A new unusual sesquiterpene alkaloid (1), as well as four known sesquiterpenes (2–5) were isolated from the fermentation broth of the cigar tobacco-derived Aspergillus ustus. Their structures were determined mainly by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compound 1 was tested for its antibacterial activity against five pathogenic strains (Staphylococcus aureus, Escherichia coli, Streptococcus pyogenes, Bacillus subtilis, and Proteus spp.). The results revealed that compound 1 showed high antibacterial activity with bacteriostatic diameter within the range 19.2 ± 1.4 24.8 ± 1.6 mm, and most of the bacteriostatic diameters of compound 1 are higher than that of the positive control. This compound has the potential to be used as a natural preservative.

Two new naphthalene derivatives, 1-acetyl-5-isopropyl-2,7-dimethoxynaphthalene (1) and 1-acetyl-5-isopropyl-2,8-dimethoxynaphthalene (2), together with five known analogs (3–7) were isolated from the fermentation products of an endophytic fungus Phomopsis fukushii originating from cigar tobacco. Their structures were elucidated using spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1 and 2 were evaluated for their anti-methicillin-resistant Staphylococcus aureus (anti-MRSA) activity. The results showed that compounds 1 and 2 showed weak inhibition with IZD of 9.4 ± 1.6 and 10.6 ± 1.8 mm, respectively.

Two new aromatic sesquiterpenes, 2-isopropyl-5-methyl-4-(4-methylfuran-2-yl)phenol (1) and 5-(hydroxymethyl)-2-isopropyl-4-(4-methylfuran-2-yl)phenol (2), as well as five known ones (3–7) were isolated from the stem bark of cigar tobacco. Their structures were determined mainly by spectroscopic methods, including extensive 1D and 2D NMR techniques. The antiviral activity of compounds 1 and 2 against tobacco mosaic virus (TMV) were detected. Interestingly, compounds 1 and 2 exhibited potential anti-TMV activities with inhibition rates with inactivation effects 30.8

A systematic understanding of the metabolic components in cigar tobacco leaves (CTLs) from different ecological regions remains limited. This study aimed to clarify the substance differences between CTLs from Yunnan and major foreign production areas and to identify potential discriminant metabolites. A total of 25 CTL samples were collected from four production areas in Yunnan and five different foreign countries. The metabolic profiles were comprehensively characterized using continuous flow analysis, ion chromatography, GC-MS, and UPLC-MS/MS. The results revealed that Yunnan CTLs were characterized by a lower sugar-nicotine ratio and significantly higher contents of starch, pectin, and lignin compared to foreign samples. Phenolic acids, alkaloids, flavonoids, amino acids and derivatives, terpenoids, and lipids were identified as the primary components across all CTLs. A total of 398 differential metabolites (248 volatile and 150 non-volatile) were identified, predominantly from the classes of amino acids and derivatives, alkaloids, terpenoids, and lipids. From these, 12 metabolites were selected as potential candidates for distinguishing CTL origin. KEGG enrichment and MetOrigin analyses indicated that the differential metabolites were mainly involved in the biosynthesis of alkaloids, amino acids, flavonoids, lipids, and terpenes, with these pathways being significantly influenced by microorganism and enzyme-mediated carbon and nitrogen coupling metabolism. This exploratory study provides a metabolic foundation for improving production techniques and for the analysis of style-defining substances in Yunnan CTLs.

