Eremophilane Sesquiterpenoids with Antibacterial and Anti-inflammatory Activities from the Endophytic Fungus Septoria rudbeckiae
Fourteen eremophilane sesquiterpenoids (1–14), including nine new congeners, septoreremophilanes A–I (1–9), together with three known sesquiterpenes (15–17), two known tetralone derivatives (18, 19), and two known cholesterol analogues (20, 21), were isolated from the endophytic fungus Septoria rudbeckiae. Compounds 1–6 and 7a belong to the family of the highly oxygenated eremophilane sesquiterpenoids with a 6/6/5 tricyclic system and bearing a hemiacetal moiety. The inhibitions of all metabolites against eight bacteria were estimated in vitro, and nine new metabolites (1–9) were tested for antineuroinflammatory activity. Notably, the effects of 4 against Pseudomonas syringae pv. actinidae and 20 against Bacillus cereus displayed potent inhibitory, with the MIC values of 6.25 and 6.25 μM, respectively. Further, scanning electron microscopy analyses indicated that 4 and 20 were to change the outer configuration of bacterial cells, respectively, and the investigations demonstrated that 4 and 20 may act as potential structure templates for the development of the agrochemical bactericides. Additionally, compound 6 displayed potent inhibition of NO generation in lipopolysaccharide-induced BV-2 microglial cells (IC50 = 12.0 ± 0.32 μM), and the conceivable anti-inflammatory mechanisms implicated were also investigated by molecular docking. Thus, the bioactive metabolites of the strain S. rudbeckiae may serve as a novel resource to be developed.
危险品化学品经营许可证（带存储）