4-Pentadecylpyridine: A Competitive Polyphenoloxidase Inhibitor

Claus T. Fuchs and G erhard Spiteller Institut für Organische Chemie I, Universität Bayreuth, Universitätsstr. 30, 95440 Bayreuth, Germany Z. Naturforsch. 52c, 761-765 (1997); received July 30/August 19, 1997 Polyphenoloxidase, o-Diphenols, 4-Pentadecylpyridine, Competitive Inhibitor, Taphrina pruni 4-Pentadecylpyridine was isolated from plums infected by Taphrina pruni. This fungal me­ tabolite has been tested for its effect on polyphenoloxidase, using the polyphenoloxidasecatalysed addition of L-proline to 4-methylcatechol in a chromogenic assay The resulting data prove that 4-pentadecylpyridine is a competitive inhibitor to polyphenoloxidase with an inhibitor constant of 3.70 ± 0.03*10-4 m . Further comparative measurements have demon­ strated that the effect is due to the pyridine moiety. Probably reduced polyphenoloxidaseactivity decreases the toxicity of o-diphenols to the fungus and thus increases susceptibility of plums to the fungus Taphrina pruni.