in electrophoreticmobility shift assay (EMSA). Three compounds significantly inhibited NF- B dependent

biological functions in cystic fibrosis IB3-1 cells infected with Pseudomonas aeruginosa(expression of IL-8). These findings on one hand validated the virtual screening approach here

presented and reinforce the successful results of our previously computational studies to adifficult target as NF- B. On the other hand, the discovered four novel compounds could be of

relevance to identify more potent inhibitors of NF- B dependent biological functions which could

be beneficial to control lung inflammation of CF patients.

175


14/23

DISCOVERY OF NEW HCV NS5B POLYMERASE INHIBITORS:

EFFORTS AND OUTCOMES

Manfroni, G.(1)

, Barreca, M. L.(1)

, Gosetto, F.(1)

, Leyssen, P.(2)

, Maga, G.(3)

, Neyts, J.(2)

, Tabarrini, O.(1)

,Cecchetti, V. (1)

(1) Dipartimento di Chimica e Tecnologia del Farmaco, University of Perugia, via del Liceo, 1, 06123,Perugia, Italy.

(2) Rega Institute for Medical Research, Katholieke Universiteit Leuven, B-3000 Leuven, Belgium.(3) Istituto di Genetica Molecolare, IGM-CNR, Via Abbiategrasso, 207, 27100, Pavia, [email protected]

World-wide more than 170 million people are chronically infected with the hepatitis C virus (HCV) and thus

at high risk of developing liver cirrhosis and hepatocellular carcinoma. Infection with HCV is the single most

important reason for liver transplantation in industrialized countries.1 The current standard of care for HCV

infection is a combination of pegylated interferon and ribavirin. This therapy is associated with severe sideeffects and a poor response rate, in particular in patients infected with genotype 1, the most prevalent

genotype in Western countries.2 Therefore, there is an urgent need for improved strategies that lead to a

complete cure of all HCV-infected patients. Most of the approaches entails the development of small

molecules directly acting against HCV target protein also named specifically targeted anti-viral therapy for

hepatitis C (STAT-C) compounds.3 Despite in the past fifteen years there have been significant advances

in our understanding of the HCV replication and the role of viral non-structural proteins (e.g. NS3/4A

protease and NS5B polymerase), no directly acting HCV drugs have been approved yet. Thus, there is still

an imperative to find new anti-HCV hits that can be optimized to drug candidates.Recently, we have started a research program aimed at identifying new chemotypes of NS5B polymerase

inhibitors.4 The NS5B polymerase is one of the key enzymes of the viral replication and has become a

leading target for drug discovery strategies. Here we report the results of our research efforts which leadto the identification of new anti-NS5B hits by using different medicinal chemistry approaches (depicted in

Figure 1). In particular, compounds belonging to unrelated chemical families exhibited anti-NS5B activity in

the micromolar range. The most potent molecules were also characterized in their kinetic mechanism

revealing an allosteric mode of polymerase inhibition. All the compounds were also evaluated for the

antiviral activity by using a cell-based HCV replicon system assay.

References1. SCHINAZI, R.F., et al., 2009. HCV drug discovery aimed at viral eradication. Journal of Viral Hepatitis,

17, 77-90.2. NEUKAM, K., et al., 2009. A Review of Current anti-HCV Treatment Regimens and Possible Future

Strategies. Expert Opinion on Pharmacology, 10, 417-433.3. DELANG, L., et al., 2010. Antiviral Therapy for Hepatitis C Virus: Beyond the Standard of Care. Viruses,

2, 826-866.4. This work is sponsored in part by Fondazione Cassa di Risparmio di Perugia (C.P. 2009.010.00413).

176


15/23

DESIGN OF NEW INHIBITORS OF THE HIV-1 REVERSETRANSCRIPTASE ASSOCIATED RIBONUCLEASE H FUNCTION: A

SYNTHETIC APPROACH.

