Abstract
3, 3′-Dimethyl-4-methoxybenzophenone (NK-049) labeled with carbon-14 at the carbonyl carbon was administered orally to female wister rats at the dosage of 500mg per kg. Carbon-14 absorbed from gastrointestinal tract was rapidly distributed into various tissues. The radiocarbon in the tissue was rapidly excreted into feces and urine; 24hr after the administration, 59.38% and 36.15% of the carbon-14 were excreted in feces and urine, respectively, so that no accumulation of the compounds in animal body was presumed. In feces, 75% of the radiocarbon (46% of the dosed NK-049) was confirmed to be an intact NK-049. Major urinary metabolites were free and conjugated 3, 3′-dimethyl-4-hydroxybenzophenone (9%) and 3′-carboxy-4-hydroxy-3-methylbenzophenone (28%), and free 3′-carboxy-3-hydroxymethyl-4-methoxybenzophenone (23%) and 3-carboxy-4-hydroxy-3′-hydroxymethylbenzophenone (9%). Other oxidized metabolites of NK-049 were found in the urine, such as 3, 3′-dicarboxy-4-methoxybenzophenone, 3′-carboxy-4-hydroxy-3-hydroxy-methylbenzophenone, 4-hydroxy-3′-hydroxymethyl-3-methylbenzophenone, 4-hydroxy-3-hydroxymethyl-3′-methylbenzophenone, 3-carboxy-3′-methyl-4-methoxybenzophenone and 3, 3′-dicarboxy-4-hydroxybenzophenone.
