Six compounds have been isolated from the methanol extract of the aerial parts of Gnidia involucrata (Thymelaeaceae). They were identified as 2,3,4',5,6-pentahydroxybenzophenone-4-C-glucoside and 2,4',6-trihydroxy-4-methoxybenzophenone-2-O- glucoside, together with mangiferin, kaempferol-3-O-glucoside, yuankanin and manniflavanone by chemical and spectroscopic means. The structures of three additional C-glycosyl flavones - vitexin, isovitexin and isoorientin - were determined on-line by LC/UV/APCI-MSn analysis of the crude extract. (C) 2000 Elsevier Science Ltd. All rights reserved.