Phytochemical profile and insecticidal activity of Drimia pancration (Asparagaceae) against adults of Stegobium paniceum (Anobiidae)

Chemical and spectroscopic investigation of the bulbs of Drimia pancration resulted in the isolation of one known flavonol (1), never isolated from this plant species, and of three previously described steroidal saponins (2–4), but whose configuration at their stereogenic centres was not clearly determined. By mean of 1H NMR, 13C NMR, nuclear overhauser effects (NOE) and two-dimensional NMR spectra the full stereochemical structures of compounds 2–4 were proved and all the 1H and 13C signals were assigned. Furthermore, the methanol and butanol extracts of D. pancration were tested against adults of Stegobium paniceum beetles. Despite the non-significant results regarding the repellent activity and contact toxicity, promising results were obtained from the feeding tests.