Synthesis, characterization, and antimicrobial evaluation of a small library of ferrocene-containing acetoacetates and phenyl analogs: the discovery of a potent anticandidal agent

A library of 16 2-substituted methyl acetoacetates containing ferrocenyl or phenyl units was designed to disclose differences in the antimicrobial activity of ferrocene-containing compounds and their phenyl analogs. Two methyl acetoacetates, whose structures do not contain an aromatic nucleus, were also included in order to probe the inherent activity of the scaffold itself. The acetoacetates were synthesized (low-to-good yields) and fully characterized by spectral (MS, IR, UV-Vis, 1D and 2D NMR) and electrochemical (cyclic voltammetry) techniques. Single-crystal X-ray analysis has been performed for methyl 2-acetyl-2-(ferrocenylmethyl)-5-methylhex-4-enoate. All compounds have demonstrated in vitro antimicrobial activity against six bacterial (three Gram-positive and three Gram-negative) and two fungal strains with minimal inhibitory concentration values of 0.0050-20.6 . The most active compound was 2-acetyl-2-(ferrocenylmethyl)-4-methylpent-4-enoate whose activity was comparable to that of nystatin against the yeast Candida albicans. Agglomerative hierarchical clustering statistical analysis of the antimicrobial assay data demonstrated that ferrocene-containing compounds have statistically different and greater antimicrobial activity when compared to their phenyl analogs

Novel organometallic cationic ruthenium(II) pentamethylcyclopentadienyl benzenesulfonamide complexes targeted to inhibit carbonic anhydrase

Cationic ruthenium(II) pentamethylcyclopentadienyl benzenesulfonamide sandwich complexes have been synthesized and screened for enzymatic inhibition of the physiologically dominant carbonic anhydrase (CA) isozymes: human CA I and II, mitochondrial isozymes VA and VB, and the cancer-associated isozyme IX. The complexes demonstrated weaker binding to CAs compared with typical aromatic sulfonamides, inhibiting the enzyme at high nanomolar concentrations. An in vitro cytotoxic evaluation of the complexes was also undertaken against a range of tumorigenic cell lines and a healthy human cell line. Complexes inhibited the growth of cancerous cells at low micromolar concentrations while expressing lower levels of toxicity towards the normal human cell line. Factors influencing the synthesis, cytotoxicity, and enzyme affinity for this series of organometallic complexes are discussed