Antiviral Rotenoids and Isoflavones Isolated from ssp. .

Three new (-) and six known rotenoids (-), along with three known isoflavones (-), were isolated from the leaves of ssp. . A new glycosylated isoflavone (), four known isoflavones (-), and one known chalcone () were isolated from the root wood extract of the same plant. The structures were elucidated by NMR and mass spectrometric analyses. The absolute configuration of the chiral compounds was established by a comparison of experimental ECD and VCD data with those calculated for the possible stereoisomers. This is the first report on the use of VCD to assign the absolute configuration of rotenoids. The crude leaves and root wood extracts displayed anti-RSV (human respiratory syncytial virus) activity with IC values of 0.7 and 3.4 μg/mL, respectively. Compounds , , , , and showed anti-RSV activity with IC values of 0.4-10 μM, while compound exhibited anti-HRV-2 (human rhinovirus 2) activity with an IC of 4.2 μM. Most of the compounds showed low cytotoxicity for laryngeal carcinoma (HEp-2) cells; however compounds , , and exhibited low cytotoxicity also in primary lung fibroblasts. This is the first report on rotenoids showing antiviral activity against RSV and HRV viruses.