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The content of terpenoids in tobacco can alter its resistance to TMV. NtSPS1 , a pivotal structural gene in tobacco, is capable to regulate the terpenoid content. In this study, we investigated the effect of NtSPS1 knockout in HD on the content of terpenoids and the anti-TMV activity of this mutant using gene editing, widely targeted metabolomics, network pharmacology, and molecular docking. 48 terpenoids (six up-regulated and five down-regulated) in NtSPS1 knockout tobacco compared with WT leaves. Notably, solanesol was remarkable downregulation which was lowered by fourfold and compounds 1 (log 2 FC = 18.2), 8 (log 2 FC = 16.7) were significant upregulation between the mutants and wild-type line leaves. The 46 terpenoid’s target network encompassed 150 nodes, 509 edges and their underlying mechanisms in the therapeutic management of TMV are discussed. Furthermore, the network pharmacology and molecular docking revealed that compounds 16 , 18 , 23 , 27 , and 36 exhibited significant affinity in their respective interactions. Ultimately, five compounds were assayed for their anti-TMV effects, noteworthily, compounds 36 showed potential anti-TMV activity. Above all, we adopted a multifaceted approach to gain a comprehensive understanding of the terpenoid content and anti-TMV properties in NtSPS1 knockout HD. It enlightens the therapeutic potential of NtSPS1 knockout tobacco and it is helpful to find undescribed anti-TMV activity inhibitors, as well as searching for new anti-TMV candidates from the mutants.

Background Powdery mildew is a fungal disease threatening major global crops such as tobacco, rice, and grapes. Pathogens cause severe yield losses by disrupting photosynthesis and inducing premature plant senescence. Traditional chemical fungicides face challenges of drug resistance, environmental pollution, and health risks, urgently requiring low-toxic and sustainable alternatives. This study aims to identify novel sesquiterpenoids against powdery mildew from the high-trichome sun-cured tobacco variety (Huize Liuye) and elucidate their antifungal mechanisms. Results Sequential chemical extraction, chromatographic purification, and spectroscopic identification (NMR and HR-ESI–MS) led to the isolation and identification of seven novel (1–7) and four known (8–11) aromatic sesquiterpenes. Compounds 5 and 6 represent the first examples of sesquiterpenes containing a 4-methylfuran-2-yl moiety, while compound 7 is a rare sesquiterpene featuring a benzo[ c ]azepin-1-one skeleton. Antifungal assays revealed that compound 7 (250 μg/mL) exhibited the highest inhibitory activity against Golovinomyces cichoracearum with an inhibition rate of 86.2% ± 5.6, surpassing the positive control carbendazim (inhibition rate: 83.5% ± 6.0, 250 μg/mL). Analyses using microscopy and scanning electron microscopy (SEM) demonstrated that compound 7 disrupts conidial morphology and inhibits hyphal development. Transcriptomic and metabolomic studies further indicated that compound 7 may enhance induced immunity in tobacco by either directly acting as an inducer or indirectly by promoting the rupture of G. cichoracearum and the release of its pathogen-associated molecular patterns (PAMPs), thereby affecting various plant defense pathways, including salicylic acid (SA), jasmonic acid (JA), and abscisic acid (ABA) mediated plant hormone signaling, the MAPK signaling pathway, and the biosynthetic pathways of antifungal secondary metabolites. Molecular docking confirmed strong interactions between compound 7 and tubulin proteins, which also supported its efficacy. Additionally, compound 7 also showed activity against Podosphaera pannosa in rose. Conclusion This study establishes Huize Liuye tobacco as a valuable resource for natural sesquiterpene-based antifungal agents, with compound 7 demonstrating exceptional potential as an efficient fungicide due to its unique chemical structure, high antifungal activity, and broad-spectrum efficacy. The findings provide a theoretical basis for utilizing tobacco byproducts, such as trichomes, as renewable sources for biopesticide development, thereby underscoring the ecological value of high-trichome crops in sustainable agriculture as substitutes for synthetic chemicals. Graphical abstract