Meleddu, R.(1), Sanna, M.L.(1), Distinto, S.(3), Esposito, F.(2), Corona, A. (2), Ortuso, F. (3), Alcaro, S.(3), Maccioni,E.(1), Cardia, M.C.(1), Tramontano

,E.(2).

(1) Dipartimento Farmaco Chimico Tecnologico, Universit degli Studi di Cagliari, Via Ospedale 72, 09124,Cagliari, Italy.

(2) Dipartimento di Scienze Applicate ai Biosistemi, Sezione di Biochimica e Biologia Molecolare, Universitdegli Studi di Cagliari, Cittadella Universitaria, 09042, Monserrato (CA), Italy.

(3) Dipartimento di Scienze Farmacobiologiche, Complesso Nin Barbieri, Universit degli Studi diCatanzaro Magna Graecia, 88021, Roccelletta di Borgia (CZ), Italy.

[email protected]

The human immunodeficiency virus (HIV) is the etiological agent of the acquiredimmunodeficiency syndrome (AIDS) in humans, establishing a persistent infection in the humanhosts. Beside the current availability of 26 drugs for HIV-1 infection treatment, that dramaticallyreduced the AIDS mortality rate in the western world [UNAIDS, http://www.unaids.org/en/], safetyand efficacy problems are still to be solved. In fact, current drug long term toxicity and the easyof selection of drug-resistant HIV strains, particularly in non-adherent to therapy patients, lead totreatment failure. Furthermore, the emergence and transmission of drug-resistant variants arebecoming a public-health concern. It is therefore essential that new antiretroviral agents becomeavailable [Green W.C., et al., 2008., Adamson, C.S., et al., 2010].In particular the exploration of new targets is becoming essential. Despite the fact that many

therapeutic agents are available for the inhibition of the virus Reverse Trascriptase (RT), only afew are active towards the RT associated Ribonuclease H function (RNase H) and have beenonly recently identified. However, the RT-associated RNase H function was proven as anessential step in the virus life cycle [Tramontano, E., 2006, Telesnitsky, A., et al., 1997, Hughes,S.H.; et al.,1998.]. Thus, efforts in the development of new compounds targeting the RNase Hactivity are relevant to enhance the antiretroviral armamentarium and constitute an attractivechallenge for the medicinal chemists.Within these few inhibitors, some have been identified by our teams of the University of Cagliariand Catanzaro and are currently under further development. In particular, we have alreadyperformed an in silicosimilarity screening, and we have now synthesised some new and efficientinhibitors for this specific target.

In this poster we will report on the synthesis and the biological activity of some newly designedscaffolds which exhibit interesting biological properties towards the RT associated RNase Hfunction.

References

1. UNAIDS: Joint United Nations Programme on HIV/AIDS http://www.unaids.org/en/2. GREEN W.C., et al., 2008. Novel targets for HIV therapy, Antiviral Research, 80, 251-265.3. ADAMSON, C.S., et al., 2010. Novel approaches to inhibiting HIV-1 replication, Antiviral Research. 85,

119-141.4. TRAMONTANO, E., 2006. HIV-1 RNase H: recent progress in an exciting, yet little explored, drug target,

Mini-Rev. Med. Chem. 6, 727-737.

5. TELESNITSKY, A., et al., 1997. Reverse Transcriptase and the generation of retroviral DNA. InRetroviruses, Coffin, J-M. et al. Eds., CSHL Press: Cold Spring Harbor, NY, 121-160.

6. HUGHES, S.H.; et al.,1998. RNase H of retroviral reverse transcriptases. In Ribonucleases H, Crouch,R.J; Toulm, J.J. Eds. Les Editions Inserm: Paris,195-224.

