Provided herein are aminoglycoside compounds, such as compounds of formula (I), (II), (III), (IV), (IVa), (V), (VI), (VIIa), or (VIIb) or pharmaceutically acceptable salts, solvates, stereoisomers, or tautomers of any of the foregoing, useful as therapeutic or prophylactic agents. Also provided herein are methods for their preparation. The compounds may be useful in treating a bacterial infection in a subject, for example a Gram-negative bacterial infection.