anti-TMV Activity Research Articles

Two New Xanthones from Comastoma pulmonarium and Their Anti-Tobacco Mosaic Virus Activity

Two new xanthones (1 and 2), together with three known xanthones (3–5), were isolated from the whole plants of Comastoma pulmonarium. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1 and 2 were also evaluated for their anti-tobacco mosaic virus (anti-TMV) activity. The results showed that compounds 1 and 2 showed high anti-TMV activity with inhibition rates of 42.8% and 52.4%, respectively. These rates are higher than that of positive control.

Natural Product Cerbinal and Its Analogues Cyclopenta[c]pyridines: Synthesis and Discovery as Novel Pest Control Agents

Owing to the changing needs of agriculture, the exploration of new pest control agents remains as critical as ever. The analogues 3a-3v of the natural product cerbinal were synthesized from genipin by an efficient and practical method under additive-free conditions. The antiviral and insecticidal effects of cerbinal and these cyclopenta[c]pyridines (3a-3v) were evaluated systematically. Most of the synthesized compounds exhibited higher anti-TMV activities than the lead compound cerbinal. Compound 3s (2-(4-methoxyphenyl)) had the most promising inhibitory activities against TMV (inactivation effect 49.0 ± 0.8%, curative effect 41.2 ± 4.3%, and protection effect 51.5 ± 2.7% at 500 μg/mL). Among the synthesized compounds, only 3v (2-(2-chloro-4-(trifluoromethoxy)phenyl)) reached the activity level of cerbinal against Plutella xylostella. This suggested that the cyclopenta[c]pyridines obtained by modifications of cerbinal at position 2 are very significant for the anti-TMV activity, and yet were exceptionally less active for the insecticidal activities.

Two New Naphthaldehyde Derivatives from Comastoma pulmonarium

Two new naphthaldehyde derivatives, 2-(hydroxymethyl)-5-methoxy-7-(2-oxopropyl)naphthalene-1-carbaldehyde (1) and 2-(hydroxymethyl)-5-methyl-7-(2-oxopropyl)naphthalene-1-carbaldehyde (2), were isolated from the whole plants of Comastoma pulmonarium. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1 and 2 were also evaluated for their anti-tobacco mosaic virus (anti-TMV) activity. The results showed that compounds 1 and 2 showed high anti-TMV activity with inhibition rates of 34.6 and 30.2%, respectively.

A polysaccharide found in Dendrobium nobile Lindl stimulates calcium signaling pathway and enhances tobacco defense against TMV

A neutral polysaccharide separated from Dendrobium nobile Lindl was designated as DNPE6(4). It was structurally characterized using a combination of spectral and chemical analysis. Its average molecule weight was 99.2 kDa. The monosaccharide composition was Araf, Glcp, Galp, and Manp in a molar ratio of 2.5:0.9:0.3:0.8. Their linkage types were →1)-L-Araf-(3→, →1)-D-Glcp-(4→, →1)-D-Galp-(3→, →1)-D-Galp-(6→, →1)-D-Manp-(3, 6→, and T-D-Manp. The polysaccharide was found to have anti-TMV and anti-CMV activities for the first time in vivo. Notably, DNPE6(4) exhibited excellent protective activity against TMV. Furthermore, several proteins related to calcium signaling pathway and pathogen related proteins were up-regulated, and we also found expression levels of EDS1, ICS1, and PR1 involved in SA pathway up-regulated after DNPE6(4) treatment. In addition, some defense enzymes increased in the same condition. All these findings revealed DNPE6(4) was an elicitor to stimulate calcium signaling pathway to enhance the tobacco defense against TMV. This study therefore revealed that DNPE6(4) was a promising antiviral agent for future study.

Flavonoids From the Flowers of Sophora davidii and Their Anti-Tobacco Mosaic Virus Activities

A new pterocarpan, named davidicarpan A (1), together with 9 known flavonoids, including 3 pterocarpans (2-4) and 6 isoflavones (5-10), were isolated from the flowers of Sophora davidii (France.) Pavol. Their structures were confirmed by high-resolution electrospray ionization-mass spectrometry, one-dimensional (1D) and 2D nuclear magnetic resonance spectroscopy, and comparison with reported literature values. Compounds 1 and 4 exhibited anti-tobacco mosaic virus (anti-TMV) activities with inhibition rates of 27.4% and 26.2%, which was higher than that of the positive control, ningnamycin.

