Disclosed are: a novel aminoglycoside antibiotic which has an excellent anti-bacterialactivity against an infection-inducing bacterium, particularly MRSA, andalso has low renal toxicity； and a process for production of the antibiotic. Morespecifically, disclosed are: a compound represented by the formula (Ia) or apharmacologically acceptable salt or solvate thereof, or a diastereomericmixture of the compound, the salt or the solvate； an antibacterial agent comprisingthe compound, the salt, the solvate or the diastereomeric mixture； and a processfor production of the compound. [Chemical formula 1] (Ia)
