T. Horie, M. Tsukayama, Y. Kawamura
1988
Citations
0
Influential Citations
12
Citations
Journal
Phytochemistry
Abstract
Abstract Seven 3,5-dihydroxy-7,8-dimethoxyflavones were synthesized from the corresponding 3,5,7,8-tetramethoxyflavones using selective demethylation and protection of 3- or 5- methoxy group, and their properties were clarified by the UV and 1 H NMR spectral data. The structures of the four natural flavones were revised as follows: the three flavones, isolated from Heteromma simplicifolium , are 5,7-dihydroxy-3,8,3′,4′-tetramethoxyflavone, 5,7-dihydroxy-3,8,3′,4′,5′-pentamethoxyflavone, and 5,7,4′-trihydroxy-3,8,3′-trimethoxyflavone, respectively; the flavone glycoside, isolated from Rudbeckia bicolor , is proposed to be 3,5,4′-trihydroxy-6,7-dimethoxyflavone 3-rhamnoside.