Flavonoid glycosides from Egyptian species of the tribe Asclepiadeae (Apocynaceae, subfamily Asclepiadoideae)

The flavonoids of 11 Egyptian species of the tribe Asclepiadeae (Apocynaceae, subfamily Asclepiadoideae) were studied: Pentatropis nivalis, Pleurostelma schimperi (subtribe Astephaninae), Glossonema boveanum, Solenostemma arghel (subtribe Glossonematinae), Cynanchum acutum, Oxystelma esculentum (subtribe Metastelmatinae), Calotropis procera, Gomphocarpus fruticosus, Gomphocarpus sinaicus, Pergularia tomentosa and Pergularia daemia (subtribe Asclepiadinae). These 11 species were found to produce flavonol glycosides. In addition, flavonol sulphates and disulphates were found in a specimen of P. nivalis. The flavonoids may provide useful taxonomic characters at several levels of classification.