Dimethomorph

Description

Dimethomorph is a morpholine fungicide that inhibits fungal cell wall formation. It inhibits mycelial growth of the oomycete fungi P. citrophthora, P. parasitica, P. capsici, and P. infestans (EC₅₀s = 0.14, 0.38, <0.1, and 0.16-0.3 μg/ml, respectively) but is less active against the green algae species C. vulgaris or S. obliquus in vitro (EC₅₀s = 47.46 and 44.87 μg/ml, respectively). It inhibits androgen receptor (AR) activity in a reporter assay in MDA-kb2 human breast cancer cells but not in a yeast antiandrogen screen (IC₂₀s = 0.263 and 38.5 μM, respectively). It is not toxic to rats (LD₅₀ = 3,900 mg/kg) or goldfish (C. auratus; LC₅₀ = >32 μg/ml).

Chemical properties

Off-White Solid

The Uses of Dimethomorph

Dimethomorph is a systemic fungicide which exhibits protectant, curative and antisporulant activities. It is active against fungal diseases such as leaf blight, downy mildew, damping off and foot-rot caused by Phytophthora spp. in/on grapes, potatoes and tomatoes.

The Uses of Dimethomorph

Agricultural fungicide.

Definition

ChEBI: A mixture of (E)- and (Z)-dimethomorph in an unspecified ratio. It is used as a systemic fungicide used on vines, potatoes, and greenhouse crops; only the Z isomer has fungicidal activity.

Agricultural Uses

Fungicide: A systemic fungicide that protects crops from mold. It also kills mold and prevents their spread; controls late blight on tomatoes; and is used as a wood preservative to control downey mildew.

Trade name

ACROBAT® WP; FORUM DC®, [manco- zeb + dimethomorph]; CME 151®; STATURE®

Metabolic pathway

Limited data are available in the open literature. Information presented in this summary is abstracted from the data evaluation published by the Pesticide Safety Directorate (PSD, 1994). Dimethomorph is a (1:l) mixture of the E- and Z-isomers. The Z-isomer has been shown to have all the intrinsic biological activities. The isomerisation of the E- and Z-isomers was observed when resolved isomers were exposed to UV light. Dimethomorph undergoes extensive degradation and metabolism in soil, plants and animals. The major metabolic pathway is the O-demethylation of one of the phenolic methoxy moieties to the corresponding phenols and conjugates. Other metabolic reactions include the oxidation of one of the CH2 moieties of the morpholine ring and the cleavage/opening of the morpholine ring (Scheme 1).

Degradation

Dimethomorph (1) is hydrolytically stable with no observable degradation in pH 4-9 buffered solutions at 70-90 °C for up to 10 weeks.
Degradation occurred when dimethomorph in pH 5 buffer solution was irradiated under Hanau Suntest apparatus (<290 nm) at 25 °C. The calculated aqueous photolytic degradation half-life (DT₅₀) was ca. 25-28 days of continuous irradiation, No sigruficant degradation product (>7% of the applied radioactivity) was identified.