Synthesis and Biological Profiling of Novel Strigolactone Derivatives for Arabidopsis Growth and Development

2D MOF@Fe₃O₄@rGO as magnetic solid-phase extraction and supercritical fluids chromatography-tandem mass spectrometry quantification of strigolactones stereoisomers in rice (Oryza sativa L.)

Strigolactones (SLs) are novel plant hormones that play crucial roles in regulating plant growth and development. The stereoisomers of SLs often exhibit distinct biological activities, making their chiral separation and analysis essential for understanding their regulatory roles in plant branching. This study focused on the chiral separation and characterization of SL stereoisomers, including GR24 (synthetic) and strigol (natural). A magnetic nanocomposite (Ni₃(HITP)₂@Fe₃O₄@rGO) was synthesized for SL extraction, combined with SFC-MS/MS for precise separation and quantification. The method exhibited excellent linearity (0.2-50 ng/mL), minimal matrix effects (1.64-2.17 %), and low detection limits (1.93-3.76 pg/mL). Recoveries ranged from 86.90 % to 106.37 % with RSDs of 2.56 %-13.54 %. Under nitrogen and phosphorus stress, only (+)-strigol was detected in the roots of Oryza sativa L., suggesting its regulatory role under stress conditions. This reliable method provides robust support for exploring the physiological roles of SL stereoisomers in plants, shedding light on their functions in stress response and development.

Development of Dispersive Liquid-Liquid Microextraction Method Based on Solidification of Floating Organic Droplets for Rapid Determination of Three Strigolactones in Rice (Oryza sativa L.) Using Ultra-High-Performance Liquid Chromatography-Tandem Mass Spectrometry

Strigolactones (SLs) are key hormones regulating branching and tillering in rice, impacting plant architecture and yield. A rapid, sensitive, and environmentally friendly method using dispersive liquid-liquid microextraction based on the solidification of floating organic droplets (DLLME-SFO), coupled with ultra-high-performance liquid chromatography and tandem mass spectrometry (UHPLC-MS/MS), has been developed for the determination of three SLs (strigol, orobanchol, and 5-deoxystrigol). The DLLME-SFO method integrates one-step low-temperature extraction and enrichment. The DLLME-SFO conditions were optimized through a single-factor experimental design. Under the best-tested conditions, the developed method exhibited excellent linearity, with the coefficient of determination (R2) values greater than 0.9993. The recoveries ranged from 83% to 96%, with precision values ranging from 4.5% to 12.4%. The limits of detection (LODs) varied from 0.6 to 1.2 pg/g fresh weight, indicating the high sensitivity of the method. Additionally, a novel assay protocol for the quantification of SLs in rice in response to nitrogen and phosphorus stress conditions was applied.

Natural α-Methylene-γ-Butyrolactone Analogues: Synthesis and Evaluation of Isoaurone Derivatives as Antifungal Agents

In order to develop novel, efficient and green fungicides, a series of novel isoaurone derivatives were designed and synthesized, which were characterized by 1H and 13C NMR, high-resolution mass spectra and melting points. The target compounds showed different inhibitory activities against seven plant pathogenic fungi. Compounds 1, 12, 17, 20, 22, 24 and intermediate A showed more than 90 % inhibition rates against S. s at 50 mg/L. Interestingly, compound 22 and intermediate A showed the great inhibitory effect against S. s with EC50 values of 4.65 and 4.24 mg/L, which were better than the lead compound isoaurone (EC50=15.62 mg/L). The EC50 values of compounds 17 and 24 against B. c were 13.94 and 22.13 mg/L. Moreover, compound 19 displayed significant antifungal activity against G. g with the EC50 value of 11.88 mg/L. Theoretical calculations by DFT revealed that the α, β-unsaturated carbonyl bond and the benzyl ring are very importantly linked to the strength of the fungicidal activity. Therefore, this study identified a valuable antifungal lead compound for further development of green fungicides.

Design, synthesis and antifungal activity of novel α-methylene-γ-butyrolactone derivatives containing benzothiophene moiety

BACKGROUND

The discovery of agricultural fungicide candidates from natural products is one of the key strategies for developing environment friendly agricultural fungicides with high efficiency, high selectivity and unique modes-of-action. Based on previous work, a series of novel α-methylene-γ-butyrolactone (MBL) derivatives containing benzothiophene moiety were designed and synthesized.

RESULTS

The majority of the proposed compounds displayed moderate to considerable antifungal efficacy against the tested pathogenic fungi and oomycetes, some exhibiting broad spectrum antifungal activity. Notably, compounds 2 (3-F-Ph) and 7 (4-Cl-Ph) showed excellent antifungal activity against Rhizoctonia with half maximal effective concentration (EC50) values of 0.94 and 0.99 mg L-1, respectively, comparable to the commercial fungicide tebuconazole (EC50 = 0.96 mg L-1), and also displayed significant inhibitory effects against V alsa mali with EC50 values of 2.26 and 1.67 mg L-1, respectively - better than famoxadone and carabrone. The in vivo protective and curative effects against R. solani of compound 2 were 57.2% and 53.7% at 100 mg L-1, respectively, which were equivalent to tebuconazole (51.6% and 52.4%). Further investigations found that compound 2 altered the ultrastructure of R. solani cell, significantly increased the relative conductivity of the cells, and reduced the activity of complex III in a dose-dependent manner. Molecular docking results showed that compound 2 matched well with the Qo pocket.

CONCLUSION

The results revealed that MBL derivatives containing benzothiophene moiety are promising antifungal candidates and provide a new backbone structure for further optimization of novel fungicides. © 2024 Society of Chemical Industry.

Chemistry of Strigolactones, Key Players in Plant Communication

Today, the use of artificial pesticides is questionable and the adaptation to global warming is a necessity. The promotion of favorable natural interactions in the rhizosphere offers interesting perspectives for changing the type of agriculture. Strigolactones (SLs), the latest class of phytohormones to be discovered, are also chemical mediators in the rhizosphere. We present in this review the diversity of natural SLs, their analogs, mimics, and probes essential for the biological studies of this class of compounds. Their biosynthesis and access by organic synthesis are highlighted especially concerning noncanonical SLs, the more recently discovered natural SLs. Organic synthesis of analogs, stable isotope-labeled standards, mimics, and probes are also reviewed here. In the last part, the knowledge about the SL perception is described as well as the different inhibitors of SL receptors that have been developed.