Bioactive Polyketides and Benzene Derivatives from Two Mangrove Sediment-Derived Fungi in the Beibu Gulf

Abstract

To discover bioactive natural products from mangrove sediment-derived microbes, a chemical investigation of the two Beibu Gulf-derived fungi strains, Talaromyces sp. SCSIO 41050 and Penicillium sp. SCSIO 41411, led to the isolation of 23 natural products. Five of them were identified as new ones, including two polyketide derivatives with unusual acid anhydride moieties named cordyanhydride A ethyl ester (1) and maleicanhydridane (4), and three hydroxyphenylacetic acid derivatives named stachylines H−J (10−12). Their structures were determined by detailed nuclear magnetic resonance (NMR) and mass spectroscopic (MS) analyses, while the absolute configurations were established by theoretical electronic circular dichroism (ECD) calculation. A variety of bioactive screens revealed three polyketide derivatives (1−3) with obvious antifungal activities, and 4 displayed moderate cytotoxicity against cell lines A549 and WPMY-1. Compounds 1 and 6 at 10 μM exhibited obvious inhibition against phosphodiesterase 4 (PDE4) with inhibitory ratios of 49.7% and 39.6%, respectively, while 5, 10, and 11 showed the potential of inhibiting acetylcholinesterase (AChE) by an enzyme activity test, as well as in silico docking analysis.

Discovery of Anti-Hypercholesterolemia Agents Targeting LXRα from Marine Microorganism-Derived Natural Products

“…A small library of marine NPs containing 205 compounds was prepared to screen for active LXRα modulators. − Those well-preserved compounds were obtained from marine microorganisms (55 from mangrove sediment-derived fungi, 50 from coral-derived fungi, 44 from sponge-derived fungi, 13 from algae-derived fungi, and 43 from marine actinomycete) by our group in recent years, and their chemical structures can be found in the Supporting Information (Figures S1–S5). Those ligands were indexed in SDF format and optimized using the Ligprep module of Schrodinger 2017.…”

Discovery of Enzyme Inhibitors from Mangrove Sediment Derived Fungus Trichoderma harzianum SCSIO 41051

“…The chemical shift of CH 3 -9 (δ C 12.5) suggested that the double bond Δ 2 was also in the E configuration (γ-gauche effect). [13,16] The absolute configuration of C-6 was determined to be S by the Mo 2 (OAc) 4 -induced ECD experiment at 300 nm, which shows a positive Cotton effect (Figure 3A). The calculated ECD spectrum for (6S,7S)-1 and (6S,7R)-1 closely resembles the experimental ECD spectrum (Figure 3B), further confirming the S configuration at C-6.…”

“…As part of our research on discovering structurally novel enzyme inhibitors from mangrove fungi, [10][11][12][13] the fungus strains of Trichoderma harzianum SCSIO 41051, obtained through in situ culture [14] in mangrove sediment, collected from Gaoqiao mangrove wetland in the Zhanjiang coastline of the northern part of Beibu Gulf. Further chemical investigations of their crude extract led to the isolation of 17 compounds, including a new fatty acid derivative (1), night known polyketides (2-10), five known alkaloids (11)(12)(13)(14)(15), and two known sesquiterpenoids (16 and 17) (Figure 1). The in vitro enzyme inhibitory assay showed that compounds 9 and 14 exhibited moderate AChE inhibitory activities and compounds 8 and 9 displayed moderate inhibition on PL.…”

Cytotoxic Compounds from Marine Fungi: Sources, Structures, and Bioactivity

“…Notably, this compound features a unique acid anhydride functional group. Maleicanhydridane (98) exhibited moderate cytotoxicity, with IC 50 values of 15.5 µM against the A549 cell line and 22.9 µM against the WPMY-1 cell line, whereas docetaxel as a positive control displayed cytotoxicity against the two cell lines, with IC 50 values of 29.95 and 0.51 µM [59]. Benzoquinone 99 was isolated from the fungus Talaromyces sp.…”