A group of antibacterial drugs (such as kanamycin, neomycin and streptomycin) which are mostly produced by fungi and which contain an amino sugar, and amino- or guanido-substituted inositol ring, and other sugar residues. They are all broad-spectrum antibiotics that inhibit bacterial protein synthesis by binding to their ribosomes. However, all these drugs are toxic to humans and aren't used except in special situations.