Complex flavonoids in farinose exudate from Pityrogramma calomelanos
摘要:
From the farinose exudate of Pityrogramma calomelanos, three new complex flavonoids named calomelanols A-C were isolated in addition to two known dihydrochalcones. The structures were characterized as 8[3-(4-methoxyphenylpropionyl)]-5,7-dihydroxydihdroneoflavone for calomelanol A, 8-[3-(4-hydroxyphenylprionyl)]-5,7-dihydroxydihydroneoflavone for calomelanol B, and 8-(3-phenylpropionyl)-5,7,4'-trihydroxydihydroneoflavone for calomelanol C, respectively, by spectroscopic evidence. The C-13 NMR assignement and the mass spectral fragmentation of the complex flavonoids are also described.