Structures of the Flavonoids Carrying Isoprenoid Substituents Isolated from Sang-Bai-Pi

Structures of the Flavonoids Carrying Isoprenoid Substituents Isolated from Sang-Bai-Pi  

Sanggenon A (163) (139), an amorphous powder, C25H24O7, [a]o -1-175°, gave positive Mg-HCl and NaBH4 tests. The UV spectrum had maxima at 208 (25700), 228 (15500), 235 (inflection, 14500), 270 (shoulder, 28800), 279 (31600), 315 (12000), and 377 nm (2300). The color reactions and the UV spectrum suggested that sanggenon A (163) was a flavanone derivative. In the UV spectra of 163 and its monoacetate (163 a), no red shift was observed upon addition of aluminium chloride. From the above results, combined with H-NMR and mass spectra studies, formula (163) was proposed for sanggenon A. 

Solvent acetone-Jg. CDCI3. SA SAMe sanggenon A trimethyl ether. 

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