PROTOGENKWANIN, A NEW FLAVONOID FROM EQUISETUM ARVENSE L.

Article abstract of DOI:10.1016/S0040-4020(01)92024-1

From the fertile sprouts of Equisetum arvense L. have been isolated protogenkwanin-4'-glucoside and gossypitrin.The structure of protogenkwanin as 5-hydroxy-2-(1,4-dihydroxy-2,5-cyclohexadienyl)-7-methoxy-4-chromenon is proved on the basis of chemical and physical evidence.It is demonstrated that articulatin, a thiamine decomposing substance, from E. arvense, is identical with the known flavonol glycoside gossypitrine (=gossypetin-7-glucoside).The synthesis of 2,5-dihydroxy-2-(4-hydroxyphenyl)-7-methoxy-4-chromanon is reported.