New pyrone and cyclopentenone derivatives from marine-derived fungus Aspergillus sydowii SCSIO 00305

Abstract

Two new 2-pyrone derivatives sydowiones A-B (1, 2), one new cyclopentenone derivative sydowione C (3), and one new sterigmatocystin derivative sydowione D (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 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 LC 50 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 IC 50 values of 46.0 and 46.6 μM, respectively.

Unravelling the Secrets of α‐Pyrones from Aspergillus Fungi: A Comprehensive Review of Their Natural Sources, Biosynthesis, and Biological Activities

“…These compounds demonstrated mild toxicity against brine shrimp nauplii, with LC 50 values of 19.5 and 14.3 μM, respectively. Moreover, they exhibited antioxidant activity, with IC 50 values of 46.0 and 46.6 μM, respectively [101] . As for the marine gorgonian‐derived fungus Aspergillus sp.…”

“…[91] During the investigation of marine-derived fungi, the previously uncharacterized Aspergillus similanensis KUFA0013, associated with a marine sponge, demonstrated remarkable prolificity in producing a novel isocoumarin derivatives. Besides the isolation of similanpyrone A (68) and B (69) and pyripyropene S (70) together with 6,8-dihydroxy-3-methylisocoumarin (99), reticulol (100), chevalone B (86), meroterpenoid S14-95 (101), and pyripyropene E (102), [77] Prompanya C. and coauthors had the opportunity in an alternative study to isolate similanpyrone C (103), a new isocoumarin derivative along with new pyripyropene analog, pyripyropene T (104), from the same fungus Aspergillus similanensis KUFA0013. [94] An in vitro test was performed to evaluate the activity of the isolated compounds, compound 104 showed only weak activity against MCF-7 (breast cancer), NCIÀ H460 (non-small cell lung cancer), and A373 (melanoma); furthermore, no antibacterial activity was detected against the tested strains.…”

Marine natural products

“…158 Aspergillus strains derived from soft corals were the source of cyclic hexapeptides 337–339 , 159 lipodepsipeptide 340 , 159 2-pyrone derivatives 341 and 342 , cyclopentenone derivative 343 and austocystin derivative 344 . 160 Co-culture of A. sydowii wth the bacterium Bacillus subtilis induced production of 25 known and new metabolites by the fungus including serine sydonate 345 and an isomer of macrolactin U 346 . 161 Furanaspermeroterpenes A 347 and B 348 , meroterpenoids with an unique 6/6/6/5/5 pentacyclic skeleton were isolated from a gastropod-derived Aspergillus terreus strain, along with five further meroterpenes 349–353 .…”

Two New Phomaligols from the Marine-Derived Fungus Aspergillus flocculosus and Their Anti-Neuroinflammatory Activity in BV-2 Microglial Cells

“…The fungal strain was fermented and extracted with EtOAc, and then the extract was evaporated under reduced pressure to yield a crude extract, which was fractionated by flash column chromatography on ODS using mixtures of MeOH/H 2 O. The fractions were purified by reversed-phase HPLC to afford two new compounds (1 and 2) together with six known compounds, sydowione A (3) [14], 2,6-dimethyl-3-O-methyl-4-(2-methylbutyryl) phloroglucinol (4) [15], phomaligol A (5) [16], phomaligol A 1 (6) [16], saccharonol A (7) [17], and phomaligol D (8) [18] (Figure 1). Their structures were elucidated by spectroscopic methods (1D, 2D NMR and HRESIMS), modified Mosher's method, acid hydrolysis and comparison of specific rotation values with the literature data as shown in Figure 1.…”