Aspertamarinolides A-C: γ-butenolides from the marine-derived fungus Aspergillus tamarii PSU-MF90

Secondary Metabolites From the Grasshopper-Derived Entomopathogenic Fungus Aspergillus Tamarii NL3 and Their Biological Activities

Chromatographic purification of the ethyl acetate extract of the entomopathogenic fungus Aspergillus tamarii NL3 culture broth led to the isolation of griseofulvin (1), isogriseofulvin (2), cytochalasin J (3), solamargine (4), and solasonine (5). The chemical structures of these compounds were identified by HRESIMS and NMR spectra, as well as by comparison with literature data. This is the first report on the isolation of 1-4 from the Aspergillus genus and compound 5 from A tamarii. Compounds 1 and 2 exhibited antifungal activity against the reference fungi with MICs of 16 to 128 µg/mL. Compound 3 displayed weak antimicrobial activity against most of the tested microorganisms with MICs ≥ 128 µg/mL, except for Bacillus subtilis and Aspergillus niger with MICs of 64 µg/mL. Compounds 4 and 5 showed activity against a wide spectrum of the reference microorganisms with MICs of 16 to 128 µg/mL but showed stronger antifungal than antibacterial activity. Furthermore, all isolates exhibited weak ABTS and DPPH scavenging activities with scavenging rates of 18.92% to 32.64% and 24.62% to 31.06%, respectively, at the concentration of 100 µg/mL.

Phytotoxic Metabolites Isolated from Aspergillus sp., an Endophytic Fungus of Crassula arborescens

Aspergillus sp., an endophytic fungus isolated from Crassula arborescens, displayed potent inhibitory activity against the seed germination of Arabidopsis thaliana. The bioactivity-guided fractionation of the culture extract of Aspergillus sp. MJ01 led to the isolation of nine compounds, including one previously undescribed furanone, namely aspertamarinoic acid (1), and eight known compounds, (-)-dihydrocanadensolide (2), kojic acid (3), citreoisocoumarin (4), astellolide A (5), astellolide B (6), astellolide G (7), cyclo-N-methylphenylalanyltryptophenyl (8) and (-)-ditryptophenaline (9). In the evaluation of the phytotoxic activities of compounds 1-9, the results suggested that 1 and 5 showed significant inhibitory activity on the seed germination of A. thaliana. This is the first report to disclose the phytotoxic activity of these compounds.

Marine natural products

Covering: 2020This review covers the literature published in 2020 for marine natural products (MNPs), with 757 citations (747 for the period January to December 2020) referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, mangroves and other intertidal plants and microorganisms. The emphasis is on new compounds (1407 in 420 papers for 2020), together with the relevant biological activities, source organisms and country of origin. Pertinent reviews, biosynthetic studies, first syntheses, and syntheses that led to the revision of structures or stereochemistries, have been included. A meta analysis of bioactivity data relating to new MNPs reported over the last five years is also presented.