Two new quinazoline alkaloids produced by Aspergillus versicolor and their antimicrobial activities.

Two new quinazoline alkaloids versicomides G-H (1 and 2), together with seven known compounds, were isolated from Aspergillus versicolor HYQZ-215 obtained from the sediment of Qarhan Salt Lake. Their structures were elucidated by NMR, HRESIMS, and quantum chemical ECD calculations data. The antimicrobial activities of these compounds were evaluated against seven agricultural pathogenic fungi and eight clinically drug-resistant bacteria.

Effect of A Polyphenol-Rich Canarium album Extract on the Composition of the Gut Microbiota of Mice Fed a High-Fat Diet.

This study investigated the influence of Canarium album extract (CAext) on intestinal microbiota composition of mice fed a high-fat diet (HFD). Kun Ming (KM) mice were fed either a normal chow diet or a HFD for six weeks. At the seventh week, HFD-fed mice were gavaged daily with saline, or a different dose of CAext for four weeks, respectively. Then, the composition of the gut microbiota was analyzed by high-throughput sequencing technology. Analysis of fecal microbial populations, grouped by phyla, showed significant increases of Firmicutes and Verrucomicrobia, but a decrease of Bacteroidetes in all CAext-fed mice. Particularly, CAext gavage in a low dose or a medium dose caused a significant increase in the proportion of Akkermansia. These findings suggested that CAext can alter the gut microbiota composition of HFD-fed mice, and had a potential prebiotic effects on Akkermansia.

Two novel eremophylane acetophenone conjugates from Colletotrichum gloeosporioides, an endophytic fungus in Salvia miltiorrhiza.

Two novel eremophylane acetophenone conjugates, colletotricholides A (1) and B (2), were isolated from the solid fermentation cultures of an endophytic fungus Colletotrichum gloeosporioides XL1200 isolated from the aerial parts of Salvia miltiorrhiza. The chemical structures of 1-2 were characterized by extensive spectroscopic methods and single-crystal X-ray crystallography. Structurally, compounds 1-2 are two unusual eremophylane acetophenone conjugates originating from the hybrid pathways of polyketide synthase and sesquiterpene synthase. In addition, compounds 1-2 were inactive against tested pathogens.

(±)-Preisomide: A new alkaloid featuring a rare naturally occurring tetrahydro-2H-1,2-oxazin skeleton from an endophytic fungus Preussia isomera by using OSMAC strategy.

A new alkaloid, named (±)-preisomide (1), together with five known polyketides (2-6), were isolated from an endophytic fungus Preussia isomera in Panax notoginseng by using one strain-many compounds (OSMAC) strategy. Their structures were identified by extensive spectroscopic experiments and comparison with literature data. Structurally, compound 1 possessed a rare naturally occurring tetrahydro-2H-1,2-oxazin ring. Compound 6 displayed significant antibacterial activity against multidrug-resistant Enterococcus faecium, methicinllin-resistant Staphylococcus aureus and multidrug-resistant Enterococcus faecalis with an MIC value of 25 µg/mL, as well as moderate antifungal activity against Gibberella saubinetii with an MIC value of 50 µg/mL.