# Eco-Friendly Crop Protection: Argyrantemum frutescens, a Source of Biofungicides

## TL;DR

This study explores Argyrantemum frutescens as a source of eco-friendly biofungicides that effectively inhibit harmful plant fungi.

## Contribution

The study identifies and validates polyacetylenes from A. frutescens as potent antifungal compounds with higher efficacy than commercial fungicides.

## Key findings

- Compounds capillin and frutescinone inhibited over 90% of Botrytis cinerea growth at low concentrations.
- Polyacetylenes showed greater antifungal activity than Fosbel-Plus and Azoxystrobin against Fusarium oxysporum.
- The study confirms A. frutescens as a viable source for cultivating biopesticides.

## Abstract

Plant-derived biopesticides are emerging as a promising and popular alternative for promoting cleaner and safer agricultural practices. The present work aims to explore Argyranthemum frutescens (Asteraceae) as a source of botanical pesticides and to validate this through a cultivation process. To this task, a bioassay-guided fractionation of the ethanolic root extracts from both wild and cultivated A. frutescens on phytopathogenic fungi of Botrytis cinerea, Fusarium oxysporum, and Alternaria alternata was conducted. This approach led to the identification of polyacetylenes with higher potency than commercial fungicides. Specifically, compounds 3 (capillin) and 5 (frutescinone) showed more than 90% growth inhibition at 0.05 mg/mL concentration on B. cinerea, while compounds 2 (capillinol) and 3 were also more active than positive controls, Fosbel-Plus and Azoxystrobin, against F. oxysporum. The structures of the isolated polyacetylenes (1–6, 9, and 10) and alkamides (7, 8, and 11) were determined through spectroscopic analysis, and the absolute configuration of stereocenter C1 of compounds 1, 2, 4 and 9 was determined by NMR-spectroscopy with (R)-(-)-α-methoxy-phenylacetic as a chiral derivatizing agent, and biogenetic considerations. Overall, this study supports the potential of polyacetylenes as promising agrochemical lead compounds against phytopathogens, and validates A. frutescens cultivation as a viable source of biopesticides.