L-Chicoric acid, a natural product isolated and purified from the herbs of Echinacea purpurea, is an inhibitor of human immunodeficiency virus type 1 (HIV-1) integrase in vitro and of HIV-1 replication in tissue culture.

Caftaric acid, a natural product isolated and purified from the herbs of Echinacea purpurea with anti-mutagenicity, is also an inhibitor of the protein-protein interactions mediated by the Src-family kinases.