Para-Substituted Functionalised Ferrocene Esters with Novel Antibacterial Properties

Abstract

Introduction Bacterial antibiotic resistance is on rise despite advances in the development of new antibiotics. In an attempt to circumvent resistance, scientists are shifting focus from modifying existent antibiotics to identifying new antibiotic compounds. Aim To assess the potential antibiotic effects of functionalised ferrocenecarboxylates para-substituted on the phenoxy pendant group to form: 4-fluorophenyl, 4-chlorophenyl, 4-bromophenyl, 4-iodophenyl and 4-(H-pyrrol-1-yl)phenyl. Materials and Methods For this, we employed the Kirby-Bauer disc diffusion method using a collection of nine bacterial species: Staphylococcus aureus, Escherichia coli, Micrococcus luteus, Pseudomonas aeruginosa, Serratia marcescens, Klebsiella pneumoniae, Bacillus subtilis, Proteus vulgaris and Enterobacter aerogenes. Results The results show that all four-halogen substituted ferrocenecarboxylates 4-fluorophenyl (23.33 μM, 11.66 μM, 5.83 μM), 4-chlorophenyl (10.16 μM, 5.08 μM, 2.54 μM), 4-bromophenyl (9.0 μM, 4.5 μM, 2.25 μM), and 4-iodophenyl (17.12 μM, 8.56 μM, 4.28 μM) exhibited an antibacterial effect by reducing proliferation of Bacillus subtilis. Meanwhile, only 4-bromophenyl (9.0 μM) and 4-chlorophenyl (10.16 μM) ferrocenecarboxylates were able to decrease the growth of Micrococcus luteus. Conclusion Hence, functionalised ferrocenecarboxylates para-substituted with small and simple groups represent a novel class of bio-organometallic compounds with the potential to be used as antibacterial agents.

Screening the antimicrobial effect of ferrocene-boronic acid on Pseudomonas aeruginosa using proteomics and metabolomics approach

“…Today various organometallic compounds like cisplatin are using as chemotherapeutic agents for various cancer types. Moreover, organometallic compounds have been studied in microbiology field to overcome antibiotic resistance problem [6][7][8]. Ferrocene based organometallic compounds have withdrawn attention for clinical applications because of their anticancer and antimicrobial properties [6,[9][10][11].…”