Medicinal Flowers. XXVII. New Flavanone and Chalcone Glycosides, Arenariumosides I II, III, and IV, and Tumor Necrosis Factor-α Inhibitors from Everlasting, Flowers of Helichrysum arenarium

The methanolic extract from the flowers of Helichrysum arenarium L. MOENCH was found to show inhibitory effect on tumor necrosis factor-alpha (TNF-alpha 1 ng/ml)-induced cytotoxicity in L929 cells. From the methanolic extract, 50 constituents including four new flavanone and chalcone glycosides named arenariumosides I (1), II (2), III (3), and IV (4) were isolated. The stereostructures of 1-4 were elucidated on the basis of chemical and physicochemical evidence. Among the constituents, naringenin 7-O-beta-D-glucopyranoside (7), apigenin 7-O-beta-D-glucopyranoside (14), apigenin 7-O-gentiobioside (16), and apigenin 7,4'-di-O-beta-D-glucopyranoside (17) significantly inhibited TNF-alpha-induced cytotoxicity in L929 cells at 30 mu m.