BackgroundSince Nicotiana tabacum (tobacco) has important significance to humans for their medicinal uses, to find antivirus activities inhibitors from tobacco, increase its medicinal value, and comprehensive utilization of its by-products, our group had investigated the chemical constituents of the stems of Y-202, a cultivar of tobacco which high resistance to tobacco mosaic virus (TMV).ResultsFour new isoindolinone-type alkaloids, nicoisoindoles A–D (1–4), along with four known isoindole derivatives (5–8) were isolated. Compounds 1–4 represent a new subclass of isoindolinone alkaloids with rare cyclopenta[f]isoindole-1-one frameworks. Among them, nicoisoindole C (3) possesses an unusual N-2-(5-methoxy-6-methylpyridin-2-yl) ethyl moiety, while nicoisoindole D (4) has a novel a N-(3-methyl-6-oxo-1,6-dihydropyridin-2-yl)methyl substituent. Interestingly, compounds 1, 3, and 4 showed high anti-TMV activities with inhibition rates of 43.8%, 58.8%, and 67.8% at the concentration of 20 μM, and IC50 values of 23.6, 19.5 and 15.4 μM, respectively, even more potent than that of positive control.ConclusionsThe successful isolation and structure identification of new oxocyclopenta[f]isoindole-1-ones provide materials for the screening of antivirus activities inhibitors, and contribute to the development and utilization of the waste from tobacco cultivation.

BackgroundTobacco mosaic virus (TMV) is a harmful plant pathogen that causes a decline in the quality and yield of many economic crops. Natural products are important potential sources of biopesticides for the prevention and treatment of TMV. This study focuses on the discovery of anti-TMV active compounds from Aspergillus versicolor and investigates their activities against TMV.ResultsIn this study, four isocoumarins 7-methoxy-3-(2-oxopropy)-5-hydroxymethyl-isocoumarin (1), 7-methyl-3-(2-oxopropy)-5-hydroxymethyl-isocoumarin (2), oryzaein A (4) and oryzaein B (5), two indole alkaloids aspergilline F (6) and aspergilline G (7), and one indole alkaloid and isocoumarin hybrid aspergillactone A (3) were isolated from Nicotiana tabacum-derived A. versicolor YNCA0363. Among them, compounds 1–3 are new isolates, compound 3 represents the first example of indole alkaloid and isocoumarin connected by C(12)-N(1′) bond. The inactivation efficacies for compounds 1, 2 and 3 were 58.9, 43.8 and 52.6% at the concentration of 50 μg/mL, respectively, which were significantly higher than that of positive control, ningnanmycin. The protective effects of these three compounds ranged from 48.6 to 62.3%, which were significantly higher than that of positive control. At the same time, the content of TMV-CP was also significantly lower than that of positive control, and compound 1 was the lowest. The curative efficacy for compound 1 was also much better than that of positive control. Transmission electron microscopy (TEM) showed that compound 1 could directly destroy viral particles into small fragments. The results of molecular docking showed that the binding ability of compounds 1, 3, 2 to TMV-CP protein decreased in turn, which was consistent with the results of activities assays.ConclusionCompounds 1–3 from A. versicolor showed potent antiviral activities against TMV including inactivation, protective and curative effects. Compound 1 can directly destroy the virus particles to achieve the effect of anti-TMV. In addition, compounds 1–3 can bind to TMV-CP protein in molecular docking experiments. The above experimental results show that TMV-CP was an important target for active indole alkaloid and isocoumarin derivatives to fracture TMV particle. The results provided evidence that indole alkaloid and isocoumarin derivatives from A. versicolor have the potential to control TMV.

