Table 2. In Vitro Antibacterial Activity against Gram-Negative Strains^a.

		MIC (μg/mL)
category	compound	E. coli	K. pneumoniae	A. baumannii	P. aeruginosa	refs
Gram-negative active	8	2.1–7.8	15.6	5.2–9.0	10.6	(211)
	41	22–43	>173	6.8–13.3	22 to >173	(212)
	42	7–15	nd	nd	nd	(213)
	43	16	64	16	128	(214)
	44	16	8	32	16–64	(215)
	45	13–26	nd	51	103	(216)
	46	8–16	nd	8–32	nd	(217)
	47	nd	nd	nd	nd	(218)
	48	>128	nd	1–4	>128	(219)

^and = not determined.