Table 2.

Influence of R₁, R₂, and R₃ substituents of various phosphinic compounds on the in vitro inhibitory potencies for NEP and APN                

Compounds	R1	R2	R3	Ki (nM)*
				NEP†	APN‡
3(A + B)	Ch2Ph	CH2Ph	CH2Ph	189 ± 70	2.9 ± 0.8
6(A + B)	CH2Ph	CH2Ph(p-Ph)	CH2Ph	150 ± 30	17 ± 3
7(A + B)	CH2Ph	CH2Ph(p-Ph)	CH3	2.3 ± 0.1	15 ± 2
8(A + B)	Ph	CH2Ph(p-Ph)	CH3	2.9 ± 0.1	14 ± 1
9(A + B)	CH3	CH2Ph(p-Ph)	CH3	1.4 ± 0.2	5.2 ± 0.4

^*Values are the mean ± SEM from three independent experiments performed in triplicate of five inhibitor concentrations. 

^†NEP activity was measured by using DGNPA as substrate. 

^‡APN activity was measured by using Ala-p.NA as substrate.