Table 2.

In vitro activity of the (Z)-methyl 2-(2-oxo-2H-benzo[b][1,4]oxazin-3(4H)ylidene)acetates^a

Compound	R1	R2	R3	IC50b (µM)	Ki (µM)	Ki’ (µM)	MICc (µg/ml)
1	H	H	H	10.0±1.0	9.1±1.2	67.0±7.9	0.64
2	Me	H	H	24.1±1.8			25
3	H	Me	H	23.1±1.0			>100
4	H	F	H	27.0±3.0	11.5±1.5	10.1±0.9	0.63
5	H	Cl	H	46.3±3.5	22.5±1.1	18.5±2.6	5
6	H	NO2	H	28.2±4.4			50
7	H	EtSO2	H	17.9±3.0			>100
8	H	H	Me	18.2±2.8			100
9	H	H	F	30.0±3.7			0.63
10	H	H	Cl	35.7±4.8			0.63
11	H	H	NO2	20.3±1.8			>100
12				>122			>100
13				>140			>100

^aMenB concentration was 150 nM.

^bCompound concentration giving 50% inhibition of enzyme activity.

^cCompound concentration giving 90% inhibition of M. tuberculosis H37Rv growth.