Phytotoxic, antifungal and antiplasmodial properties of diterpenes isolated from Copaifera resins

Abstract

Diterpenes are bioactive secondary metabolites with diverse pharmacological and agricultural applications. In this study, four diterpenes—ent-polyalthic acid (1), ent-dihydroagathic acid (2), ent-kaurenoic acid (3), and ent-kaurenol (4)—were isolated from copaiba oil-resins and evaluated for their phytotoxic, antifungal, and antiplasmodial activities. Phytotoxicity assays revealed herbicidal activity against Agrostis stolonifera, with ent-polyalthic acid and ent-kaurenoic acid exhibiting the highest efficacy, inhibiting seed germination. ent-dihydroagathic acid also showed phytotoxicity against Lemna paucicostata with IC₅₀ value of 3.8 µM. All compounds inhibited the growth of Colletotrichum fragariae in a bioautography bioassay, with ent-kaurenoic acid exhibiting the highest activity. Molecular docking studies demonstrated favorable binding affinities of ent-polyalthic acid and ent-dihydroagathic acid to Plasmodium falciparum lactate dehydrogenase. Pharmacokinetic assessments indicated adherence to Lipinski’s Rule of Five and suitable properties for oral bioavailability. These findings shows the potential of these diterpenes, particularly ent-polyalthic acid, as lead compound for herbicidal and antimalarial drug development.