LAUSR

UPLC-MSE guided isolation of CHCl3 extract from the fruits of Trichilia connaroides yielded two new mexicanolide-type limonoids trichanolide F (1) and trichanolide G (2) along with a known compound carapanolide U (3). The structures of the limonoids were established on the basis of extensive analysis of spectroscopic (IR, MS, 2D NMR) data. These limonoids (1-3) were evaluated for their antifeedancy against Spodoptera litura F. using no choice leaf disc assay. To further explore and draw the meaningful structure activity relationship studies, secophragmalin-type limonoids namely secotrichagmalin B, C (4, 5) and semi-synthetic derivatives (5a-5l) were also screened for antifeedancy. The results revealed that trichanolide F (1) displayed highest antifeedant index (AFI) and caused larval mortality at 24 h. Derivative 5b caused larval toxicity, whereas 3, 5a, 5d and 5g lead to pupal mortality and 2, 5f, 5k and 5l caused adult deformities. Overall, the study provided new insights into the antifeedant potential of isolated and chemically modified limonoids from T. connaroides for the control of spodopteran pests.