Design and synthesis of strigolactone analogues and mimics containing indolin-2-one scaffold for the Phelipanche control.

BACKGROUND

The broomrapes are root-parasitic weeds widely distributed in the temperate zone area. The effective management on the Phelipanche and Orobanche parasitic weeds still remains challenging to date.

RESULTS

Novel strigolactone (SL) analogues (X series) and mimics (O series) derived from indolin-2-one were designed and synthesized. Of them, compound O-3 showed nearly ten-fold higher seed germination activity (median effective concentration (EC50) = 0.0066 μm) towards Phelipanche aegyptiaca seeds compared to the control GR24. Moreover, it also showed prominent seed germination activity towards Phelipanche ramosa. At a dosage of 0.2 μm, the glasshouse experiment revealed that compound O-3 not only displayed the profitable P. aegyptiaca control, but also influenced fruit and plant stalk development in tomato cultivation. Theoretical computational studies indicated that compound O-3 could perfectly interact with catalytic triad of OmKAI2d4, and the oxime linker facilitate to release the active D ring species, thereby significantly improving bioactivity.

CONCLUSIONS

A class of SL mimics incorporating a unique oxime linker has been developed from indolin-2-one. Compound O-3 exhibited the highest seed germination activities toward the parasitic P. aegyptiaca and P. ramosa, and could serve as a promising lead compound for the Phelipanche control. © 2025 Society of Chemical Industry.