New and Antifungal Diterpenoids of Sunflower against Gray Mold

Abstract

Sunflower (Helianthus annuus L.) is cultivated around the world as an oil crop, and its receptacle is the byproduct and is usually deemed to be an agro-industrial waste. Then, phytochemical constituents and antifungal bioactivity of the sunflower receptacle against phytopathogenic fungi were investigated. As a result, 17 diterpenoids including 4 new compounds were isolated, and most of them showed potential antifungal activity against Botrytis cinerea, in which compounds 1, 3, 5, and 15 exhibited better inhibitory effect with the minimum inhibitory concentration values of 0.05−0.1 mg/mL. Meanwhile, four antifungal diterpenoids destructed plasma membrane integrity, suspended the biofilm formation ability, and increased the extravasation of cellular contents of B. cinerea. Moreover, the EtOAc extract of sunflower receptacle could keep 42.9% of blueberries from the invasion of B. cinerea at 1.6 mg/mL. The finding suggested that sunflower receptacle might be a biocontrol agent for preventing fruit from postharvest diseases.

Challenges and Opportunities Arising from Host–Botrytis cinerea Interactions to Outline Novel and Sustainable Control Strategies: The Key Role of RNA Interference

“…What if a waste to be disposed of at a specific cost became a weapon against B. cinerea ? This question was answered by Zhao and colleagues [ 205 ] by evaluating whether an agro-industrial waste product such as sunflower receptacles can be effective against B. cinerea . Indeed, the sunflower receptacle has proven to be a source of interesting diterpenes for use in counteracting B. cinerea infection.…”