Pesticide and antimicrobial evaluation of three labdane-type diterpenes, and one flavonoid glycoside, isolated from rhizomes of <i>Hedychium coronarium</i> J. Koenig

Three labdane-type diterpenes, namely coronalactoside I, hedychilactone A, and (<i>E</i>)-labda-8(17),12-dien-15(16)-olide, along with the flavonoid glycoside Isolinariin A, were isolated from <i>Heydichium coronarium</i>. Structural elucidation employed spectroscopic techniques (IR, MS, NMR, and DEPT) and comparison with literature data. Pesticidal and antimicrobial activities were assessed. Isolinariin A exhibited potent nematicidal activity (71.33% mortality) against <i>Meloidogyne incognita</i>, while Coronalactoside I demonstrated strong inhibition of nematode egg hatchability (26.00% at 1 µg/mL). In insecticidal activity against <i>Spodoptera litura</i>, (<i>E</i>)-labda-8(17),12-dien-15(16)-olide displayed significant mortality (93.66% at 100 µg/mL). Molecular docking studies indicated favourable interactions with target proteins, suggesting potential in pest management. These findings propose the application of these compounds to mitigate the ecological impact of synthetic pesticides.