BIOTRANSFORMATION OF (+)-MAGNOLIN AND (+)-YANGABIN IN RAT

The neutral lignans (+)-magnolin and (+)-yangabin, each containing the 2,6-diaryl-3,7-dioxabicyclo [3,3,0]octane skeleton, were administered separately to rats by intraperitoneal injection. From the urine, small amounts of glucuronide conjugates of two kinds of de-O-methylated magnolin and one de-O-methylated yangabin were obtained. These were identified to de-4'-O-methylmagnolin, de-4''-O-methylmagnolin and de-4'-O-methylyangabin. The structures of these phenolic lignans were determined by spectroscopic methods. The formation of these compounds can be explained through a specific para demethylation.