Antibiotic Coordination Frameworks against Antibiotic Resistance: How to Involve Students through Experimental Practices in the Search for Solutions to Public Health Problems

For decades, multiple varieties of antibiotics have been successfully used for therapeutic purposes. Nevertheless, antibiotic resistance is currently one of the major threats to global health. This work presents an innovative laboratory practice carried out in an inorganic medicinal chemistry course within the Degrees of Pharmacy and Biochemistry for undergraduate students. This experiment includes three classes of 2 h each. The first class consisted of the mechanochemical synthesis of an antibiotic coordination framework (ACF) using a known antibiotic (nalidixic acid) and zinc as the ligand. The prepared Zn-nalidixic acid ACF (Zn-ACF) was obtained in up to 82% yield with high purity. On the second day, the synthesized Zn-ACF was characterized by Fourier-transform infrared spectroscopy (FTIR) and powder X-ray diffraction (PXRD). Finally, during the last class, the antimicrobial activity was tested against Escherichia coli by the well diffusion method. The students verified the higher antimicrobial activity of Zn-ACF compared to nalidixic acid, proving that small changes in the chemical structure can result in great biological differences. In the end, the students presented their results in a poster format, encouraging the development of their soft skills and scientific results communication and dissemination. In the future, it is expected that such a laboratory experiment at the interface between medicinal chemistry, microbiology, analytical techniques, public health, and pharmacology will lead to the development and implementation of some service-learning practices and will serve as a model to look at for other courses and institutions

Stilbenoids as Antifungals to Counteract Rice Blast Pathogen Pyricularia oryzae

Fungi are among the greatest biotic threats to agricultural and food security. Intensive monoculture cropping and resistance to single-site fungicides in plant pathogens urge the discovery and development of novel compounds that possibly interfere with essential cellular processes in multiple ways. In this article, we describe our recent efforts addressed to the identification of natural compounds as multitarget biofungicides. A set of natural monomeric and dimeric compounds belonging to the class of stilbenoids were synthesized and tested against wild-type (WT) and strobilurin-resistant (RES) strains of Pyricularia oryzae, one of the most dangerous fungal phytopathogens. Monomers deoxyrhapontigenin, pinostilbene, and DMHS showed inhibitory activity higher than 40%, with deoxyrhapontigenin having the highest activity on mycelial growth (60–80% inhibition) on both WT and RES P. oryzae strains. Furthermore, we designed and synthesized a set of molecules having a nature-derived stilbene fragment merged with the pharmacophoric portion of strobilurins, namely, a β-methoxyacrylate moiety. We identified two molecules with activity comparable to the reference commercial fungicide azoxystrobin. However, low mycelium growth inhibition of resistant strains indicates that these compounds most likely retain the strobilurin-like mechanism of action. Overall, the results suggest that natural stilbenoids might be used as environmentally friendly biofungicides in rice blast management

Antibiotic Coordination Frameworks against Antibiotic Resistance: How to Involve Students through Experimental Practices in the Search for Solutions to Public Health Problems

For decades, multiple varieties of antibiotics have been successfully used for therapeutic purposes. Nevertheless, antibiotic resistance is currently one of the major threats to global health. This work presents an innovative laboratory practice carried out in an inorganic medicinal chemistry course within the Degrees of Pharmacy and Biochemistry for undergraduate students. This experiment includes three classes of 2 h each. The first class consisted of the mechanochemical synthesis of an antibiotic coordination framework (ACF) using a known antibiotic (nalidixic acid) and zinc as the ligand. The prepared Zn-nalidixic acid ACF (Zn-ACF) was obtained in up to 82% yield with high purity. On the second day, the synthesized Zn-ACF was characterized by Fourier-transform infrared spectroscopy (FTIR) and powder X-ray diffraction (PXRD). Finally, during the last class, the antimicrobial activity was tested against Escherichia coli by the well diffusion method. The students verified the higher antimicrobial activity of Zn-ACF compared to nalidixic acid, proving that small changes in the chemical structure can result in great biological differences. In the end, the students presented their results in a poster format, encouraging the development of their soft skills and scientific results communication and dissemination. In the future, it is expected that such a laboratory experiment at the interface between medicinal chemistry, microbiology, analytical techniques, public health, and pharmacology will lead to the development and implementation of some service-learning practices and will serve as a model to look at for other courses and institutions