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Two novel sesquiterpene derivatives, dendocarbin B (1), bisaborosaol C (2), and nine known compounds (3-11), were isolated from Nigrospora chinensis GGY-3 derived from Ilex cornuta. The structures of new compounds were elucidated using HR-ESI-MS, 1 D and 2 D NMR spectra, X-ray diffraction analysis as well as ECD calculation and comparison. Compound 1 showed moderate antifungal activities against Rhizoctonia solani and Botrytis cinerea. Compounds 5 and 6 exhibited significant inhibitory activity against Phytophthora capsici, Magnaporthe oryzae and R. solani with EC50 values ranging from 13.91 to 29.49 μg/mL. Compounds 10 and 11 displayed moderate antibacterial effects on Bacillus subtilis and Xanthomonas oryzae pv. oryzae (Xoo), with MIC values of 16-64 μg/mL. Particularly, 11 presented strong antibacterial activity against Staphylococcus aureus with an MIC value of 4 μg/mL (2 μg/mL for streptomycin sulfate). In addition, compound 11 also possessed DPPH radical scavenging capability with an IC50 value of 14.80 μg/mL. [ABSTRACT FROM AUTHOR]

Two immuno-loop-mediated isothermal amplification assays (iLAMP) were developed by using a phage-borne peptide that was isolated from a cyclic eight-peptide phage library. One assay was used to screen eight organophosphorus (OP) pesticides with limits of detection (LOD) between 2 and 128 ng mL(-1). The iLAMP consisted of the competitive immuno-reaction coupled to the LAMP reaction for detection. This method provides positive results in the visual color of violet, while a negative response results in a sky blue color; therefore, the iLAMP allows one to rapidly detect analytes in yes or no fashion. We validated the iLAMP by detecting parathion-methyl, parathion, and fenitrothion in Chinese cabbage, apple, and greengrocery, and the detection results were consistent with the enzyme-linked immunosorbent assay (ELISA). In conclusion, the iLAMP is a simple, rapid, sensitive, and economical method for detecting OP pesticide residues in agro-products with no instrumental requirement.

Succinate dehydrogenase (SDH, EC 1.3.5.1) is one of the most promising targets for fungicide development and has attracted great attention worldwide. However, existing commercial fungicides targeting SDH have led to the increasingly prominent problem of pathogen resistance, so it is necessary to develop new fungicides. Herein, we used a structure-based molecular design strategy to design and synthesize a series of novel SDHI fungicides containing an N-(alkoxy)diphenyl ether carboxamide skeleton. The mycelial growth inhibition experiment showed that compound M15 exhibited a very good control effect against four plant pathogens, with inhibition rates of more than 60% at a dose of 50 μg/mL. A structure–activity relationship study found that N-O-benzyl-substituted derivatives showed better antifungal activity than others, especially the introduction of a halogen on the benzyl. Furthermore, the molecular docking results suggested that π–π interactions with Trp35 and hydrogen bonds with Tyr33 and Trp173 were crucial interaction sites when inhibitors bound to SDH. Morphological observation of mycelium revealed that M15 could inhibit the growth of mycelia. Moreover, in vivo and in vitro tests showed that M15 not only inhibited the enzyme activity of SDH but also effectively protected rice from damage due to R. solani infection, with a result close to that of the control at a concentration of 200 μg/mL. Thus, the N-(alkoxy)diphenyl ether carboxamide skeleton is a new starting point for the discovery of new SDH inhibitors and is worthy of further investigation. [ABSTRACT FROM AUTHOR]

Equisetin was isolated from endophytic fungus Fusarium sp. JDJR1 via bioassay-guided isolation, and it was evaluated as an anti-microbial and herbicidal agent. Bioactivity assessments revealed that equisetin exhibited a broad spectrum of fungicidal and anti-bacterial activity against various plant pathogens. The EC50 values against Botrytis cinerea, Fusarium graminearum, Sclerotinia sclerotiorum, and Rhizoctonia solani ranged from 10.7 to 21.0 μg/mL. Notably, equisetin demonstrated activity against Xanthomonas oryzae pv. oryzicola, Xanthomonas oryzae pv. oryzae and Pseudomonas solanacearum with an MIC range of 4–16 μg/mL, surpassing the efficacy of the positive control: streptomycin sulfate. Equisetin, at a concentration of 100 μg/mL, could completely inhibit the spore germination of F. graminearum. In in vivo protection experiments, the protective efficacy of equisetin against B. cinerea on tomato fruits at 200 μg/mL reached 72.9%. Furthermore, in herbicidal activity tests that use the Petri dish bioassay method, equisetin had a good inhibitory effect on the root growth of weeds. At a concentration of 100 μg/mL, the inhibition rates for Echinochloa crusgalli and Eclipta prostrata root were 98.8 and 94.4%, respectively. [ABSTRACT FROM AUTHOR]

The metabolism of arachidonic acid (ARA) by cytochrome P450 ω/ω-1-hydroxylases leads to the formation of 20-hydroxyeicosatetraenoic acid (20-HETE), which is an important lipid-signaling molecule involved in regulation of vascular tone, angiogenesis, and inflammation. Development of a simple method to prepare 20-HETE would greatly facilitate the investigation of its biological activities. The nonpathogenic yeast Starmerella bombicola has been shown to convert exogenously added arachidonic acid to 20-HETE via the biosynthetic pathway of sophorolipids; however, the yield was low. Here we demonstrate that genetic knockout of multifunctional enzyme type 2 (MFE-2), which is involved in the β-oxidation of fatty acids, significantly increases the yield of ARA conversion to 20-HETE and allows practical preparation of 20-HETE.

