The Insecticidal Activity of Secondary Metabolites Produced by sp. SA61 against (Hemiptera: Aleyrodidae).

Westwood poses a significant threat to vegetable and ornamental crops in temperate zones, resulting in notable reductions in yield and substantial economic burdens. In order to find compounds with high insecticidal activity against , five compounds were isolated and identified from the crude extract of sp. SA61. These include three new polyketides, named strekingmycins F-H (-); one new diterpenoid, named phenalinolactone CD8 (); and one known compound, strekingmycin A (). Their structures were analyzed using high-resolution electrospray ionization mass spectrometry and one-dimensional and two-dimensional nuclear magnetic resonance spectroscopy data and by comparing them with previously reported data. The insecticidal activities of compounds - against were evaluated. Among them, compound exhibited the highest insecticidal activity, with an LC of 6.949 mg/L against at 72 h using the leaf-dip method. Lower insecticidal activities were found in compounds -, with LC values of 22.817, 19.150, 16.981 and 41.501 mg/L, respectively. These data indicate that strekingmycin could be a potential candidate for a novel insecticide to control