A new natural mycotoxin was isolated from the fermentation broth of Trichoderma sp. Jing-8 and the structure was determined as alternariol 1′-hydroxy-9-methyl ether (1), together with twelve known compounds. The structures were elucidated on the basis of their 1D, 2D NMR spectra and mass spectrometric data. Compounds 1, 8 and 9 indicated inhibitions against germination of the seeds of cabbage with MICs < 3 μg/mL. The compound 1 showed the antibacterial activity against Bacillus subtilis and Staphylococcus aureus with MICs at 64 μg/mL. Compound 1 and 3 showed significant DPPH radical-scavenging activities with IC50 at 12 μg/mL, respectively. The OH at C-1′ in compound 1 decreased the cytotoxicity of these mycotoxins. A primary structure–activity relationship about the alternariol derivatives was discussed. Compounds 2–7 and 8 were the first time to be isolated from the Trichoderma.
A quinoline alkaloid 1 and five known compounds (2–6) were isolated from a novel halophilic actinomycete Nocardiopsis terrae YIM 90022, and their structures were determined by spectroscopic studies as 4-oxo-1,4-dihydroquinoline-3-carboxamide (1), p-hydroxybenzoic acid (2), N-acetyl-anthranilic acid (3), indoly-3-carboxylic acid (4), cyclo(Trp-Gly) (5) and cyclo(Leu-Ala) (6). Compound 1 was isolated from natural resources for the first time. Compounds 1 and 3 showed antimicrobial activities against some plant pathogens.
Two new oxidation products-related aureonitol and cytochalasan were isolated from Chaetomium globosum fermented in Chinese yam (Dioscorea opposita) and determined as 10,11-dihydroxyl- aureonitol (1) and yamchaetoglobosin A (2). Compound 2 indicated significant inhibitory effect on nitric oxide production in LPS-activated macrophages, anti-acetylcholinesterase activity with the inhibition ratios of 92.5, 38.2% at 50 μM, and cytotoxicity to HL-60, A-549, SMMC-7721, MCF-7 and SW480 with the range of inhibition ratio at 51–96% for a concentration of 40 μM. Compounds 1, 2 showed weak anticoagulant activity with PT at 16.8 s. Few work was reported on the anti-acetylcholinesterase, and anticoagulant activities of aureonitol, and cytochalasan derivatives. The preliminary structure–activity relationship stated that the oxidation ring-opening in yamchaetoglobosin A can retain the inhibitory effect against NO production and tumor cell.
Two new metabolites named koninginins R-S (1–2) were isolated from the culture of Trichoderma koningiopsis YIM PH30002. Their chemical structures were elucidated by the extensive spectroscopic analysis. These isolated compounds showed certain antifungal activities against phytopathogens, Fusarium flocciferum and Fusarium oxysporum.
9 October 2019 in Journal of Agricultural and Food Chemistry