Bioactive terpenoids from <i>Santalum album</i> derived endophytic fungus <i>Fusarium</i> sp. YD-2

Abstract

Two new spiromeroterpenoids, namely fusariumin A (1) and B (2), along with four known terpenoids, asperterpenoid A (3), agathic acid (4), guignardone N (5), and trametenolic acid (6), were obtained from the endophytic fungus <i>Fusarium</i> sp. YD-2, derived from the twigs of <i>Santalum album</i>. Their structures were elucidated by a combination of spectroscopic analyses. The absolute configuration of 1 was determined by single-crystal X-ray diffraction using Cu Kα radiation, and that of 2 was elucidated on the basis of experimental and calculated electronic circular dichroism spectra. Compound 2 exhibited moderate anti-inflammatory activity <i>in vitro</i> by inhibiting nitric oxide (NO) production in lipopolysaccharide activated RAW264.7 cells with an IC₅₀ value of 50 μM, and compound 3 showed strong anti-inflammatory activity with an IC₅₀ value of 1.6 μM. In the antibacterial assay, compound 1 displayed significant activities against <i>Staphylococcus aureus</i> and <i>Pseudomonas aeruginosa</i> with an MIC value of 6.3 μg mL^-1, and compound 3 showed moderate activities against <i>Salmonella enteritidis</i> and <i>Micrococcus luteus</i> with MIC values of 6.3 and 25.2 μg mL^-1, respectively.