177
mailto:[email protected]://www/http://www/http://www/http://www/mailto:[email protected]


16/23

PLASMEPSIN V, A NEW PROMISING TARGET FOR

ANTIMALARIAL DRUG DISCOVERY

Romeo, S.(1), Rizzi, L.(1), Gambini, L.(1), Carucci, M.(2), Crisanti, A.(2), Russo, I.(2)

1 Department of Medicinal Chemistry and Pharmaceutical Sciences P. Pratesi, University of Milan, Via L.Mangiagalli 25, 20133, Milan, Italy

2 Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Via delGiochetto, 06122, Perugia, Italy

[email protected]

Malaria is one of the most serious infectious diseases in the world, affecting close to 300 million

individuals each year. It has been estimated that approximately 40% of the world population lives

in regions where malaria is endemic. Each year between 1 and 1.5 million people, mainly

children, die from malaria, a number that is continuously increasing due to the proliferation ofparasites that are resistant to conventional drug therapies. The rapid spread of drug resistant

parasites clearly underscores the need for new therapies and consequently the identification of

novel targets for drug development. PlasmepsinV (PMV) is a unique Plasmodiumproteolytic

enzyme. Such aspartic protease, known for about a decade, remained for long a mystery

regarding its function and cellular role. During this time a Plasmodiumspecific export systemwas unveiled and described: the PEXEL-dependent export multi-components machinery. This

machinery is indispensable to take control of the host cells. Remodelling of the cytoskeleton and

plasma membranes, new nutrient permeation pathways, cytoadherence, antigenic variation,

maintenance of the erythrocyte mechanical stability are some of the key virulence functions

depending on Plasmodiumprotein export. Proteins destined for export are synthesized in theendoplasmic reticulum and cleaved at the PEXEL motif. We demonstrated1 that PMV is the key

enzyme, missing in the multi-component machinery that cleaves the PEXEL motif. Such

processing, specific for Plasmodiumand few other pathogens, is completely unknown to the

host. PMV is highly conserved in all Plasmodiumstrains, including P. vivax, and in none of them

redundancy of PMV gene or function was detected. Our data indicate PMV essentiality by

multiple approaches and determinants of its endoplasmic location. In addition, we show

evidence of importance of PMV function in transmission forms as well as in pre-erythrocyticstages. Therefore, we propose PMV as an ideal target for drug discovery. Our approaches

aiming to maximize the chances of discovery of inhibitors are based on tests of rationally

designed libraries. We generated a panel of inhibitors that mimics the actual substrate includingan un-cleavable bond. We identified compounds with highly promising EC50 (


17/23

ONE- AND TWO- DIMENSIONAL NMR TECHNIQUES FOR THEDISCOVERY OF MARKERS OF FLORAL ORIGIN AND OF

BIOACTIVE COMPOUNDS IN HONEY

Santagati N. A. (1),Beretta G.(2), Maffei Facino R.(2)

(1) Department of Pharmaceutical Sciences, Faculty of Pharmacy, University of Catania, V.le A.Doria 6,95125 Catania, Italy.

(2) Department of Pharmaceutical Sciences Pietro Pratesi, Faculty of Pharmacy, University of Milan, ViaMangiagalli 25, 20133 Milan, Italy

[email protected]

There is growing interest in the therapeutic properties of honey which, though once considereda folk remedy, is gaining credit in dermatology for the treatment of wounds, burns, ulcers and

other topical infections resistant to conventional drugs and in other medical fields for theprevention of life-threatening pathologies such as diabetes, cardiovascular disease and cancer.

However, if honey is to earn a serious routine clinical status analytical characterization is

needed, to inform the physician about the efficacy of its active constituent(s). From a nutritionalpoint of view too, the consumer needs a guarantee about the botanical origin and quality of

honey, since this greatly influences buyers preferences. For this reason the European Council

Directive 2001/L10 states the need for methods for the verification of honeys botanical origin.

In this context, we have developed a simple and rapid procedure based on the isolation of semi-

polar and non-polar compounds contained in honey by reverse phase solid-phase extraction(SPE), followed by 1H nuclear magnetic resonance (NMR) or two-dimensional NMR analyses

(COSY, HMQC, HMBC and DOSY NMR) of the SPE extracts. Among the honey varietiesanalyzed, we have been able to unambiguously characterize reliable markers of origin for

chestnut honey: kynurenic acid (KA), a tryptophan metabolite that acts as antagonist at the a-7

nicotinic receptor and at the glycine binding site of the NMDA receptor, and its 3-(2-pyrrolidinyl)

derivative) (3-PKA), the first member of a new class of alkaloid compounds. KA and 3-PKA has

been identified in chestnut honeys from Italy, France, Poland, Slovenia, Croatia, Montenegro,Macedonia and Kosovo. The methodology has been applied to the determination of the micro-

composition of tropical honeys from Cameroon (Africa) and Amazonia (South America), varieties

which have never been investigated before.

