Table 1.

Chemical structures of title compound I and their biological activity against AtHPPD.

I1–40
compound	R1	R	AtHPPD inhibition Ki (μM)
I1	H		1.5 ± 0.031
I2	H		1.3 ± 0.017
I3	2-chloro		0.36 ± 0.012
I4	2-chloro		0.59 ± 0.043
I5	4-chloro		1.0 ± 0.036
I6	4-chloro		0.93 ± 0.032
I7	2,4-dichloro		0.36 ± 0.012
I8	2,4-dichloro		0.22 ± 0.023
I9	2,4,6-trichloro		0.31 ± 0.048
I10	2,4,6-trichloro		0.24 ± 0.003
I11	2,4,6-trichloro		0.081 ± 0.001
I12	2,4,6-trichloro		0.011 ± 0.012
I13	2-nitro		0.45 ± 0.033
I14	2-nitro		0.21 ± 0.042
I15	2-nitro		0.27 ± 0.004
I16	2-nitro		0.44 ± 0.013
I17	4-nitro		0.23 ± 0.004
I18	4-nitro		0.93 ± 0.006
I19	4-nitro		0.63 ± 0.002
I20	4-nitro		0.50 ± 0.003
I21	4-nitro		1.5 ± 0.041
I22	2-chloro-4-nitro		1.02 ± 0.009
I23	2-chloro-4-nitro		0.012 ± 0.009
I24	2-chloro-4-nitro		0.26 ± 0.012
I25	2-chloro-4-nitro		0.21 ± 0.043
I26	2-(2,4-dichlorophenoxy)-4-chloro		1.9 ± 0.001
I27	2-(2,4-dichlorophenoxy)-4-chloro		2.2 ± 0.041
I28	2-(2,4-dichlorophenoxy)-4-chloro		0.032 ± 0.002
I29	2-(2,4-dichlorophenoxy)-4-chloro		1.3 ± 0.022
I30	2,4-dimethyl		2.2 ± 0.034
I31	2,4-dimethyl		3.1 ± 0.34
I32	2,4-dmethyl		2.0 ± 0.009
I33	2,4-dimethyl		2.8 ± 0.045
I34	2,4-dimethyl		2.8 ± 0.67
I35	4-methyl-5-methoxy		3.3 ± 0.14
I36	4-methyl-5-methoxy		3.4 ± 0.21
I37	4-methyl-5-methoxy		2.7 ± 0.53
I38	4-methyl-5-methoxy		2.9 ± 0.038
I39	H		1.3 ± 0.056
I40	H		1.2 ± 0.031
mesotrione			0.013 ± 0.001