Talaromarins A–F: Six New Isocoumarins from Mangrove-Derived Fungus Talaromyces flavus TGGP35

Abstract

Six new isocoumarin derivative talaromarins A-F (1–6), along with 17 known analogues (7–23), were isolated from the mangrove-derived fungus Talaromyces flavus (Eurotiales: Trichocomaceae) TGGP35. Their structures were identified by detailed IR, UV, 1D/2D NMR and HR-ESI-MS spectra. The absolute configurations of new compounds were determined by the modified Mosher’s method and a comparison of their CD spectra with dihydroisocoumarins described in the literature. The antioxidant, antibacterial, anti-phytopathogenic and inhibitory activity against α-glucosidase of all the isolated compounds were tested. Compounds 6–11, 17–19 and 21–22 showed similar or better antioxidant activity than the IC50 values ranging from 0.009 to 0.27 mM, compared with the positive control trolox (IC50 = 0.29 mM). Compounds 10, 18, 21 and 23 exhibited strong inhibitory activities against α-glucosidase with IC50 values ranging from 0.10 to 0.62 mM, while the positive control acarbose had an IC50 value of 0.5 mM. All compounds showed no antibacterial or anti-phytopathogenic activity at the concentrations of 50 μg/mL and 1 mg/mL, respectively. These results indicated that isocoumarins will be useful to developing antioxidants and as diabetes control agents.

Bioactive polyketides and meroterpenoids from the mangrove-derived fungus Talaromyces flavus TGGP35

“…Biological activities were tested in ultra-clean workbench (Suzhou Sujing Company) and these results were tested with a full wavelength multifunctional microplate reader (BioTek, USA). Methanol, ethyl acetate, petroleum ether, chloroform, dimethyl sulfoxide, and other conventional chemical reagents used in the experimental investigations (Guangzhou Xilong Chemical Reagent Factory) (Cai et al, 2022 ).…”

“…The fungus TGGP35 was isolated from the stem of the mangrove plant Acanthus ilicifolius and the sequence data have been deposited in GenBank (accession number MT071116). The fungal strain was identified as Talaromyces flavus (Eurotiales: Trichocomaceae) (Cai et al, 2022 ).…”

“…As a part of our ongoing investigation to identify secondary metabolites from marine-derived fungus with a novel structure and potent bioactivity (Bai et al, 2019a , b , 2021 ; Liao et al, 2019 ), we obtained six new isocoumarins from the fungus Talaromyces flavus TGGP35 (separated from the medicinal mangrove Acanthus ilicifolius ) (Cai et al, 2022 ). With the aim of isolating more compounds with potent bioactivity from T. flavus TGGP35, the solid-state fermentation condition was changed (sea salt was replaced by sodium bromide).…”

Biological Secondary Metabolites from the Lumnitzera littorea-Derived Fungus Penicillium oxalicum HLLG-13

“…During our exploration of the structurally diverse and bioactive compounds from mangrove-derived fungi, some new bioactive compounds have been found [ 9 , 10 , 11 , 12 ]. In the previous study, cytotoxic oxygenated meroterpenoids and steroids with α-glucosidase inhibitory activity had been isolated from the secondary metabolites of two endophytic fungi: Penicillium sp.…”

Bio-Active Products from Mangrove Ecosystems

“…Cai et al [5] reported 6 novel isocoumarins, namely talaromarins A-F, along with 17 known analogues from the mangrove-derived fungus Talaromyces flavus TGGP35. Their structures were elucidated by extensive analysis of spectroscopic data, modified Mosher's method, and ECD spectra.…”