Hydrolysis of Pregnanediol Glucuronide by Sodium Periodate

Abstract

While this work was in progress, Vanzetti & Valente (1966) published details of a method for pregnanediol determination that also used periodate oxidation for removing glucuronide. They also used acidic conditions (pH4. 5). Subsequent purification, however, was less satisfactory, the authors relying on the precipitation of pregnanediol from aqueous solution, followed by an H2SO4 reaction. The purification procedure of Klopper et al. (1955) is clearly superior, and this method, or modifications of it, has been generally adopted. Inhibitors of [beta]-glucuronidase activity are present in urine (Levvy, 1956), a fact often advanced against the adoption of enzyme hydrolysis. On small-scale estimation (10ml of urine) the amount of enzyme used may be increased, or the glucuronides may be first extracted from urine (Edwards, Kellie & Wade, 1953), minimizing the risk of interference by inhibitors. Periodate hydrolysis makes either of these procedures unnecessary.