The original structure of hortensin, from Millingtonia hortensis, and
analysed as 4'-hydroxy-6,7-dimethoxyflavonol, has been changed once to
5,4'-dihydroxy-6,7-dimethoxyflavone (cirsimaritin). A further reinter
pretation of the NMR data of newly isolated 'hortensin' showed that it
is 5,7-dihydroxy-6,4'-dimethoxyflavone (pectolinarigenin). Several re
lated flavonoids from the same plant were also identified.