SPIROXAMINE

Description

Spiroxamine is a tertiary amine fungicide and an inhibitor of Δ¹⁴ reductase/Δ⁸→Δ⁷ isomerase. It inhibits the growth of N. parvum, B. dothidea, D. seriata, and L. theobromae isolates from grape vines (EC₅₀s = 0.97-10.28 mg/L). Spiroxamine (0.03-30 μM) reduces network formation in rat cortical cultures. It is also cytotoxic to MDA-kb2 cells (EC₂₀ = 9.29 μM).

Uses

Spiroxamine is a spiroketalamine fungicide for use on cereal crops. Spiroxamine inhibits ergosterol synthesis. Spiroxamine is used as agricultural fungicide.

Definition

ChEBI: The spiroketal resulting from the formal condensation of 4-tert-butylcyclohexanone with 3-[ethyl(propyl)amino]propane-1,2-diol. An inhibitor of ergosterol synthesis, it is a broad spectrum agricultural fungicide used particularly against powde y mildew in the production of cereals, bananas and grapes.

Metabolic pathway

Spiroxamine is metabolized rapidly in plants, soils, water, and animals via similar degradation pathways. The metabolic pathways include hydrolysis and oxidation at several places in the molecule. Side chains are also degraded to various water-soluble conjugates in animals and in plants, and at the end of complete degradation to natural constituents, carbon dioxide is formed in soils as the principal metabolite. The favorable sorption characteristics rule out any possibility of appreciable translocation in soil. In wheat, the total residue is determined in forage, grain, and harvest-ready straw. In the field studies, the residues in the grain are mostly below 0.05 mg kg^-1, and only in a few cases up to 0.3 mg kg^-1. In the milk of cows ingesting spiroxamine residues with the feed, no residues are found in the least favorable case. In eggs of laying hens, the residue concentrations are below the limit of quantification. There are no residue concentrations detected in the hen fat, meat, and liver.