BackgroundGolovinomyces cichoracearum (DC.) is the main pathogen for tobacco powdery mildew fungus disease. Its outbreaks often result in severe harvest losses for the yield and quality of tobacco. Artocarpus champeden is rich in prenylated flavonoids, which are important for the plant’s defensive strategies. With the aim of continuously exploring bioactive natural metabolites for agricultural chemicals, the chemical investigations on the twigs of A. champeden were carried out.ResultsSix new (1–6) and five known (7–11) prenylated flavonoids were isolated. Compound 1 is the first example of flavone whose prenylated side-chain is converted into an unusual 1H-pyrrol-2-yl functional group. Compounds 2 and 3 are rare flavones bearing a 4-methylfuran-2-yl moiety. The frameworks of the above three flavones are reported in natural products for the first time. Interestingly, compound 1 showed high anti-G. cichoracearum activity with an inhibition rate of 88.3% ± 6.2. This rate is higher than that of the positive control (with an inhibition rate of 81.5% ± 6.3) compared to the negative control, compounds 2–11 also showed potential activities with inhibition rates in the range of 50.9%–72.0%. In addition, the mechanistic studies on 1 revealed that it has a potent direct effect on conidiospores of G. cichoracearum and induces systemic acquired resistance for tobacco plants, which may be the reasons for its significant effects against G. cichoracearum.ConclusionsPowdery mildew is a fungal disease harmful to tobacco. Flavonoids have been identified as the sources of promising antifungal agents. For prenylated flavonoids, the combination of a flavonoid skeleton with prenylated side-chain can give the resultant more potential for biological activities. The successful isolation and structure identification of the above prenylated flavonoids provide new materials for the screening of powdery mildew inhibitors, and also contribute to the improved utilization of A. champeden.

Three new isopentylated diphenyl ethers, (1–3), together with two known isopentylated diphenyl ethers derivatives (4 and 5) were isolated from the fermentation products of an endophytic fungus Phomopsis fukushii. Their structures were elucidated by spectroscopic methods, including extensive 1D- and 2D NMR techniques. Compounds 1–3 were evaluated for their anti-methicillin-resistant Staphylococcus aureus (anti-MRSA) activity. The results showed that compounds 1–3 showed strong activity with diameter of inhibition zone (IZD) of 21.8 ± 2.4 mm, 16.8 ± 2.2 mm, and 15.6 ± 2.0 mm, respectively.

Phytochemical investigations of the leaves of Garcinia paucinervis resulted in the isolation of three new xanthones 1–3 and five known analogues 4–8. Structural elucidations of 1–3 were performed by spectral methods such as 1D and 2D (HMQC, HMBC, and ROESY) NMR spectroscopy, in addition to high resolution mass spectrometry. Compounds 1–3 showed anti-TMV activities, with inhibition rates above 20%, especially for 1, which had a lower IC50 value of 21.4 µM.

Seven compounds including a new one named as 13-angeloyloxy-diplosporin (1) were isolated from the endophytic Phomopsis sp. 0391 cultivated in the presence of a histone deacetylase inhibitor. All of these isolates were evaluated for lipase suppressive activities and we firstly found that compoundscytosporone B (5) and dothiorelone A (6) displayed significant lipase inhibited activities compared to the positive control (Orlistat, IC50 = 43 μg/mL) with the IC50 values at 115 and 275 μg/mL, respectively.

Two new inositol compounds, myoinositol-1,3-di-4-hydroxybenzoyl-2-methylbutyrate ( 1 ) and myoinositol-1,3-di-4-hydroxybenzoyl-2-isobutyrate ( 2 ), along with two known ones, were isolated from Thalictrum scabrifolium var. leve Franch., and their structures were elucidated by spectroscopic methods. Compounds 1 and 2 exhibited activities to inhibit Staphylococcus epidermidis with an MIC of 5.00 mg/mL and 4.50 mg/mL at a concentration of 5 mg/mL. Moreover, they had a certain inhibitory effect on Escherichia coli and Staphylococcus aureus.

N -(5-((3E,5E)-10-Acetoxy-5,7,9,11-tetramethyltrideca-3,5-dien-1-yl)-2-oxotetrahydrofuran-3-yl)acetamide ( 1 ), a new amide compound, and five known ones ( 2–6 ) were isolated from the EtOH extract of the solid culture of Fusarium sp. Their structures were determined by means of extensive 1D and 2D NMR techniques, as well as comparison with literature values. Additionally, compounds 1–6 were tested for their cytotoxic activities. The results showed that compounds 2 , 3 , 6 exhibited cytotoxic activities against five human cancer cell lines with IC 50 values ranging from 2.088 to 26.40 μM.