Phloroglucinol as porcine epidemic diarrhea virus and canine corona virus inhibitors from Dryoteris crassirhizoma

Abstract

Porcine epidemic diarrhea virus (PEDV) and canine corona virus (CCV) are the types of coronaviruses that cause severe disease in animals and they are grave threat to the livestock industry for a long time. The lack of effective and efficient therapeutical treatment for that virus emphasizes the importance of research for new antivirals. Following an in-vitro virus yields reduction assay, the bioactivity guided successive chromatographic fractionation of EtOH extract of Dryopteris crassirhizoma (Dryopteridaceae) rhizomes led to the isolation of four phloroglucinol type compounds (1-4). Among those, compounds norflavaspidic acidAB (3) and methylene-bis-methylphlorobutyrophenone (4) were the strongest antivirals that significantly reduced virus titers and cytopathic effect at low concentrations. Moreover, Compound (4) inhibited the spike (S), nucleocapsid (N) and membrane (M) gene transcription and the process of translation in PEDV infected to the Vero cell.