Abstract: The present invention is directed to an improved process for making PDE IV inhibitors. In specific, this application describes a process for making and purifying a chiral bisaryl alcohol, an intermediate compound necessary for the preparation of PDE IV inhibitors such as CDP 840, by asymmetric bioreduction of a pro-chiral ketone. Furthermore, the bioprocess provides for production of each enantiomer of a bisaryl alcohol at elevated optical purity.This invention takes advantage of a microorganism's ability to reduce a pro-chiral bisaryl ketone to the chiral bisaryl alcohol. The alcohol is readily isolated from the media by solvent extraction, crystallography, or other purification method known to the skilled artisan. The chiral alcohol can then be converted to a PDE IV inhibitor, such as CDP 840, by methods well known in the art.

Abstract: Recombinant hepatitis B antigen bound to yeast membranes in yeast expression systems is rapidly purified by subjecting the membrane bound protein to agents that release undesired proteins, followed by agents that release the recombinant hepatitis B antigen.

Abstract: Methods of purifying recombinant surface antigen of hepatitis B virus are disclosed. In one protocol, purification is achieved by selective extraction of the antigen from yeast membranes, followed by solubilization with urea and dithiothreitol.