New Azaphilone Derivatives from the Deep-sea Fungus Talaromyces indigoticus FS688

Three new azaphilone derivatives, talaraculones G-I (1-3), along with three known analogs (4-6), were isolated from the deep-sea-derived fungus Talaromyces indigoticus from the South China Sea. The structures of the compounds were identified through spectroscopic methods and confirmed by comparison with data reported in the literature. The absolute configurations of compounds 1 and 3 were determined using the DP4+ method and electronic circular dichroism calculations. Bioactivity assays revealed that compounds 1 and 3 exhibited significant inhibitory activities against α-glucosidase with IC₅₀ values of 58.38 ± 6.40 and 43.07 ± 6.27 µM, respectively, which were stronger than those of the positive control acarbose. Compound 4 strongly inhibited the production of nitric oxide with an IC₅₀ value of 20.95 ± 0.75 µM, showing higher potency than the positive control indomethacin.