Steroids With Insecticidal Activity Against the Larvae of Diaphorina citri Kuwayama From Tinospora sagittata

Abstract

Twelve steroids (1−12) including one undescribed and a new natural product were isolated from the roots of Tinospora sagittata. The chemical structures of those compounds were elucidated by spectroscopic methods, electronic circular dichroism (ECD) or single-crystal x-ray diffraction analysis. Notably, compounds 2 and 3 are a pair of C-5 epimers. Except for compounds 3 and 4, the remaining compounds were isolated from Tinospora sagittata (T. sagittata) for the first time. Biologically, at a concentration of 1 and 10 mg/L, two compounds showed insecticide activity. Especially, at a concentration of 10 mg/L, compounds 6 and 12 showed the potent activities, with corrected mortality rates of 68.42% and 71.07%, comparable to that of the positive control spirotetramat (71.07%). Research on the potential insecticidal mechanism of compound 12 revealed that six target proteins were predicted via network pharmacology and molecular docking analyses, with EGFR subsequently identified as the most probable target through western blot verification.