Table 3.

NOS inhibition by the N-OH and N-NH₂ derivatives and their parent compounds.^a

Compound	Ki (μM)			selectivityd
	nNOSb	iNOSc	eNOSc	n/i	n/e
L-NNA	0.61 ± 0.005	4.28	0.72	7	1.2
1	0.17 ± 0.011	18	191	106	1124
2	0.33 ± 0.019	17	72	52	218
3	0.12 ± 0.017	16	73	133	608
4	0.56 ± 0.024	37	103	66	184
5	0.31 ± 0.014	16	35	52	113

^aThe enzyme used for the K_i determinations are bovine brain nNOS, recombinant murine iNOS, and recombinant bovine eNOS. See Experimental Section.

^bK_i ± SEM. Results are given as a mean of more than or equal to two independent experiments.

^cThe K_i values represent single measurements with 5 data points and correlation coefficients (r²) 0.959–0.996.

^dThe ratio of K_i (iNOS or eNOS) to K_i (nNOS).