Stacking, a pivotal step in the preparation of composted organic manures, plays a crucial role in organic matter decomposition, nutrient availability, and soil microbial diversity, with effects dependent on the stacking duration. However, the mechanisms through which organic manures with different stacking times influence crop growth and development via alterations in the soil environment remain poorly understood. This study employed a pot experiment with tobacco plants, applying conventional fertilizers alongside organic cottonseed meal manures subjected to various stacking times (0, 10, 20, and 30 days). The primary aim was to examine the impact of cottonseed meal organic manures on the microbial community structure, function, and chemical properties of tobacco-growing soil, as well as to assess dry matter accumulation in tobacco plants. Results revealed that, compared to conventional fertilizers alone, the addition of cottonseed meal organic manures significantly enhanced soil organic matter content, with the 20d-stacked manure showing the highest increase (68.94%). Additionally, the composition of the soil microbial community was modified, which has increased the relative abundance of carbon and nitrogen metabolic functions. Dry matter accumulation in tobacco plants increased by 13.66%, 25.83%, 31.65%, and 9.69% across the different stacking times. In conclusion, composted organic manures regulate the soil-microbe system, promoting tobacco growth by enhancing the microbial structure of rhizosphere soil and improving nutrient availability. Cottonseed meal organic manures subjected to 20d of composting exhibited the most comprehensive benefits. The enrichment of beneficial microbes like Chryseobacterium and Humicola (potential antagonists of soil pathogens) might contribute to the observed enhancement in soil organic matter and available nutrients. This improvement in soil quality led to a balanced nutrient environment, ultimately promoting dry matter accumulation in tobacco plants. These findings offer robust theoretical support for the application of composted organic manures.IMPORTANCEThis study is important because it elucidates the crucial mechanisms by which composted organic manures, specifically through the regulation of the soil-microbe system, promote crop growth. It provides key evidence that the stacking duration is a critical factor, identifying a 20-day (d) composting period for cottonseed meal manure as optimal for delivering comprehensive benefits: (i) Enhanced soil health: significantly increasing soil organic matter and improving nutrient availability. (ii) Improved microbial community: shifting the soil microbial structure to favor beneficial bacteria and suppress pathogens, thereby enhancing metabolic functions related to carbon and nitrogen cycling. (iii) Direct crop promotion: leading to a substantial increase in dry matter accumulation in tobacco plants.

The Cassia genus (Leguminosae) has attracted a lot of attention as a prolific source of chromones with diverse structures and biological properties. The aim of this study was to screen the antiviral activities of chromones from Cassia alata. The extract of stem bark of this plant was separated using silica gel, MCI, ODS C18, and Sephadex LH-20 column chromatography, as well as semipreparative HPLC. As a result, two new chromones (1 and 2), together with five known analogs (3–7) were isolated. Their structures were determined by means of HR-ESI-MS and extensive 1D and 2D NMR spectroscopic studies. Interestingly, the anti-tobacco mosaic virus (TMV) test revealed that compounds 1 and 2 showed notable anti-TMV activity with inhibition rates of 40.2 ± 2.9

Two new furo[3,2-c]quinoline derivatives, 8-isopropyl-7-methoxy-3-methylfuro[3,2-c]quinoline (1) and 8-isopropyl-6-methoxy-3-methylfuro[3,2-c]quinoline (2), together with five known analogs (3–7) were isolated from the fermentation products of an endophytic fungus Aspergillus versicolor, which originated from cigar tobacco. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1 and 2 were evaluated for their antitobacco mosaic virus (anti-TMV) activity. The results revealed that compounds 1 and 2 exhibited potential anti-TMV activity, with inhibition rates of 36.5 ± 3.6 and 32.8

In this study, two new benzoazepines (1 and 2), together with five known analogs (3–7) were isolated from the cigar-tobacco-derived endophytic Aspergillus fumigatus. Their structures were determined by means of HR-ESI-MS and extensive 1D and 2D NMR spectroscopic studies. All compounds were evaluated for their antibacterial activities against five nitrosobacteria strains Nitrosomonas communis, Nitrosomonas nitrosa, Nitrosospira multiformis, Nitrobacter winogradskyi, and Nitrospira inopinata. Interestingly, compounds 1–7 exhibited notable antibacterial activity with bacteriostatic diameters within the range 13.8 ± 1.9–26.3 ± 2.5 mm against five nitrosobacteria strains, and most of the bacteriostatic diameters are higher than that of positive controls. Owing to the nitrosobacteria having the ability to convert nitrogen components into nitrite in tobacco, and then converting to tobacco-specific nitrosamines (TSNAs), the above compounds have the potential to reduce TSNAs in tobacco by inhibiting nitrosobacteria during the fermentation process of tobacco leaves.

