Miaohe Zhang

Global agricultural production relies heavily on chemical pesticides, leading to resistance, residues, and pollution, threatening sustainable agriculture. There is an urgent need to develop novel antimicrobial agents from low-toxicity, easily degradable natural products. Using formononetin as a lead compound, acylpiperidine-containing derivatives were synthesized and evaluated against one oomycete, seven plant pathogenic fungi, and four pathogenic bacteria. C25 exhibited superior inhibitory effects against Phytophthora capsici and Xanthomonas oryzaepv.oryzae, with EC50 values of 3.38 and 1.67 μg/mL, respectively, outperforming azoxystrobin and thiodiazole copper. Preliminary mode-of-action studies, including cytoplasmic leakage, membrane permeability, and defense enzyme analyses, provided initial insights into its antimicrobial properties. Seed germination assays showed no obvious phytotoxicity, and zebrafish embryos developed normally at concentrations up to 50 μg/mL, whereas sublethal effects appeared at higher concentrations. Molecular docking and density functional theory calculations provided preliminary insights into possible interactions and electronic characteristics. C25 represents a promising lead for botanical-source antimicrobial agrochemicals.

A series of thiazolidinedione derivatives containing thioamide and piperidine moieties were designed, synthesized, and evaluated for antifungal activity against plant pathogenic fungi. Several compounds exhibited potent antifungal activity, among which Z17 was the most active against Rhizoctonia solani (EC50 = 1.8 μg/mL), with substantially greater activity than azoxystrobin (Az; EC50 = 42.6 μg/mL). Physiological analyses indicated that Z17 disrupted membrane integrity and cellular energy metabolism, as reflected by increased malondialdehyde levels and decreased pyruvate kinase activity and pyruvate content. Density functional theory calculations, molecular docking, and molecular dynamics simulations suggested that Z17 forms favorable interactions with the cytochrome bc1 complex. Preliminary safety assessments showed no significant effects on rice seed germination or earthworm viability. These findings suggest Z17 as a promising lead for the development of antifungal agents against crop pathogens.

Heavy metal contamination in orchards has received increasing attention as people pay more attention to food safety issues. In this study, the levels of six heavy metals (Cu, Ni, Pb, Zn, Cd and Cr) in soil and fruit (peel and pulp) of 70 kiwifruit orchards in Xiuwen County, Guizhou Province, China, were investigated by inductively coupled plasma mass spectrometry (ICP-MS), and correlation analyses as well as dietary risk assessment. The results showed that the mean concentrations of the six heavy metals (Cu, Ni, Pb, Zn, Cd and Cr) ranged from 0.41-104.02 mg kg-1 in soil, <0.01-2.15 mg kg-1 in peel and <0.01-0.23 mg kg-1 in flesh, with the heavy metal content in flesh being significantly lower than that in peel. Among the 70 soil samples in this study, some samples of Cd, Ni, Cu and Zn exceeded the secondary standard for soil environmental quality in China, and the proportions of Cu, Ni, Pb, Zn, Cd and Cr exceeding the geochemical soil background values in Guizhou were 72.86%, 72.86%, 64.29%, 52.86%, 48.57% and 37.14%, respectively. The results of the correlation analysis indicated that the higher the Cu content in the soil, the more favorable the transfer and enrichment of Cr, Cd, Cu, Zn and Ni to kiwifruit fruit, and the less favorable the enrichment of Pb. The results of the food safety risk assessment indicated that none of the six heavy metals in kiwifruit posed a significant risk to human health. This study can provide a reference for the regular investigation of heavy metal pollution in kiwi orchards and the long-term safety of kiwifruit.

The present study involved the development of a series of novel antibacterial compounds based on the structure of the natural product formononetin. The in vitro activity experiments demonstrated that compound M34 exhibited the most potent inhibitory effects against Xanthomonas oryzae pvoryzae (Xoo) and Xanthomonas axonopodis pv citri (Xac), with EC₅₀ values of 0.9 and 2.4 μg/mL, respectively. Pot experiments verified the excellent curative and protective effects of M34 against bacterial leaf blight of rice (BLB) and citrus canker (CC). Furthermore, a series of physiological and biochemical experiments were conducted to investigate the action mechanism exerted by M34 against plant pathogens Xoo and Xac. The findings revealed that M34 effectively inhibited the expression of multiple pathogenic factors, disrupted their energy metabolism, altered their cell membrane morphology, enhanced the activity of host defense enzymes, and attenuated their virulence toward host cells. Therefore, M34 could serve as a promising candidate drug for the inhibition of crop pathogens.