Figure 1. Chemical structure of KA and 3-PKA identified in chestnut honey

179


18/23

DISCOVERY OF A NOVEL HCV HELICASE INHIBITORS BY A DE

NOVO DESIGN APPROACH

Coluccia, A.(1,3), Leyssen, P.(2), Neyts, J.(2), Kandil S.(1), Brancale A.(1), Silvestri R. (3)

(1) Welsh School of Pharmacy, Cardiff University, King Edward VII Avenue, Cardiff CF10 3NB, U.K.;(2) Rega Institute for Medical Research, Katholieke Universiteit Leuven, B-3000 Leuven, Belgium.(3) Istituto Pasteur - Fondazione Cenci Bolognetti, Dipartimento di Chimica e Tecnologie del Farmaco,

Sapienza Universit di Roma, Piazzale Aldo Moro 5, I-00185 Roma, [email protected]

Hepatitis C virus (HCV) infection is the second most common chronic viral infection in the world

with global prevalence. An estimated 180 million people are chronically infected with HCV.

Neither prophylactic nor therapeutic vaccine is available against HCV, and current standard

therapy is effective only in about 60% of the patients and is associated with severe side-effects.1,2

Herein we report a successful application of a computer-aided design approach to identify anovel HCV helicase inhibitor. De novo drug design methodology was used to generate an initial

set of structures that could potentially bind to a putative binding site. Reported inhibitors target

either NTP site or RNA binding site. Allosteric sites might also be present, but it is difficult to

identify them on crystal structures. Examining of helicase structure bound to ssDNA strand, we

noticed that Cys 431 reacted with a crystallisation reagent. It suggested that such a residue

exposed to the solvent is reactive enough to be targeted by a small molecule. Cys 431 is

conveniently placed in proximity of Arg393, a key residue involved in the RNA binding.3

I n i t i a l l y, we used LigBuilder de novo

software package to identify possible

ligands to the proposed site. We then

simplified the structure, taking into accountthe synthetic feasibility and our intuition, by

modifying the fragment library of LigBuilder.

Further structure refinement was carried out

through docking/dynamics approaches. The

most promising compound (Figure 1) was

synthesised and it exhibited a

submicromolar inhibition of the HCVhelicase.4

Figure 1. Binding mode of the most active compound in the HCVhelicase allosteric binding site. Arg 393, Arg 481 and Cys 431 are

reported in stick, H-bonds are showed as purple lines.

References

1. BRASS, V., et al., 2006. Molecular Virology of Hepatitis C Virus (HCV): 2006 Update Int. J. Med. Sci.3, 29.

2. WEBSTER, D. P., et al., 2009. Development of novel treatments for hepatitis C Lancet Infect. Dis. 9,108.

3. LAM, A., et al., 2003. Two novel conserved motifs in the hepatitis C virus NS3 protein critical for helicaseaction J. Biol. Chem. 278, 44514.4. KANDIL, S., et al. 2009. Discovery of a novel HCV helicase inhibitor by a de novo drug design approach

Bioorg Med Chem Lett. 19, 2935-2937.

