The connectivity (valency) of building blocks for constructing 3D covalent organic frameworks (COFs) has long been limited to 4, 6, 8, and 12. Developing a higher connectivity remains a great challenge in the field of COF structural design. Herein, this work reports a hierarchical expansion strategy for making 16-connected building blocks to construct 3D COFs with sqc topology.
View Article and Find Full Text PDFPlant volatile organic compounds (PVOCs) have gained increasing attention for their role in preventing fungal spoilage and insect contamination in postharvest agro-products owing to their effectiveness and sustainability. In this study, the essential oil was extracted from fresh M. alternifolia (tea tree) leaves, and the fumigation vapor of tea tree oil (TTO) completely inhibited the growth of Aspergillus flavus on agar plates at a concentration of 1.
View Article and Find Full Text PDFCovalent organic frameworks (COFs), with the features of flexible structure regulation and easy introduction of functional groups, have aroused broad interest in the field of photocatalysis. However, due to the low light absorption intensity, low photoelectron conversion efficiency, and lack of suitable active sites, it remains a great challenge to achieve efficient photocatalytic aerobic oxidation reactions. Herein, based on reticular chemistry, we rationally designed a series of three-motif molecular junction type COFs, which formed dual photosensitizer coupled redox molecular junctions containing multifunctional COF photocatalysts.
View Article and Find Full Text PDFPlant volatile compounds have great potential for preventing and controlling fungal spoilage in post-harvest grains. Recently, we have reported the antifungal effects of trans-anethole, the main volatile constituent of the Illicium verum fruit, on Aspergillus flavus. In this study, the inhibitory mechanisms of trans-anethole against the growth of A.
View Article and Find Full Text PDFThe high local electron density and efficient charge carrier separation are two important factors to affect photocatalytic activity, especially for the CO photoreduction reaction. However, the systematic studies on the structure-functional relationship regarding the above two factors based on precisely structure model are rarely reported. Herein, as a proof-of-concept, we developed a new strategy on the evaluation of local electron density by controlling the relative electron-deficient (ED) and electron-rich (ER) intensity of monomer at a molecular level based on three rational-designed vinylene-linked sp carbon-covalent organic frameworks (COFs).
View Article and Find Full Text PDFIn this work, we innovatively assembled two types of traditional photosensitizers, that is pyridine ruthenium/ferrum (Ru(bpy) /Fe(bpy) ) and porphyrin/metalloporphyrin complex (2HPor/ZnPor) by covalent linkage to get a series of dual photosensitizer-based three-dimensional metal-covalent organic frameworks (3D MCOFs), which behaved strong visible light-absorbing ability, efficient electron transfer and suitable band gap for highly efficient photocatalytic hydrogen (H ) evolution. Rubpy-ZnPor COF achieved the highest H yield (30 338 μmol g h ) with apparent quantum efficiency (AQE) of 9.68 %@420 nm, which showed one of the best performances among all reported COF based photocatalysts.
View Article and Find Full Text PDFAppl Microbiol Biotechnol
June 2023
The prevention of fungal proliferation in postharvest grains is critical for maintaining grain quality and reducing mycotoxin contamination. Fumigation with natural gaseous fungicides is a promising and sustainable approach to protect grains from fungal spoilage. In this study, the antifungal activities of (E)-2-alkenals (C-C) on Aspergillus flavus were tested in the vapor phase, and (E)-2-heptenal showed the highest antifungal activity against A.
View Article and Find Full Text PDFAppl Microbiol Biotechnol
October 2022
Biogenic volatile organic compounds hold remarkable potential for controlling fungal decay in agro- and food products. Recently, we reported that linalool, the major volatile component of the Zanthoxylum schinifolium pericarp, showed great potential as a biofumigant to control Aspergillus flavus growth in postharvest grains. In this study, the inhibitory effects of linalool on A.
View Article and Find Full Text PDFAppl Microbiol Biotechnol
August 2022
The exploitation of active ingredients from plant volatile organic compounds as natural gaseous fungicides shows remarkable potential for controlling fungal decay in postharvest agroproducts. Although 1-octanol is a common component of cereal volatiles, its antifungal potency against spoilage fungi in postharvest grains remains unclear. In this study, we studied the effectiveness of 1-octanol against Aspergillus flavus growth in postharvest grains and its mechanisms of action.
