New polyketides from the starfish-derived symbiotic fungus Penicillium sp. GGF16-1-2.

One new rare carbon-bridged citrinin dimer quinocitrindimer C (1) as a pair of epimers, two new polyketide penicilliodes D (3) and E (4) together with nine known citrinin derivatives, were isolated from the fermentation broth of starfish-derived symbiotic fungus Penicillium sp. GGF16-1-2. Their structures and configurations were elucidated by comprehensively spectroscopic data analysis and electronic circular dichroism calculations. Eleven citrinin derivatives were tested by Colletotrichum gloeosporioides, and compound 2 played a significant antifungal activity against Colletotrichum gloeosporioides with LC50 value of 0.27 µg/ml.

New Indole Diketopiperazine Alkaloids from Soft Coral-Associated Epiphytic Fungus Aspergillus versicolor CGF 9-1-2.

Two new indole diketopiperazine alkaloids (IDAs), (+)19-epi-sclerotiamide (1) and (-)19-epi-sclerotiamide (2), along with 13 known analogs (3-15), were isolated from a soft coral-associated epiphytic fungus Aspergillus versicolor CGF 9-1-2. The structures of two new compounds were established based on the combination of HR-ESI-MS, 1D and 2D NMR spectroscopy, optical rotation measurements and quantum chemical 13 C-NMR, the absolute configurations were determined by experimental and electronic circular dichroism (ECD) calculations. The results of molecular docking showed that all the compounds had a good binding with TDP1, TDP2, TOP1, TOP2, Ache, NLRP3, EGFR, EGFR L858R, EGFR T790M and EGFR T790/L858. Biological evaluation of compounds 3, 6, 8, 11 showed that 3 exerted a strong inhibitory effect on TDP2 with a rate of 81.72 %.

Bioactive Aspergteroids G-J from Soft-Coral-Associated Symbiotic and Epiphytic Fungus Aspergillus terreus EGF7-0-1.

Two new disubstituted maleimides, aspergteroids G-H (1-2), and two trisubstituted butenolides aspergteroids I-J (3-4), along with four known analogs, were isolated and structurally identified from the fermentation extract of soft-coral-associated symbiotic and epiphytic fungus Aspergillus terreus EGF7-0-1. The structures of the new compounds were established mainly via spectroscopic data analyses, and their absolute configurations were determined via X-ray diffraction analysis and comparison of the calculated and experimental electronic circular dichroism. Myocardial protection assays showed that compounds 1, 2, 5, and 6 possess protective effects against tert-butyl hydroperoxide (TBHP)-induced H9c2 (rat myocardial cells) apoptosis at low concentrations. Based on the analyses of the protein-protein interaction (PPI) network and Western blotting, compound 1 may inhibit the apoptosis and inflammatory response of cardiomyocytes after TBHP induction and improve the antioxidant capacity of cardiomyocytes. We speculate that the anti-inflammatory response of compound 1 is suppressed by the glycogen synthase kinase-3 beta (GSK-3ß), downregulated by the NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome activation, and suppressed by the expression of cysteinyl aspartate specific proteinase-3 (caspase-3) and B-cell lymphoma-2 associated X protein (Bax).