New methods of production and partial purification of an antiviral substance from Penicillium cyaneo-fulvum

Abstract

A strain of P. cyaneo-fulvum elaborates an antiviral substance in Czapek-Dox broth which inhibits the multiplication of influenza A and B and Newcastle disease viruses in modified Maitland tissue cultures. However, the multiplication of these viruses as well as mumps virus was not inhibited when tested in embryonated hens'' eggs. No antiphage activity was demonstrated against a RNA containing phage (f2) and a single-stranded DNA containing phage (oX174). The antiviral substance in a semipurified form, derived by precipitation of impurities from the culture filtrates with acetone, contains sugars, amino acids, and nucleic acid components, and shows a peak at about 270 mu in its ultraviolet absorption spectrum, with a 280 mu/260 mu ratio of 0.97. It is stable to heat, lyophilization, repeated freezing and thawing and it is not dialyzable. Results of enzyme inactivation of the active principle were not conclusive.