Antiviral Activity of Fridericia formosa (Bureau) L. G. Lohmann (Bignoniaceae) Extracts and Constituents

A phytochemical study of fridericia formosa (bignoniaceae) ethanol extracts of leaves,stems,and fruits was guided by in vitro assays against vaccinia virus western reserve (vacv-wr),human herpes virus 1 (hsv-1),murine encephalomyocarditis virus (emcv),and dengue virus type 2 (denv-2) by the mtt method. all the ethanol extracts were active against denv-2,hsv-1,and vacv-wr with best results for the fruits extract against denv-2 (si > 38.2). for vacv-wr and hsv-1,ec50 values > 200 μg ml-1 were determined,while no inhibition of the cytopathic effect was observed with emcv. five compounds were isolated and identified as the c-glucosylxanthones mangiferin (1),2′-o-trans-caffeoylmangiferin (2),2′-o-trans-coumaroylmangiferin (3),2′-o-trans-cinnamoylmangiferin (5),and the flavonoid chrysin (4). the most active compound was 2′-o-trans-coumaroylmangiferin (3) with si > 121.9 against denv-2 and 108.7 for hsv-1. these results indicate that mangiferin cinnamoyl esters might be potential antiviral drugs. © 2017 geraldo célio brandão et al.