Acylated flavone C-glycosides from Cucumis sativus

Leaves of Cucumis sativus plants treated with silicon and infected with Sphaerotheca 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). isoseoparin 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. (C) 2001 Elsevier Science Ltd. All rights reserved.