Table 1.

Analysis of sequential modifications of the 4,6-disubstituted DOS AGs^a

First AME	Activity of the following second AMEb:
	APH(2″)	AAC(3)-IV	AAC(6′)
APH(2″)	−	↓	↓
AAC(3)-IV	↑	−	x
ANT(4′)	Mix	↓	↓, =
AAC(6′)	Mix	↓	−

^aAMK, KAN, SIS, and TOB.

^bx, no second modification observed; ↓, decreased activity of the second enzyme; ↑, increased activity of the second enzyme; =, same activity for the second enzyme as for the first; −, reaction not tested; Mix, mixed results (in some cases, the activity of the second enzyme increases, whereas in others cases, it decreases).