Residues from Organic Solvents showing Gibberellin-like Biological Activity

Abstract

TWO years ago, while attempting to measure the gibberellin content of various antibiotic preparations, I was using a purification procedure that had, as its first step, the extraction with ethyl acetate of an acidified solution of the material under test. In control experiments, in which acidified, distilled water was extracted rather than a solution of the biological material under test, evaporation of the final solvent left a residue that had the properties of an unstable ‘gibberellin’ in that it promoted the synthesis of hydrolytic enzymes in de-embryonated barley, resulting in a large increase in the quantities of reducing sugars released into the culture medium¹.