Antiviral and antituberculous activity of Helichrysum melanacme constituents

Bioassay guided fractionation of the acetonic extract of Helichrysum melanacme using human Influenza virus type A and a drug-sensitive strain of Mycobacterium tuberculosis in vitro resulted in the isolation of 2 4',6'-trihydroxy-3'-prenylchalcone (1) and 4',6',5-trihydroxy-6,6-dimethyldihydropyrano[2,3-2,3] chalcone (2) as active constituents. 3-O-methylquercetin and quercetin were also isolated but were inactive against the microorganisms tested in this study. (c) 2006 Elsevier B.V. All rights reserved.