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Synthesis and Tumor Cell Growth Inhibitory Effects of New Flavonosides and Xanthonosides
Published: 01 November 2017 by MDPI in 3rd International Electronic Conference on Medicinal Chemistry session ECMC-3

Natural flavonoid and xanthone glycosides display several biological activities [1-3], with the glycoside moiety playing an important role in the mechanisms of action of these metabolites. Herein, to give further insights into the inhibitory cell growth activity of these classes of compounds, the synthesis of new flavonoid and xanthone derivatives containing one or more acetoglycoside moieties was carried out to evaluate their in vitro cell growth inhibitory activity in human tumor cell lines.

The introduction of one or two acetoglycoside moieties in the skeleton of a hydroxylated flavonoid was performed using three synthetic methods: Michael reaction, Koenigs-Knorr reaction, and through a copper-catalyzed azide-alkyne cycloaddition. Acetyl groups were introduced in rutin, diosmin, and mangiferin using acetic anhydride under microwave irradiation. The in vitro cell growth inhibitory activity of seven synthesized compounds was investigated in six human tumor cell lines: A375- C5 (malignant melanoma IL-1 insensitive), MCF-7 (breast adenocarcinoma), NCI-H460 (non-small cell lung cancer), U251 (glioblastoma astrocytoma), U373 (glioblastoma astrocytoma), and U87MG (glioblastoma astrocytoma). The most active compound in all tumor cell lines tested was a flavonoside and showed GI50 values below 10 μM.

[1] Leong, C.N.A., et al., Food Chemistry, 2008. 109(2): p. 415-420.

[2] Kumar, M., et al., Fitoterapia, 2010. 81(4): p. 234-242.

[3] Reutrakul, V., et al., Planta Medica, 2007. 73(7): p. 683-688.



The authors want to thank Fundação da Ciência e Tecnologia (FCT/MCTES, PIDDAC) and European Regional Development Fund (ERDF) for funding this research through the COMPETE – Programa Operacional Factores de Competitividade (POFC) programme (POCI-01-0145‐FEDER-016790 and POCI-01-0145-FEDER-016793), Reforçar a Investigação, o Desenvolvimento Tecnológico e a Inovação (RIDTI, Project 3599 and 9471), and INNOVMAR, reference NORTE-01-0145-FEDER-000035, Research Line NOVELMAR, under the projects PTDC/ MAR-BIO/4694/2014 and PTDC/AAG-TEC/0739/2014 and the Strategic Funding UID/Multi/04423/2013 through national funds provided by FCT and ERDF, in the framework of the programme PT2020. Ana R. Neves wants to thank FCT for the Ph.D. fellowship (SFRH/BD/114856/2016).

  • Open access
  • 97 Reads
Design of New Polymyxins with Reduced Nephrotoxicity
Published: 01 November 2017 by MDPI in 3rd International Electronic Conference on Medicinal Chemistry session Posters

There is a clear unmet medical need in the field of infectious diseases: infections caused by resistant bacteria. A major goal to fight resistant bacteria involves the design, discovery and development of new antibiotics particularly against multi-drug-resistant strains. Polymyxins, an old class of antimicrobial cyclic lipopeptides highly potent against therapeutically relevant Gram-negative bacteria, have been rescued and are now used only as last resort antibiotics in hospitals because of their nephrotoxicity and neurotoxicity that require careful monitoring of the patient. Our group has embarked in a project to design and develop new polymyxins devoid of toxicity problems using a versatile and chemically accessible scaffold structure[1,2]. Compounds show a remarkable activity against Gram-negative bacteria. Synergistic and antibiofilm activities have also been recently described in combination with imipenem[3]. Herein, the last results of our recently designed polymyxin analogs will be presented.


  1. F. Rabanal, A. Grau-Campistany, X. Vila-Farrés, J. Gonzalez-Linares, M. Borràs, J. Vila, A. Manresa and Y. Cajal. A bioinspired peptide scaffold with high antibiotic activity and low in vivo toxicity, Sci. Rep., 2015, 5, 10558.
  2. F. Rabanal, Y. Cajal, Recent advances and perspectives in the design and development of polymyxins. Natural Product Reports, 34, 886 - 908 (2017)!divAbstract  
  3. H. Rudilla, E. Fusté, Y. Cajal, F. Rabanal, T. Vinuesa and M. Viñas, Synergistic Antipseudomonal Effects of Synthetic Peptide AMP38 and Carbapenems, Molecules, 2016, 21, 1223.
  • Open access
  • 137 Reads
99m Tc-Tricarbonyl- (2-amino- 5,10-dioxide- 7(8)-fluorophenazine) as Probe for Mammary Hypoxic-tumors Imaging
Published: 01 November 2017 by MDPI in 3rd International Electronic Conference on Medicinal Chemistry session ECMC-3

Our group has previously reported potential new radiopharmaceuticals, i.e. 99m Tc-tricarbonyl-(2-amino- 5,10-dioxide- 7(8)-fluorophenazine), Tc-FZ), with the ability to detect hypoxic tumoral tissues. Previously, this probe was used to detect solid tumors, employing a model of lung carcinoma generated by inoculation of 3LL Lewis murine cells in C57BL/6 mice. The results
revealed an adequate tumor/muscle ratio, 3.8 at 2 h post-injection (p.i.), with lower tumor/blood ratio, i.e. 0.6 at 2 h p.i..

