Improved synthetic route of exo‐16,17‐dihydro‐gibberellin A5‐13‐acetate and the bioactivity of its derivatives towards Arabidopsis thaliana

Abstract

BACKGROUND: The use of exo-16,17-dihydro-gibberellin A5-13-acetate (DHGA 5 ) in agriculture has been limited by its low synthetic yield. This study was aimed at optimizing the synthetic route of DHGA 5 , designing and synthesizing new derivatives with strong plant growth inhibitory activities.RESULTS: Previous synthetic methods were replaced with a shorter, milder and faster reaction route with higher yield (76.3%) of DHGA 5 . Based on this novel route, a series of new derivatives were designed and synthesized using DHGA 5 as a lead compound and characterized and evaluated for biological activities in Arabidopsis thaliana. Among the 15 tested derivatives, compound 14j showed a lower medium inhibition concentration (IC 50 , 73 M) in Arabidopsis than that of DHGA 5 (91 M). Gibberellin deficient mutant assay further revealed that 14j had very different activities compared to DHGA 5 as it specifically inhibits gibberellin biosynthetic pathways. In addition, 14j does not influence the interaction between gibberellin receptors (GID1) and the master growth repressor (RGA) based on yeast two-hybrid assay. CONCLUSION: The optimized synthetic route provides a promising method for large-scale preparation of DHGA 5 . Our biological assays indicate that 14j likely acts on gibberellin signaling elements other than GID1. These results indicate that novel plant growth regulators can be developed. Synthesis of DHGA 5 (Compound 8)The optimized synthetic route of DHGA 5 (8) is shown in Fig. 3.Synthesis of (The intermediate 2 was prepared as described previously. 26 A mixture of GA 3 (10 g, 28.88 mmol), acetic anhydride (Ac 2 O) (20 mL) and 4-dimethylaminopyridine (DMAP) (36 mg, 0.28 mmol) in anhydrous pyridine (50 mL) was stirred at room temperature (rt) for Pest Manag Sci 2020; 76: 807-817

Design, synthesis and mode of action of novel 3‐chloro‐6‐pyrazolyl picolinate derivatives as herbicide candidates

“…In order to explore the symptomology of plants treated with designed compounds and preliminary bioactivity of synthetic compounds, A. thaliana (Columbia‐0, Col‐0) was cultured and used as a model test plant 28‐30 . Surface‐sterilized seeds were sown onto 1/2 Murashige & Skoog (MS) culture medium, containing 0.8% agar, 1% sucrose and compounds with indicated concentration.…”

o-Nitrobenzyl-Based Caged exo-16,17-Dihydro-gibberellin A5-13-acetate for Photocontrolled Release of Plant Growth Regulators

“…Synthesis of oNB-Based Caged DHGA 5 Derivatives (7a−7c). The design and synthesis of caged DHGA 5 derivatives from GA 3 were mainly based on our previous finding 22 that conjugating carboxyl with benzyl contributes to improved yield. Conventionally, the synthesis of bioactive DHGA 5 involves several steps of hydroxyl and carboxyl protection, double bond hydrogenation, C-3 hydroxyl elimination, and carboxyl group deprotection.…”

“…Additionally, in the total synthesis of DHGA 5 from GA 3 , PRPGs were employed as protecting moieties for the carboxyl, omitting the last step of the conventional synthetic route, i.e., carboxyl deprotection under high-temperature reaction conditions, providing yet another advantage over other synthetic routes (Figure and S1). , The photochemical properties of caged DHGA 5 derivatives obtained after a 6-step reaction sequence were examined. To demonstrate the potential benefits of photocontrolled release, the expression of relevant genes with and without light was monitored by qRT-PCR.…”

Manipulating Gibberellin Control Over Growth and Fertility as a Possible Target for Managing Wild Radish Weed Populations in Cropping Systems

“…The GA3OX GID1-DELLA yeast system we established to determine the GA 3-oxidase capability of RrGA3OX1a, could be used to screen for inhibitory molecules that discriminate between dicot and monocot GA3OX enzymes. In support of this, chemical screens using the basic GID1-DELLA version of this yeast system have identified inhibitors of the GID1-DELLA interaction (Yoon et al, 2013), and has been used to evaluate possible off-target inhibition of GID1-DELLA interaction by new derivatives of 16,17-dihydro-GA 5 (Tian et al, 2020). The GA3OX GID1-DELLA yeast system is semi-quantitative as the GID1-DELLA dependent yeast growth rates are sensitive to GA 4 concentrations (Supplementary Figure S12).…”