Synthesis, Anti-TMV\nActivities, and Action Mechanisms\nof a Novel Cytidine Peptide Compound

Cytidine\nhas a broad range of applications in the pharmaceutical\nfield as an intermediate of antitumor or antiviral agent. Here, a\nseries of new cytidine peptide compounds were synthesized using cytidine\nand Boc group-protected amino acids and analyzed for their antiviral\nactivities against tobacco mosaic virus (TMV). Among these compounds,\nthe structure of an effective antiviral cytidine peptide SN11 was\ncharacterized by <sup>1</sup>H NMR, <sup>13</sup>C NMR, and high-resolution\nmass spectrometer. The compound SN11 has a molecular formula of C<sub>15</sub>H<sub>22</sub>N<sub>6</sub>O<sub>8</sub> and is named 2-amino-<i>N</i>-(2- ((1- (3,4-dihydroxy-5-(hydroxymethyl) tetrahydrofuran-2-yl)\n-2-oxo-1,2-dihydropyrimidin-4-yl) amino) -2-oxyethyl) amino). The\nprotection, inactivation, and curation activities of SN11 at a concentration\nof 500 μg/mL against TMV in Nicotiana glutinosa were 82.6%, 84.2%, and 72.8%, respectively. SN11 also effectively\nsuppressed the systemic transportation of a recombinant TMV carrying\nGFP reporter gene (p35S-30B:GFP) in Nicotiana benthamiana by reducing viral accumulation to 71.3% in the upper uninoculated\nleaves and inhibited the systemic infection of TMV in <i>Nicotiana\ntabacum</i> plants. Furthermore, the results of RNA-seq showed\nthat compound SN11 induced differential expression of genes involved\nin the biogenesis and function of ribosome, plant hormone signal transduction,\nplant pathogen interaction, and chromatin. These results validate\nthe antiviral mechanisms of the cytidine peptide compound and provide\na theoretical basis for their potential application in the management\nof plant virus diseases.