Due to some models of breast cancer also being characterized by hypoxic areas, herein we decided to analyze the behavior of Tc-FZ in BALB/c mice bearing mammary tumor induced with 4T1-mouse tumoral cell line. The studied ratios revealed to be slightly a little more unfavorable than in the lung tumor-porting animals, being tumor/muscle and tumor/blood ratios, at 2 h p.i., of 3.0 and 0.23, respectively. Additionally, animals in vivo images showed that the liver masked tumor signal.

The authors want to thank the ANII for financial support.

  • Open access
  • 92 Reads
Radiolabeling Optimization and Characterization of Three 67Ga DOTA Conjugated Peptides
Published: 01 November 2017 by MDPI in 3rd International Electronic Conference on Medicinal Chemistry session ECMC-3

In this work we report a preliminary study of radioactive labeling of different peptides for possible use in oncology. For this purpose the following peptides were used: KCCYSL, a probe of aberrant expression of ErbB-2, member of the epidermal growth factor family of receptors, and it has been implicated in the formation of various malignancies including ovarian cancer; TATE, a synthetic somatostatin analog, which binds specifically to somatostatin receptors present on the cell surface of neuroendocrine tumors; Substance P, peptide which has an important role in modulating pain transmission trough neurokinin type 1 (NK1r) and 2 receptors (NK2r), may play a role in the pathogenesis of pancreatic tumors and malignant glial brain tumors as well. These three peptides are conjugated to DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) used as chelator of lanthanide ions. Different radiolabeling methods were assayed to establish the optimum conditions for obtaining the highest yield of labeled KCCYSL, TATE and substance P. Briefly, a stock solution of the three different peptides was prepared dissolving the peptides in Milli Q water (1 mmol/L each solution). After that, 20 µg of each peptide was added to three different eppendorf tubes containing 0.2 mL ammonium acetate buffer (pH 4.8, 0.5 mol/L) and 10 MBq of 67GaCl3 (0.02 mL/0.1 mol/l HCl) was added to a reaction solution. The reaction mixtures were kept for 30 min at 80 °C. After cooling down, the preparations were studied by HPLC (C18 reversed phase column with gradient system was used with 0.1 % trifluoroacetic acid/water (Solvent A) and acetonitrile (Solvent B) as mobile phase). The three peptides were successfully labeled with high yield (> 99 %) at optimized conditions and kept stable for more than 48 hours at room temperature.

The authors want to thank ANII, PEDECIBA-Quimica and PROINBIO for financial support.

  • Open access
  • 158 Reads
First Advances in the Asymmetric Synthesis of Biologically Active 2-Amino-3-cyano-4H-chromen-4yl Phosphonates
Published: 01 November 2017 by MDPI in 3rd International Electronic Conference on Medicinal Chemistry session Posters

2-Amino-3-cyanochromene is a privileged scaffold and it can be found in pharmacological agents as the antitumor Crolibulin and the pro-apoptotic HA14-1. Recent studies have also shown that chromene phosphonyl derivatives exhibit different biological activities including antifungal, antimicrobial, antioxidant and anticancer ones. Since it is known that each enantiomer could present distinct biological properties, the development of an asymmetric catalytic procedure to obtain these enantioenriched products is still desirable. Following this idea, the present research explores the use of chiral organocatalysts in several reactions for the synthesis of these interesting derivatives. To date, preliminary results obtained following two organocatalytic strategies using diarylphosphonates (Pudovik reaction) and trialkylphosphites (Abramov reaction) showed an adequate chiral induction, providing the first examples of enantioselective synthesis of chromene phosphonyl derivatives.