Five new alkaloids from Aconitum apetalum (Ranunculaceae)

Twenty-one alkaloids, including five new ones, acoapetaldines A–E (1–5), were isolated from the whole plants of Aconitum apetalum. Among them, 1 is an aconitine-type diterpenoid alkaloid, 2 and 3 are aporphine alkaloids and 4 and 5 are napelline-type diterpenoid alkaloids. The structures of the new alkaloids were elucidated by spectroscopic data analysis and that of acoapetaldine D (4) was confirmed by single crystal X-ray crystallography. Acoapetaldine A (1) and aconorine (12) exhibited moderate anti-tobacco mosaic virus (anti-TMV) activity, while corydine (15) displayed moderate antimicrobial activity against Pseudomonas aeruginosa.

Two New Flavones from Cassia pumila and Their Anti-Tobacco Mosaic Virus Activity

Two new flavones, 8-hydroxy-7-(3-hydroxypropyl)-2′-methoxyflavone (1) and 8-hydroxy-7-(2-hydroxyethyl)-2′-methoxyflavone (2), together with four known flavones (3–6), were isolated from the whole plants of Cassia pumila. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1 and 2 were evaluated for their anti-tobacco mosaic virus (anti-TMV) activity. The results showed that compounds 1 and 2 have potential anti-TMV activities with inhibition rates of 30.2% and 28.2%, respectively.

A new naphthaldehyde derivative from Comastoma pulmonarium and its anti-tobacco mosaic virus (anti-TMV) activity

A new naphthaldehyde derivative has been isolated from Comastoma pulmonarium by using various chromatographic techniques, including silica gel, Sephadex LH-20, MCI-gel resin and RP-HPLC. This compounds was determined as 5-methoxy-2-methyl-7-(2-oxopropyl)naphthalene-1-carbaldehyde(1) by NMR, MS, IR and UV spectra. This compound was also evaluated for its anti-tobacco mosaic virus (anti-TMV) activity. The result showed that it showed high anti-TMV activity with inhibition rate of 32.8%. The inhibition rate is close to that of positive control (ningnanmycin).

Two New Isoflavones from Pueraria lobata and Their Bioactivities

Two new isoflavones, 4′,6-dimethoxy-8-hydroxy-7-hydroxymethylisoflavone (1) and 4′,8-dihydroxy-7-hydroxymethyl-6-methoxyisoflavone (2), together with three known isoflavones (3–5), were isolated from Pueraria lobata. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1–5 were evaluated for their anti-tobacco mosaic virus (anti-TMV) activities. The results showed that compound 2 exhibited high anti-TMV activity with inhibition rates of 32.6%. The other compounds also showed potential anti-TMV activities with inhibition rates in the range of 21.4–25.3%, respectively. The cytotoxic activity of compounds 1–5 against five human tumor cell lines (NB4, A549, SHSY5Y, PC3, and MCF7) was also tested. The results revealed that compounds 1–5 showed weak inhibitory activities against some human tumor cell lines, with IC50 values in the range of 6.9–9.8 μM.

Design, Synthesis, and Biological Activity of β-Carboline Analogues Containing Hydantoin, Thiohydantoin, and Urea Moieties.

A series of novel β-carboline derivatives was designed by combining the anti-tobacco mosaic virus (TMV) lead compound tetrahydro-β-carboline ester with the hydantoin, thiohydantoin, and urea motifs. These derivatives were synthesized from tetrahydro-β-carboline ester via a structural diversity-oriented synthesis in one step, and their biological activities were evaluated. Most of the derivatives exhibited anti-TMV activity higher than that of commercial plant virucide ribavirin, such as compounds 2, 4, 5, 7, 9, 15, 16, 19, and 21. Compared with the lead compounds, some of these derivatives showed good insecticidal activity against Plutella xylostella and Culex pipiens pallens. At the same time, these derivatives also showed broad-spectrum fungicidal activity. The systematic study provides strong evidence that the hydantoin, thiohydantoin, and urea motifs of these molecules can improve and modulate the activities of the analogues of natural products.

Marine Natural Products for Drug Discovery: First Discovery of Kealiinines A-C and Their Derivatives as Novel Antiviral and Antiphytopathogenic Fungus Agents.

