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Tackling bacterial resistance using antibiotics as ionic liquids and organic salts
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Published: 12 November 2019 by MDPI in 5th International Electronic Conference on Medicinal Chemistry session ECMC-5

Bacterial resistance to current antibiotics has a major impact on worldwide human health, leading to 700K deaths every year. The development of novel antibiotics did not present significant progress, namely regarding clinical trials, over the last years due to low returns. Thus, innovative alternatives must be devised to tackle the continuous rise of antimicrobial resistance.

Ionic Liquids and Organic Salts from Active Pharmaceutical Ingredients (API-OSILs) have risen in academia for over 10 years as an efficient formulation for drugs with low bioavailability and permeability, as well as reduction or elimination of polymorphism, thereby potentially enhancing their pharmaceutical efficiency. To the best of our knowledge, our group is the first to perform research on the development of API-OSILs from antibiotics as a way to improve their efficiency. More specifically, we have successfully combined ampicillin, penicillin and amoxicillin as anions with biocompatible organic cations such as choline, alkylpyridiniums and alkylimidazoliums. Furthermore, we have also combined fluoroquinolones (ciprofloxacin and norfloxacin) as cations with biocompatible carboxylic and sulfonic acids.

In this communication, we present our latest developments in the synthesis and spectroscopic (NMR, FTIR) and physicochemical (DSC) characterization of ionic liquids and organic salts from these antibiotics, in addition to in vitro antimicrobial activity data, in particular towards Methicillin Resistant Staphylococcus aureus and multi-resistant Escherichia coli, as well as sensitive strains of gram-positive and gram-negative bacteria.

  • Open access
  • 144 Reads
RNA aptamers: antiviral drugs of the future

Aptamers are short DNA or RNA oligonucleotides that specifically and efficiently bind to a target molecule. Since the publication of the first reports in 1990 describing the selection of aptamers, this technology aroused great interest, and it was considered as a powerful strategy for the identification of molecular tools for a wide range of applications. It has been perhaps in recent years when the aptamers’ technology has gained the recognition from the international community of its great potential for developing specific therapeutic and diagnostic tools. Among the variety of targets against which aptamers have been obtained, targeting viral RNA genomes have attracted much interest. In this context it is framed the work carried out by our research group. In this talk I briefly summarized the successful application of this technology to the selection of efficient RNA aptamers against highly conserved structural RNA domains within the human immunodeficiency virus type 1 (HIV-1) and the hepatitis C virus (HCV) genomes. We have described the selection of a 16 nt-long RNA aptamer targeting the polyA domain of the HIV-1 genome that reduces the viral particles production higher than 85% in a viral infection model in cell culture. Similarly we have isolated a collection of RNA aptamers targeting the essential CRE (cis-replication element) of the HCV genome, which yields viral replication inhibition rates higher than 90-95% in a cell culture replication system.

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  • 109 Reads
Optimization extraction study for the isolation of a bioactive diterpene from Plectranthuns ornatus Codd.
Published: 12 November 2019 by MDPI in 5th International Electronic Conference on Medicinal Chemistry session Posters

Tuberculosis (TB) infects thousands of people every year and is a serious public health problem worldwide. The causative agent, Mycobacterium tuberculosis, is a bacterium that has elaborated survival mechanisms in the host.

The discovery of new antibiotics is essential for reducing TB deaths and natural products offer an excellent starting point for the discovery of these compounds due to their structural and functional diversity.

The genus Plectranthus belonging to the Lamiaceae family, such as mint and sage, exhibit a wide range of ethnobotanical uses. The P.ornatus species has diuretic, antipyretic, analgesic, antibiotic and anti-inflammatory properties and is used to relieve stomach and liver disorders.

Halimane's backbone diterpene (11R*-acetoxy-halima-5,13E-dien-15-oic acid) was previously isolated for the first time from an acetone extract of P.ornatus. This compound is described due to its antimicrobial, namely antitubercular activity. Thus, in this work, for a large-scale of the compound isolation, we optimized its extraction. Moreover, an acetonic ultrasound extraction was performed (extraction yield 7.082% (w / w)). Chromatographic isolation of 5.3 mg of pure diterpene, identified by HPLC-DAD, was also performed by comparison with an authentic sample. In future studies, it will be possible the exhaustive isolation of the diterpene of this extract allowing new biological studies with potential for the development of new tuberculostatic drugs.

  • Open access
  • 171 Reads
A pyrazole-containing copper coordination framework : an investigation into its Hirshfeld surface analysis, magnetic behavior and biological activity
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Published: 17 November 2019 by MDPI in 5th International Electronic Conference on Medicinal Chemistry session ECMC-5

The properties of pyrazole-based systems have been widely investigated due to their chelating ability with metallic ions as terminal ligands, bridging ligands and precursors for the design of several multi-nitrogen ligands for coordination, bioinorganic and organometallic chemistry [1], in order to build up new coordination polymeric networks and metal-organic frameworks. Additionally, they are well known for their spin-crossover behavior and their biological and medicinal properties as analgesic, anti-inflammatory agents [2], etc. As a contribution to what has been previously reported, we will be describing herein, for the first time, the magnetic properties and antimicrobial activity of a pyrazole-based copper complex [3]. Furthermore, the Hirshfeld surfaces and the 2D-figerprint graphics [4] allowing the understanding of the properties and the occurrence of each intermolecular contact around the studied complex molecules will be discussed exclusively in detail.

References :

[1] a) Montoya, V., Pons, J., Garcia-Antón, J., Solans, X., Font-Bardia, M. & Ros, J. (2007). Inorg. Chim. Acta. 360, 625–637. b) Itoh, T., Fuji, Y., Toda, T. (1996). Bull. Chem. Soc. Jpn. 69, 1265. c) Sun, Y. J., Cheng, P., Yan, S. P., Liao, D. Z., Jiang, Z. H., Shen, P. W. (2002). J. Coord. Chem. 55, 363. d) Lam, M. H. W., Tang, Y. -Y., Fung, K. -M., You, X.-Z., Wong, W.-T. (1997). Chem. Commun. 957.

[2] a) Kahn, O., Martinez, C. J. (1998). Science. 279, 44-48. b) Olguín, J., Brooker, S. (2011). Coord. Chem. Rev. 255, 203-240. c) Gürsoy, A., Demiryak, S., Çapan, G., Erol, K. & Vural, K. (2000). Eur. J. Med. Chem. 35, 359–364. d) Lynch, D. E. & McClenaghan, I. (2005). Acta Cryst. E61, o2349–o2351.

[3] Direm, A., Tursun, M., Parlak, C. & Benali-Cherif. N. (2015). J. Mol. Struct. 1093, 208–218.

[4] a) Spackman, M. A. & Jayatilaka, D. (2009). Cryst. Eng. Comm., 11, 19–32. b) Spackman, M. A. & McKinnon, J. J. (2002). Cryst. Eng. Comm. 4, 378–392.