TLC, UV AND ACIDIC TREATMENT IN THE DIFFERENTIATION OF 5,6- AND 5,8-DIHYDROXYFLAVONES, 3-METHOXYFLAVONES AND FLAVONOLS

Article abstract of DOI:10.1016/S0040-4020(01)91379-1

UV and TLC techniques constitute easy procedures to distinguish between 5,6-dihydroxy-7,8-dimethoxy- and 5,8-dihydroxy-6,7-dimethoxyflavonoids, that are difficult to characterize by NMR and classical UV techniques.The acidic treatment of the original products to obtain Wessely-Moser isomers, useful for comparison purposes, yielded novel demethylated products.UV and MS data of 5,8,4' -trihydroxy-6,7,3'-trimethoxyflavone, 5,6,8,3',4'-pentahydroxy-7-methoxyflavone and 5,6,8,4'-tetrahydroxy-7,3'-dimethoxyflavone are presented for the first time.