Azalein

2 - (3,4 -dihydroxyphenyl )-7- hydroxy-5- methoxy- 3 - ( rhamnoside ) -4H- chromen- 4-one

Pale yellow needles,

Fixed

181-185 ° C ( pentahydrate )

Template: Infobox chemical / molecular formula search available

Azalein is a flavonoid. Is the 3-O- α -L- rhamnoside of Azaleatin (2 - ( 3,4- dihydroxyphenyl) -3,7- dihydroxy -5-methoxy -4H- chromen- 4-one, quercetin -5- methyl ) and thus to a glycoside.

Occurrence

The flavonol -3- rhamnoside is part of the flower colors of rhododendron species. Described it in 1962 from Harborne and Egger.

The aglycone is also called Azaleatin ( 529-51-1; MW 316.27, MP 322 ° C, 252 & 368 nm, brilliant yellow needles ).