Isomers of sterol synthesis inhibitors: Fungicidal effects and plant growth regulator activities

The chemical diversity of fungicides and antimycotics interfering with the C‐14 demethylation of fungal sterols indicates a rather high structural flexibility of the sterol binding site at the specific cytochrome P‐450 mixed‐function oxygenase. The structural flexibility, however, is opposed by a remarkable stereochemical selectivity. A similar, though not identical, stereochemical discrimination is observed with a group of plant growth regulators chemically related to the fungicidal demethylation inhibitors. The relationship between chemical structure and stereochemical requirements is discussed for both biological activities.