A rapid and efficient method using an alkyl-functionalized magnetic nanoparticles-based extraction technique combined with Ultra-High Performance Liquid Chromatography was developed for the detection of trace amounts of polycyclic aromatic hydrocarbons in tea leaves. As a popular coating for chromatographic column packing materials, C18-alkyl has been demonstrated to be effective in separating polycyclic aromatic hydrocarbons. Additionally, the magnetism of the nanomaterials accelerates the extraction process while their high surface ratio enables desirable dispersity in the sample matrix. Meanwhile, the adsorbents can be washed and reused 30 times without compromising recovery, which greatly reduces the budget. The effects of various parameters were investigated and optimized, and the recoveries for five analytes were in the range of 84.8–105.4%. The RSD of intra-day and inter-day were below 11.9% and 6.8%, respectively. The limits of detection and limits of quantification ranged from 1.69–9.97 ng g−1 and 5.12–30.21 ng g−1, indicating satisfactory sensitivity. Thus, the proposed methodology is rapid, highly efficient, and economical, and it expands the application of magnetic cleanup approaches in complex food matrices. [ABSTRACT FROM AUTHOR]

BACKGROUND: The lack of novel fungicide and appearance of resistance are the most emergent problems in the control of Phytophthora diseases. Plant immunity elicitors that induce systemic resistance in plants are regarded as the new strategy for plant disease control. Streptomyces can produce a variety of bioactive natural products, which are important resources for lead compounds of plant immunity elicitors. RESULTS: A novel peptidendrocin C (1) together with the known analog peptidendrocin B (2) were isolated from Streptomyces pseudovenezuelae NA07424. Their structures were confirmed by spectroscopic data and Marfey's reaction. In bioactive assays, compound 1 played an important role in inducing systemic resistance of Nicotiana benthamiana against Phytophthora capsici growth, with a 90.5% inhibition ratio at 400 μg/mL, while compound 2 showed moderate activity, inhibiting P. capsici growth by a 50.8% decrease at 400 μg/mL. Simultaneously, two compounds promoted enhanced expression of the PR1 gene and callose accumulation in N. benthamiana and Arabidopsis thaliana. In this paper, we also provide the first insights into their biosynthesis by confirming their biosynthesis gene cluster and related functional genes. CONCLUSION: Our findings show that 1 and 2 have the potential to be used as lead compounds for development of new plant immunity elicitors to control Phytophthora diseases. The study of the biosynthesis pathway lays the groundwork for further application of the bioactive natural products. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The Big Five Inventory-2 (BFI-2) has received wide recognition since its publication because it strikes a good balance between content coverage and brevity. The current study translated the BFI-2 into Chinese, evaluated its psychometric properties in four diverse Chinese samples (college students, adult employees, adults treated for substance use, and adolescents), and compared its factor structure with those obtained from two U.S. samples. Across two studies, the Chinese BFI-2 demonstrated good reliability (Cronbach's α and test–retest reliability), structural validity, convergent/discriminant validity, and criterion-related validity at the domain level. At lower levels of analyses, some facets and negatively worded items functioned better among participants with higher than those with lower education levels. Implications, limitations, and future directions are discussed. [ABSTRACT FROM AUTHOR]

BACKGROUND: Phytopathogenic bacteria, such as Xanthomonas oryzae pv. oryzae (Xoo) and Ralstonia solanacearum (Rs), seriously threaten crop production and are the cause of enormous yield losses. Endophytic fungi are abundant sources of bioactive metabolites that may be potential candidates in the development of new agrochemicals. This work emphasizes the discovery of bioactive polyketides from endophytic Alternaria alternata ZHJG5 and reports their structural elucidation and antibacterial activities in detail. RESULTS: Five novel polyketide derivatives, isotalaroflavone (2), (+/−)‐5′‐dehydroxytalaroflavone (3a/3b), (+)‐talaroflavone (4b), and bialternacin G (7), along with five known compounds (1, 4a, 5, 6, and 8), were obtained from the Cercis chinensis‐derived fungus A. alternata ZHJG5. The compounds' structures were characterized using spectroscopic methods and X‐ray diffraction. Chiral high‐performance liquid chromatography was used to separate the racemates 3 and 4, whose absolute configurations were unambiguously confirmed by comparing their experimental and calculated electron circular dichroism data. All isolated compounds were tested for antibacterial activity against the phytopathogenic bacteria Xoo, Xanthomonas oryzae pv. oryzicola (Xoc) and Rs. Compounds 1, 2 and 8 showed pronounced antibacterial activity against all tested bacteria, with minimal inhibitory concentrations ranging from 0.5 to 64 μg/ml. In addition, compound 1 showed a potent protective effect against rice bacterial leaf blight caused by Xoo with a protective efficacy of 75.1% at a concentration of 200 μg/ml. CONCLUSION: These findings highlight the practical potential of antibacterial compounds as candidates for the discovery of novel bactericides. © 2021 Society of Chemical Industry [ABSTRACT FROM AUTHOR]