As an important agricultural product, cigar tobacco lacks reports on chemical compositions. The investigation on characteristic components of Yunnan local cigar tobacco revealed 15 Cembrane-type diterpenes including nine undescribed ones (1-9). Their structures were elucidated on the basis of extensive spectroscopic analysis, computational calculations, and X-ray diffraction. The skeleton of Cigarcembrane (1) with a new 6/12-ring system was previously undescribed. This is the first time to report eunicellane (2-7) and gersemiane (8-9) skeletons from plant resources. The transformation mechanism of cigarcembrane, eunicellane, and gersemiane from Cembrane during cigar fermentation was postulated. Chromatographic analysis revealed 10 as a marker for cigars. All the isolated compounds showed the promotion of hOMF cell proliferation, enlightening us to seek lead compounds in mouth care.

Phytochemical investigation on cigar tobacco led to identification of 16 alkaloids including two undescribed nicotine dimeric analogs, cigatobines A-B (1-2), as well as new natural products pyridylnicotine (3), cis-5'-(2-oxopropyl)-nicotine (8) 4-(formamido)-1-(3-pyridyl)-1-butanone (14), 5,6-dihydropyridin-2(1H)-one (15). Some chemical mechanisms including Minisci reaction and nucleophilic addition reaction were involved in formation of dimeric nicotine and its derivatives. Molecular docking on this type alkaloids with the α7-nAChR receptor disclosed five active compounds with binding affinity scores of -8.077 of 2, -7.805 of nicotine, -7.804 of 8, -5.788 of 1, -5.707 of 3, -7.452 of epibatidine. This study disclosed the difference in alkaloids between cigar and tobacco.

ABSTRACT The purpose of this study was to elucidate how the microbiota affects the metabolic state and characteristic flavor development of cigar tobacco leaves (CTL) in the fermentation process through microbial metabolism and co-metabolism with the host. The results showed that core bacterial communities in the fermentation process were Cyanobacteria, Pseudomonas, and Staphylococcus, and Aspergillus, Penicillium, and Inocybe were the most metabolically active fungi. Pseudomonas fulva, Staphylococcus nepalensis, Bacillus subtilis, Stenotrophomonas rhizophila, Alternaria alternata, and Aspergillus cristatus could degrade carbon and nitrogen compounds, such as protein, starch, lignin, and nicotine. There were 12 common non-volatile metabolites and three common volatile metabolites in DH, LC, PE, and YX before and after fermentation, of which menatetrenone, solanidine, γ-glutamylphenylalanine, carotol, and phenol, 4-(1,1,3,3-tetramethylbutyl) were significantly different before and after fermentation. The synthesis and degradation metabolism of various amino acids, alkaloids, and flavonoids are the key metabolic pathways of characteristic flavor development during CTL fermentation. Co-occurrence and interaction patterns showed that seven bacteria and 12 fungi were strictly linearly positively or negatively correlated with 72 and 55 volatile compounds, respectively. In conclusion, this study preliminarily confirmed that CTL fermentation is a microbially mediated carbon–nitrogen coupling metabolism. The carbohydrates in tobacco leaves were largely decomposed and consumed, providing energy sources for microorganisms and the carbon skeleton required for cell construction. The nitrogen-containing macromolecular compounds were degraded to form volatile compounds or flavor precursors with typical flavor.IMPORTANCEThe development of the metabolic state and characteristic flavor of cigar tobacco during fermentation is the key to process control. Innovative discoveries in the development of the metabolic state and characteristic flavor of cigar tobacco during fermentation are the key to process control. Innovative discoveries of core functional microorganisms and key metabolites were made during fermentation, suggesting potential pathways for carbon and nitrogen metabolisms. We demonstrate for the first time that cigar tobacco leaf fermentation is a microbially mediated carbon–nitrogen coupling metabolism. Many carbohydrates in tobacco leaves are decomposed and consumed to provide energy source and carbon skeleton for the construction of microbial cells, and nitrogen-containing macromolecular compounds are degraded to form volatile compounds or flavor precursors with typical flavors.

