Nine polyketides, including two new benzophenone derivatives, peniphenone (1) and methyl peniphenone (2), along with seven known xanthones (3–9) were obtained from mangrove endophytic fungus Penicillium sp. ZJ-SY2 isolated from the leaves of Sonneratia apetala. Their structures were elucidated on the basis of MS, 1D, and 2D NMR data. Compounds 1, 3, 5, and 7 showed potent immunosuppressive activity with IC50 values ranging from 5.9 to 9.3 μg/mL.
Three new isocoumarins—dichlorodiaportintone (1), desmethyldichlorodiaportintone (2) and desmethyldichlorodiaportinol (3)—as well as six known analogues (4–9) were isolated from the culture of the mangrove endophytic fungus Ascomycota sp. CYSK-4 from Pluchea indica. Their structures were elucidated by analysis of spectroscopic data. The absolute configuration of compounds 1 and 2 were determined by the modified Mosher’s method. Compound 2 showed significant anti-inflammatory activity by inhibiting the production of NO in LPS-induced RAW 264.7 cells with IC50 value of 15.8 μM, while compounds 1, 5, and 6 exhibited weak activities with IC50 values of 41.5, 33.6, and 67.2 μM, respectively. In addition, compounds 1, 5, and 6 showed antibacterial effects against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae, and Acinetobacter calcoaceticus with the MIC values in the range of 25–50 μg·mL−1.
Twelve 1, 4-naphthoquinone derivatives, including two new (1 and 2) and 10 known (3–12), were obtained from endophytic fungus Talaromyces sp. SK-S009 isolated from the fruit of Kandelia obovata. All structures were identified through extensive analysis of the nuclear magnetic resonance (NMR), mass spectrometry (MS) and circular dichroism (CD), as well as by comparison with literature data. These compounds significantly inhibited the lipopolysaccharide (LPS)-induced nitric oxide (NO) production in the murine macrophage cell line (RAW 264.7 cells). The half maximal inhibitory concentration (IC50) values, except for compound 2, were lower than that of indomethacin (26.3 μM). Compound 9 inhibited the LPS-induced inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) mRNA expressions in RAW 264.7 macrophages. Additionally, compound 9 reduced the mRNA levels of pro-inflammatory factors interleukin (IL)1β, IL-6, and tumor necrosis factor (TNF)-α. The results of this study demonstrated that these 1, 4-naphthoquinone derivatives can inhibit LPS-induced inflammation.
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 Fusarium sp. YD-2, derived from the twigs of Santalum album. 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 in vitro 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 Staphylococcus aureus and Pseudomonas aeruginosa with an MIC value of 6.3 μg mL−1, and compound 3 showed moderate activities against Salmonella enteritidis and Micrococcus luteus with MIC values of 6.3 and 25.2 μg mL−1, respectively.