Framycetin (Fradiomycin B; Neomycin B) is an aminoglycoside antibiotic. It inhibits hammerhead ribozyme with a K_i of 13.5 μM. IC50 & Target: Ki: 13.5 μM (hammerhead ribozyme)^[1] In Vitro: Neomycin B is used clinically to treat hepatic encephalopathy (by reducing ammonium levels in the gut) and enteropathogenic Escherichia coli infections. Neomycin B targets the bacterial and human ribosome and affect translation. Addition of neomycin B, to an HCC cell line selectively inhibits production of the mature miRNA, boosts a downstream protein, and inhibits invasion^[2]. Neomycin B interacts with various target RNAs that have no primary sequence homology. This means that the drug binds to a structural rather than a sequence motif of the RNA. Its primary cognate target is the decoding site of the 16S rRNA, but it also binds to the Rev-responsive element in HIV-1, group I introns, and the hammerhead ribozyme, and thus inhibits their biological function^[3]. The aminoglycoside antibiotic neomycin B induces misreading of the genetic code during translation and inhibits several ribozymes. The ribosomal target site of neomycin B is the 16 S rRNA 1400 to 1500 region, which has been clearly demonstrated by dissecting this domain from a small RNA of 27 nucleotides. This small subdomain of the 16 S rRNA is protected from chemical modification by neomycin at the same positions as in the context of the 30 S subunit^[4].