Constituents of the Argentine Liverwort Plagiochila diversifolia and Their Insecticidal Activities

Three new compounds, a bicyclogermacrene ( 1 ) and two 2,3‐secoaromadendrane esters ( 2 and 3 ), together with (13S)‐13‐hydroxylabda‐8,14‐diene ( 4 ), fusicogigantone B ( 5 ), 3α,14‐diacetoxy‐2‐hydoxybicyclogermacrene ( 6 ), fusicogigantone A ( 7 ), neofuranoplagiochilal ( 8 ), plagiochiline B ( 9 ), furanoplagiochilal ( 10 ), trans‐nerolidol, spathulenol, α‐tocopherol, and (+)‐globulol were isolated from an Argentine collection of Plagiochila diversifolia. Their structures were elucidated by extensive mono and bidimensional NMR studies. Compounds 4 , 5 , and 6 , incorporated to the larval diet at 100 μg per g of diet, reduced the larval growth of Spodoptera frugiperda (Lepidoptera: Noctuidae) by 70 ± 25, 57 ± 23, and 33 ± 16%, respectively. Compounds 4 and 5 produced 70% and 60% larval mortality at early instars. The latter also showed antifeedant properties in the Choice Test, with a feeding ratio of 0.54 ± 0.16.