Germacrone Derivatives as new Insecticidal and Acaricidal Compounds: A Structure-Activity Relationship

Area of Science:

• Natural Product Chemistry
• Organic Synthesis
• Agricultural Science

Background:

• Synthetic pesticides pose environmental and health risks.
• Excessive pesticide use drives resistance and non-target toxicity.
• Sustainable pest management requires novel, eco-friendly alternatives.

Purpose of the Study:

• To develop novel pest control agents from the natural product germacrone.
• To generate molecular diversity from germacrone for enhanced biocidal activity.
• To identify potent derivatives for sustainable agriculture and horticulture.

Main Methods:

• Germacrone was used as a starting material for synthesizing 24 derivatives.
• Some synthesized compounds were identified as known natural products.
• Novel epoxygermacrone derivatives were synthesized and characterized.
• Biocidal activity was screened against the tick *Hyalomma lusitanicum*.
• Insect antifeedant activity was tested against *Rhopalosiphum padi*.

Main Results:

• Compound 24 exhibited four times higher acaricidal activity than germacrone.
• Compound 2 demonstrated insect antifeedant potency 1000 times greater than germacrone against *Rhopalosiphum padi*.
• Several known and novel germacrone derivatives were synthesized and evaluated.
• Compounds 17, 23, and 24 were described for the first time.

Conclusions:

• Germacrone derivatives offer promising avenues for developing selective and potent pesticides.
• Compound 24 is a potential lead for new acaricides.
• Compound 2 represents a highly effective selective antifeedant for cereal pest control.
• This research contributes to sustainable pest management strategies.