A series of 2-aminothiazole derivatives (3A1–3A30) containing 9-alkyl purine moiety were designed and synthesized to explore novel antibacterial agents with unique structures and potent antibacterial activity. The structures of target compounds were characterized using ¹H NMR, ¹³C NMR, and HRMS techniques. The structure of compound 3A12 was further elucidated through single crystal X-ray diffraction analysis. Results from antibacterial activity tests indicated that compound 3A7 exhibited a significant inhibitory effect on Xanthomonas oryzae pv. oryzicola (Xoc), with an EC₅₀ (half-maximal effective concentration) value of 25.5 μg/mL, which was more than three times higher than that of the control agent thiodiazole copper (EC₅₀ = 78.4 μg/mL). Compound 3A25 has a strong inhibitory effect on Xanthomonas axonopodis pv. citric (Xac), with significantly higher activity than thiodiazole copper in terms of EC₅₀ value (47.3 vs 92.1 µg/mL). Additionally, the EC₅₀ value of compound 3A7 against Pseudomonas syringae pv. actinidiae (Psa) was measured at 57.5 µg/mL, demonstrating superior efficacy relative to the control agents bismerthiazol (EC₅₀ = 92.9 µg/mL) and thiodiazole copper (EC₅₀ = 90.2 µg/mL). The antibacterial mechanism of compound 3A7 was examined through an investigation into the production of exopolysaccharides, alterations in membrane permeability, morphological changes in bacterial cells, and the development of a molecular docking model. Through a 100 ns molecular dynamics (MD) simulation, the stability of the binding between compound 3A7 and the AvrRxo1-ORF1 protein was confirmed. Furthermore, the chemical reactivity of potential bioactive compounds was evaluated using density functional theory (DFT).

Selenium (Se) is an essential trace element that is crucial for human health. As a key component of various enzymes and proteins, selenium primarily exerts its biological functions in the form of selenoproteins within the body. Currently, over 30 types of selenoproteins have been identified, with more than 20 of them containing selenocysteine residues. Among these, glutathione peroxidases (GPXs), thioredoxin reductases (TrxRs), and iodothyronine deiodinases (DIOs) have been widely studied. Selenium boasts numerous biological functions, including antioxidant properties, immune system enhancement, thyroid function regulation, anti-cancer effects, cardiovascular protection, reproductive capability improvement, and anti-inflammatory activity. Despite its critical importance to human health, the range between selenium’s nutritional and toxic doses is very narrow. Insufficient daily selenium intake can lead to selenium deficiency, while excessive intake carries the risk of selenium toxicity. Therefore, selenium intake must be controlled within a relatively precise range. This article reviews the distribution and intake of selenium, as well as its absorption and metabolism mechanisms in the human body. It also explores the multiple biological functions and mechanisms of selenium in maintaining human health. The aim is to provide new insights and evidence for further elucidating the role of selenium and selenoproteins in health maintenance, as well as for future nutritional guidelines and public health policies.

A series of novel coumarin derivatives was successfully synthesized by combining the coumarin skeleton with a benzylamine moiety. These derivatives showed better antibacterial activities in vitro tests, especially compound, which was particularly effective. The mechanism of the antibacterial action of compound was thoroughly investigated, and the experimental results revealed that compound was able to increase the permeability of bacterial cell membranes, leading to the disruption of Xoc membranes and effectively inhibiting bacterial growth and reproduction. This finding not only elucidates the antibacterial mechanism of compound, but also provides an important scientific basis for the development of new antibacterial agents in the future.

Selenium (Se) is an essential trace element that is crucial for human health. As a key component of various enzymes and proteins, selenium primarily exerts its biological functions in the form of selenoproteins within the body. Currently, over 30 types of selenoproteins have been identified, with more than 20 of them containing selenocysteine residues. Among these, glutathione peroxidases (GPXs), thioredoxin reductases (TrxRs), and iodothyronine deiodinases (DIOs) have been widely studied. Selenium boasts numerous biological functions, including antioxidant properties, immune system enhancement, thyroid function regulation, anti-cancer effects, cardiovascular protection, reproductive capability improvement, and anti-inflammatory activity. Despite its critical importance to human health, the range between selenium's nutritional and toxic doses is very narrow. Insufficient daily selenium intake can lead to selenium deficiency, while excessive intake carries the risk of selenium toxicity. Therefore, selenium intake must be controlled within a relatively precise range. This article reviews the distribution and intake of selenium, as well as its absorption and metabolism mechanisms in the human body. It also explores the multiple biological functions and mechanisms of selenium in maintaining human health. The aim is to provide new insights and evidence for further elucidating the role of selenium and selenoproteins in health maintenance, as well as for future nutritional guidelines and public health policies.

Benzimidazole fungicides are a class of highly effective, low-toxicity, systemic broad-spectrum fungicides developed in the 1960s and 1970s, based on the fungicidal activity of the benzimidazole ring structure. They exhibit biological activities including anticancer, antibacterial, and antiparasitic effects. Due to their particularly outstanding antibacterial properties, they are widely used in agriculture to prevent and control various plant diseases caused by fungi. The main products of benzimidazole fungicides include benomyl, carbendazim, thiabendazole, albendazole, thiophanate, thiophanate-methyl, fuberidazole, methyl (1-{[(5-cyanopentyl)amino]carbonyl}-1H-benzimidazol-2-yl) carbamate, and carbendazim salicylate. This article mainly reviews the physicochemical properties, toxicological properties, disease control efficacy, and pesticide residue and detection technologies of the aforementioned nine benzimidazole fungicides and their main metabolite (2-aminobenzimidazole). On this basis, a brief outlook on the future research directions of benzimidazole fungicides is presented.