Electrochemical sterilization of beer.

Electrochemical inactivation of microorganisms was not achieved in beer but was achieved in physiological saline. Addition of carbohydrates or proteins to physiological saline prevented inactivation in this medium.

Synthesis, purification and characterization of 7-ketocholesterol and epimeric 7-hydroxycholesterols.

Various methods were assessed for the synthesis of 7-ketocholesterol and epimeric 7-hydroxycholesterols. Upon the oxidation of cholesteryl acetate with t-butyl chromate, the resulting ketosterol acetate crystallized from methanol consisted of about 25% unoxidized cholesteryl acetate. After the sterol acetates were hydrolyzed in an aqueous K(2)CO(3) medium, preparative TLC was used to fractionate the ketone from cholesterol.Of all the reducing agents employed, only LiAlH(4) reduced completely the purified 7-ketocholesterol to 7-hydroxycholesterols without side reaction products and ketone contamination. Yields of 21.3 mg of 7alpha-hydroxycholesterol and 72.6 mg of 7beta-hydroxycholesterol were obtained by preparative TLC of a diol mixture prepared by the LiAlH(4)-reduction of 100 mg of 7-ketocholesterol. To accomplish the preparative TLC separation of diol bands without overlapping, a double development of a chromatoplate with ethyl ether-cyclohexane (90ratio10, v/v) and ethyl ether was essential.Data on the melting point, optical rotation and infrared spectra, as well as TLC and GLC characteristics, were obtained for purified 7-ketocholesterol and epimeric 7-hydroxycholesterols.

Isolation and characterization of cholesterol-5B,6B-oxide from an aerated aqueous dispersion of cholesterol.

An unknown autoxidation product in an aerated cholesterol sol was isolated by preparative thin layer chromatography. This compound was identified as cholesterol-5beta,6beta-oxide by gas liquid chromatography along with infrared and mass spectrometry.