Bitertanol

Description

Bitertanol is a broad-spectrum triazole fungicide that is active against a variety of fungi, including V. inaequalis and V. pirina, which are responsible for apple and pear scab, respectively, as well as S. mors-uvae and P. ribis, which are responsible for American gooseberry mildew and leaf spot in black currants, respectively. It is active against isolates of V. inaequalis (MICs = 0.6 and 1 μg/ml) but repeated use leads to resistance and cross-resistance (MICs = 9.8-13 μg/ml for bitertanol-resistant isolates). Bitertanol inhibits the cytochrome P450 (CYP450) isoform CYP3A4 (IC₅₀ = 2.74 μM) and inhibits androgenic activity induced by the androgen receptor agonist DHT in a yeast two-hybrid assay (IC₅₀ = 79.85 μM). In rats, bitertanol (10-300 mg/kg, i.p.) increases operant responding on one- and five-minute fixed interval schedules with no effect on motor activity.

Chemical Properties

White Solid

Uses

Bitertanol is a foliar-applied triazole fungicide used to protect tropical and subtropical crops in agriculture, in particular bananas. Bitertanol has effects on behavior that are similar to those of psychomotor stimulants.

Uses

Bitertanol is used as a seed treatment on winter wheat and barley and as a foliar treatment to control diseases on bananas, ornamentals, fruit and vegetables.

Uses

Agricultural fungicide.

Definition

ChEBI: 1-(biphenyl-4-yloxy)-3,3-dimethyl-1-(1,2,4-triazol-1-yl)butan-2-ol is a member of the class of triazoles that is 3,3-dimethyl-1-(1,2,4-triazol-1-yl)butane-1,2-diol substituted at position O-1 by a biphenyl-4-yl group. It is a member of biphenyls, an aromatic ether, a member of triazoles and a secondary alcohol.

Agricultural Uses

Fungicide: A fungicide used to control a variety of diseases. Used as control for prunes when drying. Not currently registered in the U.S. or EU countries (pending). Used in many European, South American, Far Eastern and African countries, a well as in Australia for use on beans (all types) and various ornamentals. More than 20 global suppliers.

Trade name

BAYCOR®; BAY KWG 0599®; BAYMATSPRAY ®; BILOXAZOL®; KWG 0599®; SIBUTOL®, (with Fuberidazole)

Metabolic pathway

Bitertanol is a mixture of two diastereoisomeric pairs and this complicates its metabolism, each biotransfonnation affording a mixture of isomers. Metabolism has been studied under environmental conditions and in plants and mammals. Degradation in soil and sediments is slow and only small quantities of products (other than CO₂ and bound residues) are produced. Most information is available for mammals in which metabolism occurs mainly by oxidative routes followed by conjugation. The information presented below is derived from the UK MAFF Pesticide Safety Directorate (PSD, 1994).

Degradation

The hydrolytic stability of [¹⁴C]bitertanowl as measured at pH 4, 7 and 9 over 30 days at 25 and 40 °C. No decomposition was observed and the DT₅₀ was estimated at >1 year at 25 °C.
Aqueous solutions of [¹⁴C-triazole]-and [¹⁴C-biphenyl]-bitertanol were irradiated for 48 and 72 hours, respectively, using a mercury arc lamp under conditions somewhat exceeding natural sunlight. Calculated DT₅₀ values were 38-52 hours and an estimated environmental DT₅₀ was considered to be 11 days. 4-Hydroxybiphenyl (4) and 1,2,4-triazole (5) were identified as major photolysis products accounting for 12% and 53% of the radioactivity, respectively. These are shown in Scheme 1. At least six minor products were detected but these were not identified.
Very little degradation occurred under soil surface photolysis conditions simulating natural sunlight. No discrete products were detected. Bound residue increased to only 5% of the total over 35 days.