Polyacetylenes from the leaves of Vernonia scorpioides (Asteraceae) and their antiproliferative and antiherpetic activities

Seven polyacetylenes were isolated from Vernonia scorpioides and tested against Herpes virus and against non-small cell lung cancer A549. All the structures of the isolated compounds were determined based on extensive analysis of 1D and 2D NMR and MS data. •All structures were established based on extensive analysis of 1D and 2D NMR and MS data.•The relative configuration of compounds was deduced on basis of key 1D NOE NMR experiments.•Ab initio calculations including solvent effects aided the elucidation of the absolute configurations.•The compounds (1–5) presented non-selective in vitro antiviral activity, and the glycosides were inactive.•The compounds (2–8) presented no inhibitory effect against the non-small cell lung cancer A549. Polyacetylenes constitute an underexplored and unstable class of compounds that are found mainly in the Apiaceae, Araliaceae and Asteraceae families. Vernonia scorpioides (Lam.) Pers., Asteraceae is a lianous neotropical herb that usually grows in soils that have been deforested and are of poor quality. It is used in folk medicine for the treatment of several skin conditions. This study addresses the characterisation of eight polyacetylenes isolated from the leaves of V. scorpioides. Their structures were established on the basis of 1D and 2D NMR spectroscopy and MS analysis. Ab initio calculations including solvent effects were employed to aid the elucidation of the absolute configurations of the compounds. The in vitro antiproliferative and anti-herpetic activities of the polyacetylenes were determined. The isolated compounds presented no inhibitory effect against a human cell line of non-small cell lung cancer, but presented a mild non-selective in vitro antiviral activity, although their corresponding glycosides were inactive.