View Article and Find Full Text PDFDuring the seed aging process, reactive oxygen species (ROS) can induce the carbonylation of proteins, which changes their functional properties and affects seed vigor. However, the impact and regulatory mechanisms of protein carbonylation on wheat seed vigor are still unclear. In this study, we investigated the changes in wheat seed vigor, carbonyl protein content, ROS content and embryo cell structure during an artificial aging process, and we analyzed the correlation between protein carbonylation and seed vigor.
View Article and Find Full Text PDFThe exploitation of plant volatile organic compounds as biofumigants to control postharvest decaying of agro-products has received considerable research attention. Our previous study reported that 1-nonanol, the main constituent of cereal volatiles, can inhibit Aspergillus flavus growth and has the potential as a biofumigant to control the fungal spoilage of cereal grains. However, the antifungal mechanism of 1-nonanol against A.
View Article and Find Full Text PDFMethods of controlling Aspergillus flavus contamination in agro-products have attracted attention because of its impact on global food security. We previously reported that the natural cereal volatile heptanal could effectively inhibit A. flavus growth and showed great potential as a bio-preservative agent.
View Article and Find Full Text PDFAppl Microbiol Biotechnol
October 2021
Aspergillus flavus is a notorious saprophytic fungus that compromises the quantity and quality of postharvest grains and produces carcinogenic aflatoxins. The natural compound hexanal disrupts cell membrane synthesis and mitochondrial function and induces apoptosis in A. flavus; here, we investigated the molecular mechanisms underlying these effects.
View Article and Find Full Text PDFAppl Microbiol Biotechnol
May 2021
Hexanal, a natural volatile organic compound, exerts antifungal activity against Aspergillus flavus; however, the mechanisms underlying these effects are unclear. In this study, we found that the growth of A. flavus mycelium was completely inhibited following exposure to 0.
View Article and Find Full Text PDFProbiotics Antimicrob Proteins
February 2021
Aspergillus flavus infection is a major issue for safe food storage. In this study, we constructed an efficient prokaryotic expression system for puroindoline B (PINB) protein to detect its antifungal activity. The Puroindoline b gene was cloned into pET-28a (+) vector and expressed in Escherichia coli.
View Article and Find Full Text PDFTen new prenylated indole diterpene alkaloids, tolypocladin A-J (1-10), including four chlorinated metabolites, have been isolated from a culture of a mine-soil-derived fungus, Tolypocladium sp. XL115. The structures and absolute configurations of 1-10 were determined by spectroscopic analysis, ECD calculations, and comparison with known compounds.
View Article and Find Full Text PDFTwo new Tricholoma terpenoids, tricholopardins A and B, were isolated from the fruiting bodies of the basidiomycetes Tricholoma pardinum. Their structures were elucidated by spectroscopic methods, as well as electronic circular dichroism and optical rotatory dispersion calculations. Tricholopardin A potently inhibited nitric oxide production in lipopolysaccharide-induced RAW264.
View Article and Find Full Text PDFTwo novel sesquiterpenoids with an unprecedented tricyclo[4,4,2,1]hendecane scaffold, namely emericellins A (1) and B (2) representing a new skeleton, were isolated from the liquid cultures of an endophytic fungus Emericella sp. XL 029 associated with the leaves of Panax notoginseng. Their structures and relative configurations were characterized by extensive spectroscopic methods.
View Article and Find Full Text PDFEight undescribed lanostane triterpenoids, pardinols A‒H, along with one previously reported lanostane triterpenoid, namely saponaceol B, were isolated from the fruiting bodies of Tricholoma pardinum. Their structures and stereoconfigurations were established via combination of extensive spectroscopic analyses, alkaline methanolysis method and TDDFT/ECD calculations. Pardinols B and E-H exhibited certain inhibition activities of nitric oxide (NO) production with IC value ranging from 5.
View Article and Find Full Text PDFThis study features the isolation and identification of 12 lanostane-type triterpenoids, namely lepiotaprocerins A-L, 1-12, from the fruiting bodies of the Poland-collected edible mushroom Macrolepiota procera. The structures and the absolute configurations of the new compounds were ambiguously established by extensive spectroscopic analyses, ECD calculation, and single-crystal X-ray diffraction analyses. Structurally, lepiotaprocerins A-F, 1-6, are distinguished by the presence of a rare "1-en-1,11-epoxy" moiety which has not been previously described in the lanostane class.
View Article and Find Full Text PDFTwo new sesquiterpenes, daedaleanols A (1) and B (2), together with three known sesquiterpenes (3-5), were isolated from cultures of the basidiomycete Daedalea incana. Their structures were elucidated on the basis of extensive spectroscopic means. All compounds were tested for their cytotoxicities against three human cancer cell lines.
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