Topping eliminates apical dominance in tobacco, enhancing the quality of the upper leaves. However, the mechanisms by which topping influences photosynthesis and the leaf structure, and regulation of chemical composition remain unclear. This study investigated the regulatory mechanisms of different topping periods (buttoning, budding, first flower, and full flower topping and without topping) on photosynthesis, the leaf structure, and the chemical composition in tobacco by integrating photosynthetic physiology, anatomical, and chemical composition analyses. The results indicated that topping makes the leaves thinner, promotes leaf lamina opening, and results in thicker mesophyll, compact palisade tissue, and loose spongy tissue. It can also significantly enhance photosynthetic capacity. The contents of total sugar, reducing sugar, and K2O content increased significantly, while the content of chloride ions decreased significantly. The contents of total nitrogen and nicotine were moderate. In conclusion, topping promotes leaf lamina opening, enhances photosynthesis, and associated with changes in the chemical composition of tobacco leaves. Additionally, this study aims to provide a theoretical basis for the promotion of tobacco topping techniques.

Tobacco (Nicotiana tabacum L.) is one of the world’s most economically important crops, with nicotine content being a crucial factor in determining its quality and economic value. By integrating plant physiology with transcriptomics and metabolomics analyses, we gained insight into the regulation of nicotine synthesis and metabolism in tobacco seedlings under different forms of nitrogen supply. Our findings revealed that ammonium nitrogen promotes nitrogen transformation in the root system of tobacco seedlings but inhibits root growth, whereas nitrate nitrogen inhibits biochemical processes but enhances root growth. Additionally, we observed that nitrate nitrogen facilitates the NAD + pathway in nicotine biosynthesis but inhibits the polyamine pathway, whereas ammonium nitrogen has the opposite effect. Overall, our comprehensive analysis indicates that the co-application of ammonium nitrate is conducive to nicotine synthesis. These results not only contribute to identifying key genes and metabolites involved in nicotine synthesis, but also provide a theoretical basis for establishing efficient regulation theories and pathways for tobacco's nitrogen utilization. Furthermore, they offer scientific support for future efforts aimed at regulating tobacco nicotine synthesis.

GC-MS and FTIR analysis, combined with multivariate analysis methods such as PCA and PLS, were used to evaluate and identify moldy tobacco leaves, GC-MS analysis screened 9 markers of tobacco leaf mold, including 2-ethylhexanol, The lincar discriminant equation constructed by 9 key compounds, such as 4-hydroxybutyrolactone, can accurately identify tobacco leaf mold, with an initial validation accuracy of 100% and a cross-validation accuracy of 98.7%. FTIR studies have shown that the moldy process of tobacco leaves consumes a large amount of carbohydrates, proteins, and lipids, GC-MS and FTIR.

In this study, two new pyrroloisoquinolines, cigarpyrro A and B (1 and 2), together with five known pyrroloisoquinolines (3–7) were isolated from the cigar-tobacco-derived endophytic fungus Aspergillus puniceus. Their structures were determined by means of HR-ESI-MS and extensive 1D and 2D NMR spectroscopic studies. Compounds 1 and 2 were evaluated for their antibacterial activities against five pathogenic strains (Staphylococcus aureus (SEA), Escherichia coli (EPEC), Streptococcus pyogenes (GAS), Bacillus subtilis (QST713), and Proteus spp.). Interestingly, compounds 1 and 2 exhibited notable antibacterial activity with a bacteriostatic diameter within the range 15.4 ± 1.8 – 25.2 ± 1.6 mm against the above strains, and most of the bacteriostatic diameters are higher than that of the positive control. In addition, the potential values for compounds 1 and 2 used as antiseptic agents were also evaluated, and they have the potential value for use as antiseptic agents for cigarette-tipping paper.

