[Immunosuppressive and virostatic actions of sterones from Petunia hybrida Vilm].

10 Ergostan-3-on derivatives presumably in the majority ergosta-1,4-dien-3-on derivatives could be isolated from Petunia hybrida VILM. Two were identified as the known compounds petuniasterone A and petuniasterone-C-22-O-acetate. The structures of two other compounds named petuniasterone-D-diacetate and 30-hydroxypetuniasterone A could be elucidated. The molecular formulas of the remaining substances were ascertained by mass spectroscopy. The petuniasterones inhibited the proliferation of stimulated human lymphocytes in non-cytotoxic concentrations, possessing therefore possibly immunosuppressive effects. Extracts of the plant and fractions containing a synergistically effective blue fluorescing substance retarded the multiplication speed of influenza viruses; pure petuniasterones were ineffectiv under our conditions in this regard.