Interfacially Bridging Covalent Network Yields Hyperstable and Ultralong Virus-Based Fibers for Engineering Functional Materials

We present a strategy of interfacially bridging covalent network within tobacco mosaic virus (TMV) virus-like particles (VLPs). We arranged T103C cysteine to laterally conjugate adjacent subunits. In the axis direction, we set A74C mutation and systematically investigated candidate from E50C to P54C as the other thiol function site, for forming longitudinal disulfide bond chains. Significantly, the T103C-TMV-E50C-A74C shows the highest robustness in assembly capability and structural stability with the largest length, for TMV VLP to date. The fibers with lengths from several to a dozen of micrometers even survive under pH 13. The robust nature of this TMV VLP allows for reducer-free synthesis of excellent electrocatalysts for application in harshly alkaline hydrogen evolution.     

Synthesis and Antiviral Bioactivity of Novel 2‐Substituted Methlthio‐5‐(4‐Amino‐2‐Methylpyrimidin‐5‐yl)‐1,3,4‐Thiadiazole Derivatives

A series of novel 2‐substituted methlthio‐5‐(4‐amino‐2‐methylpyrimidin‐5‐yl‐)‐1,3,4‐thiadiazole derivatives were synthesized, characterized and evaluated for antiviral activities against tobacco mosaic virus (TMV). The preliminary biological results indicated that most compounds exhibit excellent antiviral activity against TMV in vivo. Among these compounds, compounds 9c , 9i , and 9p displayed the similar curative effect against TMV (EC₅₀ = 287.05–322.47 µg/mL) to that of the commercial agent Ningnanmycin (EC₅₀ = 301.83 µg/mL). In particular, compound 9d demonstrated the best curative effect against TMV (EC₅₀ = 266.21 µg/mL), which was better than that of commercial Ningnanmycin.     

Let There Be Light: Targeted Photodynamic Therapy Using High Aspect Ratio Plant Viral Nanoparticles

The development of plant viral nanoparticles (VNP) loaded with different molecular versions of a photodynamic drug is described. Specifically, tobacco mosaic virus (TMV) and tobacco mild green mosaic virus (TMGMV) are developed as drug carriers that encapsulate the monocationic, dicationic, tricationic, and tetracationic versions of a porphyrin‐based photosensitizer drug (Zn‐Por). While TMV has been extensively explored for various nanotechnology applications, this is the first study investigating TMGMV for medical applications. Light‐activated cancer cell killing of Zn‐Por‐loaded VNPs is studied in vitro using melanoma and cervical cancer models. Native and nucleolin‐targeted VNP drug carriers are developed and their efficacy assessed. A fivefold increase in cancer cell killing is observed using nucleolin‐targeted TMV loaded with tricationic Zn‐Por and displaying the nucleolin‐specific F3 peptide.     

牛心朴子草植物农药的化学成分与生物活性研究

在分离鉴定化学组分基础上结合普筛农药活性,发现牛心朴子草提取物中生物碱部位显示抗植物病毒极高活性。通过生物活性跟踪与色谱分离、结构鉴定,确定它是菲并吲哚里西啶生物碱,包括7-脱甲氧基娃儿藤碱(Antofine)(1)和N-氧代-7-脱甲氧基娃儿藤碱(N-Oxideantofine)(2)。其中2是首次从该草分离得到。Antofine(1)是该草抑制植物病毒主要成份;半中枯斑法测定它在10^-^6g/mL浓度的枯斑抑制率达60%,比对照的常用植物病毒抑制剂活性高1～2个数量级。用多种生测方法验证该草生物碱试样抗植物病毒如烟草花叶病毒(TMV)、马铃薯Y病毒(PVY)、芜菁花叶病毒(TuMV)等的生物活性。     

Synthesis and antiviral activities of novel 1,4-pentadien-3-one derivatives bearing an emodin moiety

A series of 1,5-diaryl-1,4-pentadien-3-one derivatives bearing an emodin group were designed and synthesized by the combination of natural products. The antiviral activities against tobacco mosaic virus (TMV) and cucumber mosaic virus (CMV) in vivo were evaluated. Some of the derivatives displayed promising curative effect and protective activity against TMV. Compound D5 showed appreciable curative bioactivity on TMV approximately of 50% at 306.2 mg/mL, which was superior to ningnanmycin (409.3 mg/mL).     

