Sulfoxide-Containing Bisabolane Sesquiterpenoids with Antimicrobial and Nematicidal Activities from the Marine-Derived Fungus LW09.

Phytopathogens, such as phytopathogenic bacteria, fungi, and nematodes, have caused great losses of crops every year, seriously threatening human health and agricultural production. Moreover, marine-derived fungi are abundant sources of structurally unique and bioactive secondary metabolites that could be potential candidates for anti-phytopathogenic drugs. One new sulfoxide-containing bisabolane sesquiterpenoid aspersydosulfoxide A () and nine known analogues (-) were isolated from the marine-derived LW09. The absolute configuration of the sulfur stereogenic center in was determined by electronic circular dichroism (ECD) calculations. Compound showed inhibition activity against , with a minimum inhibitory concentration (MIC) value of 32 μg/mL, whereas, compounds , , and showed antibacterial activities toward , with the same MIC value at 32 μg/mL. Meanwhile, compounds , , and inhibited the fungal spore germination of , with the half maximal effective concentration (EC) values of 54.55, 77.16, and 1.85 μg/mL, respectively, while compounds , , , and inhibited the fungal spore germination of , which could be induced by vacuolization of germ tubes, with EC values of 34.04, 44.44, 26.02, and 46.15 μg/mL, respectively. In addition, compounds , , and exhibited nematicidal activities against second-stage juveniles (J2s). In addition, compound possessed the strongest nematicidal activity of nearly 80% mortality at 60 h with the half lethal concentration (LC) values of 192.40 μg/mL. Furthermore, compounds , , and could paralyze the nematodes and then impair their pathogenicity.