Leucetta alkaloid kealiinines A-C and kealiinine B derivatives were designed, synthesized, and characterized on the basis of NMR and HR-MS. The anti-TMV and antiphytopathogenic fungus activities of these alkaloids were evaluated for the first time. Kealiinine B exhibited a higher anti-TMV activity than kealiinines A and C. Kealiinine B derivatives 2m (inhibitory rates: 68, 66, and 71% at 500 μg/mL for inactivation, curative, and protection activity in vivo, respectively) and 2y (inhibitory rates: 69, 64, and 63% at 500 μg/mL for inactivation, curative, and protection activity in vivo, respectively) showed significantly higher antiviral activity than ningnanmycin (inhibitory rates: 56, 56, and 58% at 500 μg/mL for inactivation, curative, and protection activity in vivo, respectively), thus emerging as new lead compounds for novel antiviral agent development. Structure-activity relationship research provided the basis for structural simplification of these alkaloids. Further fungicidal activity tests revealed that these alkaloids displayed broad-spectrum fungicidal activities. Compounds 2i and 2p displayed good fungicidal activities in vitro against Sclerotinia sclerotiorum and Rhizoctonia cerealis with inhibition rates of 71%/50 mg/kg and 70%/50 mg/kg, respectively.

Leveraging botanical resources for crop protection: the isolation, bioactivity and structure-activity relationships of lycoris alkaloids.

Lycoris aurea (L' Herit.) Herb (Amaryllidaceae) is a native pesticide in China. The ethanolic extract of Lycoris aureate bulbs, the total alkaloids of L. aurea bulbs and the main alkaloids of L. aurea bulbs were systematically investigated as part of a novel project to study their antiviral, fungicidal (phytopathogenic) and insecticidal activities. We also prepared 18 lycorine derivatives and evaluated their bioactivities. Lycorine had excellent larvicidal activity against Plutella xylostella (LC50 = 10.6 mg L-1 ) and was also effective during a field trial. It also showed good inhibitory activity against tobacco mosaic virus (TMV) and good fungicidal activity against Phytophthora capsici (EC50 = 7.76 mg L-1 ). Compounds 13 and 15 exhibited good anti-TMV activity, excellent fungicidal activity against Rhizoctonia cerealis (EC50 = 6.78 mg L-1 ) and excellent larvicidal activity against Culex pipiens pallens (LC50 at 0.1-0.25 mg L-1 ). Lycorine was identified as the main active component of L. aurea bulbs and showed potential for field application against P. xylostella. The activities of compounds 13 and 15 make them excellent candidates for new lead compounds in novel pesticide research. This study provides the basis for developing these alkaloids into potential agrochemicals. © 2018 Society of Chemical Industry.

Seven new anthranilamide derivatives from Aconitum apetalum

Seven new anthranilamide derivatives, acoapetalines A-G (1–7), including one new naturally occurring compound (7), together with six known ones (8–13) were isolated from the whole plants of Aconitum apetalum. Their structures were established on the basis of extensive spectroscopic analyses (IR, UV, HRESIMS, 1D and 2D NMR). All compounds were evaluated for their anti-tobacco mosaic virus (anti-TMV) activities. The results showed that compound 10 exhibited significant anti-TMV activity with an inhibition rate of 67.57% (100 μg/mL), which was higher than that of ningnamycin (52.89%).

Antiviral properties and interaction of novel chalcone derivatives containing a purine and benzenesulfonamide moiety

A new concise and facile method was explored to synthesize a series of novel chalcone derivatives containing a purine and benzenesulfonamide moiety and their antiviral properties were evaluated against TMV and CMV. Biological assays indicated that several of the derivatives exhibited significant anti-TMV and anti-CMV activities in vivo. In particular, compound d2 displayed excellent inactivating activity against TMV, with the EC50 value of 51.65 μg/mL, which was better than that of ribavirin (150.45 μg/mL). Molecular docking showed that there are four hydrogen bonds between compound d2 and TMV coat protein (TMV-CP). Compound d2 demonstrated strong binding capacity to TMV-CP with Ka = 1.58 × 105 L/mol and Kd = 12.16 μM. These findings indicated that chalcone derivatives are worthy of further research and development as templates for new antiviral agents.

Anti-Tobacco Mosaic Virus Isocoumarins from the Fermentation Products of the Endophytic Fungus Aspergillus versicolor

Two new isocoumarins, (3R)-methyl-8-hydroxy-6-(hydroxymethyl)-7-methoxydihydroisocoumarin (1) and (3R)-methyl-7,8-dimethoxy-6-(hydroxymethyl)dihydroisocoumarin (2), together with three known isocoumarins (3–5), were isolated from the fermentation products of an endophytic fungus Aspergillus versicolor. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. The anti-tobacco mosaic virus (anti-TMV) activities of compounds 1 and 2 were evaluated. Compounds 1 and 2 showed anti-TMV activities with inhibition rates of 21.8 and 18.6% at the concentration of 20 μM, respectively.