Design,Synthesis and Biological Evaluation of Isothiazole Based 1,2,4‐Trizaole Derivatives

A series of novel 3,4‐dichloroisothiazole based 1,2,4‐triazole derivatives were rationally designed and synthesized. Their structures were confirmed by ¹H NMR, ¹³C NMR, HRMS or elemental analysis; the typical crystal structure was determined by X‐ray diffraction for validation. All target compounds were evaluated for their in vitro fungicidal and in vivo anti‐TMV activities. The bioassay results indicated that compound 6b , namely 1‐(3,4‐dichloroisothiazol‐5‐yl)‐1‐(4‐fluorophenyl)‐2‐(1H‐1,2,4‐triazol‐1‐yl)ethanol, exhibited excellent growth inhibition against B. cinerea, C. arachidicola and P. piricola with median effective concentrations (EC₅₀) of 6.98, 2.73 and 3.07 μg/mL, respectively, and good in vivo anti‐TMV activity of over 60% of inactivation and induction activity at 100 μg/mL. These data demonstrate that compound 6b is both a fungicide and an anti‐TMV lead, deserving further studies.     

以烟草花叶病毒为半抗原载体的活体免疫反应

以烟草花叶病毒的赖氨酸突变体(TMV-EPMK)为半抗原载体,利用“点击化学”反应,将半抗原小分子雌三醇(E3)经由两个不同亲/疏水性的连接臂修饰在TMV-EPMK上,成功制备了TMV-EPMK/E3完全抗原。 通过免疫实验发现,以亲水性连接臂制备的TMV-EPMK/E3偶联体可在小鼠体内诱导更高水平的E3特异性免疫反应,所产生的IgG抗体的滴度达21800。 该结果表明,以烟草花叶病毒为载体制备的完全抗原,其免疫原性受连接臂性质的影响,亲水性的连接臂更有利于抗体反应的发生。     

Design,synthesis and antiviral activities of chalcone derivatives containing pyrimidine

A series of chalcone derivatives (T1-T23) containing pyrimidine were synthesized, characterized, and assessed for their antiviral activity against tobacco mosaic virus (TMV) activities. Most target compounds displayed better antiviral activities against TMV than commercial ningnanmycin. Among them, the EC₅₀ value of curative activities of compounds T1, T7, T9 and T19 (219.2, 228.2, 279.9 and 234.9 μg/mL, respectively) were superior to that of ningnanmycin (320.1 μg/mL). In addtion, the EC₅₀ value of protective activities of compounds T5, T9, T19 and T23 (235.0, 220.0, 199.5 and 187.2 μg/mL, respectively) were superior to that of ningnanmycin (307.4 μg/mL). Then, the antiviral mechanism of T19 and TMV coat protein (TMV-CP) was preliminarily investigated by microscale thermophoresis (MST) and molecular docking technology. The results showed that T19 had a strong binding affinity for TMV coat protein, and its dissociation constant (K_d) was 0.00310 ± 0.000916 μM, which was superior to ningnanmycin(0.165 ± 0.0799 μM). This study suggests that chalcone derivatives containing pyrimidine could be used as novel antiviral agents for controlling the plant viruses.     

Study of intact virus‐like particles of human papillomavirus by capillary electrophoresis

Virus‐like particles of human papillomavirus (HPV‐VLP), resulting from the self‐assembly of the capsid proteins (L1 or L1 and L2), have been widely used to study HPV as they are similar to the native virion. Moreover, two prophylactic vaccines, Gardasil^® and Cervarix^®, are based on HPV‐VLP L1. Analytical techniques currently used to characterize HPV‐VLP, such as SDS‐PAGE, Western blot, ELISA, are time‐consuming and semiquantitative. In this study, CE was evaluated for the analysis of intact HPV16‐VLP. The usefulness of capillary inner wall coating as well as various BGEs, pH, and detergent additives were investigated. Reproducible HPV‐VLP analysis in CE was achieved using poly(ethylene oxide)‐coated capillary and a BGE containing high salt concentration and low SDS concentration. The developed method enables HPV‐VLP detection in less than 10 min (migration times RSD: 1.6%). The identity of HPV‐VLP peak was confirmed by comparison with a sample obtained from a wild‐type baculovirus and with VLP‐based vaccine, Gardasil^®, after adjuvant dissolution. Finally, we applied the developed methodology to VLP‐based vaccines, demonstrating that CE could be successfully used for vaccine quality control.     

