Novel platensimycin derivatives with herbicidal activity

Area of Science:

• Natural Product Chemistry
• Agrochemical Research
• Plant Science

Background:

• Increasing weed resistance necessitates novel herbicides with different modes of action.
• Sesquiterpene lactones are explored as potential starting points for new bioactive compounds.
• Lumisantonin and five novel amides were synthesized and tested for herbicidal activity.

Purpose of the Study:

• To synthesize lumisantonin and novel amides from alpha-santonin.
• To evaluate the herbicidal activity of these compounds against various plant species.
• To identify compounds with selective herbicidal action.

Main Methods:

• Efficient synthesis of lumisantonin and five novel amides from alpha-santonin.
• Biological evaluation against two monocotyledons (Sorghum bicolor, Allium cepa) and three dicotyledons (Cucumis sativus, Solanum lycopersicum, Bidens pilosa).
• Assay of seed germination inhibition and plant growth inhibition.

Main Results:

• Lumisantonin inhibited sorghum and onion aerial part development by 76% and 67% at 1000 µM.
• One novel amide inhibited sorghum shoot and radicle growth by 80% and 71% at 1000 µM.
• All compounds demonstrated significant seed germination inhibition.

Conclusions:

• Lumisantonin exhibited the highest overall lethality across tested plant species.
• Two novel amides showed selective inhibition against monocotyledons compared to dicotyledons.
• These sesquiterpene lactones represent promising leads for developing new herbicides.