Furan-2-Carboxylic Acids from the Roots of Nicotiana tabacum and their Bioactivities

Two new furan-2-carboxylic acids, 5-(3-hydroxy-5-(hydroxymethyl)-4-methoxyphenyl)-3-methylfuran-2-carboxylic acid (1) and 5-(4-hydroxy-5-methoxy-2-methylphenyl)-3-methylfuran-2-carboxylic acid (2), together with two known furan-2-carboxylic acids (3 and 4) were isolated from the roots of Nicotiana tabacum. Their structures were determined by means of HR-ESI-MS and extensive 1D and 2D NMR spectroscopic studies. Compounds 1 and 2 were tested for their anti-tobacco mosaic virus (TMV) and cytotoxicity activities. The results revealed that compounds 1 and 2 showed high anti-TMV activity with inhibition rate of 35.8 and 32.6%. These rates are close to that of positive control. Compounds 1 and 2 also showed moderate to weak inhibitory activities against some tested human tumor cell lines with IC50 values in the range of 1.5–6.0 μM.

Two New Benzolactones from the Leaves of Yunnan Local Sun Cured Tobacco and Their Bioactivities

Two new benzolactones, 4-methoxy-6-(2-oxopropyl)isobenzofuran-1(3H)-one (1) and 4-methyl-6-(2-oxopropyl)isobenzofuran-1(3H)-one (2), were isolated from the leaves of Yunnan local sun cured tobacco. Their structures were determined by means of HR-ESI-MS and extensive 1D and 2D NMR spectroscopic studies. Compounds 1 and 2 were tested for their anti-tobacoo mosaic virus (TMV) activities and cytotoxicity activities. The results revealed that compounds 1 and 2 showed high anti-TMV activity with inhibition rates of 32.6 and 30.2%. These rates are close to that of positive control. Compounds 1 and 2 also showed weak inhibitory activities against some tested human tumor cell lines.

Design, Synthesis, and Antitobacco Mosaic Virus Activity of Water-Soluble Chiral Quaternary Ammonium Salts of Phenanthroindolizidines Alkaloids.

To study the influence of the substituent at the N-10 position on antiviral activity, the chiral quaternary ammonium salt derivatives of R- and S-tylophorine were designed, synthesized, and evaluated for antiviral activity against tobacco mosaic virus (TMV). The bioassay results indicated that most of the designed structural analogues showed good in vivo anti-TMV activity, among which propargyl quaternary ammonium salt compound S-7b showed the best anti-TMV activities (80.5%, 77.6%, 76.6%, 82.1%) at 500 μg/mL both in vitro and in vivo in the laboratory. In the field trials of antiviral efficacy against TMV, S-7b as well exhibited better activities than control plant virus inhibitors. The stability of compound S-7b was obviously increased, and its solubility was more than 500-times higher than that of S-tylophorine. Therefore, chiral quaternary ammonium salt S-7b was expected to be developed as a promising candidate as an inhibitor of plant virus.

New isolates from leaves of Nicotiana tabacum and their biological activities

Three new isolates (1−3) including one new sterol and two new flavonoids together with three known sterols (4−6) were isolated from the leaves of Nicotiana tabacum. Their structures were determined mainly by spectroscopic methods, including extensive 1D and 2D NMR techniques. All compounds were evaluated for their anti-tobacco mosaic virus and cytotoxic activities. The results showed that compounds 2 and 3 exhibited high anti-TMV activity with inhibition rate of 34.2 and 33.4%, respectively, which were roughly equivalent to that of positive control. The cytotoxicities of compounds 1 and 4–6 against five human tumour cell lines were also tested, and tested compounds showed weak inhibitory activities against some tested human tumour cell lines.

Three new sesquiterpenes from the stems of Nicotiana tabacum and their bioactivities

Three new sesquiterpenes, methyl 4-isopropyl-7-methoxy-6-methylnaphthalene-1-carboxylate (1), methyl 2-hydroxy-4-isopropyl-7-methoxy-6-methylnaphthalene-1-carboxylate (2), and methyl 2-hydroxy-6-(hydroxymethyl)-4-isopropyl-7-methoxynaphthalene-1-carboxylate (3), together with three known sesquiterpenes (4–6), were isolated from the stems of Nicotiana tabacum. Their structures were determined by means of HRESIMS and extensive 1D and 2D NMR spectroscopic studies. The results showed that compounds 2, 3, and 5 exhibited high anti-TMV activity with inhibition rates of 33.6, 35.8, and 36.7%. Compounds 1–6 showed weak inhibitory activities against some tested human tumor cell lines (NB4, A549, SHSY5Y, PC3, and MCF7) with IC50 values in the range of 6.7–9.6 μM.