180


19/23

SYNTHESIS AND BIOLOGICAL EVALUATION OF NOVELPEPTIDYL-ANTHRAQUINONES TARGETED AT VIRAL NUCLEIC

ACID SEQUENCES

Alice Sosic1, Laura Bottega1, Manlio Palumbo1, Barbara Gatto1, Francesco Frecentese2, Giuseppe Caliendo2

and Vincenzo Santagada2

1 Dipartimento di Scienze Farmaceutiche, Universit di Padova, Via Marzolo, 5, 35131 Padova, Italy2 Dipartimento di Chimica Farmaceutica e Tossicologica, Universit degli Studi di Napoli Federico II, Via

D. Montesano, 49, 80131, Napoli, [email protected]

HIV-1 reverse transcription consists of a complex series of events culminating in the synthesis

of a linear double stranded DNA copy of the viral RNA genome. Several nucleic acid sequences

and structures play fundamental roles in these early steps: reverse transcriptase (RT) uses acellular tRNA bound to the primer binding site (PBS) of viral RNA to synthesize a short stretch of

complementary DNA which is then transferred and annealed to the R regions of template RNAfor retrotranscription. The R regions contain the highly structured TAR RNA and its

complementary DNA sequence (cTAR): their stability decreases the efficiency of strand transfer

steps and eventually the completion of reverse transcription. In these multistep processes, RT

uses as cofactor NC, a viral small basic nucleic-acid binding protein with multiple roles during

virus replication, largely mediated by its chaperone activity in destabilizing highly structured

nucleic acids.

The polypurine tract (PPT) of HIV is a short purine-rich run of the viral RNA genome initially

resistant to the RNase H activity of RT. PPT is used to prime the viral DNA strand which is thenelongated by RT through the U3, R, U5 and PBS. Intercalation of planar molecules into the PPTRNA/DNA hybrid has been proposed as a possible yet under-represented mode of inhibition ofRNase H of RT: PPT selective intercalators could render the RNA-DNA hybrid substrate

unavailable for enzyme binding, or could alter its overall structure, making RNase processing

ineffective.

Our aim is to develop new therapeutic tools targeted to viral nucleic acids (RNA, DNA or

RNA/ DNA hybrid) representing substrates for the various activities of RT. We recently

determined the affinity of a library of different anthraquinones toward TAR RNA, cTAR and the

TAR/cTAR hybrid. The selectivity demonstrated by 2,6-disubstituted-anthraquinone leads toward

TAR-RNA and cTAR vs. TAR/cTAR duplex or non specific DNA prompted us to better refine and

extend our analysis. To this goal, we designed a novel set of peptidyl-anthraquinones (PA) based

on our original lead. Here we report the synthesis and the biological evaluation of the novel

series of compounds, focusing on the ability of selected derivatives to interfere with the steps

involving the viral nucleic acids implicated in the early events of HIV replication.

181


20/23

FROM THE POTENT ANTI-HIV TRANSCRIPTION INHIBITORHM13N TO AN ENLARGED SERIES OF NAPHTHYRIDONE

ANALOGUES

Massari, S.(1), Sancineto, L.(1), Manfroni, G.(1), Daelemans, D.(2), Pannecouque, C.(2), Tabarrini, O.(1),Cecchetti, V.(1)

(1) Dipartimento di Chimica e Tecnologia del Farmaco, Universita di Perugia, Via del Liceo, 1 06123 Perugia(Italy).

(2) Rega Institute for Medical Research, Katholieke Universiteit Leuven, B-3000 Leuven (Belgium)[email protected]

The emergence of multidrug-resistant human immunodeficiency virus 1 (HIV-1) strains and theinability of the highly active antiretroviral therapy (HAART) to eradicate HIV-1 virus from infected

patients, demand new drugs capable of interfering with an alternative step of the replicativecycle.The 7-[4-(1,3-benzothiazol-2-yl)piperazin-1-yl]-1-methyl-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylic acid (HM13N), recently identified by us [1], is a very promising anti-HIV compounddue to its ability to inhibit the HIV-1 Tat-mediated transcription, one of the crucial steps in the HIVreplication cycle that, to date, has not been clinically exploited. HM13N displayed a potent anti-HIV-1 and anti-HIV-2 activity on acutely infected MT-4 cells which, coupled with low cytotoxicity,resulted in very high SI values. Potent antiviral activity was also achieved on latently HIV-1infected OM-10.1 and U1 cells under both TNF-a and PMA stimulation conditions, with SI valuesover 1333 on U1 cells. The absence of any tendency to select for resistance mutations in vitro,increases the potential clinical value of this type of compound.

