Antiviral activity evaluation and action mechanism of myricetin derivatives containing thioether quinoline moiety.

Abstract

A variety of myricetin derivatives containing thioether quinoline moiety were designed and synthesized. Their structures of title compounds were determined by 1H NMR, 13C NMR, 19F NMR, and HRMS. Single-crystal X-ray diffraction experiments were carried out with B4. Antiviral activity indicated that some of the target compounds exhibited remarkable anti-tobacco mosaic virus (TMV) activity. In particular, compound B6 possessed significant activity. The half maximal effective concentration (EC50) value of the curative activity of compound B6 was 169.0μg/mL, which was superior to the control agent ningnanmycin (227.2μg/mL). Meanwhile, the EC50 value of the protective activity of compound B6 was 86.5μg/mL, which was better than ningnanmycin (179.2μg/mL). Microscale thermophoresis (MST) indicated that compound B6 had a strong binding capability to the tobacco mosaic virus coat protein (TMV-CP) with a dissociation constant (Kd) value of 0.013μmol/L, which was superior to that of myricitrin (61.447μmol/L) and ningnanmycin (3.215μmol/L). And the molecular docking studies were consistent with the experimental results. Therefore, these novel myricetin derivatives containing thioether quinoline moiety could become potential alternative templates for novel antiviral agents.