Figure 1.

Chemical structures of aminoglycoside (AG) antibiotics currently used in the clinic and 6′-N-acylated isepamicin (ISP) analogs developed in this study. Kanamycin A, kanamycin B, sisomicin, and gentamicin B are natural products, whereas amikacin, arbekacin, netilmicin, plazomicin, and ISP are semi-synthetic AGs, in which the chemically modified features are indicated by blue colors. The greenish inset depicts newly synthesized 6′-N-acylated ISP analogs and red colors represent the functional group formed by the AAC(6′)-APH(2″)-catalyzed enzymatic synthesis in this study.