Abstract
Biosynthesis of 16-epiestriol glucosiduronate was attempted with liver and small intestine preparations from several different species. Incubation of 3H-16-epiestriol with microsomal or supernatant fractions in the presence of UDPGA yielded the glucosiduronates whose separation was readily attained by column chromatography on Amberlite XAD-2 resin. The structure of 16-epiestriol glucosiduronates was elucidated by direct comparison with the synthetic samples on the thin-layer chromatogram, leading to the acetate-methyl ester for the reverse isotope dilution method and hyrolytic cleavage with β-glucuronidase. There could be seen the distinct difference in the position of conjugation depending upon the species and organ as listed in Table IV and V. The specificity and multiplicity of UDP-glucuronyltranferase toward 16-epiestriol as an acceptor have been discussed.
