Acylated flavone C-glycosides from Cucumis sativus.

Leaves of Cucumis sativus plants treated with silicon and infected with Sphaerotheca fuliginea yielded five new acylated flavone C-glycosides identified as isovitexin 2"-O-(6"'-(E)-p-coumaroyl)glucoside (6), isovitexin 2"-O-(6"'-(E)-p-coumaroyl)glucoside-4'-O-glucoside (7), isovitexin 2"-O-(6"'-(E)-feruloyl)glucoside-4'-O-glucoside (11), isoscoparin 2"-O-(6"'-(E)-p-coumaroyl)glucoside (9), and isoscoparin 2"-O-(6"'-(E)-feruloyl)glucoside-4'-O-glucoside (12). The known flavone-glycosides isovitexin (1), saponarin (2), saponarin 4'-O-glucoside (3), vicenin-2 (4), apigenin 7-O-(6"-O-p-coumaroylglucoside) (5), isovitexin 2"-O-(6"'-(E)-feruloyl)glucoside (8) and isoscoparin 2"-O-(6"'-(E)-feruloyl)glucoside (10), were also identified in this plant material.