Acylphloroglucinols-based meroterpenoid enantiomers with antiviral activities from Dryopteris crassirhizoma

•Mianma Guanzhong is a common herbal drug with high medicinal and economic values.•Ten novel meroterpenoids and six known dimeric acylphloroglucinols were isolated.•The meroterpenoids were the first example of acylphloroglucinol-nerolidol adducts.•Most isolates showed antiviral activities against two common viruses.•Acylphloroglucinols could play an important role in treatment of viral diseases.