Phytochemical studies and evaluation of the antifungal activities of Hypochaeris radicata L. leaves against rice fungi: Bipolaris oryzae and Curvularia lunata

The aim of the study is to evaluate the phytochemistry and the antifungal activities of the leaf extract of Hypochaeris radicata L. against Bipolaris oryzae and Curvularia lunata pathogenic fungi on rice. The mineral elements were analyzed using a portable XRF analyzer. Total polyphenol content was evaluated using the Folin-Ciocalteu method; total flavonoid content using aluminium trichloride and total condensed tannin content using vanillin. Anti-radical activity was evaluated using the DPPH method. The antifungal activity of the leaf extract at various concentrations was assessed following the agar dilution method with observation of mycelial growth over time. The obtained results showed that leaf powders contain iron, potassium, and magnesium. Decoction of the leaf extracts of H. radicata contain 101.08±0.47 mg GAE/g of total polyphenols, 302.92±9.35 mg QE/g of total flavonoids and 2.49±0.04 mg CE/g of tannins. The extracts also exhibit anti-radical activity with an EC₅₀ of 48.61±1.48 µg/mL. The antifungal sudies against both fungi show that the extracts caused a sterile growth of the mycelium with a decrease in the number of conidia after sporulation measurement. Therefore, one can conclude that the decocted leaf extract of H. radicata could be used as a natural antifungal against Bipolaris oryzae and Curvularia lunata.