Date of Graduation

Summer 2020

Degree

Master of Science in Chemistry

Department

Chemistry

Committee Chair

Nikolay Gerasimchuk

Keywords

cyanoximes, organoantimony(V), antimicrobial, antifungal, antibiotic-resistance, X-ray single crystal analysis

Subject Categories

Inorganic Chemistry | Microbiology

Abstract

The requirement of new antimicrobial treatments has become an urgent field recently. Multi-drug resistant (MDR) bacteria are now resistant to common antibiotics. To antagonize such bacteria 8 novel organoantimony(V) cyanoximates were synthesized to be characterized and submitted for biological activity studies. Eight organoantimony(V) cyanoximates were characterized by elemental analysis, thermal analysis, IR-, 13C{1H} NMR, some with UV-visible spectroscopy, and single crystal X-ray analysis. Antimicrobial Disk studies indicated Sb(Ph)4(ACO) and Sb(Ph)4(ECO) had significant antimicrobial effect against all three strains: two gram-negative a) Escherichia coli strain S17 and b) Pseudomonas aeruginosa strain PAO1, alongside a single gram-positive Methicillin-resistant Staphylococcus aureus strain NRS70. Sb(Ph)4(TCO) and Sb(Ph)4(TDCO) had significant effects against gram- positive Methicillin-resistant Staphylococcus aureus strain NRS70, but essentially no antimicrobial activity for gram-negative strains used. Antimicrobial broth dilution MIC assays were completed against the same strains as antimicrobial disk studies but changed the compounds tested. Using Sb(Ph)4(MCO) as the only Sb(V) cyanoximate along with free cyanoximes H(MCO), H(ECO), and Na[H(ACO)2]. Results indicated free cyanoximes have no antimicrobial effect as the DMSO solvent used in these assays contributed to the inhibition factor to the MIC of the cell cultures. Antifungal disk assays concluded that Sb(Ph)4(ECO) was effective against Cryptococcus neoformans and Candida albicans. Sb(Ph)4(TCO) followed in antifungal activity against both strains. Sb(Ph)4(ACO) and Sb(Ph)4(TDCO) were only effective at inhibition of Cryptococcus neoformans. Antifungal MIC assays were conducted and concluded that the free cyanoximes had zero effect on antifungal activity against both fungi. Sb(Ph)4(MCO) had shown MIC levels ranging from 10 - 50 μg/mL.

Copyright

© Kevin Anthony Pinks

Open Access

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