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Bitter Steroid Glucosides, Vernoniosides A1, A2, and A3, and Related B1 from a Possible Medicinal Plant, Vernonia amygdalina, Used by Wild Chimpanzees.-Three bitter steroid glucosides (Ia), (Ib), (II) (vernoniosides A1-A3, resp.) and the nonbitter vernonioside B1 (Ic) are conveniently isolated from the leaves of the title species. Their structures are fully established on the basis of spectroscopic data including single crystal X-ray data from the aglycone of (Ic). -(JISAKA, M.; OHIGASHI, H.; TAKAGAKI, T.; NOZAKI, H.; TADA, T.; HIROTA, M.; IRIE, R.; HUFFMAN, M. A.; NISHIDA, T.; KAJI, M.; KOSHIMIZU, K.; Tetrahedron 48 (1992) 4, 625-632; Dep. Food Sci. Technol., Kyoto Univ., Kyoto 606, Japan; EN)