Thus, starting from this valid lead compound, various structure modifications have beenundertaken. To clarify the role of the 8-nitrogen atomin the anti-HIV activity, it was moved to other positionson the pyridine ring synthesizing 1,5- 1,6- and 1,7-naphthyridone derivatives. New scaffolds wereobtained by replacing the pyridine ring of the 1,8-naphthyridone nucleus with bioisosteric heterocyclicrings. In addition, 1,8-naphthyridone analogues wereconstructed on the basis of the recent structure-activity relationship indications acquired for the largeseries of anti-HIV quinolones [2]. In particular, the N-1methyl group was replaced by various smallsubstituents with different electronic properties.

The design, synthesis, and anti-HIV- 1 /H I V-2 activity on various cell lines of the newnaphthyridone analogues, will be the subject of this presentation.

References

1. MASSARI, S., DAELEMANS, D., BARRECA, M.L., KNEZEVICH, A., SABATINI, S., CECCHETTI, V.,MARCELLO, A., PANNECOUQUE, C., TABARRINI, O., 2010. A 1,8-naphthyridone derivative targets

the HIV-1 Tat-mediated transcription and potently inhibits the HIV-1 replication. Journal of MedicinalChemistry, 53 (2), 641-648.

2. TABARRINI, O., MASSARI, S., CECCHETTI, V., 2010. 6-Desfluoroquinolones as HIV-1 Tat-mediatedtranscription inhibitors. Future Medicinal Chemistry, 2 (7), in press.

182


21/23

DESIGNED MULTIPLE LIGANDS (DMLS) AS INNOVATIVE ANTI-HIV

AGENTS

Sancineto, L.(1)

, Massari S.(1)

, Iraci, N.(1)

, Sabatini, S.(1)

, Daelemans, D.(2)

, Pannecouque, C.(2)

, Cecchetti, V.(1), Tabarrini, O. (1)

(1) Dipartimento di Chimica e Tecnologia del Farmaco, Universita di Perugia, Via del Liceo,1 06123 Perugia(Italy).

(2) Rega Institute for Medical Research, Katholieke Universiteit Leuven, B-3000 Leuven (Belgium)[email protected]

Improved knowledge about molecular mechanisms of disease has been the main influence in

drug discovery, that has been largely based on one molecule- one target- one disease.However, there is a growing awareness that, agents capable of modulating multiple targetssimultaneously, can be beneficial for treating a wide range of diseases such as Acquired Immune

Deficiency Syndrome (AIDS) [1]. Such inhibitors known as Designed Multiple Ligands (DMLs)

are single chemical entities that engage multiple biological targets [2].A very useful approach for generating the chemical aspect with which to begin a DML project, is

the so-called knowledge based, that relies on the methodical combination of pharmacophores

from selective ligands into a single molecule in order to design in both activities.

As a part of our program devoted to the identification of new anti-HIV agents capable of reducing

the development of drug resistance, we have designed innovative DMLs.The potent anti-HIV 6-

desfluoroquinolones (6-DFQs) developed by our research group [3], which act as Tat-mediated

transcription inhibitors (TMTIs), have been exploited as the starting molecules. In particular,

some selected quinolones have been merged with known inhibitors of other steps of the HIV

replicative cycle such as Integrase Inhibitors (INIs) and Non Nucleoside Reverse TranscriptaseInhibitors (NNRTIs).

The design, synthesis and anti-HIV activity of some Designed Multiple Ligands (TMTIs)/(INI)

and TMTIs/(NNRTIs), together with a preliminary study of their mechanism of action, will be

presented.

References

1. ZHAN, P., LIU, X., 2009. Design Multiple Ligands: an emerging anti-HIV drug discovery. Current

Pharmaceutical Design, 15 (16), 1893-1917.2. MORPHY, R., RANKOVIC, Z., 2009. Designing multiple ligands- medicinal chemistry strategies andChallenges. Current Pharmaceutical Design, 15 (6), 587-600.

