Table 1.

SAR studies of substitution of the pyrazolone ring.

Compound	R1	R2	EC50 (μM)
a	H	H	0.067
b	Me	H	0.67
c	Me	Me	>32a
d	Biotin	H	0.56
e	Peg4-Biotin	H	0.67
f	CH2CH2OH	H	>32
g	CH2CH2CH2OH	H	0.34
h	Ph	H	1.03
i		H	1.73
j		H	>32
k		H	>32
l		H	1.00
m	Bn	H	0.13
n		H	0.36
o		H	>32
p	CHO	H	0.49
q	Ac	H	0.27
r		H	0.42
s		H	0.31
t		H	0.33
u		H	1.71
v		H	0.93
w		H	1.32

^a>32 μM indicated EC₅₀ not reached at the highest concentration used.

All values are reported as the mean average of three determinations.

Average Z’ factor value = 0.5.