Die Hemmung photosynthetischer Reaktionen durch Herbicide des Biscarbamat-Typs

Abstract

3-Alkoxycarbonylaminophenyl-N-aryl- (alkyl-) carbamates, abbreviated as biscarbamates here, are potent inhibitors of photosynthetic electron transport in isolated spinach chloroplasts. By testing 50 compounds the structural requirements for maximal inhibitory activity were determined. To obtain inhibition of photosynthesis by a biscarbamate at a concentration of 10-7 Mol/l the two carbamate side chains of the biscarbamate must be in meta position on the central phenylring. N-Methylation and C-methylation in ortho position to the acidic NH groups of the carbamate side chains reduces the inhibitory activity. The biscarbamates are specific inhibitors of light reaction II of photosynthesis, since they do not inhibit cyclic photophosphorylation and photosynthetic NADP reduction at the expense of an artificial electron donor system.