Isolation and constitution of quercetagitrin, a glucoside of quercetagetin

摘要: Quercetagitrin, a monoglucoside of quercetagetin, has for the first time been isolated from flowers African Marigold (Tagetes erecta). It is not 3-glucoside since it gives red precipitate with lead acetate and does undergo easy hydrolysis acids. Further easily oxidised in cold alkali, after methylation products decomposition yield veratric acid. The glucose group, therefore, present side phenyl nucleus. By complete subsequent glucoside, pentamethyl quercetagetin obtained. This ether new compound, differs 3∶6∶7∶3′∶4′-pentamethyl all its properties, hence free hydroxyl group either 6th or 7th position. allyl this smoothly undergoes Claisen Rearrangement, indicating thereby that ortho-position respect to allyloxy unsubstituted. Hence should be 3∶5∶6∶3′∶4′-pentamethyl-7-allyl have constitution 3∶5∶6∶3′∶4′-pentamethyl quercetagetin. Consequently quercetagitrin 7-glucoside