Two new benzo[c]oxepins (1 and 2), together with three known analogues (3–5) were isolated from the cultures of the fungus Xylaria polymorpha. Their structures were determined by means of HR-ESI-MS and extensive 1D and 2D NMR spectroscopic studies. Compounds 1 and 2 were evaluated for their antibacterial activities against five nitrosobacteria strains (Nitrosomonas communis, Nitrosomonas nitrosa, Nitrosospira multiformis, Nitrobacter winogradskyi, and Nitrospira inopinata). Interestingly, compounds 1 and 2 exhibited notable antibacterial activity with bacteriostatic diameters within the range 14.8–21.8 mm against five nitrosobacteria strains, and some of the bacteriostatic diameters are greater than that of the positive control. Owing to the nitrosobacteria having the ability to convert nitrogen components into nitrite in tobacco, and then convert to tobacco-specific nitrosamines (TSNAs), compounds 1 and 2 have the potential to reduce TSNAs in tobacco by inhibiting nitrosobacteria during the fermentation process of tobacco leaves.

To further explore powdery mildew (caused by Golovinomyces cichoracearum) natural products, an extract from the fermentation of endophytic Aspergillus fumigatus was investigated. As a result, six isoindole alkaloid derivatives (1–6) were isolated. Among them, two compounds (1 and 2) were newly discovered and the activity evaluation of the purified compounds 1–6 against G. cichoracearum was studied. The results revealed that compounds 1–6 demonstrated obvious anti-G. cichoracearum activities for cigar tobacco in the range of 40.6

A new indole alkaloid, cigarindole A (1), together with five known indole alkaloids (2–6) were isolated from cigar tobacco. Their structures were elucidated using spectroscopic methods, including extensive 1D and 2D NMR techniques. Interestingly, compound 1 exhibited high antibacterial activity with bacteriostatic diameter within the range 20.6–26.7 mm against five pathogenic strains (Staphylococcus aureus, Escherichia coli, Streptococcus pneumoniae, Bacillus subtilis, and Proteus spp). Compounds 2–6 exhibited obvious antibacterial activity with bacteriostatic diameter within the range 11.9–21.8 mm. In addition, compound 1 also the potential value for use as an antiseptic agent for cigarette tipping paper.

To characterize volatile organic compounds (VOCs) and aromatic sensory properties in Yun cigar, 27 samples from four origins were analyzed using SPME-HS-GC/MS and sensory analysis. The investigation results were analyzed using principal component analysis (PCA), Fisher linear discriminant analysis (LDA), and Pearson correlation analysis. In Yunnan cigars, the content of nicotine and neophytadiene accounted for over 90% of the total VOC content. Nicotine was significantly positively correlated with neophytadiene and phytol. The cigars from four origins were clearly classified by the PCA of VOCs. Four region discrimination functions were established through the LDA of 14 compounds, and the validation accuracy was 100%. The sensory descriptors with the highest geometric mean were woody, roasted, fresh-sweet, bean, and scorched. Acetophenone, megastigmatrienone A, and thunbergene were positively correlated with multiple aroma descriptors, while nicotine was negatively correlated with multiple aroma descriptors.

The flavor characteristics of cigars are closely related to their origin.Using near infrared spectroscopy to analyze the Similarity of cigar tobacco leaves from different origins provides a basis for zoning and product design for domestic cigar planting.This study analyzed 526 tobacco leaf samples collected in Yunnan.Dominica.Brazil, and Indonesia from 2021 to 2023 using principal component analysis and Fisher's distance method to determine the similarity of tobacco leaves from different origins, The results showed that Dominican and Brazilian tobacco leaves had high similarity, while Yunnan and Dominican tobacco leaves Bad some similarity,within the Yunnan region, there was high similarity between Yuxi.Wenshan, and Pu'er, and high Similarity between Dehong and Lincang;there was some similarity between Dehong and Dominica, and some similarity between Lincang and Indonesia, The similarity results obtained within large production areas were consistent with sensory evaluations, Ind more detailed similarity analysis results can provide more detailed technical support for domestic cigar tobacco leaf planting Joningproduct design.etc.