Abstract Two new 2-pyrone derivatives sydowiones A-B (1, 2), one new cyclopentenone derivative sydowione C (3), and one new mycotoxin 6-methoxyl austocystin A (4) along with two known analogues paecilpyrone… Click to show full abstract
Abstract Two new 2-pyrone derivatives sydowiones A-B (1, 2), one new cyclopentenone derivative sydowione C (3), and one new mycotoxin 6-methoxyl austocystin A (4) along with two known analogues paecilpyrone A (5) and austocystin A (6), were isolated from the marine-derived fungus Aspergillus sydowii SCSIO 00305. The structures of 1–4 were elucidated by extensive spectroscopic analysis. The absolute configuration of C-8 in 1 was established by Mosher method, and further confirmed by calculation of the electronic circular dichroism (ECD) spectra. The absolute configuration of C-11 in 3 was also determined by calculation of ECD spectra. The absolute configuration of 6 was determined by a single-crystal X-ray diffraction experiment for the first time. Compounds 1–4 showed moderate toxicity towards brine shrine naupalii with LC50 values of 19.5, 14.3, 8.3 and 2.9 μM, respectively. And 1 and 2 also showed antioxidant activity against 2,2-diphenyl-picrylhydrazyl (DPPH) radicals with IC50 values of 46.0 and 46.6 μM, respectively.
Journal Title: Natural Product Research
Year Published: 2019
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