  • Open access
  • 109 Reads
Effect of Interaction with Micellar Media on Spectral Properties of some Amphiphilic Porphyrins
Published: 01 November 2017 by MDPI in 3rd International Electronic Conference on Medicinal Chemistry session Posters

The use of porphyrinic compounds in the field of theranostic nanomedicine, has increased substantially in the recent years due to their special features such as: long wavelength absorption and emission in the spectral region where the biological tissues absorb, a good photodynamic activity, photostability and low in vivo toxicity [1-3]. Despite significant advantages, due to the large pi conjugate systems, porphyrins easily form aggregates, which have a significantly lower ability for localization at cellular level and consequently decrease the therapeutic effect. So, before pharmaceutical formulation, it is necessary to study the spectral and aggregation properties of these compounds in membrane mimetic media, such as micelles, in order to determine the factors that modulate porphyrin−membrane interactions and that may resolve the aforementioned problems [4-6]. The present study included spectral evaluation of some amphiphilic porphyrins in TX-100/water and TX-100/cyclohexane micelles. The obtained results suggested for tested compounds the localization at the interface between the polyethylene oxide chains and the tert-octyl-phenyl etheric residue of the surfactant molecules. Considering the spectral behavior of the studied porphyrins, the experimental results confirmed the fact that incorporation in micelles will facilitate a better delivery to the cellular target without significant changes in the photophysical profile.


[1]. L.B. Josefsen, R.W. Boyle, Theranostics, 2012, 2, 916–966.

[2]. M. Ethirajan, Y. Chen, P. Joshi, R.K. Pandey, Chem. Soc. Rev., 2011, 40, 340–362.

[3]. P. Rai, S. Mallidi, X. Zheng, R. Rahmanzadeh, Y. Mir, S. Elrington, A. Khurshid, T. Hasan, Adv. Drug Deliv. Rev., 2010, 62, 1094–1124.

[4]. M. van Elk, B.P. Murphy, T. Eufrásio-da-Silva, D. P. O’Reilly, T. Vermondenf, W. E. Henninkf, G. P. Duffy, E.Ruiz-Hernández, International Journal of Pharmaceutics, 2016, 515, 132–164.

[5]. M. Cagel, F.C. Tesan, E. Bernabeu, M.J. Salgueiro, M.B. Zubillaga, M.A. Moretton, D. A. Chiappetta, European Journal of Pharmaceutics and Biopharmaceutics, 2017, 113, 211–228.

[6]. D. Silva Pellosi, I. R. Calori, L. Barcelos de Paula, N. Hioka, F. Quaglia, A. C. Tedesco, Materials Science and Engineering C, 2017, 711–719.



This study was supported by projects ERA NET: Biomark, ctr. 7-030/2010 and Nanother, ctr: 53/2016 and 54/2016 of the Romanian Ministry of Education and Research

  • Open access
  • 107 Reads
Influence of the Oligoribonucleotides-D-mannitol Complexes on Upexpression of some Genes Induced by Influenza Virus in vivo
Published: 01 November 2017 by MDPI in 3rd International Electronic Conference on Medicinal Chemistry session ECMC-3

The influenza (flu) virus infection induces an upexpression of tlr3, tlr7, tlr8, nfκb1, nfκbiα, nos2, xdh and other genes in mice lung. The nos2 and xdh upexpression causes overproduction of free radicals that lead to lung tissue damage. The upexpression of nfκb1, nfκbiα genes induce incorrect regulation of NF-κB. that regulates expression of the immune, inflammation genes and takes part in flu viral replication. The oligoribonucleotides-D-mannitol complexes (ORNs-D-M) possess antiviral activity against the flu virus in vitro and in vivo. One of mechanisms of the ORNs-D-M anti-influenza activity is direct virucidal action by blocking hemagglutinin–glycan interactions and inhibiting neuraminidase activity of flu virus. However other mechanisms of the ORNs-D-M anti-influenza activity have to be studied.

Current research was aimed at study of the ORNs-D-M effects on expression of the tlr3, tlr7, tlr8, nfkbia, nfnb1 nos2, xdh genes in mice lung under flu virus infection. To achieve this goal we applied a two-step RT-PCR assay. In mice lung after 48 h flu infection it was detected the overexpression of all investigated genes compared to the healthy ones. The ORNs-D-M injection for prevention reduced the mRNA level of tlr3, tlr7, tlr8, nfkbia, nfnb1 nos2, xdh expression by 65, 77, 76, 70, 63, 48, 32 % respectively vs the virus-infected mice. And the ORNs-D-M injection for treatment reduced the mRNA level of tlr3, tlr7, tlr8, nfkbia, nfnb1 nos2, xdh expression by 28, 17, 22, 40, 52, 41, 38 % respectively vs the virus-infected mice.

Our results show that the expression of all investigated genes is modulated by the ORNs-D-M after injection for prevention and treatment of the flu virus infection in vivo. It allows us to assume that by inhibiting the expression of tlr3, tlr7, tlr8, the ORNs-D-M impair the upregulation of nos2, xdh, nfkbia, nfkb1 induced by flu virus.

