Antibacterial activity of the nitrovinylfuran G1 (Furvina) and its conversion products

Abstract

2-Bromo-5-(2-bromo-2-nitrovinyl)furan (G1 or Furvina) is an antimicrobial with a direct reactivity against thiol groups. It is active against Gram-positive and Gram-negative bacteria, yeasts and filamentous fungi. By reacting with thiol groups it causes direct damage to proteins but, as a result, is very short-living and interconverts into an array of reaction products. Our aim was to characterize thiol reactivity of G1 and its conversion products and establish how much of antimicrobial and cytotoxic effects are due to the primary activity of G1 and how much can be attributed to its reaction products. Stability of G1 in growth media as well as its conversion in the presence of thiols was characterized. The structures of G1 decomposition products were determined using NMR and mass-spectroscopy. Concentration- and time-dependent killing curves showed that G1 is bacteriostatic for Escherichia coli at the concentration of 16 μg/ml and bactericidal at 32 μg/ml. However, G1 is inefficient against non-growing E. coli. Addition of cysteine to medium reduces the antimicrobial potency of G1. Nevertheless, the reaction products of G1 and cysteine enabled prolonged antimicrobial action of the drug. Therefore, the activity of 2-bromo-5-(2-bromo-2-nitrovinyl)furan is a sum of its immediate reactivity and the antibacterial effects of the conversion products.

Discovery of Anti-Amoebic Inhibitors from Screening the MMV Pandemic Response Box on Balamuthia mandrillaris, Naegleria fowleri, and Acanthamoeba castellanii

“…Alexidine, being a bis-biguanide, acts via phase separation as well as the interruption of domain formation in membrane lipids and has been shown to have activity against several Acanthamoeba species [90]. The synthetic nitrovinylfuran broad spectrum antibiotic, furvina, was developed in Cuba and has shown antimicrobial activity against bacteria, fungi, and yeasts by preferentially inhibiting protein synthesis at the P-site of the 30s ribosomal subunit [91]. We found ketoconazole, terbinafine, and alexidine to have reconfirmed its activity against Acanthamoeba as well as isavuconazonium and butenafine, both identified in a previous drug susceptibility screen [44,[92][93][94].…”