Synthesis and Plant Growth Regulating Activities ofiso-Abscisic Acid

The iso-abscisic acid (iso-ABA) analogs 11, 12, 13 and 14 were synthesized via regioselective addition of acetylides to enediones, selective reduction, Dess-Martin oxidation and Lindgren oxidation. The racemic mixtures 11 were resolved by chiral HPLC. These iso-ABA analogs and ABA were tested for their inhibitory activity in four bioassays. ()-iso-ABA 11 exhibited high ABA-like activity, including the ability to effectively inhibit seed germination and seedling growth. The analogs 12, 13, 14 were also prepared and biological activities were investigated. Comparison of four bioassays, the iso-abscisic acid analogs had better activity in lettuce seed germination.