Composition and Antifungal Properties of Phenolic Extracts from Sunflower Hulls

MARTINEZ, GUADALUPE; REGENTE, MARIANA; DEL RIO, MARIANELA; RADICIONI, MELISA BELÉN; PINEDO, MARCELA; SILVEYRA, MARIA XIMENA; DE LA CANAL, LAURA

SSRN Electronic Journal

Elsevier

Año: 2022

Plants produce diverse types of secondary metabolites, including phenolic compounds, which are involved in protection against fungal infections. Sunflower hulls, an under-appreciated by-product of the oil industry, is a natural source of phenolic compounds. The aim of this work was to characterize the composition of natural extracts from sunflower hulls, evaluate their ability to inhibit the growth of phytopathogenic fungi and provide insights on its mechanism of action. We obtained an extract enriched in phenolic compounds (EPC) by hydroalcoholic extraction of sunflower hulls. The analysis by LC-MS/MS showed that the main phenolic compound of EPC was chlorogenic acid. The extract exhibited strong antioxidant activity determined by radical scavenging assay using DPPH. Through different experimental approaches, we showed that the EPC exerts a potent fungicidal action against the phytopathogenic fungi Sclerotinia sclerotiorum, Fusarium solani, Fusarium oxysporum, Verticillium dalhiae and Botrytis cinerea. Our findings indicate that EPC displayed cytotoxic effects mediated by membrane permeabilization and oxidative stress on fungal cells. Our results contribute to valorize an agro-industrial by-product that is usually discarded, through its potential application as a biofungicide.