Six new triterpenoid saponins from the leaves of Ilex oblonga and their inhibitory activities against TMV replication

Six new triterpenoid saponins of the ursane types were isolated from the MeOH extract of the leaves of Ilex oblonga. They were oblonganoside A (1), oblonganoside B (2), oblonganoside C (6), oblonganoside D (8), oblonganoside E (9), and oblonganoside F (10), together with three known triterpenoid saponins. The structures of these compounds were elucidated on the basis of spectroscopic analysis, and compound 1 showed appreciable inhibitory activity against TMV replication with EC50 value 0.074 mM.     

Atom transfer radical polymerization on the interior of the P22 capsid and incorporation of photocatalytic monomer crosslinks

We have successfully used atom transfer radical polymerization (ATRP) to form linear and crosslinked polyacrylamide and polyacrylate polymers, constrained within the virus like particle (VLP) derived from the bacteriophage P22. Polymerization of Tris(hydroxymethyl)methylacrylamide was initiated, in a spatially controlled manner, using macroinitiators derived from two different mutants of P22, S39C and K118C. Initiation from the S39C mutant results in spatially confined polymer growth on the interior of P22 while initiation from the K118C site results in a polymerized VLP in which some of the polymer is partially exposed on the outside of the capsid. Using the S39C macroinitiator we have demonstrated polymerization of aminoethyl methacrylate (AEMA) monomers, crosslinked by co-polymerization with the multifunctional monomer [Ru(5-methacrylamido-phenanthroline)₃]²⁺ resulting in an active photocatalytic P22 capsid particle.     

Characterization of silica-coated tobacco mosaic virus

The deposition of silica on the surface of tobacco mosaic virus (TMV) is achieved at a higher pH (>7) as a means to enhance its usefulness as a template for the synthesis of nanostructures. Electron energy loss spectroscopy definitively shows the presence of a silica shell on the surface of the TMV while small angle X-ray scattering differentiates successfully between silica-coated TMV and silica particles in the presence of uncoated TMV. Importantly, coating reactions done in a 50% w/v methanol/water solution produce smaller silica nanostructures during the condensation of the hydrolysis intermediates, possibly aiding in obtaining uniform coating. Furthermore, TMV-templated silica coatings are found to enhance the stability of the virus particle in methanol at conditions that would ordinarily disrupt the assembled particle. Combined these findings demonstrate that TMV can function as an efficient template for the controlled deposition of silica at neutral pH.     

Antiviral activity of polysaccharides against infection of tobacco mosaic virus

In the course of searching for antiviral substances to tobacco mosaic virus (TMV), it was found that polysaccharides have a high inhibitory activity against TMV infection. The leaves of Xanthi NN tobacco were rubbed with the mixtures of TMV and polysaccharides such as chondroitin sulfate C- and A- types. The addition of polysaccharides to the inoculum solution greatly reduced the number of local lesions formed on the inoculated leaves. Here the polysaccharide did not completely prevent virus entry into the leaves and the virus particles may penetrate and multiply in leaves without forming lesions. Although the electron micrograph showed that the virus suspension was almost monodisperse, the addition of polysaccharides caused TMV to form large raft-like aggregates. The TMV solution became turbid after the addition of a large amount of polysaccharides. A threshold concentration of polysaccharides exists for virus precipitation, which is independent of the virus concentration. The size of polysaccharide at the threshold concentration agreed well with that obtained by light scattering method. The strength of the interaction between TMV and polysaccharides was found to be related to the degree of inhibitory activity of polysaccharides.     

Design,Synthesis and Biological Evaluation of Novel N‐(4‐([2,2′:5′,2′′‐Terthiophen]‐5‐yl)‐2‐methylbut‐3‐yn‐2‐yl) Benzamide Derivatives

On the basis of the principle of combination of active groups, a series of novel N‐(4‐([2,2′:5′,2′′‐terthiophen]‐5‐yl)‐2‐methylbut‐3‐yn‐2‐yl) benzamide derivatives were designed, synthesized and systematically evaluated for their antiviral activity against tobacco mosaic virus (TMV). The bioassay results showed that most of these compounds displayed good anti‐TMV activity, and some of them exhibited higher antiviral activity than commercial Ningnanmycin. Especially, compound 8e with excellent anti‐TMV activity (inactivation activity, 92.3%/500 µg·mL^?1; curative activity, 85.7%/500 µg·mL^?1 and protection activity, 64.7%/500 µg·mL^?1) emerged as a potential inhibitor of plant virus TMV. Quantitative structure‐activity relationship studies proved that the van der Waals volume (V) and electronic parameter (∑(∑σ_o+σ_p) and ∑σ_m) for the substituent R¹ were very important for antiviral activities in this class of compounds.     

