Phytochemical Study of Myrtopsis corymbosa, Perspectives for Anti-dengue Natural Compound Research

In order to find new molecules for anti-viral drug design, we screened 102 ethyl acetate extracts obtained from 51 plants native from New-Caledonia for an antiviral activity against the dengue 2 virus RNA dependant RNA polymerase (DENV-NS5 RdRp). Leaf and bark extracts of Myrtopsis corymbosa which strongly inhibited the DENV-NS5 were selected for chemical investigation. We present here the first chemical study of M. corymbosawhich led us to isolate three coumarins, namely ramosin (1), myrsellinol (1) and myrsellin (3), and three alkaloids, namely skimmianine (4), γ-fagarin (4) and haplopin (6). These compounds were identified as major compounds from the active extracts of the plant. However, they demonstrated only weak antiviral activity on the dengue virus. Further studies are necessary to know if the antiviral activity is due to a synergy between several compounds or due to the presence of other minor compounds.