2H-1-Benzopyran-3,5,7-triol,6-[[(2R,3R)-3,4-dihydro-3,5,7-trihydroxy-2-(3,4,5-trihydroxyphenyl)-2H-1-benzopyran-8-yl]methyl]-3,4-dihydro-2-(3,4,5-trihydroxyphenyl)-,(2R,3R)-