Yunqiu Li

One new compound named sinulariapeptide F (1) together with one known butyrolactone (2) and seven known peptides (3–9) were isolated from the fungus Simplicillium sp. SCSIO 41222. Their structures and absolute configurations were established using HRESIMS, NMR spectroscopy (¹H, ¹³C, HSQC, HMBC) and marfey’s method. All of these compounds were assessed their inhibitory activity of acetylcholinesterase (AChE) and pancreatic lipase (PL). Compounds 4 and 6 were selected to test for the inhibitory activity against programmed cell death-1 (PD-1)/ programmed cell death-ligand 1 (PD-L1). The results indicated that compound 4 displayed potent inhibition activity against PD-1/ PD-L1 with an IC₅₀ value of 0.656 μM. Furthermore, the docking analysis demonstrated the interactions between 4 and proteins, suggesting PD-L1 to be a probable target for compound 4.

Two new cytochalasin derivatives, peniotrinins A (1) and B (2), three new citrinin derivatives, peniotrinins C–E (4, 5, 7), and one new tetramic acid derivative, peniotrinin F (12), along with nine structurally related known compounds, were isolated from the solid culture of Peniophora sp. SCSIO41203. Their structures, including the absolute configurations of their stereogenic carbons, were fully elucidated based on spectroscopic analysis, quantum chemical calculations, and the calculated ECD. Interestingly, 1 is the first example of a rare 6/5/5/5/6/13 hexacyclic cytochalasin. We screened the above compounds for their anti-prostate cancer activity and found that compound 3 had a significant anti-prostate cancer cell proliferation effect, while compounds 1 and 2 showed weak activity at 10 μM. We then confirmed that compound 3 exerts its anti-prostate cancer effect by inducing methuosis through transmission electron microscopy and cellular immunostaining, which suggested that compound 3 might be first reported as a potential anti-prostate methuosis inducer.

Chemical investigation of the Penicillium sp. SCSIO 41038 led to the isolation and characterization of one new cyclopiazonic acid-type alkaloid, speradine I (1), and one new phloroglucinol derivative, speradine J (8), along with 13 known compounds. Their structures were determined on the basis of extensive spectroscopic analysis, and by a comparison with data from the literature. All the compounds were evaluated for their antitumor (22Rv1 and PC-3) and enzyme inhibitory activity against acetylcholinesterase (AChE) in vitro. Graphical Abstract

Two undescribed cytochalasins, emeriglobosins A (1) and B (2), together with nine previously reported analogues (3–11) and two known tetramic acid derivatives (12, 13) were isolated from the solid culture of Emericellopsis sp. SCSIO41202. Their structures, including the absolute configurations of their stereogenic carbons, were fully elucidated based on spectroscopic analysis and the calculated ECD. Some of the isolated compounds were evaluated for their cytotoxicity and enzyme inhibitory activity against acetylcholinesterase (AChE) in vitro. Among them, 8 showed potent AChE inhibitory activity, with an IC₅₀ value of 1.31 μM, and 5 showed significant cytotoxicity against PC-3 cells, with an IC₅₀ value of 2.32 μM.

The aim of this study was to characterize hydrolyzable tannins in Polygonaceous plants, as only a few plants have previously been reported to contain ellagitannins. From Persicaria chinensis, a new hydrolyzable tannin called persicarianin was isolated and characterized to be 3-O-galloyl-4,6-(S)-dehydrohexahydroxydiphenoyl-d-glucose. Interestingly, acid hydrolysis of this compound afforded ellagic acid, despite the absence of a hexahydroxydiphenoyl group. From the rhizome of Polygonum runcinatum var. sinense, a large amount of granatin A, along with minor ellagitannins, helioscpoinin A, davicratinic acids B and C, and a new ellagitannin called polygonanin A, were isolated. Based on 2D nuclear magnetic resonance (NMR) spectroscopic examination, the structure of polygonanin A was determined to be 1,6-(S)-hexahydroxydiphenoyl-2,4-hydroxychebuloyl-β-d-glucopyranose. These are the second and third hydrolyzable tannins isolated from Polygonaceous plants. In addition, oligomeric proanthocyanidins of Persicaria capitatum and P. chinensis were characterized by thiol degradation. These results suggested that some Polygonaceous plants are the source of hydrolyzable tannins not only proanthocyanidins.

Four undescribed polyketide derivatives, named arthproliferins A–D (1–4), and one undescribed phenylspirodrimane derivative, named arthproliferin E (7), along with 11 known metabolites (5, 6, 8–16) were isolated from the soft coral-associated fungus Stachybotrys chartarum SCSIO41201. Their structures were determined through spectroscopic methods, X-ray crystallography, and ECD analysis. Compounds 1 and 3–15 were evaluated for their cytotoxic, and antibacterial activities. Among them, compounds 1 and 15 displayed moderate inhibitory activity against methicillin-resistant Staphylococcus aureus ATCC 29213 with an MIC value of 78 and 39 µg/mL, respectively. Furthermore, compound 15 displayed strong cytotoxic activities against the tested cell line with IC₅₀ values less than 39 nM.

Two new polyphenols, talaversatilis A (1) and B (2), together with fifteen known compounds (3–17) were isolated from the extract of the culture broth of a soft coral-derived fungus Talaromyces sp. SCSIO 041201. The structures of these compounds were elucidated by the extensive analyses of spectroscopic data and by comparison with the reported literature. Antifouling and antibacterial activities of all purified compounds were tested and evaluated. Compounds 5 and 6 showed antifouling activity towards Bugula neritina larva, with LC₅₀ values of 3.86 μg/mL and 3.05 μg/mL, respectively. Compounds 7, 8, 10 and 13 exhibited significant antibacterial activities against E. coli, MRSA, S. aureus and E. faecalis, with MIC values ranging from 0.45 to 15.6 μg/mL. Graphical Abstract