## 1 Introduction  
Plant diseases caused by viruses are causing severe economic damage to the agricultural industry and seriously affect its development [1; 2; 3; 4]. The tobacco mosaic virus (TMV; _Tobamovirus_ genus) is one of the most common destructive phytopathogens [5; 6]. It infects more than 400 crops that have economic importance, including tobacco, vegetables, and ornamental flowers [7]. The TMV is known as plants cancer and causes fruit and leaf deformation, plant dwarfing, and a reduction in seed germination rates [8; 9]. The complete protection of plants against TMV infection presents a difficult challenge, since no efficient antiviral reagent has not yet been found. Ribavirin and ningnanamycin are widely used as antiviral reagents against TMV infection [10; 11]. Ningnanamycin and ribavirin have a moderate control effect (50\(-\)60% at 500 \(\upmu\)g/mL) against the TMV [12; 13]. Clearly, the curative rate of these antiviral reagentsis unsatisfactory, and therefore considerable attention was paid towards the screening, design, synthesis, and use of new compounds that have potential biological activity [14]. Some progress has been made with the design and use of effective antiviral agents to protect plants against specific diseases. For example, zinc oxide nanoparticles were found to be effective to protect tomato plants against the _tomato mosaic virus_[15]. In addition, salicylic acid and melatonin act as antiviral agents to protect eggplant against _alfalfa mosaic virus_ without posing a danger or being hazardous to the environment [16].  
Many attempts were made to design and synthesize new and efficient anti-TMV agents [17; 18; 19; 20; 21; 22]. New anti-TMV agents should be designed to have low toxicity, rapid degradation in the environment, and a unique mode of action. Many natural products-based agrochemicals were assessed for their use as anti-TMV agents. Research has continued to find potential alternative pesticides that do not pose a hazard to the environment [23; 24; 25; 26; 27]. Few _in silico_ studies related to the TMV have been conducted [28; 29; 30]. For example, a series of ureas and thioureas containing heterocyclic compounds (e.g., pyrimidine and piperazine moieties) were studied to investigate their TMV inhibitors. The molecular docking and molecular dynamics simulations were used to understand the interaction between the TMV coat protein and the synthesized compounds. A good agreement was found between the _in silico_ analysis and the experimental results [28]. However, there is an urgent need to find a new anti-TMV agent that is capable of preventing such a disease.  
The current study aimed to assess the _in silico_ anti-TMV activity of 43 compounds of anti confine analogue, including ningnanmycin (**1**) and ribavirin (**2**). The selected compounds were reported to have varied anti-TMV activity [9; 14; 24; 25; 26; 27; 31]. The chemical structures of the compounds are shown in Table 1. The reactivity of these compounds and their binding with the tobacco mosaic virus coat protein (TMV-CP) were simulated and compared with standard anti-TMV agents (e.g., ningnanmycin **1** and ribavirin **2**) using the Gaussian 09 software with the B3 LYP/6-31G basis set [32] and the molecular operation environment (MOE) software [33].  
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