Self-assembly of anisotropic tobacco mosaic virus nanoparticles on gold substrate

A facile approach to assembled virus film with tunable structure is presented.Rod-like tobacco mosaic virus (TMV) was selected as the prototype in this study for its anisotropic structural feature.TMV can either lie down or stand up on gold substrate by tuning the solution pH.A quartz crystal microbalance with dissipation monitoring was used to monitor the pH-dependent self-assembly behavior of TMV nanoparticles,and atomic force microscopy and single molecule force spectroscopy further confirmed the differe...     

Antiviral and Antibacterial Activities of N‐(4‐Substituted phenyl) Acetamide Derivatives Bearing 1,3,4‐Oxadiazole Moiety

In this paper, a series of N‐(4‐substituted phenyl) acetamide derivatives bearing 1,3,4‐oxadiazole moiety were synthesised. Preliminary bioassays revealed that these compounds not only exhibited favourable antiviral activities toward tobacco mosaic virus (TMV) but also demonstrated sustained inhibition activities against plant pathogenic bacteria, including Xanthomonas oryzae pv. oryzae, Ralstonia solanacearum, and Xanthomonas axonopodis pv. citri. Among the derivatives, TC ₈ and TC ₂₀ exerted the strongest curative activities against TMV, with half‐maximal effective concentration (EC₅₀) values of 239.5 and 236.2 µg/mL, respectively, which were comparable to that of ningnanmycin (EC₅₀=273.2 µg/mL). Given their simple synthesis, the target compounds can serve as alternative antiviral candidates.     

Study of the synthesis,antiviral bioactivity and interaction mechanisms of novel chalcone derivatives that contain the 1,1-dichloropropene moiety

A series of novel chalcone derivatives that contain the 1,1-dichloropropene moiety was designed and synthesized. Bioactivity assays showed that most of the target compounds exhibited moderate to good antiviral activity against tobacco mosaic virus (TMV) at 500 μg/mL. Among the target compounds, compound 7h showed the highest in vivo inactivation activity against TMV with the EC₅₀ and EC₉₀ value of 45.6 and 327.5 μg/mL, respectively, which was similar to that of Ningnanmycin (46.9 and 329.4 μg/mL) and superior to that of Ribavirin (145.1 and 793.1 μg/mL). Meanwhile, the microscale thermophoresis and fluorescence spectroscopy experiments showed that the compound 7h had a strong interaction with the tobacco mosaic virus coat protein.     

Investigation of Tomato Plant Defence Response to Tobacco Mosaic Virus by Determination of Methyl Salicylate with SPME-Capillary GC-MS

Headspace SPME was applied to investigation of tomato plant defence response to tobacco mosaic virus (TMV) by determination of compounds emitted from tomato plants at the extraction conditions of 25 °C and 15 min. It was found that TMV-inoculated tomato plant released large amount of methyl salicylate (MeSA) as response to TMV and MeSA concentration changed dramatically with time after inoculation. Gaseous MeSA as a signaling compound could induce in surrounding tomato plants to produce salicylic acid (SA) and synthesize and release MeSA. These results show that MeSA might be an airborne plant-signalling molecule in tomato plant response to TMV. The present method provided low detection limit of 2.0 ng L^–1 and needed little sample preparation time (15 min), so the method makes it easy to find the critical times of tomato plant response to TMV by fast determination of MeSA released from tomato plant.     

Studies on the conformation of a polyelectrolyte in solution: local conformation of cucumber green mottle mosaic virus RNA compared with tobacco mosaic virus RNA

The thermal stability of the local structures of cucumber green mottle mosaic virus RNA, CGMMV-RNA, and tobacco mosaic virus RNA, TMV-RNA, was studied by circular dichroism (CD) and small-angle X-ray scattering (SAXS) and compared with each other in the temperature domain from 20 to 50 degrees C. The temperature dependence of the molar ellipticity and mean-square radius of the cross section of a chain shows that the structure of CGMMV-RNA is more vulnerable than that of TMV-RNA. Such a different thermal stability of their structures was also reflected in the temperature dependence of the length and number of the constituent rods when the structures of the two RNA chains were represented by a model which consisted of rods joined with freely hinged joints. From these results, a possibility was suggested that the structural stability of CGMMV-RNA and TMV-RNA might be correlated with the infectivity of the corresponding virus, CGMMV and TMV, respectively.