  • Open access
  • 114 Reads
Hepatoprotective Effect of Oligoribonucleotides-D-mannitol Complexes under Thioacetamide-induced Hepatotoxicity
Published: 01 November 2017 by MDPI in 3rd International Electronic Conference on Medicinal Chemistry session ECMC-3

Therapeutic application of oligonucleotides is a leading trend in correction of metabolic disorders and related pathologies and is perceived as a unique foundation of innovative biomedicine. Oligoribonucleotides-D-mannitol complexes (ORNs-D-mannitol) display a vast spectrum of biological effects, including cellular metabolism stimulation with activation of endogenous synthesis of regulatory proteins, stimulation of reparation processes. The high biological activity of these complexes promotes the study of the hepatoprotective activity in acute hepatotoxicity. The objective of this research was to study hepatoprotective effects of the ORNs-D-mannitol under thioacetamide liver toxicity in mice. It was demonstrated, that a dose of 200 mg/kg of these complexes decrease lesions and inflammatory infiltration of liver parenchyma under thioacetamide-induced hepatotoxicity. The ORNs-D-mannitol attenuated thioacetamide-induced free radical damage of hepatic biopolymers that is expressed in reduction of TBA-reactive products, carbonyl derivatives and in recovery of protein thiol groups, reduced glutathione. During thioacetamide toxicity it was observed that the ORNs-D-mannitol reduced the expression mRNA level of proinflammatory (Il6, Tgf α) and profibrotic (Col1A1, αSma, Tgfβ1) genes by 65, 80, 75, 77 and 87 % respectively in comparison to control thioacetamide in the liver cells.  

Thus, the results of this work demonstrate that the ORNs-D-mannitol have the hepatoprotective effect during acute liver injury. These complexes attenuate thioacetamide-induced free-radical damage of liver biopolymers and modulate the expression of some genes, which are involved in the development of liver damage at the thioacetamide toxicity.

  • Open access
  • 137 Reads
QSAR Model: Prediction of the Clastogenic Potential of 3-Arylcoumarins
Published: 01 November 2017 by MDPI in 3rd International Electronic Conference on Medicinal Chemistry session Posters

Drug discovery is a challenging task for researchers due to the complexity of biomolecules involved in pathologic processes. Design and development of efficient drugs is still urgent for several diseases. Cheminformatics tools are useful to better understand the interaction between new chemical entities and their targets. We studied a selected series of 3-arylcoumarins with antioxidant potential, and determined how their chemical features can contribute for the clastogenic activity. A virtual screening, based on the TOPSMODE approach, using a clastogenic model, was performed. The results suggested that the presence and position of hydroxyl groups in the scaffold is important for the activity. This communication is focused on cheminformatics, and its applications in drug effectiveness and safety.

  • Open access
  • 152 Reads
Analysis of the Binding Site of αS1-Casein to its Cellular Receptor TLR4 by Selective Inhibitors and Microscale Thermophoresis
Published: 01 November 2017 by MDPI in 3rd International Electronic Conference on Medicinal Chemistry session ECMC-3

The human milk protein αS1-casein was recently reported to induce secretion of proinflammatory cytokines via Toll-like receptor 4 (TLR4)1. In this study, the binding site of αS1-casein to TLR4 was identified by selective inhibition of the intracellular binding domain and extracellular ecto-domain of TLR4.

For this, Interleukin 8 (IL-8) secretion was monitored after stimulation of TLR4/MD2 (myeloid differentiation factor 2)/CD14 (cluster of differentiation 14)-transfected HEK293 cells (TLR4+) and Mono Mac 6 cells (MM6) with recombinant αS1-casein, or lipopolysaccharide (LPS) as control. The αS1-casein-induced IL-8 secretion was inhibited by TAK-242, an antagonist of the intracellular binding site and mianserine, an antagonist of the extracellular binding domain. TAK-242 inhibited αS1-casein-induced IL-8 secretion with an IC50 of 259 nM and LPS-induced IL-8 secretion with an IC50 of 23 nM. Mianserine was found as moderate inhibitor of the αS1-casein-induced IL-8 secretion with an IC50-range between 10-51 µM. Therefore, we suggested αS1-casein as an inhibitor of the extracellular binding site of TLR4. These findings were supported by binding experiments using microscale thermophoresis (MST). Human αS1-casein bound to the purified extracellular TLR4/MD2-complex with a KD of 2.2 µM in comparison to LPS binding TLR/MD2 with a KD of 8.7 µM. Furthermore αS1-casein showed binding to MD2 with a KD of 0.3 µM and CD14 with a KD of 2.7 µM. In addition, human αS1-casein induced IL-8 secretion via TLR4 was inhibited by inhibitory anti-CD14-IgA.

Human αS1-casein induced proinflammatory effects by binding to the ecto-domain of TLR4 and CD14 is required as cofactor. Hence human αS1-casein activates TLR4 in a different manner than LPS.