3. TABARRINI, O., MASSARI, S., CECCHETTI, V., 2010. 6-Desfluoroquinolones as HIV-1 Tat-mediatedtranscription inhibitors. Future Medicinal Chemistry, 2 (7), in press.

183


22/23


23/23

MODELING SPECTROSCOPIC STUDIES AND BIOLOGY OFSYNTHETIC DIAZABICYCLO ANALOGUES OF THE HIV-1

INHIBITOR BMS-378806

Villa, S.*(1), Gelain, A(1), Cocchi, E.(1), Legnani L.(2), Toma, L.(2), Lopalco, L.(3),Pastori, C.(3), Colombo, D.(4).

(1) Dipartimento di Scienze Farmaceutiche P. Pratesi, Universita` di Milano, Via Mangiagalli 25, 20133Milano (Italy)

(2) Dipartimento di Chimica Organica, Universit di Pavia, Via Taramelli 10, 27100 Pavia (Italy)(3) Immunobiology of HIV Unit Division of Immunology, Transplantation and Infectious Diseases San

Raffaele Scientific Institute, Via Stamira Dancona 20, 20127 Milano,( Italy)(4) Dipartimento di Chimica, Biochimica e Biotecnologie per la Medicina, Universit di Milano, Via Saldini

50,20133 Milano (Italy)[email protected]

The AIDS disease is caused by the Human Immunodeficiency Virus (HIV), a retrovirus with RNAgenome.[1] The UNAIDS Report 2009 estimated that 33.4 million people worldwide were living withHIV at the end of 2008. Since the AIDS pandemic remains one of the leading global public healththreats, the discovery and development of new antiretroviral drugs with reduced toxicity, enhancedpotency, different mechanisms of action, and reduced prevalence of adverse drug-drug interactionsremain a very high priority. In particular, a promising area of investigation is the identification of agentsthat inhibit viral attachment and entry into host cells in order to block HIV infection at the early stages.The azaindole derivative BMS-378806 1, discovered at Bristol-Myers Squibb,[3] has been shown tointerfere with the HIV-1 entry process, inhibiting the interaction between the viral gp120 envelopeglycoprotein and its cellular CD4 receptors.[4,5] In this context we have synthesized analogs of

compound 1 introducing different changes in the chemical structure instead of the methyl-piperazinegroup. The new compounds of general formula 2 were synthesized and their biological activityevaluated. Finally, in an attempt to correlate the geometrical features of these compounds to theirHIV-1 inhibitory activity, a modeling study was carried out to ascertain their conformationalpreferences. The chemistry, the computational and NMR studies, and biological data will bediscussed in the poster.

12

References

1. GALLO, R.C., et al., 2003. The discovery of HIV as the cause of AIDS. The New England Journal of Medicine,349, 2283-2285.

2. BRIZ, V., et al., 2006. HIV entry inhibitors: mechanisms of action and resistance pathways. Journal ofAntimicrobial Chemotherapy, 57, 619627.

3. WANG, T., et al., 2003. Discovery of 4-benzoyl-1-[(4-methoxy-1H-pyrrolo [2, 3-b] pyridin-3-yl) oxoacetyl]-2-(R)-methylpiperazine (BMS-378806): a novel HIV-1 attachment inhibitor that interferes with CD4-gp120interactions. Journal of Medicinal. Chemistry, 46, 42364239.

4. VEAZEY R. S., et al., 2005. Protection of macaques from vaginal SHIV challenge by vaginally delivered

inhibitors of virus cell-fusion. Nature, 438, 99102.5. VILLA, S., et al., 2009. An exhaustive conformational evaluation of the HIV-1 inhibitor BMS-378806 throughtheoretical calculations and nuclear magnetic resonance spectroscopy. European journal of organicchemistry, 19, 31783183.

16 book of abs nmmc_10 poster_antibacterial_2

Documents