Study on the Constituents of the Flavonoids and Other Substances From the Peel of Citrus Sinensis (L.) Osbeck

Five compounds in the crystal form were isolated from dry peel of citrus Sinensis(L.)Osbeck collected from GuangXi province. By means of physico-chemical evidence andspectroscopic analysis(UV, IR, MS, ¹HNMR), three components were characterized as poly-methoxyflavonoids. They were 3, 5, 6, 7, 8, 3', 4'-heptamethoxy flavone (I), tangeretin (Ⅱ) andnobiletin (Ⅲ).β-sitosterol (IV) and friedelin(V), which were also identified. Among them, 3, 5, 6, 7, 8, 3', 4'-heptamethoxy flavone and friedelin were first obtained from domestic citrus peels. Heptamethoxy flavone was found having significant inhibitory action in the experiment with human Leukemic cell (K 562).