ABA and Its Derivatives: Chemistry and Physiological Functions - Abscisic Acid: Metabolism, Transport and Signaling - page 13

I

HO

N

O H

CO 2 H

N 3 N

O

41

N

S

N OH

O HO 2 C NH CO 2 H

N

O

O

42

OH

N

O

HN

N OH

CO 2 H

S

N

O

43

O

O

NH

N OH

CO 2 H

HN

H N

S O

44

Fig. 1.10 ABA analogues containing a larger functional group than found at C-4′ of ABA

surrounded by the PYL protein. This binding mode suggests that the addition
of a large substituent anywhere in the structure reduces the affinity because of
interference with gate-closing or PP2C binding. This is generally consistent