Fractionation of Estrogen-Methyl-Esters with Alumina Column Chromatography

Abstract

A chromatographical method for fractionation of estrogen methyl ethers.100ml. of late pregnancy urine was boiled for 15 minutes with 15 vol. % of conc HCl. Hydrolyzed urine was extracted twice with 150 ml. of ether and the extract was washed twice with 25 ml. of 5% NaHCO3 solution to remove acid substances and then washed three times with water (20ml.). The ether solution was dried with anhydrous Na2SO4 and was distilled to about 10 ml. in a water bath.The contents were transferred together with 25 ml. of benzene and 25 ml. of petroleum ether into a separating funnel. The benzene petroleum ether solution was extracted twice with 25 ml. of 1.6% NaOH. Then H3BO3 (0.9 gr.) was added to the given NaOH extracts. The flask was placed in a 37°C water bath and 1 ml. of dimethylsulfate was added. The flask was stirred by a magnetic stirrer at 37°C for 30 minutes and was allowed to stand at room temperature overnight.Ten ml. of 20% NaOH and 2.5 ml. of 30% H2O2 were added to the flask and the contents of the flask were transferred to a separating funnel.The methylated estrogens were chromatographed by alumina column ; the size of the column was 0.5 * 20 cm. The column was prepared by partly filling it with petroleum ether and then adding the 2.0 gr. of Brockmann alumina (activity III). The chromatograms were run at 18°C under the pressure of 10-12 cm./Hg. The eluates was divided into 2ml. for each tube.Estrone methyl ester, estradiol methyl ester, 16-epi-estriol methyl ester and estriol methyl ester were eluated with 40% petroleum ether in benzene, benzen, 1.6% methanol in benzene and 3.0% methanol in benzene, respectively.By this method, estrogens in pregnant urine were separated into four fractions and were measured. It was then determined that the 16-epi-estriol contained in late prengnancy urine was 11.5% of the total estrogens.