Role of the Ring Methyl Groups in 2′,3′-Benzoabscisic Acid Analogues

Abstract

Five analogues of iso-PhABA (20) developed earlier by our research group were designed and synthesized. The bioassay results show that the number and position of methyl groups along with the substitution of hydrogen atoms of the methyl group have a great influence on the activity. Compared with iso-PhABA, the inhibitory activity of diMe-PhABA (21) on seed germination and rice seedling growth decreased slightly; however, it significantly reduced the capability of inhibiting wheat embryo germination. Both 3′-deMe-iso-PhABA ( 22) and 2′-deMe-PhABA (23) exhibited weak inhibitory activities, and 11′methoxy iso-PhABA (24a/24b) was much more efficient than its isomer 24c/24d in all bioassays. These results reveal the preservation of quaternary carbon at the 2′ or 3′ position is necessary to maintain its ABA-like biological activity, and demethylation at the 3′ position has a more significant effect. The selectivity of these compounds to different physiological processes makes them available as selective probes for different ABA receptors.

APAn, a Class of ABA Receptor Agonism/Antagonism Switching Probes

“…thaliana Stomatal Closure Assay. 28 A. thaliana seeds were sterilized with 70% ethanol for 10 min, then they were rinsed with double distilled water for 6−7 times, and the excess water was sucked away. These seeds were dibbled in a petri dish of 1/2 MS solid culture medium, dried, sealed by a split film, and placed in a refrigerator at 4 °C for vernalization for 3 days, and the petri dish is transferred to an incubator for cultivation for 5 days under the conditions of 25 °C, 16 h of illumination, and 22 °C and 8 h of darkness.…”

A briefly overview of the research progress for the abscisic acid analogues

“…In 2019, Wan et al, designed and synthesized five analogues of an earlier 2′,3′-iso-PhABA (Wan et al, 2019). Bioassay results showed that the number and position of methyl groups and the substitution of hydrogen atoms on methyl groups have great influence on the activity.…”

An efficient and scalable synthesis of a persistent abscisic acid analog (+)-tetralone ABA

“…2). 15,[17][18][19][20][21][22] In the initial literature report describing the synthesis of the tetralone ABA 5, the (+)-enantiomer was found to have higher activity than ABA in both a corn cell growth inhibition assay as well as a seed germination inhibition assay in Arabidopsis. 15 Han et al reported that the racemic tetralone ABA (±)-5 had higher activity than racemic ABA ((±)-1) in seed germination assays in Arabidopsis, lettuce and in a rice seedling growth inhibition assay.…”