X-RAY CRYSTAL-STRUCTURE ANALYSIS AND C-13 NMR INVESTIGATION OF ESTRIOL 16-MONOGLUCURONIDE AND 17-MONOGLUCURONIDE DERIVATIVES

The crystal structure of methyl 1-O-[3,16 alpha-dihydroxy-estra-1,3,5( 10)-trien-17 ]-2,3,4-tri-O-acetyl-beta-D-glucopyranosiduronate, 1, cle arly shows the beta-linkage of the carbohydrate moiety with estriol an d unambiguously shows the trans relationship of the 17 alpha- and 16 b eta-protons. C-13 NMR studies on 1 and on other estriol 16 alpha- and 17 beta-glucuronide derivatives show differences between the two types of isomer based on the chemical shift values for C-16 and C-17 which are diagnostic, For C-17 derivatives with the beta configuration, the chemical shift difference between the C-16 and C-17 signals was about 20 ppm, whereas the difference between the resonances for the 16 alpha -derivatives was only about 5 ppm. The correlation of the 17 alpha-pro ton with the anomeric proton (H-1') from estriol 17 beta-glucuronide d erivatives, based on 2D-NOESY spectra, was also useful in distinguishi ng the estriol 17 beta-derivatives from the 16 alpha-isomers.