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Volume 7, Issue 1 (Suppl) J Biotechnol Biomater
ISSN: 2155-952X JBTBM, an open access journal
March 20-21, 2017 Rome, Italy
&
15th World Congress on
2nd International Conference on
Biotechnology And Biotech Industries Meet
Enzymology and Molecular Biology
Enzymology & Mol. Biology 2017
Biotechnology Congress 2017
March 20-21, 2017
Inhibition of the RNA-dependent RNA polymerasic activity of Flavivirus NS5 by heterocyclic compounds
Giuseppe Manfroni1, Rolando Cannalire 1, Eloise Mastrangelo2, Gilles Querat3 and Violetta Cecchetti 1
1Università degli Studi di Perugia, Italy
2Consiglio Nazionale delle Ricerche, Italy
3Aix-Marseille University, France
Among more than 70 related members of Flavivirus genus, Dengue virus (DENV), West Nile virus (WNV), Japanese encephalitis
virus (JEV), Yellow fever virus (YFV) and Zika virus (ZV) are considered (re)-emerging pathogens that were originally endemic
in the tropical regions but recently are spreading also in a wider geographic area. Indeed, there are several environmental, demographic
and ecological factors that promote the worldwide diffusion of known and/or novel flaviviruses. Flaviviruses can produce from mild
flu-like symptoms to hemorrhagic fevers, hepatitis and neuropathies, such as encephalopathy, meningitis and microcephaly in human
embryos depending on the infective agents. Vaccines are available against YFV, JEV, TBEV and more recently against DENV but
the coverage is far from being complete. Moreover, the lack of an effective and specific therapy further worsens the scenario. The
RNA-dependent RNA polymerase (RdRp) of the non-structural NS5 protein is one of the most favored targets to find new potential
anti-Flavivirus drugs. With the aim to find new inhibitors of the RdRp we undertook a research program exploiting, consecutively,
two different approaches: i) A virtual screening carried out on the NS5 polymerase domain (DENV RdRp, 2J7U) followed by a
biochemical validation on the isolate target, and ii) a direct biochemical screening carried out on DENV NS5 polymerase with the
intent to not exclude any potential hit compounds eventually missed during the in silico procedures. Both these approaches were
realized using an in-house library of about 200, published and unpublished, compounds previously designed and synthesized as
HCV NS5B inhibitors. To validate the potential of the identified hits, an anti-viral activity against a panel of Flavivirus was evaluated.
The two strategies led us to identify new RdRp inhibitors able to reduce the polymerase activity in the low micromolar range. In
particular, the in silico procedure (i) was fruitful for the identification of a pyridobenzothiazole which was extensively characterized
with biochemical and structural studies; the second approach (ii) led us to identify functionalized 2,1-benzothiaziens with promising
anti-RdRp activity, not emerged as hit compounds during the in silico studies (Figure 1). Also in this case, a representative compound
derived from a chemical optimization was better characterized in biochemical and virological assays. The strategy applied in this
study led us to identify new promising inhibitors of the NS5 polymerase, worthy of further optimization with the final aim to discover
anti-Flavivirus agents.
Biography
Giuseppe Manfroni has graduated in Pharmaceutical Chemistry and Technology (2001) and received his PhD in Medicinal Chemistry (2006) from the University
of Perugia (Italy). From 2006 to 2008, he worked as a Post-doctoral Researcher at the University of Perugia. From 2008 to date, he is an Assistant Professor in
the Department of Pharmaceutical Sciences and is a Lecturer in Pharmaceutical Analysis. He has spent short periods as a Visiting PhD Student at Rega Institute
for Medical Research (Leuven, Belgium) and at the Molecular Modeling Laboratory (University of Perugia) under the supervision of Professor Johan Neyts and
Professor Gabriele Cruciani, respectively. He is the author of 40 papers and his research is mainly focused on Medicinal Chemistry of antiviral (HIV, HCV, and
Flavivirus), antitumor and anti-inflammatory (p38 inhibitors) agents. He is an expert in the synthesis of heterocyclic compounds and microwave assisted synthesis.
Giuseppe Manfroni et al., J Biotechnol Biomater 2017, 7:1(Suppl)