Four undescribed pyrethrins from seeds of Pyrethrum cinerariifolium and their aphidicidal activity

Four undescribed pyrethrins C-F (1–4) as well as four known pyrethrins (5–8) were isolated from seeds of Pyrethrum cinerariifolium Trev. The structures of compounds 1–4 were elucidated by UV, HRESIMS, and NMR ((1)H and (13)C NMR, (1)H-(1)H COSY, HSQC, HMBC and ROESY), among which the stereostructure of compound 4 was determined by calculated ECD. Furthermore, compounds 1–4 were evaluated for their aphidicidal activities. The insecticidal assay results showed that 1–4 exhibited moderate aphidicidal activities at the concentration of 0.1 mg/mL with the 24 h mortality rates ranging from 10.58 to 52.98%. Among them, pyrethrin D (2) showed the highest aphidicidal activity, with the 24 h mortality rate of 52.98%, which was slightly lower than the positive control (pyrethrin II, 83.52%). GRAPHICAL ABSTRACT: [Image: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13659-023-00385-0.