New phenol and chromone derivatives from the endolichenic fungusDaldiniaspecies and their antiviral activities

Abstract

Three new phenolic metabolites, daldispols A-C (1-3), two new chromone derivatives, (5R,7R)-5,7-dihydroxy-2-methyl-5,6,7,8-tetrahydro-4H-chromen-4-one (9) and (5R,7R)-5,7-dihydroxy-2-propyl-5,6,7,8-tetrahydro-4H-chromen-4-one (10), together with five known phenolic compounds (4-8) and two known chromone compounds (11and12) were isolated from the endolichenic fungusDaldiniasp. CPCC 400770. Their structures were elucidated on the basis of spectroscopic methods, electronic circular dichroism (ECD), and comparison with reported data. Compounds1,3,4,9, and11exhibited significant anti-influenza A virus (IAV) activities with IC50values of 12.7, 6.4, 12.5, 16.1, and 9.0 μM, respectively, and compound8displayed significant anti-ZIKV activity with inhibitory ratio of 42.7% at 10 μM. The results demonstrated that the fungusDaldiniasp. CPCC 400770 might be a rich source for discovering anti-IAV secondary metabolites as potential novel leading compounds.