Potential effects of fungicide and algaecide extracts of Annona glabra L. (Annonaceae) on the microalgae Raphidocelis subcapitata and on the oomycete Pythium

Abstract

Annona glabra L. is a semi-deciduous tree that contains several active substances, including secondary metabolites, with antifungal activity. Phytopathogenic strains of the genus Pythium cause billion dollar losses all over the world on natural and crop species. Searching for eco-friendly algaecides and fungicides, we analyzed the effects of acetone extracts of A. glabra leaves on the algae Rhaphidocelis subcapitata (Korshikov) and on the oomycete Pythium aphanidermatum (Edson). We evaluated ten extract concentrations for each organism -0 to 400 mg L -1 for algae and 0-1000 µg disc 1 for oomycete. The results showed no effect on algae up to 75 mg L -1 , but a significant inhibitory effect at 125 mg L -1 and above, which reduced the growth rate and the final biomass of the algae. Extract concentrations above 200 mg L -1were completely inhibitory. The half maximal inhibitory concentration for 72 and 96 h of exposure to our crude extracts are comparable to those obtained with commercial fungicides and herbicides used in aquatic ecosystems. The P. aphanidermatum inhibition concentrations have effects comparable to fungicides as Cycloheximide and Bifonazole. Some substances isolated from the extracts are described as antifungals, which could explain part of anti-oomycete activity. Our results highlight the importance of searching bioactive compounds from plants.

Evaluation of the anti-Leishmania mechanisms of Annona glabra L. (Annonaceae): A brief review

“…Its popular names are: "araticum", "araticum-do-rio", "araticum-panã", "araticum do brejo", "araticum-cortiça", "araticum-da-praia", "araticum-de-jangada". Studies on A. glabra have demonstrated a large amount of compounds of diverse chemical nature present in extracts prepared from bark, stem, leaves and fruit with anti-inflammatory potential on HIV virus replication in lymphocytes, as a cytotoxic agent, trypanocidal, larvicidal, antimicrobial, vermifuge, sporicidal, analgesic, contraceptive, anti-inflammatory and anti-Leishmania (Rocha et al, 2017;Amarasingue et al, 2020). The species is abundant and common in Brazilian forests, but with few population data.…”

BIOACTIVITY ANALYSIS OF Annona glabra L. SEED EXTRACTS FOR WOOD PROTECTION AGAINST TERMITES (Cryptotermes cynocephalus Light. AND Coptotermes curvignathus Holmgren.)

“…The seed extracts of A. squamosa and A. muricata have repellent effects on Coptotermes gestroi (Acda, 2014). A. glabra is from the family of Annonaceae, which produces several secondary metabolites that have antifungal (Rocha, Matsumoto, Lombardi, & Lima, 2017), larvicidal and insecticidal activities (Mohankumar, Shivanna, & Achuttan, 2016). In general, the seed extracts contain more potent substances than the extracts from other plant parts (Saripalli & Dixit, 2016).…”