Pinnatifone A, isolated from Syringa pinnatifolia (Oleaceae), exhibits inhibitory activity against phytopathogenic fungi and can be employed to formulate a soluble concentrate agent

Abstract

BACKGROUND

In the realm of plant diseases, those caused by fungi and oomycetes are particularly challenging to manage, resulting in significant economic losses. There exist diverse active substances in natural products and developing them into fungicides holds great significance. At the initial phase of our research, we discovered that Syringa pinnatifolia extract demonstrates broad-spectrum inhibitory activity against phytopathogenic fungi.

RESULTS

S. pinnatifolia extracts showed inhibitory activity against phytopathogenic fungi in vivo and in vitro, especially Valsa mali and Botrytis cinerea. Totals of eight compounds were isolated by bio-guided isolation (SCX-1 to SCX-8). Among these compounds, 3-methoxy-4-hydroxybenzaldehyde (SCX-2) and pinnatifone A (SCX-8) were found to have excellent antifungal activities against phytopathogenic fungi, the half maximal effective concentration (EC₅₀) of SCX-2 against V. mali was 45.34 μg/mL, the EC₅₀ of compound SCX-8 against B. cinerea was 9.25 μg/mL. Here a formulation of a soluble concentrate agent is presented for the prevention and control of tomato gray mold. This formulation included 45% S. pinnatifolia extract (containing 2.1% pinnatifone A), 16% benzyl alcohol, 24% absolute ethanol, 5% ethylene glycol, and 10% pesticide emulsifier No. 602. The preparation exhibited good protective and curative efficacies against tomato gray mold at a concentration of 100 μg/mL, with efficacies of 65.32% and 54.83%.

CONCLUSION

Our findings provide valuable insights for the structural modification of active compounds derived from S. pinnatifolia and lay a foundation for the development of novel botanical fungicide products utilizing S. pinnatifolia as a raw material. © 2025 Society of Chemical Industry.